Efficacy of a Self-expanding Tract Sealant Device in the Reduction of Pneumothorax and Chest Tube Placement Rates After Percutaneous Lung Biopsy: A Matched Controlled Study Using Propensity Score Analysis.

PubMed

Ahrar, Judy U; Gupta, Sanjay; Ensor, Joe E; Mahvash, Armeen; Sabir, Sharjeel H; Steele, Joseph R; McRae, Stephen E; Avritscher, Rony; Huang, Steven Y; Odisio, Bruno C; Murthy, Ravi; Ahrar, Kamran; Wallace, Michael J; Tam, Alda L

2017-02-01

To evaluate the use of a self-expanding tract sealant device (BioSentry™) on the rates of pneumothorax and chest tube insertion after percutaneous lung biopsy. In this retrospective study, we compared 318 patients who received BioSentry™ during percutaneous lung biopsy (treated group) with 1956 patients who did not (control group). Patient-, lesion-, and procedure-specific variables, and pneumothorax and chest tube insertion rates were recorded. To adjust for potential selection bias, patients in the treated group were matched 1:1 to patients in the control group using propensity score matching based on the above-mentioned variables. Patients were considered a match if the absolute difference in their propensity scores was ≤equal to 0.02. Before matching, the pneumothorax and chest tube rates were 24.5 and 13.1% in the control group, and 21.1 and 8.5% in the treated group, respectively. Using propensity scores, a match was found for 317 patients in the treatment group. Chi-square contingency matched pair analysis showed the treated group had significantly lower pneumothorax (20.8 vs. 32.8%; p = 0.001) and chest tube (8.2 vs. 20.8%; p < 0.0001) rates compared to the control group. Sub-analysis including only faculty who had >30 cases of both treatment and control cases demonstrated similar findings: the treated group had significantly lower pneumothorax (17.6 vs. 30.2%; p = 0.002) and chest tube (7.2 vs. 18%; p = 0.001) rates. The self-expanding tract sealant device significantly reduced the pneumothorax rate, and more importantly, the chest tube placement rate after percutaneous lung biopsy.

Primary tumor resection in metastatic breast cancer: A propensity-matched analysis, 1988-2011 SEER data base.

PubMed

Vohra, Nasreen A; Brinkley, Jason; Kachare, Swapnil; Muzaffar, Mahvish

2018-03-02

Primary tumor resection (PTR) in metastatic breast cancer is not a standard treatment modality, and its impact on survival is conflicting. The primary objective of this study was to analyze impact of PTR on survival in metastatic patients with breast cancer. A retrospective study of metastatic patients with breast cancer was conducted using the 1988-2011 Surveillance, Epidemiology, and End Results (SEER) data base. Cox proportional hazards regression models were used to evaluate the relationship between PTR and survival and to adjust for the heterogeneity between the groups, and a propensity score-matched analysis was also performed. A total of 29 916 patients with metastatic breast cancer were included in the study, and 15 129 (51%) of patients underwent primary tumor resection, and 14 787 (49%) patients did not undergo surgery. Overall, decreasing trend in PTR for metastatic breast cancer in last decades was noted. Primary tumor resection was associated with a longer median OS (34 vs 18 months). In a propensity score-matched analysis, prognosis was also more favorable in the resected group (P = .0017). Primary tumor resection in metastatic breast cancer was associated with survival improvement, and the improvement persisted in propensity-matched analysis. © 2018 Wiley Periodicals, Inc.

A Review of Propensity-Score Methods and Their Use in Cardiovascular Research.

PubMed

Deb, Saswata; Austin, Peter C; Tu, Jack V; Ko, Dennis T; Mazer, C David; Kiss, Alex; Fremes, Stephen E

2016-02-01

Observational studies using propensity-score methods have been increasing in the cardiovascular literature because randomized controlled trials are not always feasible or ethical. However, propensity-score methods can be confusing, and the general audience may not fully understand the importance of this technique. The objectives of this review are to describe (1) the fundamentals of propensity score methods, (2) the techniques to assess for propensity-score model adequacy, (3) the 4 major methods for using the propensity score (matching, stratification, covariate adjustment, and inverse probability of treatment weighting [IPTW]) using examples from previously published cardiovascular studies, and (4) the strengths and weaknesses of these 4 techniques. Our review suggests that matching or IPTW using the propensity score have shown to be most effective in reducing bias of the treatment effect. Copyright © 2016 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

The effects of police contact on trajectories of violence: a group-based, propensity score matching analysis.

PubMed

Ward, Jeffrey T; Krohn, Marvin D; Gibson, Chris L

2014-02-01

This study uses a life course framework to investigate how police contacts may serve as a potential turning point in a violent crime trajectory. Drawing on the central ideas from deterrence and labeling theories, we determine whether individuals on different violent offending trajectories increase or decrease their offending following a police contact. Analyzing nine waves of data from the Rochester Youth Development Study, an integrated propensity score matching and latent class growth model was used. First, three violent trajectory groups emerged including high offenders, non-offenders, and low offenders. Second, after accounting for selection bias using propensity score matching procedures, experiencing a police contact increased the likelihood of future violent offending for the entire sample and for those who were on a low violent-offending trajectory specifically. These findings are interpreted as partial support for labeling theory. Limitations of the study and directions for future research are discussed.

Effect of Chronic Diseases on Work Productivity: A Propensity Score Analysis.

PubMed

Fouad, Ahmed Mahmoud; Waheed, Amani; Gamal, Amira; Amer, Shaimaa Ahmed; Abdellah, Rasha Farouk; Shebl, Fatma Mohamed

2017-05-01

The aim of this study was to evaluate the effect of chronic disease(s) on work productivity. Using the Health & Work Performance Questionnaire, information was collected from 516 workers on chronic disease status and work productivity. Propensity-score matching was performed to identify matched-pairs of workers. In the propensity-score matched sample, workers with chronic diseases were more likely to have increased absenteeism and presenteeism rates, 6.34 and 2.36 times the rates if no chronic diseases, respectively. In addition, they had greater odds for getting negative critical work incidents and less odds for positive incidents than none or balanced status. Multimorbidity showed more significant increase in absenteeism and presenteeism rates, as well as increased odds for excess negative critical work incidents. Chronic disease(s) can significantly reduce work productivity by increasing absenteeism, presenteeism, and net negative critical incidents.

A Two-Step Bayesian Approach for Propensity Score Analysis: Simulations and Case Study.

PubMed

Kaplan, David; Chen, Jianshen

2012-07-01

A two-step Bayesian propensity score approach is introduced that incorporates prior information in the propensity score equation and outcome equation without the problems associated with simultaneous Bayesian propensity score approaches. The corresponding variance estimators are also provided. The two-step Bayesian propensity score is provided for three methods of implementation: propensity score stratification, weighting, and optimal full matching. Three simulation studies and one case study are presented to elaborate the proposed two-step Bayesian propensity score approach. Results of the simulation studies reveal that greater precision in the propensity score equation yields better recovery of the frequentist-based treatment effect. A slight advantage is shown for the Bayesian approach in small samples. Results also reveal that greater precision around the wrong treatment effect can lead to seriously distorted results. However, greater precision around the correct treatment effect parameter yields quite good results, with slight improvement seen with greater precision in the propensity score equation. A comparison of coverage rates for the conventional frequentist approach and proposed Bayesian approach is also provided. The case study reveals that credible intervals are wider than frequentist confidence intervals when priors are non-informative.

Proton pump inhibitor use and risk of adverse cardiovascular events in aspirin treated patients with first time myocardial infarction: nationwide propensity score matched study

PubMed Central

Grove, Erik L; Hansen, Peter Riis; Olesen, Jonas B; Ahlehoff, Ole; Selmer, Christian; Lindhardsen, Jesper; Madsen, Jan Kyst; Køber, Lars; Torp-Pedersen, Christian; Gislason, Gunnar H

2011-01-01

Objective To examine the effect of proton pump inhibitors on adverse cardiovascular events in aspirin treated patients with first time myocardial infarction. Design Retrospective nationwide propensity score matched study based on administrative data. Setting All hospitals in Denmark. Participants All aspirin treated patients surviving 30 days after a first myocardial infarction from 1997 to 2006, with follow-up for one year. Patients treated with clopidogrel were excluded. Main outcome measures The risk of the combined end point of cardiovascular death, myocardial infarction, or stroke associated with use of proton pump inhibitors was analysed using Kaplan-Meier analysis, Cox proportional hazard models, and propensity score matched Cox proportional hazard models. Results 3366 of 19 925 (16.9%) aspirin treated patients experienced recurrent myocardial infarction, stroke, or cardiovascular death. The hazard ratio for the combined end point in patients receiving proton pump inhibitors based on the time dependent Cox proportional hazard model was 1.46 (1.33 to 1.61; P<0.001) and for the propensity score matched model based on 8318 patients it was 1.61 (1.45 to 1.79; P<0.001). A sensitivity analysis showed no increase in risk related to use of H2 receptor blockers (1.04, 0.79 to 1.38; P=0.78). Conclusion In aspirin treated patients with first time myocardial infarction, treatment with proton pump inhibitors was associated with an increased risk of adverse cardiovascular events. PMID:21562004

Efficacy of a Self-expanding Tract Sealant Device in the Reduction of Pneumothorax and Chest Tube Placement Rates After Percutaneous Lung Biopsy: A Matched Controlled Study Using Propensity Score Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ahrar, Judy U., E-mail: judy.ahrar@mdanderson.org; Gupta, Sanjay; Ensor, Joe E.

PurposeTo evaluate the use of a self-expanding tract sealant device (BioSentry™) on the rates of pneumothorax and chest tube insertion after percutaneous lung biopsy.Materials and MethodsIn this retrospective study, we compared 318 patients who received BioSentry™ during percutaneous lung biopsy (treated group) with 1956 patients who did not (control group). Patient-, lesion-, and procedure-specific variables, and pneumothorax and chest tube insertion rates were recorded. To adjust for potential selection bias, patients in the treated group were matched 1:1 to patients in the control group using propensity score matching based on the above-mentioned variables. Patients were considered a match if themore » absolute difference in their propensity scores was ≤equal to 0.02.ResultsBefore matching, the pneumothorax and chest tube rates were 24.5 and 13.1% in the control group, and 21.1 and 8.5% in the treated group, respectively. Using propensity scores, a match was found for 317 patients in the treatment group. Chi-square contingency matched pair analysis showed the treated group had significantly lower pneumothorax (20.8 vs. 32.8%; p = 0.001) and chest tube (8.2 vs. 20.8%; p < 0.0001) rates compared to the control group. Sub-analysis including only faculty who had >30 cases of both treatment and control cases demonstrated similar findings: the treated group had significantly lower pneumothorax (17.6 vs. 30.2%; p = 0.002) and chest tube (7.2 vs. 18%; p = 0.001) rates.ConclusionsThe self-expanding tract sealant device significantly reduced the pneumothorax rate, and more importantly, the chest tube placement rate after percutaneous lung biopsy.« less

Weight Loss Surgery Reduces Healthcare Resource Utilization and All-Cause Inpatient Mortality in Morbid Obesity: a Propensity-Matched Analysis.

PubMed

Krishna, Somashekar G; Rawal, Varun; Durkin, Claire; Modi, Rohan M; Hinton, Alice; Cruz-Monserrate, Zobeida; Conwell, Darwin L; Hussan, Hisham

2018-06-21

There is a lack of population studies evaluating the impact of bariatric surgery (BRS) on all-cause inpatient mortality. We sought to determine the impact of prior BRS on all-cause mortality and healthcare utilization in hospitalized patients. We analyzed the National Inpatient Sample database from 2007 to 2013. Participants were adult (≥ 18 years) inpatients admitted with a diagnosis of morbid obesity or a history of BRS. Propensity score-matched analyses were performed to compare mortality and healthcare resource utilization (hospital length of stay and cost). There were 9,044,103 patient admissions with morbid obesity and 1,066,779 with prior BRS. A propensity score-matched cohort analysis demonstrated that prior BRS was associated with decreased mortality (OR = 0.58; 95% CI [0.54, 0.63]), shorter length of stay (0.59 days; P < 0.001), and lower hospital costs ($2152; P < 0.001) compared to morbid obesity. A subgroup of propensity score-matched analysis among patients with high-risk of mortality (leading ten causes of mortality in morbid obesity) revealed a consistently significant reduction in odds of mortality for patients with prior BRS (OR = 0.82; 95% CI [0.72, 0.92]). Hospitalized patients with a history of BRS have lower all-cause mortality and healthcare resource utilization compared to those who are morbidly obese. These observations support the continued application of BRS as an effective and resource-conscious treatment for morbid obesity.

Does Matching Quality Matter in Mode Comparison Studies?

ERIC Educational Resources Information Center

Zeng, Ji; Yin, Ping; Shedden, Kerby A.

2015-01-01

This article provides a brief overview and comparison of three matching approaches in forming comparable groups for a study comparing test administration modes (i.e., computer-based tests [CBT] and paper-and-pencil tests [PPT]): (a) a propensity score matching approach proposed in this article, (b) the propensity score matching approach used by…

Methods for Constructing and Assessing Propensity Scores

PubMed Central

Garrido, Melissa M; Kelley, Amy S; Paris, Julia; Roza, Katherine; Meier, Diane E; Morrison, R Sean; Aldridge, Melissa D

2014-01-01

Objectives To model the steps involved in preparing for and carrying out propensity score analyses by providing step-by-step guidance and Stata code applied to an empirical dataset. Study Design Guidance, Stata code, and empirical examples are given to illustrate (1) the process of choosing variables to include in the propensity score; (2) balance of propensity score across treatment and comparison groups; (3) balance of covariates across treatment and comparison groups within blocks of the propensity score; (4) choice of matching and weighting strategies; (5) balance of covariates after matching or weighting the sample; and (6) interpretation of treatment effect estimates. Empirical Application We use data from the Palliative Care for Cancer Patients (PC4C) study, a multisite observational study of the effect of inpatient palliative care on patient health outcomes and health services use, to illustrate the development and use of a propensity score. Conclusions Propensity scores are one useful tool for accounting for observed differences between treated and comparison groups. Careful testing of propensity scores is required before using them to estimate treatment effects. PMID:24779867

Balancing Score Adjusted Targeted Minimum Loss-based Estimation

PubMed Central

Lendle, Samuel David; Fireman, Bruce; van der Laan, Mark J.

2015-01-01

Adjusting for a balancing score is sufficient for bias reduction when estimating causal effects including the average treatment effect and effect among the treated. Estimators that adjust for the propensity score in a nonparametric way, such as matching on an estimate of the propensity score, can be consistent when the estimated propensity score is not consistent for the true propensity score but converges to some other balancing score. We call this property the balancing score property, and discuss a class of estimators that have this property. We introduce a targeted minimum loss-based estimator (TMLE) for a treatment-specific mean with the balancing score property that is additionally locally efficient and doubly robust. We investigate the new estimator’s performance relative to other estimators, including another TMLE, a propensity score matching estimator, an inverse probability of treatment weighted estimator, and a regression-based estimator in simulation studies. PMID:26561539

Outcome of Intravenous Azithromycin Therapy in Patients with Complicated Scrub Typhus Compared with That of Doxycycline Therapy Using Propensity-Matched Analysis

PubMed Central

Jang, Mi-Ok; Jang, Hee-Chang; Kim, Uh Jin; Ahn, Joon Hwan; Kang, Seung-Ji; Jung, Sook-In; Shin, Hee-Young

2014-01-01

There are no well-matched, controlled studies comparing azithromycin with doxycycline for the treatment of complicated scrub typhus. A retrospective propensity score-matched case-control study was performed for patients who presented with complicated scrub typhus and were treated with doxycycline or azithromycin between 2001 and 2011. Data on comorbidities, clinical manifestations, laboratory studies, treatments, and outcomes were extracted for analysis. The clinical characteristics and outcomes of the azithromycin-treated group (n = 73) were compared to those of the doxycycline-treated group (n = 108). Of 181 patients, 73 from each group were matched by propensity scores. There were no significant differences in baseline characteristics between the matched groups. The treatment success and survival rates were not significantly different (89% [65/73 patients] versus 96% [70/73 patients] and 96% [70/73 patients] versus 96% [70/73 patients], respectively [P > 0.05]). No difference was observed in the time to defervescence or length of hospital stay between the two groups (P > 0.05). In complicated scrub typhus patients (n = 181), multivariate analysis showed that only APACHE II score was an independent risk factor for mortality (95% confidence interval, 1.11 to 1.56; P < 0.001). Our data suggest that outcomes of azithromycin therapy are comparable to those of doxycycline therapy in patients with complicated scrub typhus. PMID:24366734

Assessing covariate balance when using the generalized propensity score with quantitative or continuous exposures.

PubMed

Austin, Peter C

2018-01-01

Propensity score methods are increasingly being used to estimate the effects of treatments and exposures when using observational data. The propensity score was initially developed for use with binary exposures (e.g., active treatment vs. control). The generalized propensity score is an extension of the propensity score for use with quantitative exposures (e.g., dose or quantity of medication, income, years of education). A crucial component of any propensity score analysis is that of balance assessment. This entails assessing the degree to which conditioning on the propensity score (via matching, weighting, or stratification) has balanced measured baseline covariates between exposure groups. Methods for balance assessment have been well described and are frequently implemented when using the propensity score with binary exposures. However, there is a paucity of information on how to assess baseline covariate balance when using the generalized propensity score. We describe how methods based on the standardized difference can be adapted for use with quantitative exposures when using the generalized propensity score. We also describe a method based on assessing the correlation between the quantitative exposure and each covariate in the sample when weighted using generalized propensity score -based weights. We conducted a series of Monte Carlo simulations to evaluate the performance of these methods. We also compared two different methods of estimating the generalized propensity score: ordinary least squared regression and the covariate balancing propensity score method. We illustrate the application of these methods using data on patients hospitalized with a heart attack with the quantitative exposure being creatinine level.

Brachytherapy improves biochemical failure-free survival in low- and intermediate-risk prostate cancer compared with conventionally fractionated external beam radiation therapy: a propensity score matched analysis.

PubMed

Smith, Graham D; Pickles, Tom; Crook, Juanita; Martin, Andre-Guy; Vigneault, Eric; Cury, Fabio L; Morris, Jim; Catton, Charles; Lukka, Himu; Warner, Andrew; Yang, Ying; Rodrigues, George

2015-03-01

To compare, in a retrospective study, biochemical failure-free survival (bFFS) and overall survival (OS) in low-risk and intermediate-risk prostate cancer patients who received brachytherapy (BT) (either low-dose-rate brachytherapy [LDR-BT] or high-dose-rate brachytherapy with external beam radiation therapy [HDR-BT+EBRT]) versus external beam radiation therapy (EBRT) alone. Patient data were obtained from the ProCaRS database, which contains 7974 prostate cancer patients treated with primary radiation therapy at four Canadian cancer institutions from 1994 to 2010. Propensity score matching was used to obtain the following 3 matched cohorts with balanced baseline prognostic factors: (1) low-risk LDR-BT versus EBRT; (2) intermediate-risk LDR-BT versus EBRT; and (3) intermediate-risk HDR-BT+EBRT versus EBRT. Kaplan-Meier survival analysis was performed to compare differences in bFFS (primary endpoint) and OS in the 3 matched groups. Propensity score matching created acceptable balance in the baseline prognostic factors in all matches. Final matches included 2 1:1 matches in the intermediate-risk cohorts, LDR-BT versus EBRT (total n=254) and HDR-BT+EBRT versus EBRT (total n=388), and one 4:1 match in the low-risk cohort (LDR-BT:EBRT, total n=400). Median follow-up ranged from 2.7 to 7.3 years for the 3 matched cohorts. Kaplan-Meier survival analysis showed that all BT treatment options were associated with statistically significant improvements in bFFS when compared with EBRT in all cohorts (intermediate-risk EBRT vs LDR-BT hazard ratio [HR] 4.58, P=.001; intermediate-risk EBRT vs HDR-BT+EBRT HR 2.08, P=.007; low-risk EBRT vs LDR-BT HR 2.90, P=.004). No significant difference in OS was found in all comparisons (intermediate-risk EBRT vs LDR-BT HR 1.27, P=.687; intermediate-risk EBRT vs HDR-BT+EBRT HR 1.55, P=.470; low-risk LDR-BT vs EBRT HR 1.41, P=.500). Propensity score matched analysis showed that BT options led to statistically significant improvements in bFFS in low- and intermediate-risk prostate cancer patient populations. Copyright © 2015 Elsevier Inc. All rights reserved.

Brachytherapy Improves Biochemical Failure–Free Survival in Low- and Intermediate-Risk Prostate Cancer Compared With Conventionally Fractionated External Beam Radiation Therapy: A Propensity Score Matched Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, Graham D.; Pickles, Tom; Crook, Juanita

2015-03-01

Purpose: To compare, in a retrospective study, biochemical failure-free survival (bFFS) and overall survival (OS) in low-risk and intermediate-risk prostate cancer patients who received brachytherapy (BT) (either low-dose-rate brachytherapy [LDR-BT] or high-dose-rate brachytherapy with external beam radiation therapy [HDR-BT+EBRT]) versus external beam radiation therapy (EBRT) alone. Methods and Materials: Patient data were obtained from the ProCaRS database, which contains 7974 prostate cancer patients treated with primary radiation therapy at four Canadian cancer institutions from 1994 to 2010. Propensity score matching was used to obtain the following 3 matched cohorts with balanced baseline prognostic factors: (1) low-risk LDR-BT versus EBRT; (2)more » intermediate-risk LDR-BT versus EBRT; and (3) intermediate-risk HDR-BT+EBRT versus EBRT. Kaplan-Meier survival analysis was performed to compare differences in bFFS (primary endpoint) and OS in the 3 matched groups. Results: Propensity score matching created acceptable balance in the baseline prognostic factors in all matches. Final matches included 2 1:1 matches in the intermediate-risk cohorts, LDR-BT versus EBRT (total n=254) and HDR-BT+EBRT versus EBRT (total n=388), and one 4:1 match in the low-risk cohort (LDR-BT:EBRT, total n=400). Median follow-up ranged from 2.7 to 7.3 years for the 3 matched cohorts. Kaplan-Meier survival analysis showed that all BT treatment options were associated with statistically significant improvements in bFFS when compared with EBRT in all cohorts (intermediate-risk EBRT vs LDR-BT hazard ratio [HR] 4.58, P=.001; intermediate-risk EBRT vs HDR-BT+EBRT HR 2.08, P=.007; low-risk EBRT vs LDR-BT HR 2.90, P=.004). No significant difference in OS was found in all comparisons (intermediate-risk EBRT vs LDR-BT HR 1.27, P=.687; intermediate-risk EBRT vs HDR-BT+EBRT HR 1.55, P=.470; low-risk LDR-BT vs EBRT HR 1.41, P=.500). Conclusions: Propensity score matched analysis showed that BT options led to statistically significant improvements in bFFS in low- and intermediate-risk prostate cancer patient populations.« less

The association between the availability of sugar-sweetened beverage in school vending machines and its consumption among adolescents in California: a propensity score matching approach.

PubMed

Shi, Lu

2010-01-01

There is controversy over to what degree banning sugar-sweetened beverage (SSB) sales at schools could decrease the SSB intake. This paper uses the adolescent sample of 2005 California Health Interview Survey to estimate the association between the availability of SSB from school vending machines and the amount of SSB consumption. Propensity score stratification and kernel-based propensity score matching are used to address the selection bias issue in cross-sectional data. Propensity score stratification shows that adolescents who had access to SSB through their school vending machines consumed 0.170 more drinks of SSB than those who did not (P < .05). Kernel-based propensity score matching shows the SSB consumption difference to be 0.158 on the prior day (P < .05). This paper strengthens the evidence for the association between SSB availability via school vending machines and the actual SSB consumption, while future studies are needed to explore changes in other beverages after SSB becomes less available.

Risk of infectious complications associated with blood transfusion in elective spinal surgery-a propensity score matched analysis.

PubMed

Kato, So; Chikuda, Hirotaka; Ohya, Junichi; Oichi, Takeshi; Matsui, Hiroki; Fushimi, Kiyohide; Takeshita, Katsushi; Tanaka, Sakae; Yasunaga, Hideo

2016-01-01

Although the negative aspects of blood transfusion are increasingly recognized, less is known about transfusion-related risks in spinal surgery. This study was designed to determine whether perioperative allogeneic blood transfusion is associated with increased risk of infectious complications after elective spinal surgery. A retrospective cohort study with propensity score matched analysis was carried out. Data of patients with spinal canal stenosis and spondylolisthesis who underwent elective lumbar surgeries (decompression or fusion) were obtained from the Diagnosis Procedure Combination database, a nationwide administrative inpatient database in Japan. Clinical outcomes included in-hospital death and the occurrence of infectious complications (surgical site infection [SSI], respiratory tract infection, urinary tract infection, and sepsis). Patients' clinical information, including sex, age, type of hospital, preoperative comorbidities, duration of anesthesia, cell saver use, and volume of allogeneic blood transfused, were investigated. Patients transfused with >840 mL (6 units) were excluded. Propensity scores for receiving transfusion were calculated, with one-to-one matching based on estimated propensity scores to adjust for patients' baseline characteristics. The proportions of complications were compared in patients with and without transfusions. This study was funded by grants from the Ministry of Health, Labour and Welfare, Japan. Of the 84,650 patients identified, 5,289 patients (6.1%) received transfusions, with 4,436 (5.2%) receiving up to 840 mL. One-to-one propensity score matching resulted in 4,275 pairs with and without transfusion. Patients transfused were at increased risk of SSI (odds ratio [OR], 1.9; 95% confidence interval [CI], 1.4-2.5; p<.001) and urinary tract infection (OR, 2.5; 95% CI, 1.5-4.2; p<.001) than those not transfused. Allogeneic blood transfusion after elective lumbar surgery was associated with increased risks of SSI and urinary tract infection. Copyright © 2015 Elsevier Inc. All rights reserved.

Anesthesia Technique and Mortality after Total Hip or Knee Arthroplasty: A Retrospective, Propensity Score-matched Cohort Study.

PubMed

Perlas, Anahi; Chan, Vincent W S; Beattie, Scott

2016-10-01

This propensity score-matched cohort study evaluates the effect of anesthetic technique on a 30-day mortality after total hip or knee arthroplasty. All patients who had hip or knee arthroplasty between January 1, 2003, and December 31, 2014, were evaluated. The principal exposure was spinal versus general anesthesia. The primary outcome was 30-day mortality. Secondary outcomes were (1) perioperative myocardial infarction; (2) a composite of major adverse cardiac events that includes cardiac arrest, myocardial infarction, or newly diagnosed arrhythmia; (3) pulmonary embolism; (4) major blood loss; (5) hospital length of stay; and (6) operating room procedure time. A propensity score-matched-pair analysis was performed using a nonparsimonious logistic regression model of regional anesthetic use. We identified 10,868 patients, of whom 8,553 had spinal anesthesia and 2,315 had general anesthesia. Ninety-two percent (n = 2,135) of the patients who had general anesthesia were matched to similar patients who did not have general anesthesia. In the matched cohort, the 30-day mortality rate was 0.19% (n = 4) in the spinal anesthesia group and 0.8% (n = 17) in the general anesthesia group (risk ratio, 0.42; 95% CI, 0.21 to 0.83; P = 0.0045). Spinal anesthesia was also associated with a shorter hospital length of stay (5.7 vs. 6.6 days; P < 0.001). The results of this observational, propensity score-matched cohort study suggest a strong association between spinal anesthesia and lower 30-day mortality, as well as a shorter hospital length of stay, after elective joint replacement surgery.

Risk of poor neonatal outcome at term after medically assisted reproduction: a propensity score-matched study.

PubMed

Ensing, Sabine; Abu-Hanna, Ameen; Roseboom, Tessa J; Repping, Sjoerd; van der Veen, Fulco; Mol, Ben Willem J; Ravelli, Anita C J

2015-08-01

To study risk of birth asphyxia and related morbidity among term singletons born after medically assisted reproduction (MAR). Population cohort study. Not applicable. A total of 1,953,932 term singleton pregnancies selected from a national registry for 1999-2011. None. Primary outcome Apgar score <4; secondary outcomes Apgar score <7, intrauterine fetal death, perinatal mortality, congenital anomalies, small for gestational age, asphyxia related morbidity, and cesarean delivery. The risks of birth asphyxia and related morbidity were calculated in women who conceived either through MAR or spontaneously (SC), with a subgroup analysis for in vitro fertilization (IVF). An additional propensity score matching analysis was performed with matching on multiple maternal baseline covariates (maternal age, ethnicity, socioeconomic status, parity, year of birth, and preexistent diseases). Each MAR pregnancy was matched to three SC controls. Relative to SC, the MAR singletons had an increased risk of adverse neonatal outcomes including Apgar score <4 (adjusted odds ratio [OR] 1.29; 95% CI, 1.14-1.46) and intrauterine fetal death (adjusted OR 1.61; 95% CI, 1.35-1.91). After propensity score matching, the risk of an Apgar score <4 was comparable between MAR and SC singletons (OR 0.99; 95% CI, 0.87-1.14). Cesarean delivery for both fetal distress and nonprogressive labor occurred more among MAR pregnancies compared with SC pregnancies. Term singletons conceived after MAR have an increased risk of morbidity related to birth asphyxia. Because this is mainly due to maternal characteristics, obstetric caregivers should be aware that the increased rates of cesareans reflect the behavior of women and physicians rather than increased perinatal complications. Copyright © 2015 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Propensity-score matching in economic analyses: comparison with regression models, instrumental variables, residual inclusion, differences-in-differences, and decomposition methods.

PubMed

Crown, William H

2014-02-01

This paper examines the use of propensity score matching in economic analyses of observational data. Several excellent papers have previously reviewed practical aspects of propensity score estimation and other aspects of the propensity score literature. The purpose of this paper is to compare the conceptual foundation of propensity score models with alternative estimators of treatment effects. References are provided to empirical comparisons among methods that have appeared in the literature. These comparisons are available for a subset of the methods considered in this paper. However, in some cases, no pairwise comparisons of particular methods are yet available, and there are no examples of comparisons across all of the methods surveyed here. Irrespective of the availability of empirical comparisons, the goal of this paper is to provide some intuition about the relative merits of alternative estimators in health economic evaluations where nonlinearity, sample size, availability of pre/post data, heterogeneity, and missing variables can have important implications for choice of methodology. Also considered is the potential combination of propensity score matching with alternative methods such as differences-in-differences and decomposition methods that have not yet appeared in the empirical literature.

Graphic report of the results from propensity score method analyses.

PubMed

Shrier, Ian; Pang, Menglan; Platt, Robert W

2017-08-01

To increase transparency in studies reporting propensity scores by using graphical methods that clearly illustrate (1) the number of participant exclusions that occur as a consequence of the analytic strategy and (2) whether treatment effects are constant or heterogeneous across propensity scores. We applied graphical methods to a real-world pharmacoepidemiologic study that evaluated the effect of initiating statin medication on the 1-year all-cause mortality post-myocardial infarction. We propose graphical methods to show the consequences of trimming and matching on the exclusion of participants from the analysis. We also propose the use of meta-analytical forest plots to show the magnitude of effect heterogeneity. A density plot with vertical lines demonstrated the proportion of subjects excluded because of trimming. A frequency plot with horizontal lines demonstrated the proportion of subjects excluded because of matching. An augmented forest plot illustrates the amount of effect heterogeneity present in the data. Our proposed techniques present additional and useful information that helps readers understand the sample that is analyzed with propensity score methods and whether effect heterogeneity is present. Copyright © 2017 Elsevier Inc. All rights reserved.

Eicosapentaenoic Acid (EPA) Decreases the All-Cause Mortality in Hemodialysis Patients.

PubMed

Inoue, Tomoko; Okano, Kazuhiro; Tsuruta, Yuki; Tsuruta, Yukio; Tsuchiya, Ken; Akiba, Takashi; Nitta, Kosaku

2015-01-01

Atherosclerosis, which causes cardiovascular disease, is a major cause of death in hemodialysis (HD) patients. Eicosapentaenoic acid (EPA), an anti-hyperlipidemic agent, is known to have antioxidative or anti-inflammatory effects, resulting in improvements in atherosclerosis. In the present study, we examined whether EPA improves the all-cause mortality in patients receiving regular HD therapy. We enrolled 176 patients treated with maintenance HD therapy and performed a longitudinal observational cohort study for three years. We divided the patients into two groups based on whether or not the received EPA treatment [EPA(+) and EPA(-), respectively]. The primary end-point was all-cause death. We also matched the two groups using propensity score matching and examined the effect of EPA. Before matching, the all-cause mortality rates were 24.0% in the EPA(+) and 11.8% in the EPA(-) groups, which were significantly different (p=0.044). After propensity score matching, the EPA(+) group still showed a significantly better prognosis than the EPA(-) group (p=0.038). A multivariate analysis showed that EPA treatment significantly reduced the risk of all-cause mortality both before and after propensity score matching. EPA treatment is independently associated with lower mortality in HD patients.

Improving participant selection in disease management programmes: insights gained from propensity score stratification.

PubMed

Linden, Ariel; Adams, John L

2008-10-01

While the randomized controlled trial (RCT) remains the gold-standard study design for evaluating treatment effect, outcomes researchers turn to powerful quasi-experimental designs when only observational studies can be conducted. Within these designs, propensity score matching is one of the most popular to evaluate disease management (DM) programme effectiveness. Given that DM programmes generally have a much smaller number of participants than non-participants in the population, propensity score matching will typically result in all or nearly all participants finding successful matches, while most of the non-participants in the population remain unmatched and thereby excluded from the analysis. By excluding data from the unmatched population, the effect of non-treatment in the remaining population with the disease is not captured. In the present study, we examine changes in hospitalization rates stratified by propensity score quintiles across the entire population allowing us to gain insight as to how well the programme chose its participants, or if the programme could have been effective on those individuals not explicitly targeted for the intervention. These data indicate the presence of regression to the mean, and suggest that the DM programme may be overly limited to only the highest strata when there is evidence of a potential benefit for those in all the lower strata as well.

Statin use and kidney cancer outcomes: A propensity score analysis.

PubMed

Nayan, Madhur; Finelli, Antonio; Jewett, Michael A S; Juurlink, David N; Austin, Peter C; Kulkarni, Girish S; Hamilton, Robert J

2016-11-01

Studies evaluating the association between statin use and survival outcomes in renal cell carcinoma have demonstrated conflicting results. Our objective was to evaluate this association in a large clinical cohort by using propensity score methods to reduce confounding from measured covariates. We performed a retrospective review of 893 patients undergoing nephrectomy for unilateral, M0 renal cell carcinoma between 2000 and 2014 at a tertiary academic center. Inverse probability of treatment weights were derived from a propensity score model based on clinical, surgical, and pathological characteristics. We used Cox proportional hazard models to evaluate the association between statin use and disease-free survival, cancer-specific survival, and overall survival in the sample weighted by the inverse probability of treatment weights. A secondary analysis was performed matching statin users 1:1 to statin nonusers on the propensity score. Of the 893 patients, 259 (29%) were on statins at the time of surgery. Median follow-up was 47 months (interquartile range: 20-80). Statin use was not significantly associated with disease-free survival (hazard ratio [HR] = 1.09, 95% CI: 0.65-1.81), cancer-specific survival (HR = 0.90, 95% CI: 0.40-2.01), or overall survival (HR = 0.89, 95% CI: 0.55-1.44). Similar results were observed when using propensity score matching. The present study found no significant association between statin use and kidney cancer outcomes. Population-based studies are needed to further evaluate the role of statins in kidney cancer therapy. Copyright © 2016 Elsevier Inc. All rights reserved.

Propensity score-matched analysis of comprehensive local therapy for oligometastatic non-small cell lung cancer that did not progress after front-line chemotherapy.

PubMed

Sheu, Tommy; Heymach, John V; Swisher, Stephen G; Rao, Ganesh; Weinberg, Jeffrey S; Mehran, Reza; McAleer, Mary Frances; Liao, Zhongxing; Aloia, Thomas A; Gomez, Daniel R

2014-11-15

To retrospectively analyze factors influencing survival in patients with non-small cell lung cancer presenting with ≤3 synchronous metastatic lesions. We identified 90 patients presenting between 1998 and 2012 with non-small cell lung cancer and ≤3 metastatic lesions who had received at least 2 cycles of chemotherapy followed by surgery or radiation therapy before disease progression. The median number of chemotherapy cycles before comprehensive local therapy (CLT) (including concurrent chemoradiation as first-line therapy) was 6. Factors potentially affecting overall (OS) or progression-free survival (PFS) were evaluated with Cox proportional hazards regression. Propensity score matching was used to assess the efficacy of CLT. Median follow-up time was 46.6 months. Benefits in OS (27.1 vs 13.1 months) and PFS (11.3 months vs 8.0 months) were found with CLT, and the differences were statistically significant when propensity score matching was used (P ≤ .01). On adjusted analysis, CLT had a statistically significant benefit in terms of OS (hazard ratio, 0.37; 95% confidence interval, 0.20-0.70; P ≤ .01) but not PFS (P=.10). In an adjusted subgroup analysis of patients receiving CLT, favorable performance status (hazard ratio, 0.43; 95% confidence interval, 0.22-0.84; P=.01) was found to predict improved OS. Comprehensive local therapy was associated with improved OS in an adjusted analysis and seemed to favorably influence OS and PFS when factors such as N status, number of metastatic lesions, and disease sites were controlled for with propensity score-matched analysis. Patients with favorable performance status had improved outcomes with CLT. Ultimately, prospective, randomized trials are needed to provide definitive evidence as to the optimal treatment approach for this patient population. Copyright © 2014 Elsevier Inc. All rights reserved.

Cancer Recurrence After Esophagectomy: Impact of Postoperative Infection in Propensity-Matched Cohorts.

PubMed

Tam, Vernissia; Luketich, James D; Winger, Daniel G; Sarkaria, Inderpal S; Levy, Ryan M; Christie, Neil A; Awais, Omar; Shende, Manisha R; Nason, Katie S

2016-11-01

Postoperative infection increases cancer recurrence and worsens survival in colorectal cancer, but the relationship for esophagogastric adenocarcinoma after esophagectomy is not well defined. We aimed to determine whether recurrence and survival after minimally invasive esophagectomy for esophagogastric adenocarcinoma were influenced by postoperative infection using propensity-matched analysis. We abstracted data for 810 patients (1997-2010) and defined exposure as at least 1 in-hospital or 30-day infectious complication (n = 206 [25%]). Using 29 pretreatment/intraoperative variables, patients were propensity-score matched (caliper = 0.05). Time to cancer recurrence and survival (Kaplan-Meier curves and the Breslow test), and associated factors (Cox regression with shared frailty) were assessed. After propensity matching (n = 167 pairs), median bias across propensity-score variables was reduced from 12.9% (p < 0.001) to 4.4% (p = 1.000). Postoperative infection was not associated with rate (n = 60 versus 63; McNemar p = 0.736) or time to recurrence in those in whom disease recurred (median, 10.7 versus 11.1 months; Wilcoxon signed-rank p = 0.455) but was associated with shorter overall survival (n = 124 versus 102 deaths; median, 26 versus 41 months; Breslow p = 0.002). After adjusting for age, body mass index, neoadjuvant therapy, sex, comorbidity score, positive resection margins, pathologic stage, R0 resection, and recurrence, postoperative infection was associated with a 44% greater hazard for death (hazard ratio, 1.44; 95% confidence interval, 1.10-1.89). In patients with esophagogastric adenocarcinoma, infections after esophagectomy were not associated with an increased rate or earlier time to recurrence when baseline characteristics associated with infection risk were balanced using propensity-score matching. Despite this, overall survival was shorter in patients with infectious complications. After adjusting for other important survival predictors, infections after esophagectomy continued to be independently associated with worse survival. Copyright © 2016 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Calcium supplementation improves clinical outcome in intensive care unit patients: a propensity score matched analysis of a large clinical database MIMIC-II.

PubMed

Zhang, Zhongheng; Chen, Kun; Ni, Hongying

2015-01-01

Observational studies have linked hypocalcemia with adverse clinical outcome in critically ill patients. However, calcium supplementation has never been formally investigated for its beneficial effect in critically ill patients. To investigate whether calcium supplementation can improve 28-day survival in adult critically ill patients. Secondary analysis of a large clinical database consisting over 30,000 critical ill patients was performed. Multivariable analysis was performed to examine the independent association of calcium supplementation and 28-day morality. Furthermore, propensity score matching technique was employed to investigate the role of calcium supplementation in improving survival. none. Primary outcome was the 28-day mortality. 90-day mortality was used as secondary outcome. A total of 32,551 adult patients, including 28,062 survivors and 4489 non-survivors (28-day mortality rate: 13.8 %) were included. Calcium supplementation was independently associated with improved 28-day mortality after adjusting for confounding variables (hazard ratio: 0.51; 95 % CI 0.47-0.56). Propensity score matching was performed and the after-matching cohort showed well balanced covariates. The results showed that calcium supplementation was associated with improved 28- and 90-day mortality (p < 0.05 for both Log-rank test). In adult critically ill patients, calcium supplementation during their ICU stay improved 28-day survival. This finding supports the use of calcium supplementation in critically ill patients.

Effects of the body mass index (BMI) on the surgical outcomes of laparoscopic fundoplication for gastro-esophageal reflux disease: a propensity score-matched analysis.

PubMed

Hoshino, Masato; Omura, Nobuo; Yano, Fumiaki; Tsuboi, Kazuto; Yamamoto, Se Ryung; Akimoto, Shunsuke; Masuda, Takahiro; Kashiwagi, Hideyuki; Yanaga, Katsuhiko

2018-02-01

In the present study, we examined how the body mass index (BMI) affected the outcomes of laparoscopic fundoplication for GERD in patients, whose backgrounds were matched in a propensity score-matched analysis. We divided the patients into two groups (BMI <25 kg/m 2 and BMI ≥25 kg/m 2 ). The following background information was matched for the propensity score-matched analysis: sex, age, degree of esophageal hiatal hernia, acid exposure time, and degree of reflux esophagitis. In total, 105 subjects were extracted in each group. The surgical outcomes and postoperative outcomes of patients with BMI <25 kg/m 2 (Group A) and those with BMI ≥25 kg/m 2 (Group B) were compared and examined. There were no differences in the surgical procedure, intraoperative complications, or estimated blood loss (p = 0.876, p = 0.516, p = 0.438, respectively); however, the operative time was significantly prolonged in Group B (p = 0.003). The rate of postoperative recurrence in Group A was 17% (15/87 patients), while that in Group B was 11% (12/91 patients), and did not differ to a statistically significant extent (p = 0.533). Although the operative time for GERD in obese patients was prolonged in comparison with non-obese patients, there was no difference in the rate of postoperative recurrence.

The Safety of Ovarian Preservation in Stage I Endometrial Endometrioid Adenocarcinoma Based on Propensity Score Matching.

PubMed

Hou, Ting; Sun, Yidi; Li, Junyi; Liu, Chenglin; Wang, Zhen; Li, Yixue; Lu, Yuan

2017-01-01

Most patients with early stage endometrial endometrioid adenocarcinoma (EEAC) are treated with hysterectomy and bilateral oophorectomy. But this surgical menopause leads to long-term sequelae for premenopausal women, especially for young women of childbearing age. This population-based study was to evaluate the safety of ovarian preservation in young women with stage I EEAC. Patients of age 50 or younger with stage I EEAC were explored from the Surveillance, Epidemiology and End Results program database during 2004 to 2013. Propensity score matching was used to randomize the data set and reduce the selection biases of doctors. Univariate analysis and multivariate cox proportional hazards model were utilized to estimate the safety of ovarian preservation. A total of 7183 patients were identified, and ovarian preservation was performed in 863 (12 %) patients. Compared with women treated with oophorectomy, patients with ovarian preservation significantly tend to be younger at diagnosis (P-value < 0.001) and more likely diagnosed as stage IA EEAC, to have better differentiated tumor tissues and smaller tumors, as well as less likely to undergo radiation and lymphadenectomy. 863 patients treated with oophorectomy were selected by propensity score matching. After propensity score matching, the differences of all characteristics between ovarian preservation and oophorectomy were not significant and potential confounders in the two groups decreased. In univariate analysis of matched population, ovarian preservation had no effect on overall (P-value=0.928) and cancer-specific (P-value=0.390) mortality. In propensityadjusted multivariate analysis, ovarian preservation was not significantly associated with overall (HR=0.69, 95%CI=0.41-1.68, P-value=0.611) and cancer-specific (HR=1.65, 95%CI=0.54-5.06, Pvalue= 0.379) survival. Ovarian preservation is safe for young women with stage I EEAC, which is not significantly associated with overall and cancer-specific mortality. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Sociodemographic Differences in the Association Between Obesity and Stress: A Propensity Score-Matched Analysis from the Korean National Health and Nutrition Examination Survey (KNHANES).

PubMed

Mak, Kwok-Kei; Kim, Dae-Hwan; Leigh, J Paul

2015-01-01

Few population-based studies have used an econometric approach to understand the association between two cancer risk factors, obesity and stress. This study investigated sociodemographic differences in the association between obesity and stress among Korean adults (6,546 men and 8,473 women). Data were drawn from the Korean National Health and Nutrition Examination Survey for 2008, 2009, and 2010. Ordered logistic regression models and propensity score matching methods were used to examine the associations between obesity and stress, stratified by gender and age groups. In women, the stress level of the obese group was found to be 27.6% higher than the nonobese group in the ordered logistic regression; the obesity effect on stress was statistically significant in the propensity score-matched analysis. Corresponding evidence for the effect of obesity on stress was lacking among men. Participants who were young, well-educated, and working were more likely to report stress. In Korea, obesity causes stress in women but not in men. Young women are susceptible to a disproportionate level of stress. More cancer prevention programs targeting young and obese women are encouraged in developed Asian countries.

Are Two Years Better than One Year? A Propensity Score Analysis of the Impact of Head Start Program Duration on Children's School Performance in Kindergarten

ERIC Educational Resources Information Center

Wen, Xiaoli; Leow, Christine; Hahs-Vaughn, Debbie L.; Korfmacher, Jon; Marcus, Sue M.

2012-01-01

Using data from a nationally representative sample, this study examined Head Start children's school outcome differences by the end of Kindergarten between children who attended Head Start program for two years and the ones who attended for one year. Propensity scores were used to match children who experienced different durations of the program…

Association between long work hours and depressive state: a pilot study of propensity score matched Japanese white-collar workers.

PubMed

Uchida, Mitsuo; Morita, Hiroshi

2018-06-01

Although long work hours have been associated with various physical health problems, studies of their association with mental health have yielded inconsistent results, due to differences in study settings, study outcome and/or unmeasured background factors. In this study, we used a propensity score method to evaluate the association between work hours and depressive state. A total of 467 Japanese white-collar workers were surveyed and divided into long and regular work hour groups according to overtime work records. Propensity score matching was performed based on 32 individual background and workplace factors, yielding 74 pairs of propensity-matched subjects. CES-D score, an indicator of depressive state, did not differ significantly among the two groups (p=0.203). However, work motivation, work control, social support and emotional stability correlated with CES-D score. These findings suggest that work control and social support factors are more associated with depressive state than control of work hours. These results also suggest that it is possible to use propensity score matching to evaluate the association between work hours and mental health in occupational study settings. Further studies, in larger populations, are required to determine the association between work hours and mental health parameters.

Examining Moderation Analyses in Propensity Score Methods: Application to Depression and Substance Use

PubMed Central

Green, Kerry M.; Stuart, Elizabeth A.

2014-01-01

Objective This study provides guidance on how propensity score methods can be combined with moderation analyses (i.e., effect modification) to examine subgroup differences in potential causal effects in non-experimental studies. As a motivating example, we focus on how depression may affect subsequent substance use differently for men and women. Method Using data from a longitudinal community cohort study (N=952) of urban African Americans with assessments in childhood, adolescence, young adulthood and midlife, we estimate the influence of depression by young adulthood on substance use outcomes in midlife, and whether that influence varies by gender. We illustrate and compare five different techniques for estimating subgroup effects using propensity score methods, including separate propensity score models and matching for men and women, a joint propensity score model for men and women with matching separately and together by gender, and a joint male/female propensity score model that includes theoretically important gender interactions with matching separately and together by gender. Results Analyses showed that estimating separate models for men and women yielded the best balance and, therefore, is a preferred technique when subgroup analyses are of interest, at least in this data. Results also showed substance use consequences of depression but no significant gender differences. Conclusions It is critical to prespecify subgroup effects before the estimation of propensity scores and to check balance within subgroups regardless of the type of propensity score model used. Results also suggest that depression may affect multiple substance use outcomes in midlife for both men and women relatively equally. PMID:24731233

Effect of perioperative oral care on prevention of postoperative pneumonia associated with esophageal cancer surgery: A multicenter case-control study with propensity score matching analysis.

PubMed

Soutome, Sakiko; Yanamoto, Souichi; Funahara, Madoka; Hasegawa, Takumi; Komori, Takahide; Yamada, Shin-Ichi; Kurita, Hiroshi; Yamauchi, Chika; Shibuya, Yasuyuki; Kojima, Yuka; Nakahara, Hirokazu; Oho, Takahiko; Umeda, Masahiro

2017-08-01

The aim of this study was to investigate the effectiveness of oral care in prevention of postoperative pneumonia associated with esophageal cancer surgery.Postoperative pneumonia is a severe adverse event associated with esophageal cancer surgery. It is thought to be caused by aspiration of oropharyngeal fluid containing pathogens. However, the relationship between oral health status and postoperative pneumonia has not been well investigated.This study included 539 patients with esophageal cancer undergoing surgery at 1 of 7 university hospitals. While 306 patients received perioperative oral care, 233 did not. Various clinical factors as well as occurrence of postoperative pneumonia were retrospectively evaluated. Propensity-score matching was performed to minimize selection biases associated with comparison of retrospective data between the oral care and control groups. Factors related to postoperative pneumonia were analyzed by logistic regression analysis.Of the original 539 patients, 103 (19.1%) experienced postoperative pneumonia. The results of multivariate analysis of the 420 propensity score-matched patients revealed longer operation time, postoperative dysphagia, and lack of oral care intervention to be significantly correlated with postoperative pneumonia.The present findings demonstrate that perioperative oral care can reduce the risk of postoperative pneumonia in patients undergoing esophageal cancer surgery.

The Association between the Availability of Sugar-Sweetened Beverage in School Vending Machines and Its Consumption among Adolescents in California: A Propensity Score Matching Approach

PubMed Central

Shi, Lu

2010-01-01

There is controversy over to what degree banning sugar-sweetened beverage (SSB) sales at schools could decrease the SSB intake. This paper uses the adolescent sample of 2005 California Health Interview Survey to estimate the association between the availability of SSB from school vending machines and the amount of SSB consumption. Propensity score stratification and kernel-based propensity score matching are used to address the selection bias issue in cross-sectional data. Propensity score stratification shows that adolescents who had access to SSB through their school vending machines consumed 0.170 more drinks of SSB than those who did not (P < .05). Kernel-based propensity score matching shows the SSB consumption difference to be 0.158 on the prior day (P < .05). This paper strengthens the evidence for the association between SSB availability via school vending machines and the actual SSB consumption, while future studies are needed to explore changes in other beverages after SSB becomes less available. PMID:20976298

Effects of statin therapy on clinical outcomes after acute myocardial infarction in patients with advanced renal dysfunction: A propensity score-matched analysis.

PubMed

Kim, Jin Sug; Kim, Weon; Park, Ji Yoon; Woo, Jong Shin; Lee, Tae Won; Ihm, Chun Gyoo; Kim, Yang Gyun; Moon, Ju-Young; Lee, Sang Ho; Jeong, Myung Ho; Jeong, Kyung Hwan

2017-01-01

Lipid lowering therapy is widely used for the prevention of cardiovascular complications after acute myocardial infarction (AMI). However, some studies show that this benefit is uncertain in patients with renal dysfunction, and the role of statins is based on the severity of renal dysfunction. In this study, we investigated the impact of statin therapy on major adverse cardiac events (MACEs) and all-cause mortality in patients with advanced renal dysfunction undergoing percutaneous coronary intervention (PCI) after AMI. This study was based on the Korea Acute Myocardial Infarction Registry database. We included 861 patients with advanced renal dysfunction from among 33,205 patients who underwent PCI after AMI between November 2005 and July 2012. Patients were divided into two groups: a statin group (n = 537) and a no-statin group (n = 324). We investigated the 12-month MACEs (cardiac death, myocardial infarction, repeated PCI or coronary artery bypass grafting) and all-cause mortality of each group. Subsequently, a propensity score-matched analysis was performed. In the total population studied, no significant differences were observed between the two groups with respect to the rate of recurrent MI, repeated PCI, coronary artery bypass grafting (CABG), or all-cause mortality. However, the cardiac death rate was significantly lower in the statin group (p = 0.009). Propensity score-matched analysis yielded 274 pairs demonstrating, results similar to those obtained from the total population. However, there was no significant difference in the cardiac death rate in the propensity score-matched population (p = 0.103). Cox-regression analysis revealed only left ventricular ejection fraction to be an independent predictor of 12-month MACEs (Hazard ratio [HR] of 0.979, 95% confidence interval [CI], 0962-0.996, p = 0.018). Statin therapy was not significantly associated with a reduction in the 12-month MACEs or all-cause mortality in patients with advanced renal dysfunction undergoing PCI after AMI.

Advanced Issues in Propensity Scores: Longitudinal and Missing Data

ERIC Educational Resources Information Center

Kupzyk, Kevin A.; Beal, Sarah J.

2017-01-01

In order to investigate causality in situations where random assignment is not possible, propensity scores can be used in regression adjustment, stratification, inverse-probability treatment weighting, or matching. The basic concepts behind propensity scores have been extensively described. When data are longitudinal or missing, the estimation and…

Propensity score models in observational comparative effectiveness studies: cornerstone of design or statistical afterthought?

PubMed

Robinson, John W

2012-03-01

Propensity score models are increasingly used in observational comparative effectiveness studies to reduce confounding by covariates that are associated with both a study outcome and treatment choice. Any such potentially confounding covariate will bias estimation of the effect of treatment on the outcome, unless the distribution of that covariate is well-balanced between treatment and control groups. Constructing a subsample of treated and control subjects who are matched on estimated propensity scores is a means of achieving such balance for covariates that are included in the propensity score model. If, during study design, investigators assemble a comprehensive inventory of known and suspected potentially confounding covariates, examination of how well this inventory is covered by the chosen dataset yields an assessment of the extent of bias reduction that is possible by matching on estimated propensity scores. These considerations are explored by examining the designs of three recently published comparative effectiveness studies.

Impact of prestroke selective serotonin reuptake inhibitor treatment on stroke severity and mortality.

PubMed

Mortensen, Janne Kaergaard; Larsson, Heidi; Johnsen, Søren Paaske; Andersen, Grethe

2014-07-01

Selective serotonin reuptake inhibitors (SSRIs) have been associated with an increased risk of bleeding but also a possible neuroprotective effect in stroke. We aimed to examine the implications of prestroke SSRI use in hemorrhagic and ischemic stroke. We conducted a registry-based propensity score-matched follow-up study among first-ever patients with hemorrhage and ischemic stroke in Denmark (2003-2012). Multiple conditional logistic regression was used to compute adjusted odds ratios of severe stroke and death within 30 days. Among 1252 hemorrhagic strokes (626 prestroke SSRI users and 626 propensity score-matched nonusers), prestroke SSRI use was associated with an increased risk of the strokes being severe (adjusted propensity score-matched odds ratios, 1.41; confidence interval, 1.08-1.84) and an increased risk of death within 30 days (adjusted propensity score-matched odds ratios, 1.60; confidence interval, 1.17-2.18). Among 8956 patients with ischemic stroke (4478 prestroke SSRI users and 4478 propensity score-matched nonusers), prestroke SSRI use was not associated with the risk of severe stroke or death within 30 days. Prestroke SSRI use is associated with increased stroke severity and mortality in patients with hemorrhagic stroke. Although prestroke depression in itself may increase stroke severity and mortality, this was not found in SSRI users with ischemic stroke. © 2014 American Heart Association, Inc.

A comparison of 12 algorithms for matching on the propensity score.

PubMed

Austin, Peter C

2014-03-15

Propensity-score matching is increasingly being used to reduce the confounding that can occur in observational studies examining the effects of treatments or interventions on outcomes. We used Monte Carlo simulations to examine the following algorithms for forming matched pairs of treated and untreated subjects: optimal matching, greedy nearest neighbor matching without replacement, and greedy nearest neighbor matching without replacement within specified caliper widths. For each of the latter two algorithms, we examined four different sub-algorithms defined by the order in which treated subjects were selected for matching to an untreated subject: lowest to highest propensity score, highest to lowest propensity score, best match first, and random order. We also examined matching with replacement. We found that (i) nearest neighbor matching induced the same balance in baseline covariates as did optimal matching; (ii) when at least some of the covariates were continuous, caliper matching tended to induce balance on baseline covariates that was at least as good as the other algorithms; (iii) caliper matching tended to result in estimates of treatment effect with less bias compared with optimal and nearest neighbor matching; (iv) optimal and nearest neighbor matching resulted in estimates of treatment effect with negligibly less variability than did caliper matching; (v) caliper matching had amongst the best performance when assessed using mean squared error; (vi) the order in which treated subjects were selected for matching had at most a modest effect on estimation; and (vii) matching with replacement did not have superior performance compared with caliper matching without replacement. © 2013 The Authors. Statistics in Medicine published by John Wiley & Sons, Ltd.

A comparison of 12 algorithms for matching on the propensity score

PubMed Central

Austin, Peter C

2014-01-01

Propensity-score matching is increasingly being used to reduce the confounding that can occur in observational studies examining the effects of treatments or interventions on outcomes. We used Monte Carlo simulations to examine the following algorithms for forming matched pairs of treated and untreated subjects: optimal matching, greedy nearest neighbor matching without replacement, and greedy nearest neighbor matching without replacement within specified caliper widths. For each of the latter two algorithms, we examined four different sub-algorithms defined by the order in which treated subjects were selected for matching to an untreated subject: lowest to highest propensity score, highest to lowest propensity score, best match first, and random order. We also examined matching with replacement. We found that (i) nearest neighbor matching induced the same balance in baseline covariates as did optimal matching; (ii) when at least some of the covariates were continuous, caliper matching tended to induce balance on baseline covariates that was at least as good as the other algorithms; (iii) caliper matching tended to result in estimates of treatment effect with less bias compared with optimal and nearest neighbor matching; (iv) optimal and nearest neighbor matching resulted in estimates of treatment effect with negligibly less variability than did caliper matching; (v) caliper matching had amongst the best performance when assessed using mean squared error; (vi) the order in which treated subjects were selected for matching had at most a modest effect on estimation; and (vii) matching with replacement did not have superior performance compared with caliper matching without replacement. © 2013 The Authors. Statistics in Medicine published by John Wiley & Sons, Ltd. PMID:24123228

Propensity Score Matching within Prognostic Strata

ERIC Educational Resources Information Center

Kelcey, Ben

2013-01-01

A central issue in nonexperimental studies is identifying comparable individuals to remove selection bias. One common way to address this selection bias is through propensity score (PS) matching. PS methods use a model of the treatment assignment to reduce the dimensionality of the covariate space and identify comparable individuals. parallel to…

Double propensity-score adjustment: A solution to design bias or bias due to incomplete matching.

PubMed

Austin, Peter C

2017-02-01

Propensity-score matching is frequently used to reduce the effects of confounding when using observational data to estimate the effects of treatments. Matching allows one to estimate the average effect of treatment in the treated. Rosenbaum and Rubin coined the term "bias due to incomplete matching" to describe the bias that can occur when some treated subjects are excluded from the matched sample because no appropriate control subject was available. The presence of incomplete matching raises important questions around the generalizability of estimated treatment effects to the entire population of treated subjects. We describe an analytic solution to address the bias due to incomplete matching. Our method is based on using optimal or nearest neighbor matching, rather than caliper matching (which frequently results in the exclusion of some treated subjects). Within the sample matched on the propensity score, covariate adjustment using the propensity score is then employed to impute missing potential outcomes under lack of treatment for each treated subject. Using Monte Carlo simulations, we found that the proposed method resulted in estimates of treatment effect that were essentially unbiased. This method resulted in decreased bias compared to caliper matching alone and compared to either optimal matching or nearest neighbor matching alone. Caliper matching alone resulted in design bias or bias due to incomplete matching, while optimal matching or nearest neighbor matching alone resulted in bias due to residual confounding. The proposed method also tended to result in estimates with decreased mean squared error compared to when caliper matching was used.

Outcome of Early Initiation of Peritoneal Dialysis in Patients with End-Stage Renal Failure

PubMed Central

Oh, Kook-Hwan; Hwang, Young-Hwan; Cho, Jung-Hwa; Kim, Mira; Ju, Kyung Don; Joo, Kwon Wook; Kim, Dong Ki; Kim, Yon Su; Ahn, Curie

2012-01-01

Recent studies reported that early initiation of hemodialysis may increase mortality. However, studies that assessed the influence of early initiation of peritoneal dialysis (PD) yielded controversial results. In the present study, we evaluated the prognosis of early initiation of PD on the various outcomes of end stage renal failure patients by using propensity-score matching methods. Incident PD patients (n = 491) who started PD at SNU Hospital were enrolled. The patients were divided into 'early starters (n = 244)' and 'late starters (n = 247)' on the basis of the estimated glomerular filtration rate (eGFR) at the start of dialysis. The calculated propensity-score was used for one-to-one matching. After propensity-score-based matching (n = 136, for each group), no significant differences were observed in terms of all-cause mortality (P = 0.17), technique failure (P = 0.62), cardiovascular event (P = 0.96) and composite event (P = 0.86) between the early and late starters. Stratification analysis in the propensity-score quartiles (n = 491) exhibited no trend toward better or poorer survival in terms of all-cause mortality. In conclusion, early commencement of PD does not reduce the mortality risk and other outcomes. Although the recent guidelines suggest that initiation of dialysis at higher eGFR, physicians should not determine the time to initiate PD therapy simply rely on the eGFR alone. PMID:22323864

Matching weights to simultaneously compare three treatment groups: Comparison to three-way matching

PubMed Central

Yoshida, Kazuki; Hernández-Díaz, Sonia; Solomon, Daniel H.; Jackson, John W.; Gagne, Joshua J.; Glynn, Robert J.; Franklin, Jessica M.

2017-01-01

BACKGROUND Propensity score matching is a commonly used tool. However, its use in settings with more than two treatment groups has been less frequent. We examined the performance of a recently developed propensity score weighting method in the three treatment group setting. METHODS The matching weight method is an extension of inverse probability of treatment weighting (IPTW) that reweights both exposed and unexposed groups to emulate a propensity score matched population. Matching weights can generalize to multiple treatment groups. The performance of matching weights in the three-group setting was compared via simulation to three-way 1:1:1 propensity score matching and IPTW. We also applied these methods to an empirical example that compared the safety of three analgesics. RESULTS Matching weights had similar bias, but better mean squared error (MSE) compared to three-way matching in all scenarios. The benefits were more pronounced in scenarios with a rare outcome, unequally sized treatment groups, or poor covariate overlap. IPTW’s performance was highly dependent on covariate overlap. In the empirical example, matching weights achieved the best balance for 24 out of 35 covariates. Hazard ratios were numerically similar to matching. However, the confidence intervals were narrower for matching weights. CONCLUSIONS Matching weights demonstrated improved performance over three-way matching in terms of MSE, particularly in simulation scenarios where finding matched subjects was difficult. Given its natural extension to settings with even more than three groups, we recommend matching weights for comparing outcomes across multiple treatment groups, particularly in settings with rare outcomes or unequal exposure distributions. PMID:28151746

Double propensity-score adjustment: A solution to design bias or bias due to incomplete matching

PubMed Central

2016-01-01

Propensity-score matching is frequently used to reduce the effects of confounding when using observational data to estimate the effects of treatments. Matching allows one to estimate the average effect of treatment in the treated. Rosenbaum and Rubin coined the term “bias due to incomplete matching” to describe the bias that can occur when some treated subjects are excluded from the matched sample because no appropriate control subject was available. The presence of incomplete matching raises important questions around the generalizability of estimated treatment effects to the entire population of treated subjects. We describe an analytic solution to address the bias due to incomplete matching. Our method is based on using optimal or nearest neighbor matching, rather than caliper matching (which frequently results in the exclusion of some treated subjects). Within the sample matched on the propensity score, covariate adjustment using the propensity score is then employed to impute missing potential outcomes under lack of treatment for each treated subject. Using Monte Carlo simulations, we found that the proposed method resulted in estimates of treatment effect that were essentially unbiased. This method resulted in decreased bias compared to caliper matching alone and compared to either optimal matching or nearest neighbor matching alone. Caliper matching alone resulted in design bias or bias due to incomplete matching, while optimal matching or nearest neighbor matching alone resulted in bias due to residual confounding. The proposed method also tended to result in estimates with decreased mean squared error compared to when caliper matching was used. PMID:25038071

Hunger and overweight in Canadian school-aged children: A propensity score matching analysis.

PubMed

Sentenac, Mariane; Gariepy, Geneviève; McKinnon, Britt; Elgar, Frank J

2016-12-27

The last decade saw a higher prevalence of overweight reported among food-insecure families in Canada, but no robust evidence exists on the covariate-adjusted association in children. In this study, we examined the association between hunger and overweight in Canadian students, using a propensity score matching analysis to reduce confounding. This research used data from the 2009/2010 Canadian Health Behaviour in School-aged Children study on a representative national sample of students in Grades 6 through 10. Students self-reported their height and weight and how often they have gone to school or to bed hungry due to a lack of food at home. Multivariate logistic regression modeling was conducted on the total sample (N = 17,694) and on the sample matched on propensity scores (n = 7,788). The overall prevalence of overweight among students was 20.2% with a significant difference between students who reported hunger (24.0%; 95% CI: 22.1-26.0) and students who did not (19.0%; 95% CI: 17.9-20.2). Analysis on the matched sample revealed a significant association between hunger and overweight in children (adjusted odds ratio: 1.30; 95% CI: 1.12-1.50). A substantial number of Canadian students have reported being hungry because of a lack of food at home. These students are at increased risk of overweight, regardless of their social class. Child hunger and household food insecurity exist in Canada and constitute a call for policy action at a national level.

Cold snare polypectomy reduced delayed postpolypectomy bleeding compared with conventional hot polypectomy: a propensity score-matching analysis

PubMed Central

Yamashina, Takeshi; Fukuhara, Manabu; Maruo, Takanori; Tanke, Gensho; Marui, Saiko; Sada, Ryota; Taki, Mio; Ohara, Yoshiaki; Sakamoto, Azusa; Henmi, Shinichiro; Sawai, Yugo; Saito, Sumio; Nishijima, Norihiro; Nasu, Akihiro; Komekado, Hideyuki; Sekikawa, Akira; Asada, Masanori; Tumura, Takehiko; Kita, Ryuichi; Kimura, Toru; Osaki, Yukio

2017-01-01

Background and study aims  Cold snare polypectomy (CSP) for small colorectal polyps has lower incidence of adverse events, especially delayed postpolypectomy bleeding (DPPB). However, few data are available on comparisons of the incidence of DPPB of CSP and hot polypectomy (HP). The aim of this study was to evaluate the incidence of DPPB after CSP and compare it with that of HP. A propensity score model was used as a secondary analysis. Patients and methods  This was a retrospective cohort study conducted in a single municipal hospital. We identified 539 patients with colorectal polyps from 2 mm to 11 mm in size who underwent CSP (804 polyps in 330 patients) or HP (530 polyps in 209 patients) between July 2013 and June 2015. Results  There were no cases of DPPB in the CSP group. Conversely, DPPB occurred in 4 patients (1.9 %) after HP, resulting in a significant difference between the CSP and HP groups (0.008 % vs 0 %, P  = 0.02). Propensity score-matching analysis created 402 matched pairs, yielding a significantly higher DPPB rate in the HP group than CSP group (0.02 % vs 0 %, P  = 0.04). However, significantly more patients in the CSP group had unclear horizontal margins that precluded assessment (83 vs 38 cases, P  < 0.001). The retrieval failure rate was significantly higher in the CSP group than in the HP group (3 % vs 0.7 %, P  = 0.01). Conclusions  DPPB was less frequent with CSP than HP, as selected by the propensity score-matching model. Our findings indicate that CSP is recommended polypectomy in daily clinical setting. However, special care should be taken during polyp retrieval and horizontal margin assessment, and these issues could be taken into account in follow-up after CSP. PMID:28670615

Patients with type 2 diabetes benefit from primary care-based disease management: a propensity score matched survival time analysis.

PubMed

Drabik, Anna; Büscher, Guido; Thomas, Karsten; Graf, Christian; Müller, Dirk; Stock, Stephanie

2012-08-01

This study aimed to assess the impact of a nationwide German diabetes mellitus disease management program (DMP) on survival time and costs in comparison to routine care. The authors conducted a retrospective observational cohort study using routine administration data from Germany's largest sickness fund to identify insured suffering from diabetes in 2002. A total of 95,443 insured with type 2 diabetes mellitus who were born before January 1, 1962 met the defined inclusion criteria, resulting in 19,888 pairs of DMP participants and nonparticipants matched for socioeconomic and health status using propensity score matching methods. This is the first time propensity score matching has been used to evaluate a survival benefit of DMPs. In the time frame analyzed (3 years), mean survival time for the DMP group was 1045 days vs. 985 days for the routine care group (P<0.001). Mean daily hospital and total costs (including DMP administration and medical costs) were lower for the DMP group in the case of deceased insureds (92€ vs. 139€ and 122€ vs. 169€, respectively) as well as for censored observations (6€ vs. 7€ and 12.9€ vs. 13.4€, respectively). Mean daily drug costs were slightly lower for deceased insured in the DMP group (difference 0.6€), while no identifiable difference was found for censored observations. In this study, insured who were enrolled in a DMP for diabetes mellitus in the German Statutory Health Insurance showed a significant benefit in survival time. They also incurred lower costs compared to propensity score matched insured in routine care.

Using Propensity Score Matching to Test the Community College Penalty Assumption

ERIC Educational Resources Information Center

Dietrich, Cecile C.; Lichtenberger, Eric J.

2015-01-01

Research studies have been ambivalent about whether enrolling in community college makes completing a bachelor's degree less likely than directly enrolling in a four-year institution. This study uses propensity score matching with a posttreatment adjustment to determine the treatment effect associated with taking the community college to four-year…

An Assessment of Propensity Score Matching as a Nonexperimental Impact Estimator: Evidence from Mexico's PROGRESA Program

ERIC Educational Resources Information Center

Diaz, Juan Jose; Handa, Sudhanshu

2006-01-01

Not all policy questions can be addressed by social experiments. Nonexperimental evaluation methods provide an alternative to experimental designs but their results depend on untestable assumptions. This paper presents evidence on the reliability of propensity score matching (PSM), which estimates treatment effects under the assumption of…

The performance of different propensity score methods for estimating absolute effects of treatments on survival outcomes: A simulation study.

PubMed

Austin, Peter C; Schuster, Tibor

2016-10-01

Observational studies are increasingly being used to estimate the effect of treatments, interventions and exposures on outcomes that can occur over time. Historically, the hazard ratio, which is a relative measure of effect, has been reported. However, medical decision making is best informed when both relative and absolute measures of effect are reported. When outcomes are time-to-event in nature, the effect of treatment can also be quantified as the change in mean or median survival time due to treatment and the absolute reduction in the probability of the occurrence of an event within a specified duration of follow-up. We describe how three different propensity score methods, propensity score matching, stratification on the propensity score and inverse probability of treatment weighting using the propensity score, can be used to estimate absolute measures of treatment effect on survival outcomes. These methods are all based on estimating marginal survival functions under treatment and lack of treatment. We then conducted an extensive series of Monte Carlo simulations to compare the relative performance of these methods for estimating the absolute effects of treatment on survival outcomes. We found that stratification on the propensity score resulted in the greatest bias. Caliper matching on the propensity score and a method based on earlier work by Cole and Hernán tended to have the best performance for estimating absolute effects of treatment on survival outcomes. When the prevalence of treatment was less extreme, then inverse probability of treatment weighting-based methods tended to perform better than matching-based methods. © The Author(s) 2014.

A Propensity Score Matching Analysis of the Effects of Special Education Services

PubMed Central

Morgan, Paul L.; Frisco, Michelle; Farkas, George; Hibel, Jacob

2013-01-01

We sought to quantify the effectiveness of special education services as naturally delivered in U.S. schools. Specifically, we examined whether children receiving special education services displayed (a) greater reading or mathematics skills, (b) more frequent learning-related behaviors, or (c) less frequent externalizing or internalizing problem behaviors than closely matched peers not receiving such services. To do so, we used propensity score matching techniques to analyze data from the Early Childhood Longitudinal—Study Kindergarten Cohort, 1998–1999, a large scale, nationally representative sample of U.S. schoolchildren. Collectively, results indicate that receipt of special education services has either a negative or statistically non-significant impact on children’s learning or behavior. However, special education services do yield a small, positive effect on children’s learning-related behaviors. PMID:23606759

A Propensity Score Matching Analysis of the Effects of Special Education Services.

PubMed

Morgan, Paul L; Frisco, Michelle; Farkas, George; Hibel, Jacob

2010-02-01

We sought to quantify the effectiveness of special education services as naturally delivered in U.S. schools. Specifically, we examined whether children receiving special education services displayed (a) greater reading or mathematics skills, (b) more frequent learning-related behaviors, or (c) less frequent externalizing or internalizing problem behaviors than closely matched peers not receiving such services. To do so, we used propensity score matching techniques to analyze data from the Early Childhood Longitudinal-Study Kindergarten Cohort, 1998-1999, a large scale, nationally representative sample of U.S. schoolchildren. Collectively, results indicate that receipt of special education services has either a negative or statistically non-significant impact on children's learning or behavior. However, special education services do yield a small, positive effect on children's learning-related behaviors.

Measuring the impact of Hurricane Katrina on access to a personal healthcare provider: the use of the National Survey of Children's Health for an external comparison group.

PubMed

Stehling-Ariza, Tasha; Park, Yoon Soo; Sury, Jonathan J; Abramson, David

2012-04-01

This paper examined the effect of Hurricane Katrina on children's access to personal healthcare providers and evaluated the use of propensity score methods to compare a nationally representative sample of children, as a proxy for an unexposed group, with a smaller exposed sample. 2007 data from the Gulf Coast Child and Family Health (G-CAFH) Study, a longitudinal cohort of households displaced or greatly impacted by Hurricane Katrina, were matched with 2007 National Survey of Children's Health (NSCH) data using propensity score techniques. Propensity scores were created using poverty level, household educational attainment, and race/ethnicity, with and without the addition of child age and gender. The outcome was defined as having a personal healthcare provider. Additional confounders (household structure, neighborhood safety, health and insurance status) were also examined. All covariates except gender differed significantly between the exposed (G-CAFH) and unexposed (NSCH) samples. Fewer G-CAFH children had a personal healthcare provider (65 %) compared to those from NSCH (90 %). Adjusting for all covariates, the propensity score analysis showed exposed children were 20 % less likely to have a personal healthcare provider compared to unexposed children in the US (OR = 0.80, 95 % CI 0.76, 0.84), whereas the logistic regression analysis estimated a stronger effect (OR = 0.28, 95 % CI 0.21, 0.39). Two years after Hurricane Katrina, children exposed to the storm had significantly lower odds of having a personal health care provider compared to unexposed children. Propensity score matching techniques may be useful for combining separate data samples when no clear unexposed group exists.

Impact of non-anticoagulant therapy on patients with sepsis-induced disseminated intravascular coagulation: A multicenter, case-control study.

PubMed

Kudo, Daisuke; Hayakawa, Mineji; Ono, Kota; Yamakawa, Kazuma

2018-03-01

Anticoagulant therapy for patients with sepsis is not recommended in the latest Surviving Sepsis Campaign guidelines, and non-anticoagulant therapy is the global standard treatment approach at present. We aimed at elucidating the effect of non-anticoagulant therapy on patients with sepsis-induced disseminated intravascular coagulation (DIC), as evidence on this topic has remained inconclusive. Data from 3195 consecutive adult patients admitted to 42 intensive care units for the treatment of severe sepsis were retrospectively analyzed via propensity score analyses with and without multiple imputation. The primary outcome was in-hospital all-cause mortality. Among 1784 patients with sepsis-induced DIC, 745 (41.8%) were not treated with anticoagulants. The inverse probability of treatment-weighted (with and without multiple imputation) and quintile-stratified propensity score analyses (without multiple imputation) indicated a significant association between non-anticoagulant therapy and higher in-hospital all-cause mortality (odds ratio [95% confidence interval]: 1.59 [1.19-2.12], 1.32 [1.02-1.81], and 1.32 [1.03-1.69], respectively). However, quintile-stratified propensity score analyses with multiple imputation and propensity score matching analysis with and without multiple imputation did not show this association. Survival duration was not significantly different between patients in the propensity score-matched non-anticoagulant therapy group and those in the anticoagulant therapy group (Cox regression analysis with and without multiple imputation: hazard ratio [95% confidence interval]: 1.26 [1.00-1.60] and 1.22 [0.93-1.59], respectively). It remains controversial if non-anticoagulant therapy is harmful, equivalent, or beneficial compared with anticoagulant therapy in the treatment of patients with sepsis-induced DIC. Copyright © 2018 Elsevier Ltd. All rights reserved.

Acceleration in Elementary School: Using Propensity Score Matching to Estimate the Effects on Academic Achievement

ERIC Educational Resources Information Center

Kretschmann, Julia; Vock, Miriam; Lüdtke, Oliver

2014-01-01

Using German data, we examined the effects of one specific type of acceleration--grade skipping--on academic performance. Prior research on the effects of acceleration has suffered from methodological restrictions, especially due to a lack of appropriate comparison groups and a priori measurements. For this reason, propensity score matching was…

Comparison of the effect of endodontic-periodontal combined lesion on the outcome of endodontic microsurgery with that of isolated endodontic lesion: survival analysis using propensity score analysis.

PubMed

Song, Minju; Kang, Minji; Kang, Dae Ryong; Jung, Hoi In; Kim, Euiseong

2018-05-01

The purpose of this retrospective clinical study was to evaluate the effect of lesion types related to endodontic microsurgery on the clinical outcome. Patients who underwent endodontic microsurgery between March 2001 and March 2014 with a postoperative follow-up period of at least 1 year were included in the study. Survival analyses were conducted to compare the clinical outcomes between isolated endodontic lesion group (endo group) and endodontic-periodontal combined lesion group (endo-perio group) and to evaluate other clinical variables. To reduce the effect of selection bias in this study, the estimated propensity scores were used to match the cases of the endo group with those of the endo-perio group. Among the 414 eligible cases, the 83 cases in the endo-perio group were matched to 166 out of the 331 cases in the endo group based on propensity score matching (PSM). The cumulated success rates of the endo and endo-perio groups were 87.3 and 72.3%, respectively. The median success period of the endo-perio group was 12 years (95% CI: 5.507, 18.498). Lesion type was found to be significant according to both Log-rank test (P = 0.002) and Cox proportional hazard regression analysis (P = 0.001). Among the other clinical variables, sex (female or male), age, and tooth type (anterior, premolar, or molar) were determined to be significant in Cox regression analysis (P < 0.05). Endodontic-periodontal combined lesions had a negative effect on the clinical outcome based on an analysis that utilized PSM, a useful statistical matching method for observational studies. Lesion type is a significant predictor of the outcome of endodontic microsurgery.

Propensity score-matching analysis of hybrid video-assisted thoracoscopic surgery and thoracoscopic lobectomy for clinical stage I lung cancer†.

PubMed

Iwata, Hisashi; Shirahashi, Koyo; Yamamoto, Hirotaka; Marui, Tsutomu; Matsumoto, Shinsuke; Mizuno, Yoshimasa; Matsumoto, Mitsuyoshi; Mitta, Shohei; Miyamoto, Yusaku; Komuro, Hiroyasu

2016-04-01

Video-assisted thoracoscopic surgery (VATS) lobectomy is classified into hybrid VATS (direct and video vision) and thoracoscopic VATS (video vision only). In this study, the outcomes of hybrid VATS and thoracoscopic VATS for clinical stage I lung cancer were compared using a propensity score-matching analysis. Hybrid and thoracoscopic VATS were performed in 178 and 76 patients, respectively. Propensity scores were calculated using logistic regression analysis and matched within a score of ±0.03 for age, sex, size of tumour, Charlson comorbidity index, preoperative therapy, percent vital capacity, forced expiratory volume in 1 s, clinical stage, pathological stage and histology. In the non-matched analysis, the results for hybrid and thoracoscopic VATS, respectively, were as follows: mean age, 69 ± 9 and 66 ± 10 years (P = 0.04); tumour size, 24 ± 10 and 20 ± 7 mm (P < 0.01); 2-deoxy-2 [F-18]fluorodeoxyglucose positron emission tomography SUV, 5.6 ± 4.4 and 3.6 ± 3.2 (P < 0.01); clinical stage (IA/IB), 130/48 and 69/7 (P < 0.01); pathological stage (IA/IB/IIA and IIB/IIIA and IIIB), 89/56/15/18 and 57/14/2/3 (P < 0.01); postoperative complications, 66 (37.1%) and 16 (21.1%; P = 0.01); respiratory complications, 32 (18.0%) and 6 (7.9%; P = 0.04); 5-year overall survival (OS), 77.0 and 88.8% (log-rank P = 0.045); and 5-year disease-free survival (DFS), 67.2 and 81.1% (log-rank P = 0.02). In 66 matched cases, the results for hybrid and thoracoscopic VATS, respectively, were as follows: mean operative time, 245 ± 96 and 285 ± 85 min (P = 0.01); blood loss, 95 ± 100 and 86 ± 123 ml (P = 0.67); mean duration of drainage, 3.6 ± 2.7 and 3.2 ± 2.2 days (P = 0.37); postoperative complications, 21 (31.8%) and 14 (21.2%; P = 0.17); respiratory complications, 11 (16.7%) and 5 (7.6%; P = 0.11); 5-year OS, 72.5 and 86.0% (log-rank P = 0.25); and 5-year DFS, 68.4 and 77.2% (log-rank P = 0.17). In this single-institution, propensity score-matched study, hybrid VATS showed a shorter operative time and similar outcomes compared with thoracoscopic lobectomy for clinical stage IA lung cancer. © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

On the Bias-Amplifying Effect of Near Instruments in Observational Studies

ERIC Educational Resources Information Center

Steiner, Peter M.; Kim, Yongnam

2014-01-01

In contrast to randomized experiments, the estimation of unbiased treatment effects from observational data requires an analysis that conditions on all confounding covariates. Conditioning on covariates can be done via standard parametric regression techniques or nonparametric matching like propensity score (PS) matching. The regression or…

Propensity Score Matching Helps to Understand Sources of DIF and Mathematics Performance Differences of Indonesian, Turkish, Australian, and Dutch Students in PISA

ERIC Educational Resources Information Center

Arikan, Serkan; van de Vijver, Fons J. R.; Yagmur, Kutlay

2018-01-01

We examined Differential Item Functioning (DIF) and the size of cross-cultural performance differences in the Programme for International Student Assessment (PISA) 2012 mathematics data before and after application of propensity score matching. The mathematics performance of Indonesian, Turkish, Australian, and Dutch students on released items was…

Analyzing Propensity Matched Zero-Inflated Count Outcomes in Observational Studies

PubMed Central

DeSantis, Stacia M.; Lazaridis, Christos; Ji, Shuang; Spinale, Francis G.

2013-01-01

Determining the effectiveness of different treatments from observational data, which are characterized by imbalance between groups due to lack of randomization, is challenging. Propensity matching is often used to rectify imbalances among prognostic variables. However, there are no guidelines on how appropriately to analyze group matched data when the outcome is a zero inflated count. In addition, there is debate over whether to account for correlation of responses induced by matching, and/or whether to adjust for variables used in generating the propensity score in the final analysis. The aim of this research is to compare covariate unadjusted and adjusted zero-inflated Poisson models that do and do not account for the correlation. A simulation study is conducted, demonstrating that it is necessary to adjust for potential residual confounding, but that accounting for correlation is less important. The methods are applied to a biomedical research data set. PMID:24298197

Assessing the independent contribution of maternal educational expectations to children's educational attainment in early adulthood: a propensity score matching analysis.

PubMed

Pingault, Jean Baptiste; Côté, Sylvana M; Petitclerc, Amélie; Vitaro, Frank; Tremblay, Richard E

2015-01-01

Parental educational expectations have been associated with children's educational attainment in a number of long-term longitudinal studies, but whether this relationship is causal has long been debated. The aims of this prospective study were twofold: 1) test whether low maternal educational expectations contributed to failure to graduate from high school; and 2) compare the results obtained using different strategies for accounting for confounding variables (i.e. multivariate regression and propensity score matching). The study sample included 1,279 participants from the Quebec Longitudinal Study of Kindergarten Children. Maternal educational expectations were assessed when the participants were aged 12 years. High school graduation—measuring educational attainment—was determined through the Quebec Ministry of Education when the participants were aged 22-23 years. Findings show that when using the most common statistical approach (i.e. multivariate regressions to adjust for a restricted set of potential confounders) the contribution of low maternal educational expectations to failure to graduate from high school was statistically significant. However, when using propensity score matching, the contribution of maternal expectations was reduced and remained statistically significant only for males. The results of this study are consistent with the possibility that the contribution of parental expectations to educational attainment is overestimated in the available literature. This may be explained by the use of a restricted range of potential confounding variables as well as the dearth of studies using appropriate statistical techniques and study designs in order to minimize confounding. Each of these techniques and designs, including propensity score matching, has its strengths and limitations: A more comprehensive understanding of the causal role of parental expectations will stem from a convergence of findings from studies using different techniques and designs.

Effectiveness of penicillin, dicloxacillin and cefuroxime for penicillin-susceptible Staphylococcus aureus bacteraemia: a retrospective, propensity-score-adjusted case-control and cohort analysis.

PubMed

Nissen, Jette Lindbjerg; Skov, Robert; Knudsen, Jenny Dahl; Ostergaard, Christian; Schønheyder, Henrik Carl; Frimodt-Møller, Niels; Benfield, Thomas

2013-08-01

Penicillin-susceptible Staphylococcus aureus isolates account for a fifth of cases of S. aureus bacteraemia (SAB) in Denmark, but little is known about treatment outcomes with penicillins or other antimicrobials. Here we compare penicillin, dicloxacillin and cefuroxime as definitive treatments in relation to 30 day mortality. A retrospective chart review of 588 penicillin-susceptible S. aureus cases at five centres from January 1995 to December 2010. Data on demographics, antimicrobial treatment, clinical signs and symptoms, and mortality at day 30 were collected. Hazard ratios (HRs) with 95% CIs associated with mortality were modelled using propensity-score-adjusted Cox proportional hazards regression analysis. Propensity-score-matched case-control studies were carried out. Definitive therapy with cefuroxime was associated with an increased risk of 30 day mortality compared with penicillin (adjusted HR 2.54, 95% CI 1.49-4.32). Other variables that were statistically significantly associated with 30 day mortality included increasing age, disease severity and a primary respiratory focus. Osteomyelitis/arthritis was associated with a lower risk of death than were other secondary manifestations. Propensity-score-matched case-control studies confirmed an increased risk of 30 day mortality: cefuroxime treatment (39%) versus penicillin treatment (20%), P = 0.037; and cefuroxime treatment (38%) versus dicloxacillin treatment (10%), P = 0.004. Definitive therapy for penicillin-susceptible SAB with cefuroxime was associated with a significantly higher mortality than was seen with therapy with penicillin or dicloxacillin.

Combination of post-operative radiotherapy and cetuximab for high-risk cutaneous squamous cell cancer of the head and neck: A propensity score analysis.

PubMed

Palmer, Joshua D; Schneider, Charles J; Hockstein, Neil; Hanlon, Alexandra L; Silberg, Jordan; Strasser, Jon; Mauer, Elizabeth A; Dzeda, Michael; Witt, Robert; Raben, Adam

2018-03-01

The objective of this study was to investigate the safety, tolerability and preliminary efficacy of radiotherapy plus cetuximab in high risk CSCC patients. Patients with high-risk CSCC diagnosed between 2006 and 2013 were analyzed. Patients were divided into two groups: radiotherapy alone versus radiotherapy plus cetuximab. Among 68 patients meeting study criteria, we identified 29 treated with cetuximab plus RT and 39 with RT alone. Primary analysis examined disease-free and overall survival, freedom from local and distant recurrence in the propensity score matched cohort. Propensity score analysis was performed with weighted factors including: Charlson Comorbidity Index score, age. KPS, primary location, T and N stage, recurrent status, margin status, LVSI, PNI and grade. Toxicity was assessed using the CTCAE v4.0. Median follow-up for living patients was 30 months. Patients in the cetuximab group were more likely to have advanced N stage, positive margins and recurrent disease. After propensity score matching the groups were well balanced. Six patients experienced ≥ grade 3 acute toxicity in the cetuximab group. The 1-year, 2-year and 5-year progression free survival (PFS) for patients in the cetuximab group were 86%, 72% and 66%, respectively. The 1-year, 2-year and 5-year overall survival (OS) for patients in the cetuximab group was 98%, 80% and 80%, respectively. Although limited by small numbers, the combination of cetuximab and radiotherapy in CSCC appears well tolerated there were more long-term survivors and less distant metastasis in the cetuximab group. These promising finding warrant further studies. Copyright © 2018 Elsevier Ltd. All rights reserved.

Sequential cohort design applying propensity score matching to analyze the comparative effectiveness of atorvastatin and simvastatin in preventing cardiovascular events.

PubMed

Helin-Salmivaara, Arja; Lavikainen, Piia; Aarnio, Emma; Huupponen, Risto; Korhonen, Maarit Jaana

2014-01-01

Sequential cohort design (SCD) applying matching for propensity scores (PS) in accrual periods has been proposed to mitigate bias caused by channeling when calendar time is a proxy for strong confounders. We studied the channeling of patients according to atorvastatin and simvastatin initiation in Finland, starting from the market introduction of atorvastatin in 1998, and explored the SCD PS approach to analyzing the comparative effectiveness of atorvastatin versus simvastatin in the prevention of cardiovascular events (CVE). Initiators of atorvastatin or simvastatin use in the 45-75-year age range in 1998-2006 were characterized by their propensity of receiving atorvastatin over simvastatin, as estimated for 17 six-month periods. Atorvastatin (10 mg) and simvastatin (20 mg) initiators were matched 1∶1 on the PS, as estimated for the whole cohort and within each period. Cox regression models were fitted conventionally, and also for the PS matched cohort and the periodically PS matched cohort, to estimate the hazard ratios (HR) for CVEs. Atorvastatin (10 mg) was associated with a 11%-12% lower incidence of CVE in comparison with simvastatin (20 mg). The HR estimates were the same for a conventional Cox model (0.88, 95% confidence interval 0.85-0.91), for the analysis in which the PS was used to match across all periods and the Cox model was adjusted for strong confounders (0.89, 0.85-0.92), and for the analysis in which PS matching was applied within sequential periods (0.88, 0.84-0.92). The HR from a traditional PS matched analysis was 0.80 (0.77-0.83). The SCD PS approach produced effect estimates similar to those obtained in matching for PS within the whole cohort and adjusting the outcome model for strong confounders, but at the cost of efficiency. A traditional PS matched analysis without further adjustment in the outcome model produced estimates further away from unity.

Impact of nutrition support on clinical outcome and cost-effectiveness analysis in patients at nutritional risk: A prospective cohort study with propensity score matching.

PubMed

Zhang, Hui; Wang, Yang; Jiang, Zhu-Ming; Kondrup, Jens; Fang, Hai; Andrews, Martha; Nolan, Marie T; Mu, Shao-Yu; Zhang, Jun; Yu, Kang; Lu, Qian; Kang, Wei-Ming

2017-05-01

There is a lack of evidence regarding the economic effects of nutrition support in patients at nutritional risk. The aim of this study was to perform a cost-effectiveness analysis by comparing an adequate nutrition support cohort with a no-support cohort. A prospective observational study was performed in the surgical and medical gastroenterology wards. We identified patients at nutritional risk and the provision of nutrition support by the staff, unaware of the risk status, was recorded. Cost data were obtained from each patient's statement of accounts, and effectiveness was measured by the rate of infectious complication. To control for potential confounding variables, the propensity score method with matching was carried out. The incremental cost-effectiveness ratio was calculated based on the matched population. We screened 3791 patients, and 440 were recruited for the analysis. Patients in the nutrition support cohort had a lower incidence of infectious complications than those in the no-support cohort (9.1 versus 18.1%; P = 0.007). This result was similar in the 149 propensity matched pairs (9.4 versus 24.2%; P < 0.001). The median hospital length of stay was significantly reduced among the matched nutrition support patients (13 versus 15 d; P < 0.001). The total costs were similar among the matched pairs (US $6219 versus $6161). The incremental cost-effectiveness analysis suggested that nutrition support cost US $392 per patient prevented from having infectious complications. Nutrition support was associated with fewer infectious complications and shorter length of stay in patients at nutritional risk. The incremental cost-effectiveness ratio indicated that nutrition support had not increased costs significantly. Copyright © 2016 Elsevier Inc. All rights reserved.

[Are Two-Year Vocational Retraining Programs Really Better than One-Year Programs? Findings of a Propensity Score Matched Analysis].

PubMed

Bethge, M; Streibelt, M

2015-12-01

To analyze if one- and 2-year vocational retraining programs achieve similar effects on employment. Analyses were performed with longitudinal administrative data. We included persons aged 18-59 years, who started their retraining between January and June 2005. One- and 2-year program participants were matched by propensity scores. The matched groups were balanced regarding all baseline scores (one-year program: n=514; 2-year program: n=514). 4 and 5 years after start of the vocational retraining program, annual income, the duration of welfare benefits and the risk of a disability pension were comparable in both groups. However, the accumulative income between 2005 and 2009 was 9 294 Euro higher (95% CI: 3 656-14 932 Euro) in one-year retraining participants. Moreover, participants of one-year programs received less welfare benefits. The development of a vocational rehabilitation strategy needs to consider the accumulative advantage of one-year programs. © Georg Thieme Verlag KG Stuttgart · New York.

Robot-assisted laparoscopic partial nephrectomy versus laparoscopic partial nephrectomy: A propensity score-matched comparative analysis of surgical outcomes and preserved renal parenchymal volume.

PubMed

Tachibana, Hidekazu; Takagi, Toshio; Kondo, Tsunenori; Ishida, Hideki; Tanabe, Kazunari

2018-04-01

To compare surgical outcomes, including renal function and the preserved renal parenchymal volume, between robot-assisted laparoscopic partial nephrectomy and laparoscopic partial nephrectomy using propensity score-matched analyses. In total, 253 patients, with a normal contralateral kidney, who underwent laparoscopic partial nephrectomy (n = 131) or robot-assisted laparoscopic partial nephrectomy (n = 122) with renal arterial clamping between 2010 and 2015, were included. Patients' background and tumor factors were adjusted by propensity score matching. Surgical outcomes, including postoperative renal function, complications, warm ischemia time and preserved renal parenchymal volume, evaluated by volumetric analysis, were compared between the surgical procedures. After matching, 64 patients were assigned to each group. The mean age was 56-57 years, and the mean tumor size was 22 mm. Approximately 50% of patients had low complexity tumors (RENAL nephrometry score 4-7). The incidence rate of acute kidney failure was significantly lower in the robot-assisted laparoscopic partial nephrectomy (11%) than laparoscopic partial nephrectomy (23%) group (P = 0.049), and warm ischemia time shorter in the robot-assisted laparoscopic partial nephrectomy (17 min) than laparoscopic partial nephrectomy (25 min) group (P < 0.0001). The preservation rate of renal function, measured by the estimated glomerular filtration rate, at 6 months post-surgery was 96% for robot-assisted laparoscopic partial nephrectomy and 90% for laparoscopic partial nephrectomy (P < 0.0001). The preserved renal parenchymal volume was higher for robot-assisted laparoscopic partial nephrectomy (89%) than laparoscopic partial nephrectomy (77%; P < 0.0001). The rate of perioperative complications, surgical margin status and length of hospital stay were equivalent for both techniques. Robot-assisted laparoscopic partial nephrectomy allows to achieve better preservation of renal function and parenchymal volume than laparoscopic partial nephrectomy. © 2018 The Japanese Urological Association.

Propensity score matching with clustered data. An application to the estimation of the impact of caesarean section on the Apgar score.

PubMed

Arpino, Bruno; Cannas, Massimo

2016-05-30

This article focuses on the implementation of propensity score matching for clustered data. Different approaches to reduce bias due to cluster-level confounders are considered and compared using Monte Carlo simulations. We investigated methods that exploit the clustered structure of the data in two ways: in the estimation of the propensity score model (through the inclusion of fixed or random effects) or in the implementation of the matching algorithm. In addition to a pure within-cluster matching, we also assessed the performance of a new approach, 'preferential' within-cluster matching. This approach first searches for control units to be matched to treated units within the same cluster. If matching is not possible within-cluster, then the algorithm searches in other clusters. All considered approaches successfully reduced the bias due to the omission of a cluster-level confounder. The preferential within-cluster matching approach, combining the advantages of within-cluster and between-cluster matching, showed a relatively good performance both in the presence of big and small clusters, and it was often the best method. An important advantage of this approach is that it reduces the number of unmatched units as compared with a pure within-cluster matching. We applied these methods to the estimation of the effect of caesarean section on the Apgar score using birth register data. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

A comparison of risperidone and haloperidol for the risk of ischemic stroke in the elderly: a propensity score-matched cohort analysis.

PubMed

Shin, Ju-Young; Choi, Nam-Kyong; Lee, Joongyub; Park, Mi-Ju; Lee, Shin Haeng; Park, Byung-Joo

2015-08-01

With an increase in antipsychotic use in the elderly, the safety profile of antipsychotics has been emphasized. Strong concerns have been raised about whether the risk of ischemic stroke differs between risperidone and haloperidol. This study compared the risk of ischemic stroke between elderly patients taking risperidone and haloperidol. We conducted a retrospective cohort study using the Korea Health Insurance Review and Assessment Service database, applying a propensity-matched analysis. The cohort consisted of elderly patients who were newly prescribed haloperidol or risperidone between January 1, 2006 and December 31, 2009. Patients with prior cerebrovascular diseases (ICD-10, I60-I69), transient ischemic attack (ICD-10, G45), or cerebral tumors (ICD-10, C31) during 365 days prior to the initiation date were excluded. The study subjects were selected by propensity score matching. The outcome was defined as the first hospitalization for ischemic stroke (ICD-10, I63). Cox regression models were used to estimate the hazard ratio (HR) and 95% confidence intervals (95% CI) for ischemic stroke with haloperidol compared with risperidone use. A total of 14,103 patients were included in the propensity-matched cohort for each drug. Overall, the incidence rate was higher for haloperidol users compared to the risperidone users (6.43 per 1000 person-years vs. 2.88 per 1000 person-years). A substantially increased risk was observed in haloperidol users (adjusted HR = 2.02, 95% CI, 1.12-3.62). The evidence showed that haloperidol should be prescribed in the elderly with caution. © The Author(s) 2015.

Early administration of epinephrine (adrenaline) in patients with cardiac arrest with initial shockable rhythm in hospital: propensity score matched analysis

PubMed Central

Andersen, Lars W; Kurth, Tobias; Chase, Maureen; Berg, Katherine M; Cocchi, Michael N; Callaway, Clifton

2016-01-01

Objectives To evaluate whether patients who experience cardiac arrest in hospital receive epinephrine (adrenaline) within the two minutes after the first defibrillation (contrary to American Heart Association guidelines) and to evaluate the association between early administration of epinephrine and outcomes in this population. Design Prospective observational cohort study. Setting Analysis of data from the Get With The Guidelines-Resuscitation registry, which includes data from more than 300 hospitals in the United States. Participants Adults in hospital who experienced cardiac arrest with an initial shockable rhythm, including patients who had a first defibrillation within two minutes of the cardiac arrest and who remained in a shockable rhythm after defibrillation. Intervention Epinephrine given within two minutes after the first defibrillation. Main outcome measures Survival to hospital discharge. Secondary outcomes included return of spontaneous circulation and survival to hospital discharge with a good functional outcome. A propensity score was calculated for the receipt of epinephrine within two minutes after the first defibrillation, based on multiple characteristics of patients, events, and hospitals. Patients who received epinephrine at either zero, one, or two minutes after the first defibrillation were then matched on the propensity score with patients who were “at risk” of receiving epinephrine within the same minute but who did not receive it. Results 2978patients were matched on the propensity score, and the groups were well balanced. 1510 (51%) patients received epinephrine within two minutes after the first defibrillation, which is contrary to current American Heart Association guidelines. Epinephrine given within the first two minutes after the first defibrillation was associated with decreased odds of survival in the propensity score matched analysis (odds ratio 0.70, 95% confidence interval 0.59 to 0.82; P<0.001). Early epinephrine administration was also associated with a decreased odds of return of spontaneous circulation (0.71, 0.60 to 0.83; P<0.001) and good functional outcome (0.69, 0.58 to 0.83; P<0.001). Conclusion Half of patients with a persistent shockable rhythm received epinephrine within two minutes after the first defibrillation, contrary to current American Heart Association guidelines. The receipt of epinephrine within two minutes after the first defibrillation was associated with decreased odds of survival to hospital discharge as well as decreased odds of return of spontaneous circulation and survival to hospital discharge with a good functional outcome. PMID:27053638

Early administration of epinephrine (adrenaline) in patients with cardiac arrest with initial shockable rhythm in hospital: propensity score matched analysis.

PubMed

Andersen, Lars W; Kurth, Tobias; Chase, Maureen; Berg, Katherine M; Cocchi, Michael N; Callaway, Clifton; Donnino, Michael W

2016-04-06

To evaluate whether patients who experience cardiac arrest in hospital receive epinephrine (adrenaline) within the two minutes after the first defibrillation (contrary to American Heart Association guidelines) and to evaluate the association between early administration of epinephrine and outcomes in this population. Prospective observational cohort study. Analysis of data from the Get With The Guidelines-Resuscitation registry, which includes data from more than 300 hospitals in the United States. Adults in hospital who experienced cardiac arrest with an initial shockable rhythm, including patients who had a first defibrillation within two minutes of the cardiac arrest and who remained in a shockable rhythm after defibrillation. Epinephrine given within two minutes after the first defibrillation. Survival to hospital discharge. Secondary outcomes included return of spontaneous circulation and survival to hospital discharge with a good functional outcome. A propensity score was calculated for the receipt of epinephrine within two minutes after the first defibrillation, based on multiple characteristics of patients, events, and hospitals. Patients who received epinephrine at either zero, one, or two minutes after the first defibrillation were then matched on the propensity score with patients who were "at risk" of receiving epinephrine within the same minute but who did not receive it. 2978 patients were matched on the propensity score, and the groups were well balanced. 1510 (51%) patients received epinephrine within two minutes after the first defibrillation, which is contrary to current American Heart Association guidelines. Epinephrine given within the first two minutes after the first defibrillation was associated with decreased odds of survival in the propensity score matched analysis (odds ratio 0.70, 95% confidence interval 0.59 to 0.82; P<0.001). Early epinephrine administration was also associated with a decreased odds of return of spontaneous circulation (0.71, 0.60 to 0.83; P<0.001) and good functional outcome (0.69, 0.58 to 0.83; P<0.001). Half of patients with a persistent shockable rhythm received epinephrine within two minutes after the first defibrillation, contrary to current American Heart Association guidelines. The receipt of epinephrine within two minutes after the first defibrillation was associated with decreased odds of survival to hospital discharge as well as decreased odds of return of spontaneous circulation and survival to hospital discharge with a good functional outcome. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Generalizing Observational Study Results: Applying Propensity Score Methods to Complex Surveys

PubMed Central

DuGoff, Eva H; Schuler, Megan; Stuart, Elizabeth A

2014-01-01

ObjectiveTo provide a tutorial for using propensity score methods with complex survey data. Data SourcesSimulated data and the 2008 Medical Expenditure Panel Survey. Study DesignUsing simulation, we compared the following methods for estimating the treatment effect: a naïve estimate (ignoring both survey weights and propensity scores), survey weighting, propensity score methods (nearest neighbor matching, weighting, and subclassification), and propensity score methods in combination with survey weighting. Methods are compared in terms of bias and 95 percent confidence interval coverage. In Example 2, we used these methods to estimate the effect on health care spending of having a generalist versus a specialist as a usual source of care. Principal FindingsIn general, combining a propensity score method and survey weighting is necessary to achieve unbiased treatment effect estimates that are generalizable to the original survey target population. ConclusionsPropensity score methods are an essential tool for addressing confounding in observational studies. Ignoring survey weights may lead to results that are not generalizable to the survey target population. This paper clarifies the appropriate inferences for different propensity score methods and suggests guidelines for selecting an appropriate propensity score method based on a researcher’s goal. PMID:23855598

Generalizing observational study results: applying propensity score methods to complex surveys.

PubMed

Dugoff, Eva H; Schuler, Megan; Stuart, Elizabeth A

2014-02-01

To provide a tutorial for using propensity score methods with complex survey data. Simulated data and the 2008 Medical Expenditure Panel Survey. Using simulation, we compared the following methods for estimating the treatment effect: a naïve estimate (ignoring both survey weights and propensity scores), survey weighting, propensity score methods (nearest neighbor matching, weighting, and subclassification), and propensity score methods in combination with survey weighting. Methods are compared in terms of bias and 95 percent confidence interval coverage. In Example 2, we used these methods to estimate the effect on health care spending of having a generalist versus a specialist as a usual source of care. In general, combining a propensity score method and survey weighting is necessary to achieve unbiased treatment effect estimates that are generalizable to the original survey target population. Propensity score methods are an essential tool for addressing confounding in observational studies. Ignoring survey weights may lead to results that are not generalizable to the survey target population. This paper clarifies the appropriate inferences for different propensity score methods and suggests guidelines for selecting an appropriate propensity score method based on a researcher's goal. © Health Research and Educational Trust.

Assessing the Impact of School-Based Health Centers on Academic Achievement and College Preparation Efforts: Using Propensity Score Matching to Assess School-Level Data in California

ERIC Educational Resources Information Center

Bersamin, Melina; Garbers, Samantha; Gaarde, Jenna; Santelli, John

2016-01-01

This study examines the association between school-based health center (SBHC) presence and school-wide measures of academic achievement and college preparation efforts. Publicly available educational and demographic data from 810 California public high schools were linked to a list of schools with an SBHC. Propensity score matching, a method to…

Laparoscopic versus open distal pancreatectomy-a propensity score-matched analysis from the German StuDoQ|Pancreas registry.

PubMed

Wellner, Ulrich Friedrich; Lapshyn, Hryhoriy; Bartsch, Detlef K; Mintziras, Ioannis; Hopt, Ulrich Theodor; Wittel, Uwe; Krämling, Hans-Jörg; Preissinger-Heinzel, Hubert; Anthuber, Matthias; Geissler, Bernd; Köninger, Jörg; Feilhauer, Katharina; Hommann, Merten; Peter, Luisa; Nüssler, Natascha C; Klier, Thomas; Mansmann, Ulrich; Keck, Tobias

2017-02-01

The aim of this study was to assess intraoperative, postoperative, and oncologic outcome in patients undergoing laparoscopic distal pancreatectomy (LDP) versus open distal pancreatectomy (ODP) for benign and malignant lesions of the pancreas. Data from patients undergoing distal pancreatic resection were extracted from the StuDoQ|Pancreas registry of the German Society for General and Visceral Surgery. After propensity score case matching, groups of LDP and ODP were compared regarding demography, comorbidities, operative details, histopathology, and perioperative outcome. At the time of data extraction, the StuDoQ|Pancreas registry included over 3000 pancreatic resections from over 50 surgical departments in Germany. Data from 353 patients undergoing ODP (n = 254) or LDP (n = 99) from September 2013 to February 2016 at 29 institutions were included in the analysis. Baseline data showed a strong selection bias in LDP patients, which disappeared after 1:1 propensity score matching. A comparison of the matched groups disclosed a significantly longer operation time, higher rate of spleen preservation, more grade A pancreatic fistula, shorter hospital stay, and increased readmissions for LDP. In the small group of patients operated for pancreatic cancer, a lower lymph node yield with a lower lymph node ratio was apparent in LDP. LDP needed more time but potential advantages include increased spleen preservation and shorter hospital stay, as well as a trend for less transfusion, ventilation, and mortality. LDP for pancreatic cancer was performed rarely and will need critical evaluation in the future. Data from a prospective randomized registry trial is needed to confirm these results.

Association between Down syndrome and mortality in young children with critical illness: a propensity-matched analysis.

PubMed

Gupta, Punkaj; Rettiganti, Mallikarjuna

2015-11-01

To evaluate the outcomes among critically ill young children with Down syndrome using propensity score matching from a national database. Patients in the age group from one day through 24 months admitted to an intensive care unit during their hospital stay at a Pediatric Health Information System (PHIS)-participating hospital (2004-2013) were included. Of the 293,697 patients who qualified for inclusion, 12,282 (4%) were classified in the Down syndrome group. Using propensity score matching, 10,477 patients with Down syndrome were matched one to one to patients without Down syndrome. Prior to matching, the mortality was significantly lower among the patients with Down syndrome (with vs. without Down syndrome, odds ratio (OR), 0.74; 95% confidence interval (CI), 0.69-0.79; p < 0.001). After matching, the mortality was similar in both groups (OR, 0.96; 95% CI, 0.87-1.07; p = 0.51). The mortality risk increased among the Down syndrome patients with increasing hospital length of stay (LOS). In this large, contemporary cohort, Down syndrome did not confer a significantly higher mortality risk among children with critical illness. However, children with Down syndrome followed a time-dependent, differential mortality risk with increased risk noted in relation to increasing hospital LOS. ©2015 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

Estimating the Effectiveness of Health-Risk Communications with Propensity-Score Matching: Application to Arsenic Groundwater Contamination in Four US Locations

PubMed Central

Leidner, Andrew J.

2014-01-01

This paper provides a demonstration of propensity-score matching estimation methods to evaluate the effectiveness of health-risk communication efforts. This study develops a two-stage regression model to investigate household and respondent characteristics as they contribute to aversion behavior to reduce exposure to arsenic-contaminated groundwater. The aversion activity under study is a household-level point-of-use filtration device. Since the acquisition of arsenic contamination information and the engagement in an aversion activity may be codetermined, a two-stage propensity-score model is developed. In the first stage, the propensity for households to acquire arsenic contamination information is estimated. Then, the propensity scores are used to weight observations in a probit regression on the decision to avert the arsenic-related health risk. Of four potential sources of information, utility, media, friend, or others, information received from a friend appears to be the source of information most associated with aversion behavior. Other statistically significant covariates in the household's decision to avert contamination include reported household income, the presence of children in household, and region-level indicator variables. These findings are primarily illustrative and demonstrate the usefulness of propensity-score methods to estimate health-risk communication effectiveness. They may also be suggestive of areas for future research. PMID:25349622

Propensity Score–Matched Analysis of Comprehensive Local Therapy for Oligometastatic Non-Small Cell Lung Cancer That Did Not Progress After Front-Line Chemotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sheu, Tommy; Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas; Heymach, John V.

2014-11-15

Purpose: To retrospectively analyze factors influencing survival in patients with non-small cell lung cancer presenting with ≤3 synchronous metastatic lesions. Methods and Materials: We identified 90 patients presenting between 1998 and 2012 with non-small cell lung cancer and ≤3 metastatic lesions who had received at least 2 cycles of chemotherapy followed by surgery or radiation therapy before disease progression. The median number of chemotherapy cycles before comprehensive local therapy (CLT) (including concurrent chemoradiation as first-line therapy) was 6. Factors potentially affecting overall (OS) or progression-free survival (PFS) were evaluated with Cox proportional hazards regression. Propensity score matching was used to assessmore » the efficacy of CLT. Results: Median follow-up time was 46.6 months. Benefits in OS (27.1 vs 13.1 months) and PFS (11.3 months vs 8.0 months) were found with CLT, and the differences were statistically significant when propensity score matching was used (P ≤ .01). On adjusted analysis, CLT had a statistically significant benefit in terms of OS (hazard ratio, 0.37; 95% confidence interval, 0.20-0.70; P ≤ .01) but not PFS (P=.10). In an adjusted subgroup analysis of patients receiving CLT, favorable performance status (hazard ratio, 0.43; 95% confidence interval, 0.22-0.84; P=.01) was found to predict improved OS. Conclusions: Comprehensive local therapy was associated with improved OS in an adjusted analysis and seemed to favorably influence OS and PFS when factors such as N status, number of metastatic lesions, and disease sites were controlled for with propensity score–matched analysis. Patients with favorable performance status had improved outcomes with CLT. Ultimately, prospective, randomized trials are needed to provide definitive evidence as to the optimal treatment approach for this patient population.« less

Betahistine plus piracetam dual therapy versus betahistine monotherapy for peripheral vestibular vertigo: a confounder-corrected subanalysis of the OSVaLD study.

PubMed

Melnikov, Oleg A; Lilenko, Sergey V; Nauta, Jos; Ouwens, Mario J N M

2015-11-01

This subanalysis compared the efficacy of betahistine plus piracetam dual therapy versus betahistine monotherapy using data from OSVaLD, a 3 month, open-label, observational study conducted in 2272 patients with peripheral vestibular vertigo. Of the 1898 patients included in the original efficacy population, 1076 were from countries where betahistine plus piracetam dual therapy was prescribed to >1 patient; 114 of these 1076 patients (11%) received the dual therapy and 567 (53%) were treated with betahistine monotherapy; these patients were selected for analysis. Efficacy was assessed using the Dizziness Handicap Inventory (DHI) total and subscale scores. Propensity-score matching was used to correct potential differences in patient baseline characteristics between treatment groups. In addition, a subgroup analysis evaluated 103 patients treated with betahistine because of insufficient efficacy with their existing treatment. In the propensity-score matched, total-population evaluation, improvements in the DHI total and subscale scores were numerically greater in the betahistine plus piracetam group (n = 88) versus the betahistine group (n = 89) (DHI total, -42.9 vs. -37.6, respectively; DHI physical, -12.1 vs. -10.4; DHI emotional, -13.5 vs. -13.2) and statistically significant for the DHI functional score (-17.3 vs. -14.0, respectively, p = 0.01). The percentage of patients with no impairment at final visit was 27% with betahistine and 47% with betahistine plus piracetam; odds ratio: 2.3, 95% confidence interval: 1.3-2.4 (p = 0.007). Similar results were obtained in the subgroup analyses for patients whose current vertigo treatment was insufficient. The overall incidence of adverse events was low and similar in both groups, and there were no discontinuations due to drug-related adverse events. By using propensity-score matching, which controls for potential heterogeneity in patient baseline characteristics and small patient numbers, the results of this analysis suggest that combined betahistine and piracetam may be more effective than betahistine alone in patients with peripheral vestibular vertigo.

Health related quality of life among myocardial infarction survivors in the United States: a propensity score matched analysis.

PubMed

Mollon, Lea; Bhattacharjee, Sandipan

2017-12-04

Little is known regarding the health-related quality of life among myocardial infarction (MI) survivors in the United States. The purpose of this population-based study was to identify differences in health-related quality of life domains between MI survivors and propensity score matched controls. This retrospective, cross-sectional matched case-control study examined differences in health-related quality of life (HRQoL) among MI survivors of myocardial infarction compared to propensity score matched controls using data from the 2015 Behavioral Risk Factor Surveillance System (BRFSS) survey. Propensity scores were generated via logistic regression for MI survivors and controls based on gender, race/ethnicity, age, body mass index (BMI), smoking status, and comorbidities. Chi-square tests were used to compare differences between MI survivors to controls for demographic variables. A multivariate analysis of HRQoL domains estimated odds ratios. Life satisfaction, sleep quality, and activity limitations were estimated using binary logistic regression. Social support, perceived general health, perceived physical health, and perceived mental health were estimated using multinomial logistic regression. Significance was set at p < 0.05. The final sample consisted of 16,729 MI survivors matched to 50,187 controls (n = 66,916). Survivors were approximately 2.7 times more likely to report fair/poor general health compared to control (AOR = 2.72, 95% CI: 2.43-3.05) and 1.5 times more likely to report limitations to daily activities (AOR = 1.46, 95% CI: 1.34-1.59). Survivors were more likely to report poor physical health >15 days in the month (AOR = 1.63, 95% CI: 1.46-1.83) and poor mental health >15 days in the month (AOR = 1.25, 95% CI: 1.07-1.46) compared to matched controls. There was no difference in survivors compared to controls in level of emotional support (rarely/never: AOR = 0.75, 95% CI: 0.48-1.18; sometimes: AOR = 0.73, 95% CI: 0.41-1.28), hours of recommended sleep (AOR = 1.14, 95% CI: 0.94-1.38), or life satisfaction (AOR = 1.62, 95% CI: 0.99-2.63). MI survivors experienced lower HRQoL on domains of general health, physical health, daily activity, and mental health compared to the general population.

Self-reported hand washing behaviors and foodborne illness: a propensity score matching approach.

PubMed

Ali, Mir M; Verrill, Linda; Zhang, Yuanting

2014-03-01

Hand washing is a simple and effective but easily overlooked way to reduce cross-contamination and the transmission of foodborne pathogens. In this study, we used the propensity score matching methodology to account for potential selection bias to explore our hypothesis that always washing hands before food preparation tasks is associated with a reduction in the probability of reported foodborne illness. Propensity score matching can simulate random assignment to a condition so that pretreatment observable differences between a treatment group and a control group are homogenous on all the covariates except the treatment variable. Using the U.S. Food and Drug Administration's 2010 Food Safety Survey, we estimated the effect of self-reported hand washing behavior on the probability of self-reported foodborne illness. Our results indicate that reported washing of hands with soap always before food preparation leads to a reduction in the probability of reported foodborne illness.

Oncologic outcomes of single-incision versus conventional laparoscopic anterior resection for sigmoid colon cancer: a propensity-score matching analysis.

PubMed

Kim, Chang Woo; Cho, Min Soo; Baek, Se Jin; Hur, Hyuk; Min, Byung Soh; Kang, Jeonghyun; Baik, Seung Hyuk; Lee, Kang Young; Kim, Nam Kyu

2015-03-01

The aim of this study was to investigate oncologic outcomes, as well as perioperative and pathologic outcomes, of single-incision laparoscopic anterior resection (SILAR) compared with conventional laparoscopic anterior resection (CLAR) for sigmoid colon cancer using propensity-score matching analysis. From July 2009 through April 2012, a total of 407 patients underwent laparoscopic anterior resection for sigmoid colon cancer. Data on short- and long-term outcomes were collected prospectively and reviewed. Propensity-score matching was applied at a ratio of 1:2 comparing the SILAR (n = 60) and CLAR (n = 120) groups. There was no difference in operation time, estimated blood loss, time to soft diet, and length of hospital stay; however, the SILAR group showed less pain on postoperative day 2 (mean 2.6 vs. 3.6; p = 0.000) and shorter length of incision (3.3 vs. 7.7 cm; p = 0.000) compared with the CLAR group. Morbidity, mortality, and pathologic outcomes were similar in both groups. The 3-year overall survival rates were 94.5 versus 97.1% (p = 0.223), and disease-free survival rates were 89.5 versus 87.4% (p = 0.751) in the SILAR and CLAR groups, respectively. The long-term oncologic outcomes, as well as short-term outcomes, of SILAR are comparable with those of CLAR. Although SILAR might have some technical difficulties, it appears to be a safe and feasible option, with better cosmetic results.

Comparing the therapeutic efficacies of third-generation cephalosporins and broader-spectrum β-lactams as appropriate empirical therapy in adults with community-onset monomicrobial Enterobacteriaceae bacteraemia: a propensity score matched analysis.

PubMed

Lee, Chung-Hsun; Hsieh, Chih-Chia; Hong, Ming-Yuan; Hung, Yuan-Pin; Ko, Wen-Chien; Lee, Ching-Chi

2017-05-01

In this study, the therapeutic efficacy of third-generation cephalosporins (3GCs) was compared with that of broader-spectrum β-lactams (BSBLs) [fourth-generation cephalosporins (4GCs) and carbapenems] as empirical therapy in adults with community-onset monomicrobial Enterobacteriaceae bacteraemia. Compared with those in the 3GC group (n = 477), a significantly higher proportion of patients in the BSBL group (n = 141) had initial presentation with severe sepsis or septic shock, critical illness (Pitt bacteraemia score ≥4) at bacteraemia onset and fatal co-morbidities (McCabe classification). For propensity score matching, 318 of the 477 patients in the 3GC group were matched with 106 patients in the BSBL group with the closest propensity scores on the basis of five independent predictors of 28-day mortality. After appropriate matching, no significant differences were observed in major baseline characteristics between the 3GC and BSBL groups in terms of causative micro-organism, bacteraemia severity, major source of bacteraemia, major co-morbidities and severity of co-morbidity. Consequently, the early clinical failure rate (12.9% vs. 12.3%; P = 0.87), bacteraemia severity (Pitt bacteraemia score ≥4; 4.6% vs. 8.2%; P = 0.17) at Day 3, and 3-day (3.8% vs. 7.5%; P = 0.11) and 28-day (13.2% vs. 17.0%; P = 0.33) crude mortality rates between the two groups were similar. These data suggest that the efficacy of 3GCs is similar to that of 4GCs or carbapenems when used as empirical antimicrobial therapy for community-onset Enterobacteriaceae bacteraemia. Copyright © 2017 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

Perioperative and mid-term oncologic outcomes of robotic assisted radical cystectomy with totally intracorporeal neobladder: Results of a propensity score matched comparison with open cohort from a single-centre series.

PubMed

Simone, Giuseppe; Tuderti, Gabriele; Misuraca, Leonardo; Anceschi, Umberto; Ferriero, Mariaconsiglia; Minisola, Francesco; Guaglianone, Salvatore; Gallucci, Michele

2018-04-17

In this study, we compared perioperative and oncologic outcomes of patients treated with either open or robot-assisted radical cystectomy and intracorporeal neobladder at a tertiary care center. The institutional prospective bladder cancer database was queried for "cystectomy with curative intent" and "neobladder". All patients underwent robot-assisted radical cystectomy and intracorporeal neobladder or open radical cystectomy and orthotopic neobladder for high-grade non-muscle invasive bladder cancer or muscle invasive bladder cancer with a follow-up length ≥2 years were included. A 1:1 propensity score matching analysis was used. Kaplan-Meier method was performed to compare oncologic outcomes of selected cohorts. Survival rates were computed at 1,2,3 and 4 years after surgery and the log rank test was applied to assess statistical significance between the matched groups. Overall, 363 patients (299 open and 64 robotic) were included. Open radical cystectomy patients were more frequently male (p = 0.08), with higher pT stages (p = 0.003), lower incidence of urothelial histologies (p = 0.05) and lesser adoption of neoadjuvant chemotherapy (<0.001). After applying the propensity score matching, 64 robot-assisted radical cystectomy patients were matched with 46 open radical cystectomy cases (all p ≥ 0.22). Open cohort showed a higher rate of perioperative overall complications (91.3% vs 42.2%, p 0.001). At Kaplan-Meier analysis robotic and open cohorts displayed comparable disease-free survival (log-rank p = 0.746), cancer-specific survival (p = 0.753) and overall-survival rates (p = 0.909). Robot-assisted radical cystectomy and intracorporeal neobladder provides comparable oncologic outcomes of open radical cystectomy and orthotopic neobladder at intermediate term survival analysis. Copyright © 2018 Elsevier Ltd, BASO ~ The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.

The use of propensity score methods with survival or time-to-event outcomes: reporting measures of effect similar to those used in randomized experiments.

PubMed

Austin, Peter C

2014-03-30

Propensity score methods are increasingly being used to estimate causal treatment effects in observational studies. In medical and epidemiological studies, outcomes are frequently time-to-event in nature. Propensity-score methods are often applied incorrectly when estimating the effect of treatment on time-to-event outcomes. This article describes how two different propensity score methods (matching and inverse probability of treatment weighting) can be used to estimate the measures of effect that are frequently reported in randomized controlled trials: (i) marginal survival curves, which describe survival in the population if all subjects were treated or if all subjects were untreated; and (ii) marginal hazard ratios. The use of these propensity score methods allows one to replicate the measures of effect that are commonly reported in randomized controlled trials with time-to-event outcomes: both absolute and relative reductions in the probability of an event occurring can be determined. We also provide guidance on variable selection for the propensity score model, highlight methods for assessing the balance of baseline covariates between treated and untreated subjects, and describe the implementation of a sensitivity analysis to assess the effect of unmeasured confounding variables on the estimated treatment effect when outcomes are time-to-event in nature. The methods in the paper are illustrated by estimating the effect of discharge statin prescribing on the risk of death in a sample of patients hospitalized with acute myocardial infarction. In this tutorial article, we describe and illustrate all the steps necessary to conduct a comprehensive analysis of the effect of treatment on time-to-event outcomes. © 2013 The authors. Statistics in Medicine published by John Wiley & Sons, Ltd.

Impact of gender on long-term outcomes after surgical repair for acute Stanford A aortic dissection: a propensity score matched analysis.

PubMed

Sabashnikov, Anton; Heinen, Stephanie; Deppe, Antje Christin; Zeriouh, Mohamed; Weymann, Alexander; Slottosch, Ingo; Eghbalzadeh, Kaveh; Popov, Aron-Frederik; Liakopoulos, Oliver; Rahmanian, Parwis B; Madershahian, Navid; Kroener, Axel; Choi, Yeong-Hoon; Kuhn-Régnier, Ferdinand; Simon, André R; Wahlers, Thorsten; Wippermann, Jens

2017-05-01

Previous research suggests that female gender is associated with increased mortality rates after surgery for Stanford A acute aortic dissection (AAD). However, women with AAD usually present with different clinical symptoms that may bias outcomes. Moreover, there is a lack of long-term results regarding overall mortality and freedom from major cerebrovascular events. We analysed the impact of gender on long-term outcomes after surgery for Stanford A AAD by comparing genders with similar risk profiles using propensity score matching. A total of 240 patients operated for Stanford A AAD were included in this study. To control for selection bias and other confounders, propensity score matching was applied to gender groups. After propensity score matching, the gender groups were well balanced in terms of risk profiles. There were no statistically significant differences regarding duration of cardiopulmonary bypass ( P  = 0.165) and duration of aortic cross-clamp time ( P  = 0.111). Female patients received less fresh frozen plasma ( P  = 0.021), had shorter stays in the intensive care unit ( P  = 0.031), lower incidence of temporary neurological dysfunction ( P  < 0.001) and lower incidence of dialysis ( P  = 0.008). There were no significant differences regarding intraoperative mortality ( P  = 1.000), 30-day mortality ( P  = 0.271), long-term overall cumulative survival ( P  = 0.954) and long-term freedom from cerebrovascular events ( P  = 0.235) with up to a 9-year follow-up. Considering patients with similar risk profiles, female gender per se is not associated with worse long-term survival and freedom from stroke after surgical aortic repair. Moreover, female patients might even benefit from a smoother early postoperative course and lower incidence of early postoperative complications. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Assessing the Independent Contribution of Maternal Educational Expectations to Children’s Educational Attainment in Early Adulthood: A Propensity Score Matching Analysis

PubMed Central

Pingault, Jean Baptiste; Côté, Sylvana M.; Petitclerc, Amélie; Vitaro, Frank; Tremblay, Richard E.

2015-01-01

Background Parental educational expectations have been associated with children’s educational attainment in a number of long-term longitudinal studies, but whether this relationship is causal has long been debated. The aims of this prospective study were twofold: 1) test whether low maternal educational expectations contributed to failure to graduate from high school; and 2) compare the results obtained using different strategies for accounting for confounding variables (i.e. multivariate regression and propensity score matching). Methodology/Principal Findings The study sample included 1,279 participants from the Quebec Longitudinal Study of Kindergarten Children. Maternal educational expectations were assessed when the participants were aged 12 years. High school graduation – measuring educational attainment – was determined through the Quebec Ministry of Education when the participants were aged 22–23 years. Findings show that when using the most common statistical approach (i.e. multivariate regressions to adjust for a restricted set of potential confounders) the contribution of low maternal educational expectations to failure to graduate from high school was statistically significant. However, when using propensity score matching, the contribution of maternal expectations was reduced and remained statistically significant only for males. Conclusions/Significance The results of this study are consistent with the possibility that the contribution of parental expectations to educational attainment is overestimated in the available literature. This may be explained by the use of a restricted range of potential confounding variables as well as the dearth of studies using appropriate statistical techniques and study designs in order to minimize confounding. Each of these techniques and designs, including propensity score matching, has its strengths and limitations: A more comprehensive understanding of the causal role of parental expectations will stem from a convergence of findings from studies using different techniques and designs. PMID:25803867

Usefulness of a traction method using dental floss and a hemoclip for gastric endoscopic submucosal dissection: a propensity score matching analysis (with videos).

PubMed

Suzuki, Sho; Gotoda, Takuji; Kobayashi, Yoshiyuki; Kono, Shin; Iwatsuka, Kunio; Yagi-Kuwata, Naoko; Kusano, Chika; Fukuzawa, Masakatsu; Moriyasu, Fuminori

2016-02-01

Although endoscopic submucosal dissection (ESD) is a significant advancement in therapeutic endoscopy, it is a complicated technique and requires considerable expertise. In this exploratory study, we evaluated the efficacy of a simple traction method that uses dental floss and a hemoclip (DFC) and was developed to overcome the technical difficulties of ESD. In total, 238 early gastric cancers treated by ESD between May 2012 and December 2014 at Tokyo Medical University were retrospectively reviewed. Lesions treated by conventional ESD (n = 185) and by ESD with DFC (ESD-DFC) (n = 53) were compared. Multivariable analyses and propensity score matching were used to compensate for the differences in age, sex, resected specimen size, lesion location, lesion position, presence of ulceration, and operator level. The procedure time, rate of en bloc and complete resection, and rates of adverse events were evaluated between the 2 groups. Propensity score matching analysis created 43 matched pairs. Adjusted comparisons between ESD-DFC and conventional ESD showed similar treatment outcomes (en bloc resection rate: 97.7% vs 100%, P = .315; complete resection rate: 90.7% vs 95.3%, P = .397; perforation during ESD rate: 2.3% vs 2.3%, P = 1.000; post-ESD bleeding rate: 4.7% vs 4.7%, P = 1.000) but a significantly shorter procedure time for ESD-DFC (82.2 ± 79.5 minutes vs 118.2 ± 71.6 minutes, P = .002). ESD-DFC facilitated rapid ESD with good visualization and traction while ensuring high curability and safety. Copyright © 2016 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.

Emergency coronary artery bypass grafting using minimized versus standard extracorporeal circulation – a propensity score analysis

PubMed Central

2013-01-01

Background The impact of minimized extracorporeal circulation (MECC) for emergency revascularization remains controversial. Methods A total of 348 patients underwent emergency CABG with MECC (n=146) or conventional extracorporeal circulation (CECC; n=175) between January 2005 and December 2010. Using propensity score matching after binary logistic regression, 100 patients, who underwent CABG with MECC could be matched with 100 patients, who underwent CABG with CECC. Primary outcome was 30-day mortality. Results Unadjusted 30-day mortality was 14.8% in patients with CECC and 6.9% in those with MECC (mean difference −7.9%; p=0.03). The adjusted mean difference (average treatment effect of the treated, ATT) after matching was −1.0% (95% CI −8.6 to 7.6; p=1.0). Intensive care unit stay (adjusted mean difference 1.0; 95% CI −0.2 to 3.2; p=0.70) and hospital stay (adjusted mean difference 1.0; 95% CI −2.0 to 3.6; p=0.40) did not show significant differences between both groups. The adjusted mean difference for postoperative low cardiac output syndrome was −1.1% (95% CI −7.3 to 7.1; p=0.83) without significant differences between CECC and MECC. Postoperative mechanical ventilation time, drain loss, postoperative rethoracotomy, postoperative neurological events, new onset renal replacement therapy and respiratory failure also had insignificant average treatment effects of the treated. In addition, all average treatment effects (ATEs) did not significantly differ between both groups. Conclusion Using propensity score estimation and matching, we did not observe significant differences in terms of survival and further outcomes in patients who undergo emergency CABG with CECC or MECC, but our results call for further analysis. PMID:23547910

Neoadjuvant luteinizing-hormone-releasing hormone agonist plus low-dose estramustine phosphate improves prostate-specific antigen-free survival in high-risk prostate cancer patients: a propensity score-matched analysis.

PubMed

Koie, Takuya; Mitsuzuka, Koji; Yoneyama, Takahiro; Narita, Shintaro; Kawamura, Sadafumi; Kaiho, Yasuhiro; Tsuchiya, Norihiko; Tochigi, Tatsuo; Habuchi, Tomonori; Arai, Yoichi; Ohyama, Chikara; Yoneyama, Tohru; Tobisawa, Yuki

2015-10-01

The optimal treatment for high-risk prostate cancer (Pca) remains to be established. We previously reported favorable biochemical recurrence-free survival (BRFS) in high-risk Pca patients treated with a neoadjuvant therapy comprising a luteinizing-hormone-releasing hormone (LHRH) agonist plus low dose estramustine phosphate (EMP) (LHRH+EMP) followed by radical prostatectomy (RP). In the present study, we used a retrospective design via propensity score matching to elucidate the clinical benefit of neoadjuvant LHRH+EMP for high-risk Pca. The Michinoku Urological Cancer Study Group database contained data for 1,268 consecutive Pca patients treated with RP alone at 4 institutions between April 2000 and March 2011 (RP alone group). In the RP alone group, we identified 386 high-risk Pca patients. The neoadjuvant LHRH+EMP group included 274 patients with high-risk Pca treated between September 2005 and November 2013 at Hirosaki University. Neoadjuvant LHRH+EMP therapy included LHRH and EMP administration at a dose of 280 mg/day for 6 months before RP. The outcome measures were overall survival (OS) and BRFS. The propensity score-matched analysis indicated 210 matched pairs from both groups. The 5-year BRFS rates were 90.4 and 65.8 % for the neoadjuvant LHRH+EMP and RP alone groups, respectively (P < 0.0001). The 5-year OS rates were 100 and 96.1 % for the neoadjuvant LHRH+EMP and RP alone groups, respectively (P = 0.110). Although the present study was not randomized, neoadjuvant LHRH+EMP therapy followed by RP appeared to reduce the risk of biochemical recurrence. A prospective randomized study is warranted to determine the clinical implications of the neoadjuvant therapy described here.

Clinical outcomes of atherectomy prior to percutaneous coronary intervention: A comparison of outcomes following rotational versus orbital atherectomy (COAP-PCI study).

PubMed

Meraj, Perwaiz M; Shlofmitz, Evan; Kaplan, Barry; Jauhar, Rajiv; Doshi, Rajkumar

2018-04-29

Because of the challenges in treating calcified coronary artery disease (CAD), lesion preparation has become increasingly important prior to percutaneous coronary intervention (PCI). Despite growing data for both rotational atherectomy (RA) and orbital atherectomy (OA), there have been no multicenter studies comparing the safety and efficacy of both. We sought to examine the clinical outcomes of patients with calcified CAD who underwent atherectomy. A total of 39 870 patients from five tertiary care hospitals who had PCI from January 2011 to January 2017 were identified. 907 patients who had RA or OA were included. This multicenter, prospectively collected observational analysis compared OA and RA. The primary end-point was myocardial infarction and safety outcomes including significant dissection, perforation, cardiac tamponade, and vascular complications. Propensity score matching (1:1) was performed to reduce selection bias. After matching, 546 patients were included in the final analysis. The primary endpoint, myocardial infarction occurred less frequently with OA compared to RA (6.7% vs 13.8%, P ≤ 0.01) in propensity score matched cohorts. Procedural safety outcomes were comparable between the groups. The secondary outcome of death on discharge occurred less in the OA group as compared with RA (0% vs 2.2%, P = 0.01). Fluoroscopy time was less in patients who were treated with OA (21.9 vs 25.6 min, P ≤ 0.01). Additional secondary outcomes were comparable between groups. In this non-randomized, multicenter comparison of contemporary atherectomy devices, OA was associated with significantly decreased in-hospital myocardial infarction and mortality after propensity score matching with decreased fluoroscopy time. © 2018, Wiley Periodicals, Inc.

Freedom Solo Versus Trifecta Bioprotheses: Clinical and Hemodynamic Evaluation after Propensity Score Matching.

PubMed

J Cerqueira, Rui; Melo, Renata; Moreira, Soraia; A Saraiva, Francisca; Andrade, Marta; Salgueiro, Elson; Almeida, Jorge; J Amorim, Mário; Pinho, Paulo; Lourenço, André; F Leite-Moreira, Adelino

2017-01-01

To compare stentless Freedom Solo and stented Trifecta aortic bioprostheses regarding hemodynamic profile, left ventricular mass regression, early and late postoperative outcomes and survival. Longitudinal cohort study of consecutive patients undergoing aortic valve replacement (from 2009 to 2016) with either Freedom Solo or Trifecta at one centre. Local databases and national records were queried. Postoperative echocardiography (3-6 months) was obtained for hemodynamic profile (mean transprosthetic gradient and effective orifice area) and left ventricle mass determination. After propensity score matching (21 covariates), Kaplan-Meier analysis and cumulative incidence analysis were performed for survival and combined outcome of structural valve deterioration and endocarditis, respectively. Hemodynamics and left ventricle mass regression were assessed by a mixed- -effects model including propensity score as a covariate. From a total sample of 397 Freedom Solo and 525 Trifecta patients with a median follow-up time of 4.0 (2.2- 6.0) and 2.4 (1.4-3.7) years, respectively, a matched sample of 329 pairs was obtained. Well-balanced matched groups showed no difference in survival (hazard ratio=1.04, 95% confidence interval=0.69-1.56) or cumulative hazards of combined outcome (subhazard ratio=0.54, 95% confidence interval=0.21-1.39). Although Trifecta showed improved hemodynamic profile compared to Freedom Solo, no differences were found in left ventricle mass regression. Trifecta has a slightly improved hemodynamic profile compared to Freedom Solo but this does not translate into differences in the extent of mass regression, postoperative outcomes or survival, which were good and comparable for both bioprostheses. Long-term follow-up is needed for comparisons with older models of bioprostheses.

Genome-wide association analysis accounting for environmental factors through propensity-score matching: application to stressful live events in major depressive disorder.

PubMed

Power, Robert A; Cohen-Woods, Sarah; Ng, Mandy Y; Butler, Amy W; Craddock, Nick; Korszun, Ania; Jones, Lisa; Jones, Ian; Gill, Michael; Rice, John P; Maier, Wolfgang; Zobel, Astrid; Mors, Ole; Placentino, Anna; Rietschel, Marcella; Aitchison, Katherine J; Tozzi, Federica; Muglia, Pierandrea; Breen, Gerome; Farmer, Anne E; McGuffin, Peter; Lewis, Cathryn M; Uher, Rudolf

2013-09-01

Stressful life events are an established trigger for depression and may contribute to the heterogeneity within genome-wide association analyses. With depression cases showing an excess of exposure to stressful events compared to controls, there is difficulty in distinguishing between "true" cases and a "normal" response to a stressful environment. This potential contamination of cases, and that from genetically at risk controls that have not yet experienced environmental triggers for onset, may reduce the power of studies to detect causal variants. In the RADIANT sample of 3,690 European individuals, we used propensity score matching to pair cases and controls on exposure to stressful life events. In 805 case-control pairs matched on stressful life event, we tested the influence of 457,670 common genetic variants on the propensity to depression under comparable level of adversity with a sign test. While this analysis produced no significant findings after genome-wide correction for multiple testing, we outline a novel methodology and perspective for providing environmental context in genetic studies. We recommend contextualizing depression by incorporating environmental exposure into genome-wide analyses as a complementary approach to testing gene-environment interactions. Possible explanations for negative findings include a lack of statistical power due to small sample size and conditional effects, resulting from the low rate of adequate matching. Our findings underscore the importance of collecting information on environmental risk factors in studies of depression and other complex phenotypes, so that sufficient sample sizes are available to investigate their effect in genome-wide association analysis. Copyright © 2013 Wiley Periodicals, Inc.

The importance of extent of choroid plexus cauterization in addition to endoscopic third ventriculostomy for infantile hydrocephalus: a retrospective North American observational study using propensity score-adjusted analysis.

PubMed

Fallah, Aria; Weil, Alexander G; Juraschka, Kyle; Ibrahim, George M; Wang, Anthony C; Crevier, Louis; Tseng, Chi-Hong; Kulkarni, Abhaya V; Ragheb, John; Bhatia, Sanjiv

2017-12-01

OBJECTIVE Combined endoscopic third ventriculostomy (ETC) and choroid plexus cauterization (CPC)-ETV/CPC- is being investigated to increase the rate of shunt independence in infants with hydrocephalus. The degree of CPC necessary to achieve improved rates of shunt independence is currently unknown. METHODS Using data from a single-center, retrospective, observational cohort study involving patients who underwent ETV/CPC for treatment of infantile hydrocephalus, comparative statistical analyses were performed to detect a difference in need for subsequent CSF diversion procedure in patients undergoing partial CPC (describes unilateral CPC or bilateral CPC that only extended from the foramen of Monro [FM] to the atrium on one side) or subtotal CPC (describes CPC extending from the FM to the posterior temporal horn bilaterally) using a rigid neuroendoscope. Propensity scores for extent of CPC were calculated using age and etiology. Propensity scores were used to perform 1) case-matching comparisons and 2) Cox multivariable regression, adjusting for propensity score in the unmatched cohort. Cox multivariable regression adjusting for age and etiology, but not propensity score was also performed as a third statistical technique. RESULTS Eighty-four patients who underwent ETV/CPC had sufficient data to be included in the analysis. Subtotal CPC was performed in 58 patients (69%) and partial CPC in 26 (31%). The ETV/CPC success rates at 6 and 12 months, respectively, were 49% and 41% for patients undergoing subtotal CPC and 35% and 31% for those undergoing partial CPC. Cox multivariate regression in a 48-patient cohort case-matched by propensity score demonstrated no added effect of increased extent of CPC on ETV/CPC survival (HR 0.868, 95% CI 0.422-1.789, p = 0.702). Cox multivariate regression including all patients, with adjustment for propensity score, demonstrated no effect of extent of CPC on ETV/CPC survival (HR 0.845, 95% CI 0.462-1.548, p = 0.586). Cox multivariate regression including all patients, with adjustment for age and etiology, but not propensity score, demonstrated no effect of extent of CPC on ETV/CPC survival (HR 0.908, 95% CI 0.495-1.664, p = 0.755). CONCLUSIONS Using multiple comparative statistical analyses, no difference in need for subsequent CSF diversion procedure was detected between patients in this cohort who underwent partial versus subtotal CPC. Further investigation regarding whether there is truly no difference between partial versus subtotal extent of CPC in larger patient populations and whether further gain in CPC success can be achieved with complete CPC is warranted.

Propensity score matching of the gymnastics for diabetes mellitus using logistic regression

NASA Astrophysics Data System (ADS)

Otok, Bambang Widjanarko; Aisyah, Amalia; Purhadi, Andari, Shofi

2017-12-01

Diabetes Mellitus (DM) is a group of metabolic diseases with characteristics shows an abnormal blood glucose level occurring due to pancreatic insulin deficiency, decreased insulin effectiveness or both. The report from the ministry of health shows that DMs prevalence data of East Java province is 2.1%, while the DMs prevalence of Indonesia is only 1,5%. Given the high cases of DM in East Java, it needs the preventive action to control factors causing the complication of DM. This study aims to determine the combination factors causing the complication of DM to reduce the bias by confounding variables using Propensity Score Matching (PSM) with the method of propensity score estimation is binary logistic regression. The data used in this study is the medical record from As-Shafa clinic consisting of 6 covariates and health complication as response variable. The result of PSM analysis showed that there are 22 of 126 DMs patients attending gymnastics paired with patients who didnt attend to diabetes gymnastics. The Average Treatment of Treated (ATT) estimation results showed that the more patients who didnt attend to gymnastics, the more likely the risk for the patients having DMs complications.

Multilevel Propensity Score Matching within and across Schools

ERIC Educational Resources Information Center

Kelcey, Benjamin

2011-01-01

A central issue in nonexperimental studies is the identification of comparable individuals (e.g. students) to remove selection bias. One such increasingly common method to identify comparable individuals and address selection bias is the propensity score (PS). PS methods rely on a model of the treatment assignment to identify comparable…

Moving to a Highly Walkable Neighborhood and Incidence of Hypertension: A Propensity-Score Matched Cohort Study.

PubMed

Chiu, Maria; Rezai, Mohammad-Reza; Maclagan, Laura C; Austin, Peter C; Shah, Baiju R; Redelmeier, Donald A; Tu, Jack V

2016-06-01

The impact of moving to a neighborhood more conducive to utilitarian walking on the risk of incident hypertension is uncertain. Our study aimed to examine the effect of moving to a highly walkable neighborhood on the risk of incident hypertension. A population-based propensity-score matched cohort study design was used based on the Ontario population from the Canadian Community Health Survey (2001-2010). Participants were adults ≥ 20 years of age who moved from a low-walkability neighborhood (defined as any neighborhood with a Walk Score < 90) to either a high- (Walk Score ≥ 90) or another low-walkability neighborhood. The incidence of hypertension was assessed by linking the cohort to administrative health databases using a validated algorithm. Propensity-score matched Cox proportional hazard models were used. Annual health examination was used as a control event. Among the 1,057 propensity-score matched pairs there was a significantly lower risk of incident hypertension in the low to high vs. the low to low-walkability groups [hazard ratio = 0.46; 95% CI, 0.26, 0.81, p < 0.01]. The crude hypertension incidence rates were 18.0 per 1,000 person-years (95% CI: 11.6, 24.8) among the low- to low-walkability movers compared with 8.6 per 1,000 person-years (95% CI: 5.3, 12.7) among the low- to high-walkability movers (p < 0.001). There were no significant differences in the hazard of annual health examination between the two mover groups. Moving to a highly walkable neighborhood was associated with a significantly lower risk of incident hypertension. Future research should assess whether specific attributes of walkable neighborhoods (e.g., amenities, density, land-use mix) may be driving this relationship. Chiu M, Rezai MR, Maclagan LC, Austin PC, Shah BR, Redelmeier DA, Tu JV. 2016. Moving to a highly walkable neighborhood and incidence of hypertension: a propensity-score matched cohort study. Environ Health Perspect 124:754-760; http://dx.doi.org/10.1289/ehp.1510425.

Safety and Long-Term Outcomes of Catheter Ablation of Atrial Fibrillation Using Magnetic Navigation versus Manual Conventional Ablation: A Propensity-Score Analysis.

PubMed

Adragão, Pedro Pulido; Cavaco, Diogo; Ferreira, António Miguel; Costa, Francisco Moscoso; Parreira, Leonor; Carmo, Pedro; Morgado, Francisco Bello; Santos, Katya Reis; Santos, Pedro Galvão; Carvalho, Maria Salomé; Durazzo, Anai; Marques, Hugo; Gonçalves, Pedro Araújo; Raposo, Luís; Mendes, Miguel

2016-03-01

Whether or not the potential advantages of using a magnetic navigation system (MNS) translate into improved outcomes in patients undergoing atrial fibrillation (AF) ablation is a question that remains unanswered. In this observational registry study, we used propensity-score matching to compare the outcomes of patients with symptomatic drug-refractory AF who underwent catheter ablation using MNS with the outcomes of those who underwent catheter ablation using conventional manual navigation. Among 1,035 eligible patients, 287 patients in each group had similar propensity scores and were included in the analysis. The primary efficacy outcome was the rate of AF relapse after a 3-month blanking period. At a mean follow-up of 2.6 ± 1.5 years, AF ablation with MNS was associated with a similar risk of AF relapse as compared with manual navigation (18.4% per year and 22.3% per year, respectively; hazard ratio 0.81, 95% CI 0.63-1.05; P = 0.108). Major complications occurred in two patients (0.7%) using MNS, and in six patients (2.1%) undergoing manually navigated ablation (P = 0.286). Fluoroscopy times were 21 ± 10 minutes in the manual navigation group, and 12 ± 9 minutes in the MNS group (P < 0.001), whereas total procedure times were 152 ± 52 minutes and 213 ± 58 minutes, respectively (P < 0.001). In this propensity-score matched comparison, magnetic navigation and conventional manual AF ablations seem to have similar relapse rates and a similar risk of complications. AF ablations with magnetic navigation take longer to perform but expose patients to significantly shorter fluoroscopy times. © 2015 Wiley Periodicals, Inc.

Atrial natriuretic peptide therapy and in-hospital mortality in acute myocardial infarction patients undergoing percutaneous coronary intervention.

PubMed

Isogai, Toshiaki; Matsui, Hiroki; Tanaka, Hiroyuki; Fushimi, Kiyohide; Yasunaga, Hideo

2016-11-01

Atrial natriuretic peptide (ANP) therapy has been reported to have beneficial effects in patients with acute myocardial infarction (AMI); however, its impact on in-hospital mortality remains unclear. This study aimed to investigate the effects of ANP therapy on in-hospital mortality in AMI patients undergoing percutaneous coronary intervention (PCI). This was a retrospective cohort study using the Diagnosis Procedure Combination inpatient database in Japan. We identified AMI patients who underwent PCI with stent implantation on the day of admission, between 2010 and 2014. We compared 30-day in-hospital mortality between patients who started ANP therapy on the day of admission (ANP group) and those who received no ANP therapy during hospitalization (control group), using propensity score and instrumental variable methods. Of 60,592 eligible patients (8189 ANP group, 52,403 control group) from 850 hospitals, 1:1 propensity score matching created 8027 pairs. There was no significant difference in 30-day in-hospital mortality between the ANP and control groups (3.4% vs. 3.8%, respectively; p=0.162; risk difference, -0.42%; 95% confidence interval [CI], -1.00% to 0.15%) in the propensity score-matched cohort. Logistic regression analysis with adjustment for propensity score deciles found no significant association between ANP therapy and 30-day in-hospital mortality (odds ratio, 0.99; 95% CI, 0.82 to 1.19). Instrumental variable analysis also showed no significant association between ANP therapy and 30-day in-hospital mortality (risk difference, -0.59%; 95% CI, -1.24% to 0.05%). This study found no significant association between ANP therapy and in-hospital mortality in AMI patients undergoing PCI. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

The effect of intrapartum antibiotics on early-onset neonatal sepsis in Dhaka, Bangladesh: a propensity score matched analysis

PubMed Central

2014-01-01

Background We estimate the effect of antibiotics given in the intrapartum period on early-onset neonatal sepsis in Dhaka, Bangladesh using propensity score techniques. Methods We followed 600 mother-newborn pairs as part of a cohort study at a maternity center in Dhaka. Some pregnant women received one dose of intravenous antibiotics during labor based on clinician discretion. Newborns were followed over the first seven days of life for early-onset neonatal sepsis defined by a modified version of the World Health Organization Young Infants Integrated Management of Childhood Illnesses criteria. Using propensity scores we matched women who received antibiotics with similar women who did not. A final logistic regression model predicting sepsis was run in the matched sample controlling for additional potential confounders. Results Of the 600 mother-newborn pairs, 48 mothers (8.0%) received antibiotics during the intrapartum period. Seventy-seven newborns (12.8%) were classified with early-onset neonatal sepsis. Antibiotics appeared to be protective (odds ratio 0.381, 95% confidence interval 0.115–1.258), however this was not statistically significant. The results were similar after adjusting for prematurity, wealth status, and maternal colonization status (odds ratio 0.361, 95% confidence interval 0.106–1.225). Conclusions Antibiotics administered during the intrapartum period may reduce the risk of early-onset neonatal sepsis in high neonatal mortality settings like Dhaka. PMID:24742087

Effect of Radiotherapy Planning Complexity on Survival of Elderly Patients With Unresected Localized Lung Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, Chang H.; Bonomi, Marcelo; Cesaretti, Jamie

2011-11-01

Purpose: To evaluate whether complex radiotherapy (RT) planning was associated with improved outcomes in a cohort of elderly patients with unresected Stage I-II non-small-cell lung cancer (NSCLC). Methods and Materials: Using the Surveillance, Epidemiology, and End Results registry linked to Medicare claims, we identified 1998 patients aged >65 years with histologically confirmed, unresected stage I-II NSCLC. Patients were classified into an intermediate or complex RT planning group using Medicare physician codes. To address potential selection bias, we used propensity score modeling. Survival of patients who received intermediate and complex simulation was compared using Cox regression models adjusting for propensity scoresmore » and in a stratified and matched analysis according to propensity scores. Results: Overall, 25% of patients received complex RT planning. Complex RT planning was associated with better overall (hazard ratio 0.84; 95% confidence interval, 0.75-0.95) and lung cancer-specific (hazard ratio 0.81; 95% confidence interval, 0.71-0.93) survival after controlling for propensity scores. Similarly, stratified and matched analyses showed better overall and lung cancer-specific survival of patients treated with complex RT planning. Conclusions: The use of complex RT planning is associated with improved survival among elderly patients with unresected Stage I-II NSCLC. These findings should be validated in prospective randomized controlled trials.« less

Propensity score method: a non-parametric technique to reduce model dependence

PubMed Central

2017-01-01

Propensity score analysis (PSA) is a powerful technique that it balances pretreatment covariates, making the causal effect inference from observational data as reliable as possible. The use of PSA in medical literature has increased exponentially in recent years, and the trend continue to rise. The article introduces rationales behind PSA, followed by illustrating how to perform PSA in R with MatchIt package. There are a variety of methods available for PS matching such as nearest neighbors, full matching, exact matching and genetic matching. The task can be easily done by simply assigning a string value to the method argument in the matchit() function. The generic summary() and plot() functions can be applied to an object of class matchit to check covariate balance after matching. Furthermore, there is a useful package PSAgraphics that contains several graphical functions to check covariate balance between treatment groups across strata. If covariate balance is not achieved, one can modify model specifications or use other techniques such as random forest and recursive partitioning to better represent the underlying structure between pretreatment covariates and treatment assignment. The process can be repeated until the desirable covariate balance is achieved. PMID:28164092

Clinical Outcomes of Root Reimplantation and Bentall Procedure: Propensity Score Matching Analysis.

PubMed

Lee, Heemoon; Cho, Yang Hyun; Sung, Kiick; Kim, Wook Sung; Park, Kay-Hyun; Jeong, Dong Seop; Park, Pyo Won; Lee, Young Tak

2018-03-26

This study aimed to evaluate the clinical outcomes of aortic root replacement(ARR) surgery:Root reimplantation as valve-sparing root replacement(VSR) and the Bentall procedure. We retrospectively reviewed 216 patients who underwent ARR between 1995 and 2013 at Samsung Medical Center. Patients were divided into two groups, depending on the procedure they underwent: Bentall(n=134) and VSR(n=82). The mean follow-up duration was 100.9±56.4 months. There were 2 early deaths in the Bentall group and none in the VSR group(p=0.53). Early morbidities were not different between the groups. Overall mortality was significantly lower in the VSR group (HR=0.12,p=0.04). Despite the higher reoperation rate in the VSR group(p=0.03), major adverse valve-related events(MAVRE) did not differ between the groups(p=0.28). Bleeding events were significantly higher in the Bentall group during follow-up(10 in Bentall group, 0 in VSR group, p=0.04). here were 6 thromboembolic events only in the Bentall group(p=0.11). We performed a propensity score matching analysis comparing the groups(134 Bentall vs 43 VSR). Matched analysis gave similar results, i.e. HR=0.17 and p=0.10 for overall mortality and HR=1.01 and p=0.99 for MAVRE. Although there was marginal significance in the propensity matched analysis, it is plausible to anticipate a survival benefit with VSR during long-term follow-up. Despite a higher reoperation for aortic valves, VSR can be a viable option in patients who decline life-long anticoagulation, especially the young or the patients in whom anticoagulation is contraindicated. Copyright © 2018. Published by Elsevier Inc.

Reduced 30-day mortality in men after elective coronary artery bypass surgery with minimized extracorporeal circulation-a propensity score analysis

PubMed Central

2012-01-01

Background Impact of minimized extracorporeal circulation (MECC) for coronary surgery on mortality remains controversial and gender significantly influence outcome. Methods We analyzed 3,139 male patients undergoing elective coronary surgery between 01/2004 and 05/2009. Using propensity score matching after binary logistic regression, 1,005 patients (from 1,119 patients) undergoing surgery with MECC could be matched with 1,005 patients (from 2,020 patients) undergoing surgery with conventional extracorporeal circulation (CECC). Primary outcome was 30-day mortality. Results Unadjusted 30-day mortality was 2.7% in patients with CECC and 0.8% in those with MECC (mean difference -1.9%; p < 0.001). The adjusted mean difference (average treatment effect of the treated) after matching was -1.5% (95% confidence interval (CI) -2.6 to -0.4; p = 0.006). Postoperative hospital stay was shorter in patients operated with minimized systems (adjusted mean difference -0.8 days; 95% CI -1.46 to -0.09; p = 0.03) and incidence of postoperative neurocognitive dysfunction was also lower (adjusted mean difference -1.3%; 95% CI -2.2 to -0.4; p = 0.001). Chest tube drainage (adjusted mean difference +22 mL; 95% CI -47 to 91; p = 0.5) and risk for acute kidney injury, kidney injury and failure according to RIFLE criteria (adjusted mean difference -1.0%; 95% CI -2.5 to 0.6; p = 0.24) proved to be insignificant between both groups. Apart from reduced 30-day mortality, however, average treatment effects for intensive care unit stay, postoperative hospital stay, chest tube drainage and kidney injury did not significantly differ. Conclusion Using propensity score analysis, we observed an association between MECC and reduced 30-day mortality in men, but our results call for further analysis. PMID:22424497

Costs of Clostridium difficile infection in pediatric operations: A propensity score-matching analysis.

PubMed

Kulaylat, Afif N; Rocourt, Dorothy V; Podany, Abigail B; Engbrecht, Brett W; Twilley, Marianne; Santos, Mary C; Cilley, Robert E; Hollenbeak, Christopher S; Dillon, Peter W

2017-05-01

The purpose of this analysis was to assess the burden of Clostridium difficile infection in the hospitalized pediatric surgical population and to characterize its influence on the costs of care. There were 313,664 patients age 1-18 years who underwent a general thoracic or abdominal procedure in the Kids' Inpatient Database during 2003, 2006, 2009, and 2012. Logistic regression was used to model factors associated with the development of C difficile infection. A propensity score-matching analysis was performed to evaluate the influence of C difficile infection on mortality, duration of stay, and costs in similar patient cohorts. Population weights were used to estimate the national excess burden of C difficile infection on these outcomes. The overall prevalence of C difficile infection in the sampled cohort was 0.30%, with an increasing trend of C difficile infection over time in non-children's hospitals (P < .001). C difficile infection was associated with younger age, nonelective procedures, increasing comorbidities, and urban teaching hospital status (P < .001). An estimated 1,438 children developed C difficile infection after operation. After propensity score matching, the mean excess duration of stay and costs attributable to C difficile infection were 5.8 days and $12,801 (P < .001), accounting for 8,295 days spent in the hospital and $18.4 million (2012 USD) in spending annually. C difficile infection is a relatively uncommon but costly complication after pediatric operative procedures. Given the increasing trend of C difficile infection among hospitalized surgical patients, there is substantial opportunity for reduction of inpatient burden and associated costs in this potentially preventable nosocomial infection. Copyright © 2016 Elsevier Inc. All rights reserved.

A Retrospective Propensity Score-Matched Early Thromboembolic Event Analysis of Prothrombin Complex Concentrate vs Fresh Frozen Plasma for Warfarin Reversal Prior to Emergency Neurosurgical Procedures.

PubMed

Agarwal, Prateek; Abdullah, Kalil G; Ramayya, Ashwin G; Nayak, Nikhil R; Lucas, Timothy H

2017-06-29

Reversal of therapeutic anticoagulation prior to emergency neurosurgical procedures is required in the setting of intracranial hemorrhage. Multifactor prothrombin complex concentrate (PCC) promises rapid efficacy but may increase the probability of thrombotic complications compared to fresh frozen plasma (FFP). To compare the rate of thrombotic complications in patients treated with PCC or FFP to reverse therapeutic anticoagulation prior to emergency neurosurgical procedures in the setting of intracranial hemorrhage at a level I trauma center. Sixty-three consecutive patients on warfarin therapy presenting with intracranial hemorrhage who received anticoagulation reversal prior to emergency neurosurgical procedures were retrospectively identified between 2007 and 2016. They were divided into 2 cohorts based on reversal agent, either PCC (n = 28) or FFP (n = 35). The thrombotic complications rates within 72 h of reversal were compared using the χ 2 test. A multivariate propensity score matching analysis was used to limit the threat to interval validity from selection bias arising from differences in demographics, laboratory values, history, and clinical status. Thrombotic complications were uncommon in this neurosurgical population, occurring in 1.59% (1/63) of treated patients. There was no significant difference in the thrombotic complication rate between groups, 3.57% (1/28; PCC group) vs 0% (0/35; FFP group). Propensity score matching analysis validated this finding after controlling for any selection bias. In this limited sample, thrombotic complication rates were similar between use of PCC and FFP for anticoagulation reversal in the management of intracranial hemorrhage prior to emergency neurosurgical procedures. Copyright © 2017 by the Congress of Neurological Surgeons

Single Marital Status and Infectious Mortality in Women With Cervical Cancer in the United States.

PubMed

Machida, Hiroko; Eckhardt, Sarah E; Castaneda, Antonio V; Blake, Erin A; Pham, Huyen Q; Roman, Lynda D; Matsuo, Koji

2017-10-01

Unmarried status including single marital status is associated with increased mortality in women bearing malignancy. Infectious disease weights a significant proportion of mortality in patients with malignancy. Here, we examined an association of single marital status and infectious mortality in cervical cancer. This is a retrospective observational study examining 86,555 women with invasive cervical cancer identified in the Surveillance, Epidemiology, and End Results Program between 1973 and 2013. Characteristics of 18,324 single women were compared with 38,713 married women in multivariable binary logistic regression models. Propensity score matching was performed to examine cumulative risk of all-cause and infectious mortality between the 2 groups. Single marital status was significantly associated with young age, black/Hispanic ethnicity, Western US residents, uninsured status, high-grade tumor, squamous histology, and advanced-stage disease on multivariable analysis (all, P < 0.05). In a prematched model, single marital status was significantly associated with increased cumulative risk of all-cause mortality (5-year rate: 32.9% vs 29.7%, P < 0.001) and infectious mortality (0.5% vs 0.3%, P < 0.001) compared with the married status. After propensity score matching, single marital status remained an independent prognostic factor for increased cumulative risk of all-cause mortality (adjusted hazards ratio [HR], 1.15; 95% confidence interval [CI], 1.11-1.20; P < 0.001) and those of infectious mortality on multivariable analysis (adjusted HR, 1.71; 95% CI, 1.27-2.32; P < 0.001). In a sensitivity analysis for stage I disease, single marital status remained significantly increased risk of infectious mortality after propensity score matching (adjusted HR, 2.24; 95% CI, 1.34-3.73; P = 0.002). Single marital status was associated with increased infectious mortality in women with invasive cervical cancer.

Management of Severe Pancreatic Fistula After Pancreatoduodenectomy.

PubMed

Smits, F Jasmijn; van Santvoort, Hjalmar C; Besselink, Marc G; Batenburg, Marilot C T; Slooff, Robbert A E; Boerma, Djamila; Busch, Olivier R; Coene, Peter P L O; van Dam, Ronald M; van Dijk, David P J; van Eijck, Casper H J; Festen, Sebastiaan; van der Harst, Erwin; de Hingh, Ignace H J T; de Jong, Koert P; Tol, Johanna A M G; Borel Rinkes, Inne H M; Molenaar, I Quintus

2017-06-01

Postoperative pancreatic fistula is a potentially life-threatening complication after pancreatoduodenectomy. Evidence for best management is lacking. To evaluate the clinical outcome of patients undergoing catheter drainage compared with relaparotomy as primary treatment for pancreatic fistula after pancreatoduodenectomy. A multicenter, retrospective, propensity-matched cohort study was conducted in 9 centers of the Dutch Pancreatic Cancer Group from January 1, 2005, to September 30, 2013. From a cohort of 2196 consecutive patients who underwent pancreatoduodenectomy, 309 patients with severe pancreatic fistula were included. Propensity score matching (based on sex, age, comorbidity, disease severity, and previous reinterventions) was used to minimize selection bias. Data analysis was performed from January to July 2016. First intervention for pancreatic fistula: catheter drainage or relaparotomy. Primary end point was in-hospital mortality; secondary end points included new-onset organ failure. Of the 309 patients included in the analysis, 209 (67.6%) were men, and mean (SD) age was 64.6 (10.1) years. Overall in-hospital mortality was 17.8% (55 patients): 227 patients (73.5%) underwent primary catheter drainage and 82 patients (26.5%) underwent primary relaparotomy. Primary catheter drainage was successful (ie, survival without relaparotomy) in 175 patients (77.1%). With propensity score matching, 64 patients undergoing primary relaparotomy were matched to 64 patients undergoing primary catheter drainage. Mortality was lower after catheter drainage (14.1% vs 35.9%; P = .007; risk ratio, 0.39; 95% CI, 0.20-0.76). The rate of new-onset single-organ failure (4.7% vs 20.3%; P = .007; risk ratio, 0.15; 95% CI, 0.03-0.60) and new-onset multiple-organ failure (15.6% vs 39.1%; P = .008; risk ratio, 0.40; 95% CI, 0.20-0.77) were also lower after primary catheter drainage. In this propensity-matched cohort, catheter drainage as first intervention for severe pancreatic fistula after pancreatoduodenectomy was associated with a better clinical outcome, including lower mortality, compared with primary relaparotomy.

Relationships between iron dose, hospitalizations and mortality in incident haemodialysis patients: a propensity-score matched approach.

PubMed

Varas, Javier; Ramos, Rosa; Aljama, Pedro; Pérez-García, Rafael; Moreso, Francesc; Pinedo, Miguel; Ignacio Merello, José; Stuard, Stefano; Canaud, Bernard; Martín-Malo, Alejandro

2018-01-01

Intravenous iron management is common in the haemodialysis population. However, the safest dosing strategy remains uncertain, in terms of the risk of hospitalization and mortality. We aimed to determine the effects of cumulative monthly iron doses on mortality and hospitalization. This multicentre observational retrospective propensity-matched score study included 1679 incident haemodialysis patients. We measured baseline demographic variables, haemodialysis clinical parameters and laboratory analytical values. We compared outcomes among quartiles of cumulative iron dose (mg/kg/month). We implemented propensity-score matching (PSM) to reduce confounding due to indication. In the PSM cohort (330 patients), we compared outcomes between groups that received cumulative iron doses above and below 5.66 mg/kg/month. Kaplan-Meier analyses showed that the high iron dose group had significantly worse survival than the low iron dose group. A univariate analysis indicated that the monthly iron dose could significantly predict mortality. However, a multivariate regression did not confirm that finding. The multivariate regression analysis revealed that iron doses  >5.58 mg/kg/month were not associated with elevated mortality risk, but they were associated with elevated risks of all-cause and cardiovascular-related hospitalizations. These results were ratified in the PSM population. Intravenous iron administration is advisable for maintaining haemoglobin levels in patients that receive haemodialysis. Our data suggested that large monthly iron doses, adjusted for body weight, were associated with more hospitalizations, but not with mortality or infection-related hospitalizations. © The Author 2017. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

Outcomes for youth receiving intensive in-home therapy or residential care: a comparison using propensity scores.

PubMed

Barth, Richard P; Greeson, Johanna K P; Guo, Shenyang; Green, Rebecca L; Hurley, Sarah; Sisson, Jocelyn

2007-10-01

This study compares outcomes for behaviorally troubled children receiving intensive in-home therapy (IIHT) and those receiving residential care (RC). Propensity score matching is used to identify matched pairs of youth (n = 786) with equivalent propensity for IIHT. The majority of pretreatment differences between the IIHT and RC groups are eliminated following matching. Logistic regression is then conducted on outcome differences at 1 year postdischarge. Results show that IIHT recipients had a greater tendency (.615) toward living with family, making progress in school, not experiencing trouble with the law, and placement stability compared with RC youth (.558; p < .10). This suggests that IIHT is at least as effective for achieving positive outcomes. Given IIHT's reduced restrictiveness and cost, intensive in-home services should be the preferred treatment over RC in most cases.

Propensity Score Matching: Retrospective Randomization?

PubMed

Jupiter, Daniel C

Randomized controlled trials are viewed as the optimal study design. In this commentary, we explore the strength of this design and its complexity. We also discuss some situations in which these trials are not possible, or not ethical, or not economical. In such situations, specifically, in retrospective studies, we should make every effort to recapitulate the rigor and strength of the randomized trial. However, we could be faced with an inherent indication bias in such a setting. Thus, we consider the tools available to address that bias. Specifically, we examine matching and introduce and explore a new tool: propensity score matching. This tool allows us to group subjects according to their propensity to be in a particular treatment group and, in so doing, to account for the indication bias. Copyright © 2017 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Periodontitis and early mortality among adults treated with hemodialysis: a multinational propensity-matched cohort study.

PubMed

Ruospo, Marinella; Palmer, Suetonia C; Wong, Germaine; Craig, Jonathan C; Petruzzi, Massimo; De Benedittis, Michele; Ford, Pauline; Johnson, David W; Tonelli, Marcello; Natale, Patrizia; Saglimbene, Valeria; Pellegrini, Fabio; Celia, Eduardo; Gelfman, Ruben; Leal, Miguel R; Torok, Marietta; Stroumza, Paul; Bednarek-Skublewska, Anna; Dulawa, Jan; Frantzen, Luc; Del Castillo, Domingo; Schon, Staffan; Bernat, Amparo G; Hegbrant, Jorgen; Wollheim, Charlotta; Gargano, Letizia; Bots, Casper P; Strippoli, Giovanni Fm

2017-05-22

Periodontitis is associated with cardiovascular mortality in the general population and adults with chronic diseases. However, it is unclear whether periodontitis predicts survival in the setting of kidney failure. ORAL-D was a propensity matched analysis in 3338 dentate adults with end-stage kidney disease treated in a hemodialysis network in Europe and South America designed to examine the association between periodontitis and all-cause and cardiovascular-related mortality in people on long-term hemodialysis. Participants were matched 1:1 on their propensity score for moderate to severe periodontitis assessed using the World Health Organization Community Periodontal Index. A random-effects Cox proportional hazards model was fitted with shared frailty to account for clustering of mortality risk within countries. Among the 3338 dentate participants, 1355 (40.6%) had moderate to severe periodontitis at baseline. After using propensity score methods to generate a matched cohort of participants with periodontitis similar to those with none or mild periodontal disease, moderate to severe periodontitis was associated with a lower risk of all-cause (9.1 versus 13.0 per 100 person years, hazard ratio 0.74, 95% confidence interval 0.61 to 0.90) and cardiovascular (4.3 versus 6.9 per 100 person years, hazard ratio 0.67, 0.51 to 0.88) mortality. These associations were not changed substantially when participants were limited to those with 12 or more natural teeth and when accounting for competing causes of cardiovascular death. In contrast to the general population, periodontitis does not appear to be associated with an increased risk of early death in adults treated with hemodialysis.

Assessing Student Achievement in Large-Scale Educational Programs Using Hierarchical Propensity Scores

ERIC Educational Resources Information Center

Vaughan, Angela L.; Lalonde, Trent L.; Jenkins-Guarnieri, Michael A.

2014-01-01

Many researchers assessing the efficacy of educational programs face challenges due to issues with non-randomization and the likelihood of dependence between nested subjects. The purpose of the study was to demonstrate a rigorous research methodology using a hierarchical propensity score matching method that can be utilized in contexts where…

Understanding Foster Youth Outcomes: Is Propensity Scoring Better than Traditional Methods?

ERIC Educational Resources Information Center

Berzin, Stephanie Cosner

2010-01-01

Objectives: This study seeks to examine the relationship between foster care and outcomes using multiple comparison methods to account for factors that put foster youth at risk independent of care. Methods: Using the National Longitudinal Survey of Youth 1997, matching, propensity scoring, and comparisons to the general population are used to…

The Use of Propensity Scores as a Matching Strategy

ERIC Educational Resources Information Center

John, Lindsay; Wright, Robin; Duku, Eric K.; Willms, J. Douglas

2008-01-01

Objectives: This study reports on the concept and method of linear propensity scores used to obtain a comparison group from the National Longitudinal Survey of Children and Youth to assess the effects of a longitudinal, structured arts program for Canadian youth (aged 9 to 15 years) from low-income, multicultural communities. Method: This study…

Clinicopathologic Characteristics and Prognosis of Xp11.2 Translocation Renal Cell Carcinoma: Multicenter, Propensity Score Matching Analysis.

PubMed

Choo, Min Soo; Jeong, Chang Wook; Song, Cheryn; Jeon, Hwang Gyun; Seo, Seong Il; Hong, Sung Kyu; Byun, Seok-Soo; Chung, Jin Soo; Hong, Sung-Hoo; Hwang, Eu Chang; Kim, Hyeon Hoe; Kwak, Cheol

2017-10-01

We evaluated the clinicopathologic characteristics and prognosis of Xp11.2 translocation (Xp11.2t) renal cell carcinoma (RCC) from a multicenter study and compare them with clear-cell RCC using a propensity score matching analysis. Between 2004 and 2013, 8384 consecutive patients from 7 institutions who were diagnosed with RCC were reviewed, and the pathologically confirmed Xp11.2t cases were enrolled. The oncological outcomes of Xp11.2t were compared with those of clear-cell RCC by selecting matched cases using 1:3 propensity score matching methods in a precollected clear-cell RCC data set from our hospital. The patients were divided into 2 subgroups on the basis of age of onset, either before (early) or after (late) 45 years old. Xp11.2t was found in 61 cases, corresponding to 0.72% of RCC cases for the 10 years. The mean age was 38.2 ± 19.4 years, and the mean tumor size was 6.2 ± 3.9 cm. The Xp11.2t cases were at more advanced stages and showed tendencies to involve lymph nodes at diagnosis. After the matching, there were no significant differences in recurrence-free and overall survival compared with clear-cell RCC. The age of incidence for Xp11.2t had a bimodal distribution, which was most common in the 30s and smaller peak in the 60s. Xp11.2t corresponded to a significantly worse prognosis for overall survival in late onset (after 45 years) subgroup (P = .038; hazard ratio, 3.199; 95% confidence interval, 1.065-9.609). This neoplasm has more aggressive clinicopathologic features at diagnosis. In older patients with onset age > 45 years, Xp11.2t showed a significantly worse prognosis than clear-cell RCC. Copyright © 2017 Elsevier Inc. All rights reserved.

Dialyzer Reuse with Peracetic Acid Does Not Impact Patient Mortality

PubMed Central

Bond, T. Christopher; Krishnan, Mahesh; Wilson, Steven M.; Mayne, Tracy

2011-01-01

Summary Background and objectives Numerous studies have shown the overall benefits of dialysis filter reuse, including superior biocompatibility and decreased nonbiodegradable medical waste generation, without increased risk of mortality. A recent study reported that dialyzer reprocessing was associated with decreased patient survival; however, it did not control for sources of potential confounding. We sought to determine the effect of dialyzer reprocessing with peracetic acid on patient mortality using contemporary outcomes data and rigorous analytical techniques. Design, setting, participants, & measurements We conducted a series of analyses of hemodialysis patients examining the effects of reuse on mortality using three techniques to control for potential confounding: instrumental variables, propensity-score matching, and time-dependent survival analysis. Results In the instrumental variables analysis, patients at high reuse centers had 16.2 versus 15.9 deaths/100 patient-years in nonreuse centers. In the propensity-score matched analysis, patients with reuse had a lower death rate per 100 patient-years than those without reuse (15.2 versus 15.5). The risk ratios for the time-dependent survival analyses were 0.993 (per percent of sessions with reuse) and 0.995 (per unit of last reuse), respectively. Over the study period, 13.8 million dialyzers were saved, representing 10,000 metric tons of medical waste. Conclusions Despite the large sample size, powered to detect miniscule effects, neither the instrumental variables nor propensity-matched analyses were statistically significant. The time-dependent survival analysis showed a protective effect of reuse. These data are consistent with the preponderance of evidence showing reuse limits medical waste generation without negatively affecting clinical outcomes. PMID:21566107

Reduced Hospital Mortality With Surgical Ligation of Patent Ductus Arteriosus in Premature, Extremely Low Birth Weight Infants: A Propensity Score-matched Outcome Study.

PubMed

Tashiro, Jun; Perez, Eduardo A; Sola, Juan E

2016-03-01

To evaluate outcomes after surgical ligation (SL) of patent ductus arteriosus (PDA) in premature, extremely low birth weight (ELBW) infants. Optimal management of PDA in this specialized population remains undefined. Currently, surgical therapy is largely reserved for infants failing medical management. To date, a large-scale, risk-matched population-based study has not been performed to evaluate differences in mortality and resource utilization. Data on identified premature (<37 weeks) and ELBW (<1000  g) infants with PDA (International Classification of Diseases, 9th revision, Clinical Modification, 747.0) and respiratory distress (769) were obtained from Kids' Inpatient Database (2003-2009). Overall, 12,470 cases were identified, with 3008 undergoing SL. Propensity score-matched analysis of 1620 SL versus 1584 non-SL found reduced mortality (15% vs 26%) and more routine disposition (48% vs 41%) for SL (P < 0.001). SL had longer length of stay and higher total cost (P < 0.001). On multivariate analysis, SL mortality predictors were necrotizing enterocolitis (NEC; surgical odds ratio, 5.95; medical odds ratio, 4.42) and sepsis (3.43) (P < 0.006). Length of stay increased with bronchopulmonary dysplasia (BPD; 1.77), whereas total cost increased with surgical NEC (1.82) and sepsis (1.26) (P < 0.04). Non-SL mortality predictors were NEC (surgical, 76.3; medical, 6.17), sepsis (2.66), and intraventricular hemorrhage (1.97) (P < 0.005). Length of stay increased with BPD (2.92) and NEC (surgical, 2.04; medical, 1.28) (P < 0.03). Total cost increased with surgical NEC (2.06), medical NEC (1.57), sepsis (1.43), and BPD (1.30) (P < 0.001). Propensity score-matched analysis demonstrates reduced mortality in premature/ELBW infants with SL for PDA. NEC and sepsis are predictors of mortality and resource utilization.

Infant Formula Feeding at Birth Is Common and Inversely Associated with Subsequent Breastfeeding Behavior in Vietnam123

PubMed Central

Nguyen, Tuan T; Withers, Mellissa; Hajeebhoy, Nemat; Frongillo, Edward A

2016-01-01

Background: The association between infant formula feeding at birth and subsequent feeding patterns in a low- or middle-income context is not clear. Objective: We examined the association of infant formula feeding during the first 3 d after birth with subsequent infant formula feeding and early breastfeeding cessation in Vietnam. Methods: In a cross-sectional survey, we interviewed 10,681 mothers with children aged 0−23 mo (mean age: 8.2 mo; 52% boys) about their feeding practices during the first 3 d after birth and on the previous day. We used stratified analysis, multiple logistic regression, propensity score-matching analysis, and structural equation modeling to minimize the limitation of the cross-sectional design and to ensure the consistency of the findings. Results: Infant formula feeding during the first 3 d after birth (50%) was associated with a higher prevalence of subsequent infant formula feeding [stratified analysis: 7−28% higher (nonoverlapping 95% CIs for most comparisons); propensity score-matching analysis: 13% higher (P < 0.001); multiple logistic regression: OR: 1.47 (95% CI: 1.30, 1.67)]. This practice was also associated with a higher prevalence of early breastfeeding cessation (e.g., <24 mo) [propensity score-matching analysis: 2% (P = 0.08); OR: 1.33 (95% CI: 1.12, 1.59)]. Structural equation modeling showed that infant formula feeding during the first 3 d after birth was associated with a higher prevalence of subsequent infant formula feeding (β: 0.244; P < 0.001), which in turn was linked to early breastfeeding cessation (β: 0.285; P < 0.001). Conclusions: Infant formula feeding during the first 3 d after birth was associated with increased subsequent infant formula feeding and the early cessation of breastfeeding, which underscores the need to make early, exclusive breastfeeding normative and to create environments that support it. PMID:27605404

Propensity Score Analysis of Radical Cystectomy Versus Bladder-Sparing Trimodal Therapy in the Setting of a Multidisciplinary Bladder Cancer Clinic.

PubMed

Kulkarni, Girish S; Hermanns, Thomas; Wei, Yanliang; Bhindi, Bimal; Satkunasivam, Raj; Athanasopoulos, Paul; Bostrom, Peter J; Kuk, Cynthia; Li, Kathy; Templeton, Arnoud J; Sridhar, Srikala S; van der Kwast, Theodorus H; Chung, Peter; Bristow, Robert G; Milosevic, Michael; Warde, Padraig; Fleshner, Neil E; Jewett, Michael A S; Bashir, Shaheena; Zlotta, Alexandre R

2017-07-10

Purpose Multidisciplinary management improves complex treatment decision making in cancer care, but its impact for bladder cancer (BC) has not been documented. Although radical cystectomy (RC) currently is viewed as the standard of care for muscle-invasive bladder cancer (MIBC), radiotherapy-based, bladder-sparing trimodal therapy (TMT) that combines transurethral resection of bladder tumor, chemotherapy for radiation sensitization, and external beam radiotherapy has emerged as a valid treatment option. In the absence of randomized studies, this study compared the oncologic outcomes between patients treated with RC or TMT by using a propensity score matched-cohort analysis. Methods Data from patients treated in a multidisciplinary bladder cancer clinic (MDBCC) from 2008 to 2013 were reviewed retrospectively. Those who received TMT for MIBC were identified and matched (for sex, cT and cN stage, Eastern Cooperative Oncology Group status, Charlson comorbidity score, treatment date, age, carcinoma in situ status, and hydronephrosis) with propensity scores to patients who underwent RC. Overall survival and disease-specific survival (DSS) were assessed with Cox proportional hazards modeling and a competing risk analysis, respectively. Results A total of 112 patients with MIBC were included after matching (56 who had been treated with TMT, and 56 who underwent RC). The median age was 68.0 years, and 29.5% had stage cT3/cT4 disease. At a median follow-up of 4.51 years, there were 20 deaths (35.7%) in the RC group (13 as a result of BC) and 22 deaths (39.3%) in the TMT group (13 as a result of BC). The 5-year DSS rate was 73.2% and 76.6% in the RC and TMT groups, respectively ( P = .49). Salvage cystectomy was performed in 6 (10.7%) of 56 patients who received TMT. Conclusion In the setting of a MDBCC, TMT yielded survival outcomes similar to those of matched patients who underwent RC. Appropriately selected patients with MIBC should be offered the opportunity to discuss various treatment options, including organ-sparing TMT.

The influence of prehospital systemic corticosteroid use on development of acute respiratory distress syndrome and hospital outcomes.

PubMed

Karnatovskaia, Lioudmila V; Lee, Augustine S; Gajic, Ognjen; Festic, Emir

2013-07-01

The role of systemic corticosteroids in pathophysiology and treatment of acute respiratory distress syndrome is controversial. Use of prehospital systemic corticosteroid therapy may prevent the development of acute respiratory distress syndrome and improve hospital outcomes. This is a preplanned retrospective subgroup analysis of the prospectively identified cohort from a trial by the U.S. Critical Illness and Injury Trials Group designed to validate the Lung Injury Prediction Score. Twenty-two acute care hospitals. : Five thousand eighty-nine patients with at least one risk factor for acute respiratory distress syndrome at the time of hospitalization. Propensity-based analysis of previously recorded data. Three hundred sixty-four patients were on systemic corticosteroids. Prevalence of acute respiratory distress syndrome was 7.7% and 6.9% (odds ratio, 1.1 [95% CI, 0.8-1.7]; p = 0.54) for patients on systemic corticosteroid and not on systemic corticosteroids, respectively. A propensity for being on systemic corticosteroids was derived through logistic regression by using all available covariates. Subsequently, 354 patients (97%) on systemic corticosteroids were matched to 1,093 not on systemic corticosteroids by their propensity score for a total of 1,447 patients in the matched set. Adjusted risk for acute respiratory distress syndrome (odds ratio, 0.96 [95% CI, 0.54-1.38]), invasive ventilation (odds ratio, 0.84 [95% CI, 0.62-1.12]), and in-hospital mortality (odds ratio, 0.97 [95% CI, 0.63-1.49]) was then calculated from the propensity-matched sample using conditional logistic regression model. No significant associations were present. Prehospital use of systemic corticosteroids neither decreased the development of acute respiratory distress syndrome among patients hospitalized with at one least risk factor, nor affected the need for mechanical ventilation or hospital mortality.

Does non-central nervous system tuberculosis increase the risk of ischemic stroke? A population-based propensity score-matched follow-up study.

PubMed

Wu, Chueh-Hung; Chen, Li-Sheng; Yen, Ming-Fang; Chiu, Yueh-Hsia; Fann, Ching-Yuan; Chen, Hsiu-Hsi; Pan, Shin-Liang

2014-01-01

Previous studies on the association between tuberculosis and the risk of developing ischemic stroke have generated inconsistent results. We therefore performed a population-based, propensity score-matched longitudinal follow-up study to investigate whether contracting non-central nervous system (CNS) tuberculosis leads to an increased risk of ischemic stroke. We used a logistic regression model that includes age, sex, pre-existing comorbidities and socioeconomic status as covariates to compute the propensity score. A total of 5804 persons with at least three ambulatory visits in 2001 with the principal diagnosis of non-CNS tuberculosis were enrolled in the tuberculosis group. The non-tuberculosis group consisted of 5804, propensity score-matched subjects without tuberculosis. The three-year ischemic stroke-free survival rates for these 2 groups were estimated using the Kaplan-Meier method. The stratified Cox proportional hazards regression was used to estimate the effect of tuberculosis on the occurrence of ischemic stroke. During three-year follow-up, 176 subjects in the tuberculosis group (3.0%) and 207 in the non-tuberculosis group (3.6%) had ischemic stroke. The hazard ratio for developing ischemic stroke in the tuberculosis group was 0.92 compared to the non-tuberculosis group (95% confidence interval: 0.73-1.14, P = 0.4299). Non-CNS tuberculosis does not increase the risk of subsequent ischemic stroke.

Hemiarch Reconstruction Vs Clamped Aortic Anastomosis for Concomitant Ascending Aortic Aneurysm.

PubMed

Sultan, Ibrahim; Bianco, Valentino; Yajzi, Ibrahim; Kilic, Arman; Dufendach, Keith; Cardounel, Arturo; Althouse, Andrew D; Masri, Ahmad; Navid, Forozan; Gleason, Thomas G

2018-05-03

Deep hypothermic circulatory arrest (DHCA) is often avoided in patients with concomitant ascending aortic pathology when treating other cardiac disease to avoid increased risk of morbidity and mortality. We hypothesized that the use of DHCA with retrograde cerebral perfusion (RCP) does not add incremental risk to ascending aortic replacement alone in the setting of concomitant cardiac surgery. 408 ascending aortic ± hemiarch replacements and aortic (root)/mitral/tricuspid valve(s), CABG, or MAZE procedures were performed for concomitant cardiac disease. DHCA with RCP was used for all hemiarch replacements or the ascending aorta was replaced with an aortic cross-clamp proximal to the innominate artery. Propensity-score matching was used to match similar ascending patients vs. hemiarch patients; the final propensity score matched patients on age, gender, BMI, previous heart surgery, pre-op aortic insufficiency, pre-op aortic stenosis, pre-op EF, and operative variables. Propensity-score matching yielded 116 pairs of Non-hemiarch patients vs. 116 hemiarch patients. Within the propensity-score matched cohort, there were no differences in postoperative stroke (1.7% vs. 3.4%, p = 0.41), new postoperative dialysis (6.0% vs. 5.2%, p = 0.78), postoperative renal insufficiency (27.6% vs. 19.8%, p = 0.16), 30-day mortality (2.6% vs. 3.4%, p = 0.701), or 1-year mortality (4.3% vs. 4.3%, p = 1.00) CONCLUSIONS: Hemiarch replacement using DHCA with RCP does not increase the risk of operative complications compared to a normothermic, clamped-distal aortic anastomosis, and therefore its use should not be limited when planning complex multi-procedural reconstructions during elective ascending thoracic aortic replacement with concomitant cardiac surgery. Copyright © 2018. Published by Elsevier Inc.

Positive association between hypertension and urinary bladder cancer: epidemiologic evidence involving 79,236 propensity score-matched individuals.

PubMed

Kok, Victor C; Zhang, Han-Wei; Lin, Chin-Teng; Huang, Shih-Chung; Wu, Ming-Feng

2018-06-18

We hypothesized that hypertensive patients harbor a higher risk of urinary bladder (UB) cancer. We performed a population-based cohort study on adults using a National Health Insurance Research Database (NHIRD) dataset. Hypertension and comparison non-hypertensive (COMP) groups comprising 39,618 patients each were propensity score-matched by age, sex, index date, and medical comorbidities. The outcome was incident UB cancer validated using procedure codes. We constructed multivariable Cox models to derive adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs). Cumulative incidence was compared using a log-rank test. During a total follow-up duration of 380,525 and 372,020 person-years in the hypertension and COMP groups, 248 and 186 patients developed UB cancer, respectively, representing a 32% increase in the risk (aHR, 1.32; 95% CI, 1.09-1.60). Hypertensive women harbored a significantly increased risk of UB cancer (aHR, 1.55; 95% CI, 1.12-2.13) compared with non-hypertensive women, whereas men with hypertension had a statistically non-significant increased risk (aHR, 1.22; 95% CI, 0.96-1.55). The sensitivity analysis demonstrated that the increased risk was sustained throughout different follow-up durations for the entire cohort; a statistical increase in the risk was also noted among hypertensive men. This nationwide population-based propensity score-matched cohort study supports a positive association between hypertension and subsequent UB cancer development.

Role of breastfeeding in childhood cognitive development: a propensity score matching analysis.

PubMed

Boutwell, Brian B; Beaver, Kevin M; Barnes, James C

2012-09-01

To examine whether the association between breastfeeding and childhood cognitive development is direct or whether the association is spurious owing to confounding variables. The current study conducted a propensity score matching (PSM) analysis using data from the Early Childhood Longitudinal Study, Birth Cohort.   The results of PSM models revealed that prior to matching, the association between breastfeeding and cognitive functioning was significant (mean difference = 3.20, t-value = 7.86, 95% confidence interval (CI) = 2.40-4.00, P ≤ 0.05). After controlling for a range of confounding factors, the mean difference was reduced by 40% (mean difference = 1.92, t-value = 3.75, 95% CI = 0.92-2.93, P ≤ 0.05); however, significant differences remained between groups. The results produced in the current study provide tentative evidence that breastfeeding may have an influence on the development of cognitive abilities in children. Additional research is necessary, however, in order to further evaluate the causal impact and exact developmental pathway of breastfeeding on childhood cognitive growth. © 2012 The Authors. Journal of Paediatrics and Child Health © 2012 Paediatrics and Child Health Division (Royal Australasian College of Physicians).

Advanced age does not affect abdominal wall reconstruction outcomes using acellular dermal matrix: A comparative study using propensity score analysis.

PubMed

Giordano, Salvatore; Schaverien, Mark; Garvey, Patrick B; Baumann, Donald P; Liu, Jun; Butler, Charles E

2017-06-01

We hypothesized that elderly patients (≥65 years) experience worse outcomes following abdominal wall reconstruction (AWR) for hernia or oncologic resection. We included all consecutive patients who underwent complex AWR using acellular dermal matrix (ADM) between 2005 and 2015. Propensity score analysis was performed for risk adjustment in multivariable analysis and for one-to-one matching. The primary outcome was hernia recurrence; the secondary outcomes included surgical site occurrence (SSO) and bulging. Mean follow-up for the 511 patients was 31.4 months; 184 (36%) patients were elderly. The elderly and non-elderly groups had similar rates of hernia recurrence (7.6% vs 10.1%, respectively; p = 0.43) and SSO (24.5% vs 23.5%, respectively; p = 0.82). Bulging occurred significantly more often in elderly patients (6.5% vs 2.8%, respectively; p = 0.04). After adjustment through the propensity score, which included 130 pairs, these results persisted. Contrary to our hypothesis, elderly patients did not have worse outcomes in AWR with ADM. Surgeons should not deny elderly patients AWR solely because of their age. Copyright © 2016 Elsevier Inc. All rights reserved.

Clinical outcome of statin plus ezetimibe versus high-intensity statin therapy in patients with acute myocardial infarction propensity-score matching analysis.

PubMed

Ji, Mi Seon; Jeong, Myung Ho; Ahn, Young Keun; Kim, Sang Hyung; Kim, Young Jo; Chae, Shung Chull; Hong, Taek Jong; Seong, In Whan; Chae, Jei Keon; Kim, Chong Jin; Cho, Myeong Chan; Rha, Seung-Woon; Bae, Jang Ho; Seung, Ki Bae; Park, Seung Jung

2016-12-15

It is unclear whether simvastatin-ezetimibe could be an alternative therapy to high-intensity statin therapy in high-risk patients. The aim of this study was to compare the clinical outcomes of simvastatin-ezetimibe and high-intensity statin therapy in patients with acute myocardial infarction (AMI), and especially in those with high-risk factor. A total of 3520 AMI patients in the KAMIR (Korea Acute Myocardial Infarction Registry) were classified into simvastatin-ezetimibe group (n=1249) and high-intensity statin group (n=2271). Multivariate analysis and propensity-score matching analysis were performed. The primary endpoint was major adverse cardiac events (MACE) at 12-months follow-up. In overall AMI patients, MACE occurred in 116 patients (9.3%) in simvastatin-ezetimibe group and 116 patients (5.1%) in high-intensity statin group. The difference in MACE between groups was driven by repeat revascularization (5.9% vs. 2.2%). After propensity matching analysis, simvastatin-ezetimibe was associated with a higher incidence of MACE than high-intensity statin therapy (adjusted hazard ratio: 3.090, 95% confidence interval: 1.715 to 5.566, p<0.001). However, in patients with high-risk factors, such as diabetes, old age, or heart failure, simvastatin-ezetimibe had similar incidence of MACE compared with high-intensity statin therapy in further adjusted analysis. In overall AMI patients, high-intensity statin therapy had better clinical outcomes than simvastatin-ezetimibe. However, in patients with high-risk factor, simvastatin-ezetimibe had comparable clinical outcomes to high-intensity statin therapy. Therefore, simvastatin-ezetimibe could be used as an alternative to high-intensity statin therapy in such patients. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Comparison of amlodipine versus other calcium channel blockers on blood pressure variability in hypertensive patients in China: a retrospective propensity score-matched analysis.

PubMed

Zhang, Lin; Yang, JinKui; Li, LanTing; Liu, DongDong; Xie, XiaoPing; Dong, Peng; Lin, Yong

2018-06-11

Reducing the fluctuation of blood pressure has recently been recognized as a potential target for improving management of hypertension to prevent cardiovascular events, particularly for strokes. Some randomized controlled trials demonstrated that amlodipine can effectively reduce blood pressure as a well-established, long-acting calcium channel blocker (CCB). However, few data are available for amlodipine on blood pressure variability (BPV) in China in a real-world setting. This study aimed to assess the effect of amlodipine versus other CCB antihypertensive agents on BPV. A retrospective propensity score-matched analysis was conducted, which retrieved the encounter data from 5582 hypertensive inpatients (with a median age of 69, female percentage of 48%, diastolic blood pressure ≥40 and <150 mmHg; systolic blood pressure (SBP) ≥70 mmHg and <260 mmHg), who had taken at least one antihypertensive agent and completed at least three SBP measurements during the visit. International Classification of Diseases was used to identify the hypertensive patients. BPV was calculated with standard deviation (SD) and coefficient of variation (CV) of SBP during a single inpatient visit. The Propensity Score Matching was used to balance the cohort of patients prescribed amlodipine or other CCBs. A series of appropriate statistical tests were applied to the propensity score-matched samples to examine the different effects on BPV. Additionally, the hypertensive patients with comorbidity such as coronary artery disease, diabetes mellitus, myocardial infarction, heart failure and chronic kidney disease were analyzed. For the hypertensive patients (n = 1756, for each cohort), patients prescribed amlodipine showed lower BPV than patients prescribed other CCBs (12.90 vs 13.76 mmHg, p < 0.05 [SD] and 9.47 vs 10.06, p < 0.05 [CV]). For the hypertensive patients with comorbidity (n = 1080, for each cohort), patients prescribed amlodipine had lower BPV than patients prescribed other CCBs as well (13.24 vs 14.23 mmHg, p < 0.05 [SD] and 9.66 vs 10.28, p < 0.05 [CV]). amlodipine was associated with lower BPV than other CCBs for both hypertensive patients and hypertensive patients with comorbidity.

A Propensity Score Matching Analysis of the Effects of Special Education Services

ERIC Educational Resources Information Center

Morgan, Paul L.; Frisco, Michelle L.; Farkas, George; Hibel, Jacob

2010-01-01

We sought to quantify the effectiveness of special education services as naturally delivered in U.S. schools. Specifically, we examined whether children receiving special education services displayed (a) greater reading or mathematics skills, (b) more frequent learning-related behaviors, or (c) less frequent externalizing or internalizing problem…

Impact of Inadequate Empirical Therapy on the Mortality of Patients with Bloodstream Infections: a Propensity Score-Based Analysis

PubMed Central

Retamar, Pilar; Portillo, María M.; López-Prieto, María Dolores; Rodríguez-López, Fernando; de Cueto, Marina; García, María V.; Gómez, María J.; del Arco, Alfonso; Muñoz, Angel; Sánchez-Porto, Antonio; Torres-Tortosa, Manuel; Martín-Aspas, Andrés; Arroyo, Ascensión; García-Figueras, Carolina; Acosta, Federico; Corzo, Juan E.; León-Ruiz, Laura; Escobar-Lara, Trinidad

2012-01-01

The impact of the adequacy of empirical therapy on outcome for patients with bloodstream infections (BSI) is key for determining whether adequate empirical coverage should be prioritized over other, more conservative approaches. Recent systematic reviews outlined the need for new studies in the field, using improved methodologies. We assessed the impact of inadequate empirical treatment on the mortality of patients with BSI in the present-day context, incorporating recent methodological recommendations. A prospective multicenter cohort including all BSI episodes in adult patients was performed in 15 hospitals in Andalucía, Spain, over a 2-month period in 2006 to 2007. The main outcome variables were 14- and 30-day mortality. Adjusted analyses were performed by multivariate analysis and propensity score-based matching. Eight hundred one episodes were included. Inadequate empirical therapy was administered in 199 (24.8%) episodes; mortality at days 14 and 30 was 18.55% and 22.6%, respectively. After controlling for age, Charlson index, Pitt score, neutropenia, source, etiology, and presentation with severe sepsis or shock, inadequate empirical treatment was associated with increased mortality at days 14 and 30 (odds ratios [ORs], 2.12 and 1.56; 95% confidence intervals [95% CI], 1.34 to 3.34 and 1.01 to 2.40, respectively). The adjusted ORs after a propensity score-based matched analysis were 3.03 and 1.70 (95% CI, 1.60 to 5.74 and 0.98 to 2.98, respectively). In conclusion, inadequate empirical therapy is independently associated with increased mortality in patients with BSI. Programs to improve the quality of empirical therapy in patients with suspicion of BSI and optimization of definitive therapy should be implemented. PMID:22005999

Which is the best antiaggregant or anticoagulant therapy after TAVI? A propensity-matched analysis from the ITER registry. The management of DAPT after TAVI.

PubMed

D'Ascenzo, Fabrizio; Benedetto, Umberto; Bianco, Matteo; Conrotto, Federico; Moretti, Claudio; D'Onofrio, Augusto; Agrifoglio, Marco; Colombo, Antonio; Ribichini, Flavio; Tarantini, Giuseppe; D'Amico, Maurizio; Salizzoni, Stefano; Rinaldi, Mauro

2017-12-08

The safety and efficacy of single vs. dual antiplatelet therapy (DAPT) in patients undergoing TAVI remain to be addressed. The aim of our study was to evaluate the usefulness of a DAPT compared to a single platelet therapy in patients undergoing TAVI with a balloon-expandable prosthesis. All consecutive patients enrolled in the ITER registry were included. Patients undergoing TAVI discharged with aspirin alone were compared to those taking DAPT before and after selection using propensity score with matching. Subgroup analysis was performed for those on OAT. Prosthetic heart valve dysfunction at follow-up was the primary endpoint, whereas all-cause death, cardiovascular death, bleedings, vascular complications and cerebrovascular accidents were the secondary ones. From 1,364 patients, after propensity score with matching, 605 were selected for each group (aspirin alone vs. DAPT). At 30 days, rates of VARC mortality were lower in patients with aspirin alone (1.5% vs. 4.1%, p=0.003), mainly driven by a reduction of major vascular complications (5.3% vs. 10.7%, p<0.001) and of major bleedings (6.6% vs. 11.5%, p<0.001), without a difference in prosthetic heart valve dysfunction after 45±14 months (2.8% vs. 3.0%, p=0.50). These results were confirmed on multivariable analysis. After TAVI with a balloon-expandable prosthesis, aspirin alone does not increase the risk of prosthetic valve dysfunction, and reduces the risk of periprocedural complications and of 30-day all-cause death.

Propensity Score Analysis Comparing Videothoracoscopic Lobectomy With Thoracotomy: A French Nationwide Study.

PubMed

Pagès, Pierre-Benoit; Delpy, Jean-Philippe; Orsini, Bastien; Gossot, Dominique; Baste, Jean-Marc; Thomas, Pascal; Dahan, Marcel; Bernard, Alain

2016-04-01

Video-assisted thoracoscopic surgery (VATS) lobectomy has recently become the recommended approach for stage I non-small cell lung cancer. However, these guidelines are not based on any large randomized control trial. Our study used propensity scores and a sensitivity analysis to compare VATS lobectomy with open thoracotomy. From 2005 to 2012, 24,811 patients (95.1%) were operated on by open thoracotomy and 1,278 (4.9%) by VATS. The end points were 30-day postoperative death, postoperative complications, hospital stay, overall survival, and disease-free survival. Two propensity scores analyses were performed: matching and inverse probability of treatment weighting, and one sensitivity analysis to unmask potential hidden bias. A subgroup analysis was performed to compare "high-risk" with "low-risk" patients. Results are reported by odds ratios or hazard ratios and their 95% confidence intervals. Postoperative death was not significantly reduced by VATS whatever the analysis. Concerning postoperative complications, VATS significantly decreased the occurrence of atelectasis and pneumopathy with both analysis methods, but there were no differences in the occurrence of other postoperative complications. VATS did not provide a benefit for high-risk patients. The VATS approach decreased the hospital length of stay from 2.4 days (95% confidence interval, -1.7 to -3 days) to -4.68 days (95% confidence interval, -8.5 to 0.9 days). Overall survival and disease-free survival were not influenced by the surgical approach. The sensitivity analysis showed potential biases. The results must be interpreted carefully because of the differences observed according to the propensity scores method used. A multicenter randomized controlled trial is necessary to limit the biases. Copyright © 2016 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Long-term consequences of adolescent parenthood among African-American urban youth: a propensity score matching approach.

PubMed

Assini-Meytin, Luciana C; Green, Kerry M

2015-05-01

The aim of this study was to improve understanding of long-term socioeconomic consequences of teen parenting for men and women. Analysis is based on the Woodlawn Study, a longitudinal study of an African-American cohort from a socially disadvantaged community in Chicago; data were collected at childhood (N = 1,242), adolescence (N = 705), young adulthood (age 32 years, N = 952), and midlife (age 42 years, N = 833). This analysis focused on the 1,050 individuals with data on teen parenting. We used propensity score matching to account for differences in background characteristics between teenage parents and their peers and used multiple imputation to account for differential attrition. The regression models after propensity score matching showed that at the age of 32 years, in comparison to nonteen mothers, teenage mothers were more likely to be unemployed, live in poverty, depend on welfare, and have earned a GED or completed high school compared to finishing college. At the age of 32 years, teen fathers were more likely to be without a job than nonteen fathers. At the age of 42 years, the effect of teen parenting for women remained statistically significant for education and income. There were no significant associations between teen parenting and outcomes for men at the age of 42 years. Socioeconomic consequences of teenage parenting among African-Americans from disadvantaged background seem to be primarily concentrated in women and persist throughout adulthood. In addition to promoting the delay of parenting after the teenage years, it is critical to provide programs at early stages in the life course to mitigate the negative socioeconomic consequences of teenage motherhood as effects for women are broad. Copyright © 2015 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Prehospital helicopter transport and survival of patients with traumatic brain injury.

PubMed

Bekelis, Kimon; Missios, Symeon; Mackenzie, Todd A

2015-03-01

To investigate the association of helicopter transport with survival of patients with traumatic brain injury (TBI), in comparison with ground emergency medical services (EMS). Helicopter utilization and its effect on the outcomes of TBI remain controversial. We performed a retrospective cohort study involving patients with TBI who were registered in the National Trauma Data Bank between 2009 and 2011. Regression techniques with propensity score matching were used to investigate the association of helicopter transport with survival of patients with TBI, in comparison with ground EMS. During the study period, there were 209,529 patients with TBI who were registered in the National Trauma Data Bank and met the inclusion criteria. Of these patients, 35,334 were transported via helicopters and 174,195 via ground EMS. For patients transported to level I trauma centers, 2797 deaths (12%) were recorded after helicopter transport and 8161 (7.8%) after ground EMS. Multivariable logistic regression analysis demonstrated an association of helicopter transport with increased survival [OR (odds ratio), 1.95; 95% confidence interval (CI), 1.81-2.10; absolute risk reduction (ARR), 6.37%]. This persisted after propensity score matching (OR, 1.88; 95% CI, 1.74-2.03; ARR, 5.93%). For patients transported to level II trauma centers, 1282 deaths (10.6%) were recorded after helicopter transport and 5097 (7.3%) after ground EMS. Multivariable logistic regression analysis demonstrated an association of helicopter transport with increased survival (OR, 1.81; 95% CI, 1.64-2.00; ARR 5.17%). This again persisted after propensity score matching (OR, 1.73; 95% CI, 1.55-1.94; ARR, 4.69). Helicopter transport of patients with TBI to level I and II trauma centers was associated with improved survival, in comparison with ground EMS.

Prehospital Helicopter Transport and Survival of Patients With Traumatic Brain Injury

PubMed Central

Mackenzie, Todd A.

2015-01-01

Objective To investigate the association of helicopter transport with survival of patients with traumatic brain injury (TBI), in comparison with ground emergency medical services (EMS). Background Helicopter utilization and its effect on the outcomes of TBI remain controversial. Methods We performed a retrospective cohort study involving patients with TBI who were registered in the National Trauma Data Bank between 2009 and 2011. Regression techniques with propensity score matching were used to investigate the association of helicopter transport with survival of patients with TBI, in comparison with ground EMS. Results During the study period, there were 209,529 patients with TBI who were registered in the National Trauma Data Bank and met the inclusion criteria. Of these patients, 35,334 were transported via helicopters and 174,195 via ground EMS. For patients transported to level I trauma centers, 2797 deaths (12%) were recorded after helicopter transport and 8161 (7.8%) after ground EMS. Multivariable logistic regression analysis demonstrated an association of helicopter transport with increased survival [OR (odds ratio), 1.95; 95% confidence interval (CI), 1.81–2.10; absolute risk reduction (ARR), 6.37%]. This persisted after propensity score matching (OR, 1.88; 95% CI, 1.74–2.03; ARR, 5.93%). For patients transported to level II trauma centers, 1282 deaths (10.6%) were recorded after helicopter transport and 5097 (7.3%) after ground EMS. Multivariable logistic regression analysis demonstrated an association of helicopter transport with increased survival (OR, 1.81; 95% CI, 1.64–2.00; ARR 5.17%). This again persisted after propensity score matching (OR, 1.73; 95% CI, 1.55–1.94; ARR, 4.69). Conclusions Helicopter transport of patients with TBI to level I and II trauma centers was associated with improved survival, in comparison with ground EMS. PMID:24743624

Night-eating syndrome and the severity of self-reported depressive symptoms from the Korea Nurses' Health Study: analysis of propensity score matching and ordinal regression.

PubMed

Kim, O-S; Kim, M S; Lee, J E; Jung, H

2016-12-01

The prevalence of night-eating syndrome (NES) and depression is increasing worldwide. Although nurses, in particular, are exposed to work in an environment of irregular eating, shift work, and stressful settings, limited research exist. In fact, the prevalence of NES among Korean nurses has never been reported. The aim of this study was to determine the prevalence of NES as well as the association between NES and severity of self-reported depressive symptoms among South Korean female nurses. The Korea Nurses' Health Study, following the protocols of the Nurses' Health Study led by the Harvard University, collected data on Korean female nurses. Survey responses from 3617 participants were included, and 404 responses were analyzed in this cross-sectional study using propensity score matching. Descriptive, Spearman's and Cramer's correlations, propensity score matching, and multivariable ordinal logistic regression were conducted as statistical analysis. The prevalence of both NES and self-reported depressive symptoms among Korean female nurses were higher compared with nurses in prior studies. Nurses with NES were 1.65 times more likely to have greater severity of depressive symptoms than those without NES (95% confidence interval [1.19-2.10], odds ratio = 1.65) after adjusting for covariates including sociodemographic characteristics, health behavioural factors, and shift work. This study suggests significant association between NES and the severity of self-reported depressive symptoms among Korean female nurses after adjusting for covariates. Policy makers and hospital managers need to develop strategies to reduce depression and NES among nurses for enhancement of nurses' mental and physical health as well as for improvement of care quality. Copyright © 2016 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

Facility Volume and Survival in Nasopharyngeal Carcinoma.

PubMed

Yoshida, Emi J; Luu, Michael; David, John M; Kim, Sungjin; Mita, Alain; Scher, Kevin; Shiao, Stephen L; Tighiouart, Mourad; Lee, Nancy Y; Ho, Allen S; Zumsteg, Zachary S

2018-02-01

Definitive treatment of nasopharyngeal carcinoma (NPC) is challenging owing to its rarity, complicated regional anatomy, and the intensity of therapy. In contrast to other head and neck cancers, the effect of facility volume has not been well described for NPC. The National Cancer Database was queried for patients with stage II-IVB NPC diagnosed from 2004 to 2014 and treated with definitive radiation. Patients with incomplete staging, unknown receipt or timing of treatment, unknown follow-up duration, incomplete socioeconomic information, or treatment outside the reporting facility were excluded. High-volume facilities (HVFs) were defined as the top 5% of facilities according to the annual facility volume. The present analysis included 3941 NPC patients treated at 804 facilities with a median follow-up duration of 59.4 months, including 1025 patients (26.0%) treated at HVFs. Treatment at HVFs was associated with significantly improved overall survival (OS) on multivariable analysis (hazard ratio 0.79, 95% confidence interval 0.69-0.90; P=.001). In propensity score-matched cohorts, 5-year OS was 69.1% versus 63.3% at HVFs versus lower volume facilities (LVFs), respectively (P=.003). Similar results were seen when facility volume was analyzed as a continuous variable. The effect of facility volume on survival varied by academic status (P=.002 for interaction). At academic centers, the propensity score-matched cohorts had 5-year OS of 71.4% compared with 62.4% (P<.001) at HVFs and LVFs, respectively. In contrast, the 5-year OS was 63.5% versus 67.9% (P=.68) in propensity score-matched patients at nonacademic HVFs and LVFs. Treatment at HVFs was associated with improved OS for patients with NPC, with the effect exclusively seen at academic centers. Copyright © 2017 Elsevier Inc. All rights reserved.

The effect of smoking on surgical outcomes in ventral hernia repair: a propensity score matched analysis of the National Surgical Quality Improvement Program data.

PubMed

Borad, N P; Merchant, A M

2017-12-01

Although studies have implicated smoking as a positive predictor of post-operative outcomes in inguinal hernia repair, its impact on ventral hernia repair (VHR) is not as clear. This study aims to fill this gap by investigating the impact of smoking on developing adverse 30-day post-operative outcomes in VHR. Patients undergoing VHR between 2005 and 2014 were extracted from the American College of Surgeons National Surgical Quality Improvement Program database. Patients were stratified by smoking status and compared for significant differences in baseline characteristics. Logistic regression modeled the impact of smoking on the primary outcome variable of 30-day mortality and the secondary outcome variables of 30-day overall, cardiac, respiratory, or wound morbidity. To evaluate the influence of smoking in comparable groups undergoing VHR, a propensity score matched analysis was performed. Out of 169,458 patients identified, 32,973 (19.5%) were classified as current smokers. Smokers and non/ex-smokers differed significantly in multiple pre-operative baseline characteristics. Unmatched univariate analyses revealed smoking status as a positive predictor of every post-operative outcome. These findings were validated with propensity score matching analyses, which found current smokers have an increased likelihood of 30-day mortality (OR 1.42), overall morbidity (OR 1.39), wound (OR 1.40), respiratory (OR 1.14), or cardiac morbidity (OR 1.88) compared to non/ex-smokers (p < 0.05 for all). Smoking is a modifiable risk factor with a detrimental impact on outcomes in patients undergoing ventral hernia repair. Delaying VHR and promoting smoking cessation prior to surgery may help reduce the odds of adverse 30-day post-operative outcomes.

Prognostic significance of normal-sized ovary in advanced serous epithelial ovarian cancer.

PubMed

Paik, E Sun; Kim, Ji Hye; Kim, Tae Joong; Lee, Jeong Won; Kim, Byoung Gie; Bae, Duk Soo; Choi, Chel Hun

2018-01-01

We compared survival outcomes of advanced serous type epithelial ovarian cancer (EOC) patients with normal-sized ovaries and enlarged-ovarian tumors by propensity score matching analysis. The medical records of EOC patients treated at Samsung Medical Center between 2002 and 2015 were reviewed retrospectively. We investigated EOC patients with high grade serous type histology and International Federation of Gynecology and Obstetrics (FIGO) stage IIIB, IIIC, or IV who underwent primary debulking surgery (PDS) and adjuvant chemotherapy to identify patients with normal-sized ovaries. Propensity score matching was performed to compare patients with normal-sized ovaries to patients with enlarged-ovarian tumors (ratio, 1:3) according to age, FIGO stage, initial cancer antigen (CA)-125 level, and residual disease status after PDS. Of the 419 EOC patients, 48 patients had normal-sized ovary. Patients with enlarged-ovarian tumor were younger (54.0±10.3 vs. 58.4±9.2 years, p=0.005) than those with normal-sized ovary, and there was a statistically significant difference in residual disease status between the 2 groups. In total cohort with a median follow-up period of 43 months (range, 3-164 months), inferior overall survival (OS) was shown in the normal-sized ovary group (median OS, 71.2 vs. 41.4 months; p=0.003). After propensity score matching, the group with normal-sized ovary showed inferior OS compared to the group with enlarged-ovarian tumor (median OS, 72.1 vs. 41.4 months; p=0.031). In multivariate analysis for OS, normal-sized ovary remained a significant factor. Normal-sized ovary was associated with poor OS compared with the common presentation of enlarged ovaries in EOC, independent of CA-125 level or residual disease. Copyright © 2018. Asian Society of Gynecologic Oncology, Korean Society of Gynecologic Oncology

Chronic Azithromycin Use in Cystic Fibrosis and Risk of Treatment-Emergent Respiratory Pathogens.

PubMed

Cogen, Jonathan D; Onchiri, Frankline; Emerson, Julia; Gibson, Ronald L; Hoffman, Lucas R; Nichols, David P; Rosenfeld, Margaret

2018-02-23

Azithromycin has been shown to improve lung function and reduce the number of pulmonary exacerbations in cystic fibrosis patients. Concerns remain, however, regarding the potential emergence of treatment-related respiratory pathogens. To determine if chronic azithromycin use (defined as thrice weekly administration) is associated with increased rates of detection of eight specific respiratory pathogens. We performed a new-user, propensity-score matched retrospective cohort study utilizing data from the Cystic Fibrosis Foundation Patient Registry. Incident azithromycin users were propensity-score matched 1:1 with contemporaneous non-users. Kaplan-Meier curves and Cox proportional hazards regression were used to evaluate the association between chronic azithromycin use and incident respiratory pathogen detection. Analyses were performed separately for each pathogen, limited to patients among whom that pathogen had not been isolated in the two years prior to cohort entry. After propensity score matching, mean age of the cohorts was ~12 years. Chronic azithromycin users had a significantly lower risk of detection of new methicillin-resistant Staphylococcus aureus, non-tuberculous mycobacteria, and Burkholderia cepacia complex compared to non-users. The risk of acquiring the remaining five pathogens was not significantly different between users and non-users. Using an innovative new-user, propensity-score matched study design to minimize indication and selection biases, we found in a predominantly pediatric cohort that chronic azithromycin users had a lower risk of acquiring several cystic fibrosis-related respiratory pathogens. These results may ease concerns that chronic azithromycin exposure increases the risk of acquiring new respiratory pathogens among pediatric cystic fibrosis patients.

Antegrade or Retrograde Cerebral Perfusion in Ascending Aorta and Hemiarch Surgery? A Propensity-Matched Analysis.

PubMed

Perreas, Konstantinos; Samanidis, George; Thanopoulos, Apostolis; Georgiopoulos, Georgios; Antoniou, Theofani; Khoury, Mazen; Michalis, Alkiviadis; Bairaktaris, Andreas

2016-01-01

Over the years, numerous options have been proposed for surgical management of ascending aorta and aortic arch pathology in an attempt to minimize postoperative morbidity and probability of death. We present a propensity score-matching analysis of 259 patients from a single unit who were operated on under deep hypothermic arrest with retrograde cerebral perfusion (DHCA/RCP) or moderate hypothermic circulatory arrest with selective antegrade cerebral perfusion (via common carotid artery) (MHCA/ACP). Between 2006 and 2014 a total of 259 consecutive patients underwent ascending aorta and hemiarch correction under HCA. DHCA/RCP and MHCA/ACP were performed on 207 and 52 patients, respectively. Baseline patient characteristics accounted for in the propensity matching were age, sex, acute aortic dissection, emergency operation, re-operation, preoperative hemodynamic instability, preoperative kidney injury, and CA time. After propensity scoring 40 pairs (80 patients) were successfully matched (p = 0.732). Outcomes were defined as the incidence of postoperative neurologic complications, 30-day mortality, and all-cause midterm mortality. Surgical procedure that involved the MHCA/ACP technique was associated with 76.5% decreased risk (risk ratio, 0.235; 95% CI, 0.079 to 0.699) of postoperative neurologic complications (p = 0.009). In addition to MHCA/ACP in surgical procedure for acute aortic dissection a relevant trend was established for 30-day mortality (risk ratio, 0.333; 95% CI, 0.09 to 1.23). For midterm all-cause mortality, MHCA/ACP modestly decreased the number of deaths (p = 0.0456) in comparison with the DHCA/RCP technique. MHCA/ACP in aortic arch surgical procedure is associated with a decreased risk of all types of neurologic complications and a trend toward decreased 30-day and midterm mortality in comparison with DHCA/RCP. Copyright © 2016 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Severe lymphopenia during neoadjuvant chemoradiation for esophageal cancer: A propensity matched analysis of the relative risk of proton versus photon-based radiation therapy.

PubMed

Shiraishi, Yutaka; Fang, Penny; Xu, Cai; Song, Juhee; Krishnan, Sunil; Koay, Eugene J; Mehran, Reza J; Hofstetter, Wayne L; Blum-Murphy, Mariela; Ajani, Jaffer A; Komaki, Ritsuko; Minsky, Bruce; Mohan, Radhe; Hsu, Charles C; Hobbs, Brian P; Lin, Steven H

2017-12-13

Circulating lymphocytes are exquisitely sensitive to radiation exposure, even to low scattered doses which can vary drastically between radiation modalities. We compared the relative risk of radiation-induced lymphopenia between intensity modulated radiation therapy (IMRT) or proton beam therapy (PBT) in esophageal cancer (EC) patients undergoing neoadjuvant chemoradiation therapy (nCRT). EC patients treated with IMRT and PBT were propensity matched based on key clinical variables. Treatment-associated lymphopenia was graded using CTCAE v.4.0. Using matched cohorts, univariate and multivariable multiple logistic regression was used to identify factors associated with increased risk of grade 4 lymphopenia as well as characterize their relative contributions. Among the 480 patients treated with nCRT, 136 IMRT patients were propensity score matched with 136 PBT patients. In the matched groups, a greater proportion of the IMRT patients (55/136, 40.4%) developed grade 4 lymphopenia during nCRT compared with the PBT patients (24/136, 17.6%, P < 0.0001). On multivariable analysis, PBT was significantly associated with a reduction in grade 4 lymphopenia risk (odds ratio, 0.29; 95% confidence interval, 0.16-0.52; P < 0.0001). PBT is associated with significant risk reduction in grade 4 lymphopenia during nCRT in esophageal cancer. Copyright © 2017 Elsevier B.V. All rights reserved.

Understanding Student Success and Institutional Outcomes in Service-Learning Coursework at a North Carolina Community College: A Propensity Score Study

ERIC Educational Resources Information Center

Marts, Jennifer Leigh

2016-01-01

Service-learning has roots deep in higher education. Community colleges and service-learning have an organic relationship as they both strive to represent and support their local communities. This study implemented propensity score matching to study the impact of service-learning on student outcomes for community college students. Much of the…

Propensity Scores in Pharmacoepidemiology: Beyond the Horizon.

PubMed

Jackson, John W; Schmid, Ian; Stuart, Elizabeth A

2017-12-01

Propensity score methods have become commonplace in pharmacoepidemiology over the past decade. Their adoption has confronted formidable obstacles that arise from pharmacoepidemiology's reliance on large healthcare databases of considerable heterogeneity and complexity. These include identifying clinically meaningful samples, defining treatment comparisons, and measuring covariates in ways that respect sound epidemiologic study design. Additional complexities involve correctly modeling treatment decisions in the face of variation in healthcare practice, and dealing with missing information and unmeasured confounding. In this review, we examine the application of propensity score methods in pharmacoepidemiology with particular attention to these and other issues, with an eye towards standards of practice, recent methodological advances, and opportunities for future progress. Propensity score methods have matured in ways that can advance comparative effectiveness and safety research in pharmacoepidemiology. These include natural extensions for categorical treatments, matching algorithms that can optimize sample size given design constraints, weighting estimators that asymptotically target matched and overlap samples, and the incorporation of machine learning to aid in covariate selection and model building. These recent and encouraging advances should be further evaluated through simulation and empirical studies, but nonetheless represent a bright path ahead for the observational study of treatment benefits and harms.

Assisted reproductive technology has no association with autism spectrum disorders: The Taiwan Birth Cohort Study.

PubMed

Lung, For-Wey; Chiang, Tung-Liang; Lin, Shio-Jean; Lee, Meng-Chih; Shu, Bih-Ching

2018-04-01

The use of assisted reproduction technology has increased over the last two decades. Autism spectrum disorders and assisted reproduction technology share many risk factors. However, previous studies on the association between autism spectrum disorders and assisted reproduction technology have shown inconsistent results. The purpose of this study was to investigate the association between assisted reproduction technology and autism spectrum disorder diagnosis in a national birth cohort database. Furthermore, the results from the assisted reproduction technology and autism spectrum disorder propensity score matching exact matched datasets were compared. For this study, the 6- and 66-month Taiwan Birth Cohort Study datasets were used (N = 20,095). In all, 744 families were propensity score matching exact matched and selected as the assisted reproduction technology sample (ratio of assisted reproduction technology to controls: 1:2) and 415 families as the autism spectrum disorder sample (ratio of autism spectrum disorder to controls: 1:4). Using a national birth cohort dataset, controlling for the confounding factors of assisted reproduction technology conception and autism spectrum disorder diagnosis, both assisted reproduction technology and autism spectrum disorder propensity score matching matched datasets showed the same results of no association between assisted reproduction technology and autism spectrum disorder. Further study on the detailed information regarding the processes and methods of assisted reproduction technology may provide us with more information on the association between assisted reproduction technology and autism spectrum disorder.

Five Steps to Successfully Implement and Evaluate Propensity Score Matching in Clinical Research Studies.

PubMed

Staffa, Steven J; Zurakowski, David

2018-01-09

In clinical research, the gold standard level of evidence is the randomized controlled trial (RCT). The availability of nonrandomized retrospective data is growing; however, a primary concern of analyzing such data is comparability of the treatment groups with respect to confounding variables. Propensity score matching (PSM) aims to equate treatment groups with respect to measured baseline covariates to achieve a comparison with reduced selection bias. It is a valuable statistical methodology that mimics the RCT, and it may create an "apples to apples" comparison while reducing bias due to confounding. PSM can improve the quality of anesthesia research and broaden the range of research opportunities. PSM is not necessarily a magic bullet for poor-quality data, but rather may allow the researcher to achieve balanced treatment groups similar to a RCT when high-quality observational data are available. PSM may be more appealing than the common approach of including confounders in a regression model because it allows for a more intuitive analysis of a treatment effect between 2 comparable groups.We present 5 steps that anesthesiologists can use to successfully implement PSM in their research with an example from the 2015 Pediatric National Surgical Quality Improvement Program: a validated, annually updated surgery and anesthesia pediatric database. The first step of PSM is to identify its feasibility with regard to the data at hand and ensure availability of data on any potential confounders. The second step is to obtain the set of propensity scores from a logistic regression model with treatment group as the outcome and the balancing factors as predictors. The third step is to match patients in the 2 treatment groups with similar propensity scores, balancing all factors. The fourth step is to assess the success of the matching with balance diagnostics, graphically or analytically. The fifth step is to apply appropriate statistical methodology using the propensity-matched data to compare outcomes among treatment groups.PSM is becoming an increasingly more popular statistical methodology in medical research. It often allows for improved evaluation of a treatment effect that may otherwise be invalid due to a lack of balance between the 2 treatment groups with regard to confounding variables. PSM may increase the level of evidence of a study and in turn increases the strength and generalizability of its results. Our step-by-step approach provides a useful strategy for anesthesiologists to implement PSM in their future research.

The Effect of Latent Binary Variables on the Uncertainty of the Prediction of a Dichotomous Outcome Using Logistic Regression Based Propensity Score Matching.

PubMed

Szekér, Szabolcs; Vathy-Fogarassy, Ágnes

2018-01-01

Logistic regression based propensity score matching is a widely used method in case-control studies to select the individuals of the control group. This method creates a suitable control group if all factors affecting the output variable are known. However, if relevant latent variables exist as well, which are not taken into account during the calculations, the quality of the control group is uncertain. In this paper, we present a statistics-based research in which we try to determine the relationship between the accuracy of the logistic regression model and the uncertainty of the dependent variable of the control group defined by propensity score matching. Our analyses show that there is a linear correlation between the fit of the logistic regression model and the uncertainty of the output variable. In certain cases, a latent binary explanatory variable can result in a relative error of up to 70% in the prediction of the outcome variable. The observed phenomenon calls the attention of analysts to an important point, which must be taken into account when deducting conclusions.

Confronting ‘confounding by health system use’ in Medicare Part D: Comparative effectiveness of propensity score approaches to confounding adjustment

PubMed Central

Polinski, Jennifer M.; Schneeweiss, Sebastian; Glynn, Robert J.; Lii, Joyce; Rassen, Jeremy

2012-01-01

Purpose Under Medicare Part D, patient characteristics influence plan choice, which in turn influences Part D coverage gap entry. We compared pre-defined propensity score (PS) and high-dimensional propensity score (hdPS) approaches to address such ‘confounding by health system use’ in assessing whether coverage gap entry is associated with cardiovascular events or death. Methods We followed 243,079 Medicare patients aged 65+ with linked prescription, medical, and plan-specific data in 2005–2007. Patients reached the coverage gap and were followed until an event or year’s end. Exposed patients were responsible for drug costs in the gap; unexposed patients (patients with non-Part D drug insurance and Part D patients receiving a low-income subsidy (LIS)) received financial assistance. Exposed patients were 1:1 PS- or hdPS-matched to unexposed patients. The PS model included 52 predefined covariates; the hdPS model added 400 empirically identified covariates. Hazard ratios for death and any of five cardiovascular outcomes were compared. In sensitivity analyses, we explored residual confounding using only LIS patients in the unexposed group. Results In unadjusted analyses, exposed patients had no greater hazard of death (HR=1.00; 95% CI, 0.84–1.20) or other outcomes. PS- (HR=1.29;0.99–1.66) and hdPS- (HR=1.11;0.86–1.42) matched analyses showed elevated but non-significant hazards of death. In sensitivity analyses, the PS analysis showed a protective effect (HR=0.78;0.61–0.98), while the hdPS analysis (HR=1.06;0.82–1.37) confirmed the main hdPS findings. Conclusion Although the PS-matched analysis suggested elevated though non-significant hazards of death among patients with no financial assistance during the gap, the hdPS analysis produced lower estimates that were stable across sensitivity analyses. PMID:22552984

Studying a Rare Disease Using Multi-Institutional Research Collaborations vs Big Data: Where Lies the Truth?

PubMed

Johnson, Aileen C; Ethun, Cecilia G; Liu, Yuan; Lopez-Aguiar, Alexandra G; Tran, Thuy B; Poultsides, George; Grignol, Valerie; Howard, J Harrison; Bedi, Meena; Gamblin, T Clark; Tseng, Jennifer; Roggin, Kevin K; Chouliaras, Konstantinos; Votanopoulos, Konstantinos; Cullinan, Darren; Fields, Ryan C; Delman, Keith A; Wood, William C; Cardona, Kenneth; Maithel, Shishir K

2018-06-12

Multi-institutional collaborations provide granularity lacking in epidemiologic datasets to enable in-depth study of rare diseases. For pts with superficial, high-grade soft tissue sarcomas (STS) of the trunk/extremity, the value of radiation therapy (RT) is not clear. We aimed to utilize the 7-institution US-Sarcoma-Collaborative (USSC) and the National Cancer Database (NCDB) to investigate this issue. All adult pts with superficial truncal/extremity high-grade STS who underwent primary curative-intent resection from 2000-2016 at USSC institutions or were included in the NCDB from 2004-2013 were analyzed. Propensity-score matching was performed. Endpoints were locoregional recurrence-free survival(LRFS), overall-survival(OS), and disease-specific survival(DSS). Of 4,153pts in the USSC, 169pts with superficial high-grade tumors underwent primary curative-intent resection, of whom 38% received RT. On multivariable Cox-regression analysis, RT was not associated with improved LRFS(p=0.56), OS(p=0.31), or DSS(p=0.20). On analysis of 51 propensity-score matched-pairs, RT was still not associated with increased LRFS, OS, or DSS. Analysis of 631 propensity-score matched-pairs in the NCDB demonstrated improved 5-yr OS associated with RT (80%vs70%;p=0.02). LRFS and DSS were not evaluable. Granular data afforded by collaborative research enables in-depth analysis of patient outcomes. The NCDB, although powered with large numbers, cannot assess many relevant outcomes (recurrence, DSS, or complications). In this study, the approaches yielded conflicting results. USSC data suggested no value of radiation while the NCDB demonstrated improved overall survival, contradicting all randomized-controlled trials in sarcoma. The pros/cons of either approach must be considered when applying results to clinical practice, and underscore the importance of randomized-controlled trials. Copyright © 2018. Published by Elsevier Inc.

Acute kidney injury and edaravone in acute ischemic stroke: the Fukuoka Stroke Registry.

PubMed

Kamouchi, Masahiro; Sakai, Hironori; Kiyohara, Yutaka; Minematsu, Kazuo; Hayashi, Kunihiko; Kitazono, Takanari

2013-11-01

A free radical scavenger, edaravone, which has been used for the treatment of ischemic stroke, was reported to cause acute kidney injury (AKI) as a fatal adverse event. The aim of the present study was to clarify whether edaravone is associated with AKI in patients with acute ischemic stroke. From the Fukuoka Stroke Registry database, 5689 consecutive patients with acute ischemic stroke who were hospitalized within 24 hours of the onset of symptoms were included in this study. A logistic regression analysis for the Fukuoka Stroke Registry cohort was done to identify the predictors for AKI. A propensity score-matched nested case-control study was also performed to elucidate any association between AKI and edaravone. Acute kidney injury occurred in 128 of 5689 patients (2.2%) with acute ischemic stroke. A multivariate analysis revealed that the stroke subtype, the basal serum creatinine level, and the presence of infectious complications on admission were each predictors of developing AKI. In contrast, a free radical scavenger, edaravone, reduced the risk of developing AKI (multivariate-adjusted odds ratio [OR] .45, 95% confidence interval [CI] .30-.67). Propensity score-matched case-control study confirmed that edaravone use was negatively associated with AKI (propensity score-adjusted OR .46, 95% CI .29-.74). Although AKI has a significant impact on the clinical outcome of hospital inpatients, edaravone has a protective effect against the development of AKI in patients with acute ischemic stroke. Copyright © 2013 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Root replacement using stentless valves in the small aortic root: a propensity score analysis.

PubMed

Kunihara, Takashi; Schmidt, Kathrin; Glombitza, Petra; Dzindzibadze, Vachtang; Lausberg, Henning; Schäfers, Hans-Joachim

2006-10-01

Root replacement using a stentless bioprosthesis may be the optimal approach to avoid patient-prosthesis mismatch in patients with a small aortic root. Primary root replacement, however, is considered to be associated with increased surgical risk. We compared early outcome of full root replacement with a stentless bioprosthesis with that of aortic valve replacement with a stented bioprosthesis using propensity score-matching analysis. Of 231 patients undergoing elective, first-time aortic valve replacement with a small root (< or = 22 mm), 120 patients were selected using propensity score-matching analysis. They underwent either root replacement using a 23-mm stentless bioprosthesis (stentless group, n = 60) or supra-annular aortic valve replacement using a 21-mm stented bioprosthesis (stented group, n = 60). Preoperative characteristics and frequency of concomitant operations were identical. Duration of operation (196 +/- 54 versus 174 +/- 49 minutes), cardiopulmonary bypass (112 +/- 36 versus 91 +/- 33 minutes), and aortic cross-clamping (76 +/- 21 versus 61 +/- 21 minutes) were significantly longer in the stentless group. However, the need for perioperative transfusion and the incidence of postoperative reexploration for bleeding (3% versus 8%) was lower, and ventilation time was shorter. Mean duration of intensive care and hospital stay were also significantly shorter (2.3 +/- 1.7 versus 4.0 +/- 3.9 days, 8.9 +/- 3.1 versus 12.4 +/- 5.7 days). In-hospital mortality was identical (5% each). No independent predictor for in-hospital mortality was identified. Full root replacement using a stentless bioprosthesis does not increase postoperative morbidity or mortality of aortic valve replacement and may be advantageous in patients with a small aortic root.

Efficacy of the treatment of transarterial chemoembolization combined with radiotherapy for hepatocellular carcinoma with portal vein tumor thrombus: A propensity score analysis.

PubMed

Li, Xiao-Long; Guo, Wei-Xing; Hong, Xiao-Dong; Yang, Liang; Wang, Kang; Shi, Jie; Li, Nan; Wu, Meng-Chao; Cheng, Shu-Qun

2016-10-01

The survival outcome of patients with unresectable hepatocellular carcinoma (HCC) with portal vein tumor thrombus (PVTT) who received transarterial chemoembolization (TACE) combined with radiotherapy (RT) remains unclear. A total of 112 and 735 HCC patients with PVTT undergoing TACE combined with RT and TACE alone, respectively, were evaluated. One hundred and eight pairs of matched patients were selected from each treatment arm by using a propensity score matching (PSM) analysis. Of the whole study population, TACE combined with RT showed significant survival benefits compared with TACE in all patients (median survival, 11.0 vs 4.8 months; P < 0.001), especially in patients with PVTT involving the right/left portal vein (median survival, 12.5 vs 5.2 months; P < 0.001) and main portal vein trunk (median survival, 8.9 vs 4.3 months; P < 0.001). After one-to-one PSM, 108 pairs of matched patients were selected for further analysis. In the propensity model, the median survival time was 10.9 versus 4.1 months (P < 0.001) in all patients, 12.5 versus 4.4 months (P = 0.002) in patients with PVTT involving the right/left portal vein and 8.9 versus 4.0 months (P < 0.001) in patients with PVTT involving the main portal vein trunk. The treatment, maximum lesion diameter and main trunk PVTT were the independent prognostic factors for survival at uni- and multivariate analysis. TACE combined with RT provides a significantly better survival outcome than TACE for unresectable HCC patients with PVTT, especially for patients with PVTT involving the right/left portal vein or main trunk. © 2016 The Japan Society of Hepatology.

Effects of a Self-Exercise Program on Activities of Daily Living in Patients After Acute Stroke: A Propensity Score Analysis Based on the Japan Association of Rehabilitation Database.

PubMed

Shiraishi, Nariaki; Suzuki, Yusuke; Matsumoto, Daisuke; Jeong, Seungwon; Sugiyama, Motoya; Kondo, Katsunori

2017-03-01

To investigate whether self-exercise programs for patients after stroke contribute to improved activities of daily living (ADL) at hospital discharge. Retrospective, observational, propensity score (PS)-matched case-control study. General hospitals. Participants included patients after stroke (N=1560) hospitalized between January 3, 2006, and December 26, 2012, satisfying the following criteria: (1) data on age, sex, duration from stroke to hospital admission, length of stay, FIM score, modified Rankin Scale (mRS) score, Glasgow Coma Scale score, Japan Stroke Scale score, and self-exercise program participation were available; and (2) admitted within 7 days after stroke onset, length of stay was between 7 and 60 days, prestroke mRS score was ≤2, and not discharged because of FIM or mRS exacerbation. A total of 780 PS-matched pairs were selected for each of the self-exercise program and no-self-exercise program groups. Self-exercise program participation. At discharge, FIM motor score, FIM cognitive score, FIM motor score gain (discharge value - admission value), FIM motor score gain rate (gain/length of stay), a binary variable divided by the median FIM motor score gain rate (high efficiency or no-high efficiency), and mRS score. Patients were classified into a self-exercise program (n=780) or a no-self-exercise program (n=780) group. After matching, there were no significant between-group differences, except motor system variables. The receiver operating characteristic curve for PS had an area under the curve value of .71 with a 95% confidence interval of .68 to .73, and the model was believed to have a relatively favorable fit. A logistic regression analysis of PS-matched pairs suggested that the self-exercise program was effective, with an overall odds ratio for ADL (high efficiency or no-high efficiency) of 2.2 (95% confidence ratio, 1.75-2.70). SEPs may contribute to improving ADL. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Marital Dissolution and Major Depression in Midlife: A Propensity Score Analysis.

PubMed

Sbarra, David A; Emery, Robert E; Beam, Christopher R; Ocker, Bailey L

2014-05-01

Marital dissolution is commonly assumed to cause increased depression among adults, but causality can be questioned based on directionality and third variable concerns. The present study improves upon past research by using a propensity score matching algorithm to identify a sub-sample of continuously married participants equivalent in divorce risk to participants who actually experienced separation/divorce between two waves of the nationally representative study, Midlife Development in the United States (MIDUS). After correcting for participants' propensity to separate/divorce, increased rates of depression at the second assessment were observed only among participants who were (a) depressed at the initial assessment, and (b) experienced a separation/divorce. Participants who were not depressed at the initial assessment but who experienced a separation/divorce were not at increased risk for a later major depressive disorder (MDE). Thus, both social selection and social causation contribute to the increased risk for a MDE found among separated/divorced adults.

A Two-Step Bayesian Approach for Propensity Score Analysis: Simulations and Case Study

ERIC Educational Resources Information Center

Kaplan, David; Chen, Jianshen

2012-01-01

A two-step Bayesian propensity score approach is introduced that incorporates prior information in the propensity score equation and outcome equation without the problems associated with simultaneous Bayesian propensity score approaches. The corresponding variance estimators are also provided. The two-step Bayesian propensity score is provided for…

Drawing causal inferences using propensity scores: a practical guide for community psychologists.

PubMed

Lanza, Stephanie T; Moore, Julia E; Butera, Nicole M

2013-12-01

Confounding present in observational data impede community psychologists' ability to draw causal inferences. This paper describes propensity score methods as a conceptually straightforward approach to drawing causal inferences from observational data. A step-by-step demonstration of three propensity score methods-weighting, matching, and subclassification-is presented in the context of an empirical examination of the causal effect of preschool experiences (Head Start vs. parental care) on reading development in kindergarten. Although the unadjusted population estimate indicated that children with parental care had substantially higher reading scores than children who attended Head Start, all propensity score adjustments reduce the size of this overall causal effect by more than half. The causal effect was also defined and estimated among children who attended Head Start. Results provide no evidence for improved reading if those children had instead received parental care. We carefully define different causal effects and discuss their respective policy implications, summarize advantages and limitations of each propensity score method, and provide SAS and R syntax so that community psychologists may conduct causal inference in their own research.

Drawing Causal Inferences Using Propensity Scores: A Practical Guide for Community Psychologists

PubMed Central

Lanza, Stephanie T.; Moore, Julia E.; Butera, Nicole M.

2014-01-01

Confounding present in observational data impede community psychologists’ ability to draw causal inferences. This paper describes propensity score methods as a conceptually straightforward approach to drawing causal inferences from observational data. A step-by-step demonstration of three propensity score methods – weighting, matching, and subclassification – is presented in the context of an empirical examination of the causal effect of preschool experiences (Head Start vs. parental care) on reading development in kindergarten. Although the unadjusted population estimate indicated that children with parental care had substantially higher reading scores than children who attended Head Start, all propensity score adjustments reduce the size of this overall causal effect by more than half. The causal effect was also defined and estimated among children who attended Head Start. Results provide no evidence for improved reading if those children had instead received parental care. We carefully define different causal effects and discuss their respective policy implications, summarize advantages and limitations of each propensity score method, and provide SAS and R syntax so that community psychologists may conduct causal inference in their own research. PMID:24185755

One-year clinical outcomes of patients treated with everolimus-eluting bioresorbable vascular scaffolds versus everolimus-eluting metallic stents: a propensity score comparison of patients enrolled in the ABSORB EXTEND and SPIRIT trials.

PubMed

de Ribamar Costa, José; Abizaid, Alexandre; Bartorelli, Antonio L; Whitbourn, Robert; Jepson, Nigel; Perin, Marco; Steinwender, Clemens; Stuteville, Marrianne; Ediebah, Divine; Sudhir, Krishnankutty; Serruys, Patrick W

2016-11-20

We sought to compare the outcomes of low/moderate complexity patients treated with the Absorb BVS from the ABSORB EXTEND trial with patients treated with the XIENCE everolimus-eluting stent (EES), using propensity score (PS) matching of pooled data from the SPIRIT trials (SPIRIT II, SPIRIT III, SPIRIT IV) and the XIENCE V USA trial. ABSORB EXTEND was a prospective, single-arm, open-label clinical study in which 812 patients were enrolled at 56 sites. This study allowed the treatment of lesions ≤28 mm in length and with a reference vessel diameter of 2.0-3.8 mm (as assessed by online QCA). The propensity score was obtained by fitting a logistic regression model with the cohort indicator as the binary outcome and other variables as the predictor variables. At one-year clinical follow-up, there was no statistical difference between groups with regard to MACE (5.0% vs. 4.8%, p=0.83), target lesion failure (5.0% vs. 4.7%, p=0.74), ischaemia-driven target vessel revascularisation (2.3% vs. 3.0%, p=0.38) and device thrombosis (1.0% vs. 0.3%, p=0.11). Myocardial infarction was higher with Absorb (3.3% vs. 1.5%, p=0.02), at the expense of periprocedural CK-MB elevation. Independent predictors of MACE among patients receiving Absorb BVS were treatment of multivessel disease, insulin-dependent diabetes and performance of post-dilation. At one-year follow-up, propensity score-matched analysis demonstrated that the clinical safety and effectiveness of Absorb are comparable to those of XIENCE EES among non-complex patients treated with PCI.

Decompressive craniectomy or medical management for refractory intracranial hypertension: an AAST-MIT propensity score analysis.

PubMed

Nirula, Ram; Millar, D; Greene, Tom; McFadden, Molly; Shah, Lubdha; Scalea, Thomas M; Stein, Deborah M; Magnotti, Louis J; Jurkovich, Gregory J; Vercruysse, Gary; Demetriades, Demetrios; Scherer, Lynette A; Peitzman, Andrew; Sperry, Jason; Beauchamp, Kathryn; Bell, Scott; Feiz-Erfan, Iman; O'Neill, Patrick; Coimbra, Raul

2014-04-01

Moderate/severe traumatic brain injury (TBI) management involves minimizing cerebral edema to maintain brain oxygen delivery. While medical therapy (MT) consisting of diuresis, hyperosmolar therapy, ventriculostomy, and barbiturate coma is the standard of care, decompressive craniectomy (DC) for refractory intracranial hypertension (ICH) has gained renewed interest. Since TBI treatment guidelines consider DC a second-tier intervention after MT failure, we sought to determine if early DC (<48 hours) was associated with improved survival in patients with refractory ICH. Eleven Level 1 trauma centers provided clinical data and head computed tomographic scans for patients with a Glasgow Coma Scale (GCS) score of 13 or less and radiographic evidence of TBI excluding deaths within 48 hours. Computed tomographic scans were graded according to the Marshall classification. A propensity score to receive DC (regardless of whether DC was performed) was calculated for each patient based on patient characteristics, physiology, injury severity, GCS, severity of intracranial injury, and treatment center. Patients who actually received a DC were matched to patients with similar propensity scores who received MT for analysis. Outcomes were compared between early (<48 hours of injury) primary or secondary DC and matched controls and then between early primary DC only and matched controls. There were 2,602 patients who met the inclusion criteria ,of whom 264 (10.1%) received DC (either primary or secondary to another cranial procedure) and 109 (5%) had a DC that was primary. Variables associated with performing a DC included sex, race, intracranial pressure monitor placement, in-house trauma attending, traumatic subarachnoid hemorrhage, midline shift, and basal cistern compression. There was no survival benefit with early primary DC compared with the controls (relative risk, 1.07; 95% confidence interval, 0.67-1.73; p = 0.77), and resource use was higher. Early DC does not seem to significantly improve mortality in patients with refractory ICH compared with MT. Neurosurgeons should pause before entertaining this resource-demanding form of therapy. Therapeutic care/management, level III.

Healthy Choices for Every Body Adult Curriculum Improves Participants' Food Resource Management Skills and Food Safety Practices.

PubMed

Adedokun, Omolola A; Plonski, Paula; Jenkins-Howard, Brooke; Cotterill, Debra B; Vail, Ann

2018-06-01

To evaluate the impact of the University of Kentucky's Healthy Choices for Every Body (HCEB) adult nutrition education curriculum on participants' food resource management (FRM) skills and food safety practices. A quasi-experimental design was employed using propensity score matching to pair 8 intervention counties with 8 comparison counties. Independent-samples t tests and ANCOVA models compared gains in FRM skills and food safety practices between the intervention and comparison groups (n = 413 and 113, respectively). Propensity score matching analysis showed a statistical balance and similarities between the comparison and intervention groups. Food resource management and food safety gain scores were statistically significantly higher for the intervention group (P < .001), with large effect sizes (d = 0.9) for both variables. The group differences persisted even after controlling for race and age in the ANCOVA models. The HCEB curriculum was effective in improving the FRM skills and food safety practices of participants. Copyright © 2018 Society for Nutrition Education and Behavior. Published by Elsevier Inc. All rights reserved.

Venous thromboembolism after induced abortion: a population-based, propensity-score-matched cohort study in Canada.

PubMed

Liu, Ning; Vigod, Simone N; Farrugia, M Michèle; Urquia, Marcelo L; Ray, Joel G

2018-06-08

A woman's risk of venous thromboembolism during pregnancy is estimated to be two-to-six times higher than her risk when she is not pregnant. Such risk estimates are largely based on pregnancies that result in delivery of a newborn baby; no estimates exist for the risk of venous thromboembolism after induced abortion, another common pregnancy outcome. To fill this knowledge gap, we aimed to assess the risk of venous thromboembolism in women whose first pregnancy ended with induced abortion. We did this propensity score-matched cohort study using data from the universal health-care system of Ontario, Canada. We included primigravid women who had an induced abortion between Jan 1, 2003, and Dec 31, 2015, and used a propensity score to match them to primigravid women who had a livebirth (1:1) or nulligravid women who were not pregnant on the procedure date of their matched counterpart and who did not conceive within 1 year afterwards (5:1). We excluded from our analysis women younger than 15 years or older than 49 years and individuals who had missing or invalid information about their sex, area of residence, residential income, or world region of origin. The primary outcome was risk of any venous thromboembolism within 42 days of the index date (defined as the date of an induced abortion, delivery date for livebirth, or for non-pregnant women the induced abortion date of their matched counterpart). We compared the rate of venous thromboembolism in primigravid women who had an induced abortion with the rate of venous thromboembolism in propensity-score-matched non-pregnant women and propensity-score-matched primigravid women whose pregnancy ended with a livebirth. We generated hazard ratios (HRs) of 42-day risk of venous thromboembolism after induced abortion using Cox proportional hazard models. We identified 194 086 eligible women whose first pregnancy ended with induced abortion, of whom 176 001 (90·7%) could be matched with women whose first pregnancy ended in delivery of a newborn. These 176 001 women were also matched to 880 005 non-pregnant women. The rate of venous thromboembolism within 42 days of an induced abortion was 30·1 (95% CI 22·0-38·2) per 100 000 women compared with 13·5 (11·1-16·0) per 100 000 women in the non-pregnant group (HR 2·23, 95% CI 1·61-3·08). The HR was 0·16 (95% CI 0·12-0·22) when compared with the women in the livebirth cohort, whose venous thromboembolism rate within 42 days postpartum was 184·7 (95% CI 164·6-204·7) per 100 000 women. The 42-day risk of venous thromboembolism after an induced abortion is double that of a matched non-pregnant woman, and is significantly lower than after a livebirth. This novel information can inform estimates of peri-procedural risk of venous thromboembolism after induced abortion. Clinicians could consider a lower threshold for ordering a diagnostic test to rule out venous thromboembolism after induced abortion than they would in a non-pregnant woman. Institute for Clinical Evaluative Sciences. Copyright © 2018 Elsevier Ltd. All rights reserved.

The Impact of Undergraduate Debt on the Graduate School Enrollment of STEM Baccalaureates

ERIC Educational Resources Information Center

Malcom, Lindsey E.; Dowd, Alicia C.

2012-01-01

While student loans provide college opportunity for many, undergraduate student debt resulting from typical and heavy borrowing hinders future investments in human capital. Propensity score matching analysis of the NSF's 2003 National Survey of Recent College Graduates demonstrates that debt negatively affects the graduate school enrollment of…

A Comparative Analysis of Recidivism with Propensity Score Matching of Informal and Formal Juvenile Probationers

ERIC Educational Resources Information Center

Onifade, Eyitayo; Wilkins, Jeffrey; Davidson, William; Campbell, Christina; Petersen, Jodi

2011-01-01

Given service costs and evidence suggesting mixing young offenders of different risk levels increases recidivism, this study determined the extent to which differential disposition and risk determined subsequent recidivism. Furthermore, this study entailed a comparison of offense outcomes for informal probationers (n = 581) and formal probationers…

Republication of "A Propensity Score Matching Analysis of the Effects of Special Education Services"

ERIC Educational Resources Information Center

Morgan, Paul L.; Frisco, Michelle L.; Farkas, George; Hibel, Jacob

2017-01-01

Since the landmark enactment of Education of the Handicapped Act in 1975, special education supports and services have been provided to children with disabilities. Although costly, the intentionality of these specialized services has been to advance the educational and societal opportunities of children with disabilities as they progress to…

Student Employment and Persistence: Evidence of Effect Heterogeneity of Student Employment on College Dropout

ERIC Educational Resources Information Center

Choi, Yool

2018-01-01

This study explores how student employment affects college persistence and how these effects differ by individual likelihood of participating in student employment. I analyze data from the National Longitudinal Survey of Youth 1997 using propensity score matching and stratification-multilevel analysis. This study finds that engaging in intense…

Effectiveness of the polysaccharide hemostatic powder in non-variceal upper gastrointestinal bleeding: Using propensity score matching.

PubMed

Park, Jun Chul; Kim, Yeong Jin; Kim, Eun Hye; Lee, Jinae; Yang, Hyun Su; Kim, Eun Hwa; Hahn, Kyu Yeon; Shin, Sung Kwan; Lee, Sang Kil; Lee, Yong Chan

2018-02-07

Recently, the application of hemostatic powder to the bleeding site has been used to treat active upper gastrointestinal bleeding (UGIB). We aimed to assess the effectiveness of the polysaccharide hemostatic powder (PHP) in patients with non-variceal UGIB. We reviewed prospectively collected 40 patients with UGIB treated with PHP therapy between April 2016 and January 2017 (PHP group) and 303 patients with UGIB treated with conventional therapy between April 2012 and October 2014 (conventional therapy group). We compared the rate of successful hemostasis and the rebleeding between the two groups after as well as before propensity score matching using the Glasgow-Blatchford score and Forrest classification. Thirty patients treated with the PHP and 60 patients treated with conventional therapy were included in the matched groups. Baseline patient characteristics including comorbidities, vital signs, and bleeding scores were similar in the matched groups. The rate of immediate hemostasis and 7-day and 30-day rebleeding were also similar in the two groups before and after matching. In the subgroup analysis, no significant differences in immediate hemostasis or rebleeding rate were noted between PHP in monotherapy and PHP combined with a conventional hemostatic method. At 30 days after the therapy, there were no significant PHP-related complications or mortality. Given its safety, the PHP proved feasible for endoscopic treatment of UGIB, having similar effectiveness as that of conventional therapy. The PHP may become a promising hemostatic method for non-variceal UGIB. © 2018 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.

Role of liver-directed local tumor therapy in the management of hepatocellular carcinoma with extrahepatic metastases: a SEER database analysis.

PubMed

Abdel-Rahman, Omar

2017-02-01

This study assessed the prognostic impact of the liver-directed local tumor therapy in the management of hepatocellular carcinoma (HCC) with extrahepatic metastases. Metastatic HCC patients diagnosed between 2004 and 2013 were identified from the SEER (Surveillance, Epidemiology, and End Results) database. Propensity-matched analysis was performed considering baseline characteristics (age, gender, race, histology, TNM stage, site of metastases, fibrosis score and alpha fetoprotein). A total of 2529 patients were identified. The median age was 65 years, and 151 patients received liver-directed local treatment (either surgical treatment or local destructive treatment). Both before and after propensity score matching, cancer-specific and overall survival (p < 0.0001 for all) were better in the liver-directed local therapy group. When the overall survival was stratified by the type of local treatment (surgical resection versus destructive treatment), both types of treatment improved overall survival (p < 0.0001 for both). In multivariate analysis of the matched population, the only factor correlated with better survival receiving is local therapy (p < 0.0001). This analysis suggests that liver-directed local treatment may play a role -in addition to systemic treatment- in the management of selected patients with metastatic HCC. Further prospective randomized controlled trials are needed to confirm or deny this hypothesis.

Management of Severe Pancreatic Fistula After Pancreatoduodenectomy

PubMed Central

Smits, F. Jasmijn; van Santvoort, Hjalmar C.; Besselink, Marc G.; Batenburg, Marilot C. T.; Slooff, Robbert A. E.; Boerma, Djamila; Busch, Olivier R.; Coene, Peter P. L. O.; van Dam, Ronald M.; van Dijk, David P. J.; van Eijck, Casper H. J.; Festen, Sebastiaan; van der Harst, Erwin; de Hingh, Ignace H. J. T.; de Jong, Koert P.; Tol, Johanna A. M. G.; Borel Rinkes, Inne H. M.

2017-01-01

Importance Postoperative pancreatic fistula is a potentially life-threatening complication after pancreatoduodenectomy. Evidence for best management is lacking. Objective To evaluate the clinical outcome of patients undergoing catheter drainage compared with relaparotomy as primary treatment for pancreatic fistula after pancreatoduodenectomy. Design, Setting, and Participants A multicenter, retrospective, propensity-matched cohort study was conducted in 9 centers of the Dutch Pancreatic Cancer Group from January 1, 2005, to September 30, 2013. From a cohort of 2196 consecutive patients who underwent pancreatoduodenectomy, 309 patients with severe pancreatic fistula were included. Propensity score matching (based on sex, age, comorbidity, disease severity, and previous reinterventions) was used to minimize selection bias. Data analysis was performed from January to July 2016. Exposures First intervention for pancreatic fistula: catheter drainage or relaparotomy. Main Outcomes and Measures Primary end point was in-hospital mortality; secondary end points included new-onset organ failure. Results Of the 309 patients included in the analysis, 209 (67.6%) were men, and mean (SD) age was 64.6 (10.1) years. Overall in-hospital mortality was 17.8% (55 patients): 227 patients (73.5%) underwent primary catheter drainage and 82 patients (26.5%) underwent primary relaparotomy. Primary catheter drainage was successful (ie, survival without relaparotomy) in 175 patients (77.1%). With propensity score matching, 64 patients undergoing primary relaparotomy were matched to 64 patients undergoing primary catheter drainage. Mortality was lower after catheter drainage (14.1% vs 35.9%; P = .007; risk ratio, 0.39; 95% CI, 0.20-0.76). The rate of new-onset single-organ failure (4.7% vs 20.3%; P = .007; risk ratio, 0.15; 95% CI, 0.03-0.60) and new-onset multiple-organ failure (15.6% vs 39.1%; P = .008; risk ratio, 0.40; 95% CI, 0.20-0.77) were also lower after primary catheter drainage. Conclusions and Relevance In this propensity-matched cohort, catheter drainage as first intervention for severe pancreatic fistula after pancreatoduodenectomy was associated with a better clinical outcome, including lower mortality, compared with primary relaparotomy. PMID:28241220

Analgesic Choice in Management of Rib Fractures: Paravertebral Block or Epidural Analgesia?

PubMed

Malekpour, Mahdi; Hashmi, Ammar; Dove, James; Torres, Denise; Wild, Jeffrey

2017-06-01

Rib fractures are commonly encountered in the setting of trauma. The aim of this study was to assess the association between the clinical outcome of rib fracture and epidural analgesia (EA) versus paravertebral block (PVB) using the National Trauma Data Bank (NTDB). Using the 2011 and 2012 versions of the NTDB, we retrieved completed records for all patients above 18 years of age who were admitted with rib fractures. Primary outcome was in-hospital mortality. Secondary outcomes were length of stay (LOS), intensive care unit (ICU) admission, ICU LOS, mechanical ventilation, duration of mechanical ventilation, development of pneumonia, and development of any other complication. Clinical outcomes were first compared between propensity score-matched EA and PVB patients. Then, EA and PVB patients were combined into the procedure group and the outcomes were compared with propensity score-matched patients that received neither intervention (no-procedure group). A total of 194,766 patients were included in the study with 1073 patients having EA, 1110 patients having PVB, and 192,583 patients having neither procedure. After propensity score matching, comparison of primary and secondary outcomes between EA and PVB patients showed no difference. Comparison of propensity score-matched procedure and no-procedure patients showed prolonged LOS and more frequent ICU admissions in patients receiving a procedure (both P < .0001), yet having no procedure was associated with a significantly increased odds of mortality (odds ratio: 2.25; 95% confidence interval, 1.14-3.84; P = .002). Using the NTDB, EA and PVB were not found to be significantly different in management of rib fractures. There was an association between use of a block and improved outcome, but this could be explained by selection of healthier patients to receive a block. Prospective study of this association is recommended.

Prenatal exposure to maternal smoking and childhood behavioural problems: a quasi-experimental approach.

PubMed

McCrory, Cathal; Layte, Richard

2012-11-01

This retrospective cross-sectional paper examines the relationship between maternal smoking during pregnancy and children's behavioural problems at 9 years of age independent of a wide range of possible confounders. The final sample comprised 7,505 nine-year-old school children participating in the first wave of the Growing Up in Ireland study. The children were selected through the Irish national school system using a 2-stage sampling method and were representative of the nine-year population. Information on maternal smoking during pregnancy was obtained retrospectively at 9 years of age via parental recall and children's behavioural problems were assessed using the Strengths and Difficulties Questionnaire across separate parent and teacher-report instruments. A quasi-experimental approach using propensity score matching was used to create treatment (smoking) and control (non-smoking) groups which did not differ significantly in their propensity to smoke in terms of 16 observed characteristics. After matching on the propensity score, children whose mothers smoked during pregnancy were 3.5 % (p < 0.001) and 3.4 % (p < 0.001) more likely to score in the problematic range on the SDQ total difficulties index according to parent and teacher-report respectively. Maternal smoking during pregnancy was more strongly associated with externalising than internalising behavioural problems. Analysis of the dose-response relationship showed that the differential between matched treatment and control groups increased with level of maternal smoking. Given that smoking is a modifiable risk factor, the promotion of successful cessation in pregnancy may prevent potentially adverse long-term consequences.

Retrospective Comparison of Single-Port Sleeve Gastrectomy Versus Three-Port Laparoscopic Sleeve Gastrectomy: a Propensity Score Adjustment Analysis.

PubMed

Mauriello, Claudio; Chouillard, Elie; d'alessandro, Antonio; Marte, Gianpaolo; Papadimitriou, Argyri; Chahine, Elias; Kassir, Radwan

2018-04-16

Evaluate the efficacy of single-port sleeve gastrectomy (SPSG) and then compare it to a less-invasive sleeve approach (three-port) (3PSG) according to a propensity score (PS) matching analysis. We analyzed all patients who underwent SG through a three-port or a single-port laparoscopic approach. After 2 years, the follow-up was completed in 84% patients treated with 3PSG and 95% patients of the SPSG group. Excess weight loss (EWL) was comparable for the first year of follow-up within the two groups except for the controls at 3 months in which the SPSG group showed a higher EWL (p = 0.0243). We demonstrated the efficacy of SPSG in bariatric surgery even compared to another, less invasive, laparoscopic SG approach (three-port).

Home health care and patterns of subsequent VA and medicare health care utilization for veterans.

PubMed

Van Houtven, Courtney Harold; Jeffreys, Amy S; Coffman, Cynthia J

2008-10-01

The Veterans Affairs or VA health care system is in the process of significantly expanding home health care (HHC) nationwide. We describe VA HHC use in 2003 for all VA HHC users from 2002; we examine whether VA utilization across a broad spectrum of services differed for a sample of VA HHC users and their propensity-score-matched controls. We also consider crossover between the VA and Medicare. This is a retrospective study using propensity score and stratified analysis to control for selection bias on observable characteristics. We examined the full cohort of 2002 VA HHC users (n = 24,169) and a 2:1 sample of age- and race-based nonusers (n = 53,356). Utilization measures included VA and Medicare outpatient, inpatient, nursing home, and hospice use, as well as VA home-based primary care, respite care, and adult day health care. VA HHC users had a higher absolute probability of outpatient use by around 3%, of inpatient use by 12%, and nursing home use by 6% than their propensity-score-matched controls. Veterans who used HHC services had a higher rate of VA service use in the subsequent year than controls did, even after we adjusted for differences in observed health status, eligibility advantages, and supplemental insurance status. High utilization for VA home health users spilled over into high Medicare utilization.

Prognostic score–based balance measures for propensity score methods in comparative effectiveness research

PubMed Central

Stuart, Elizabeth A.; Lee, Brian K.; Leacy, Finbarr P.

2013-01-01

Objective Examining covariate balance is the prescribed method for determining when propensity score methods are successful at reducing bias. This study assessed the performance of various balance measures, including a proposed balance measure based on the prognostic score (also known as the disease-risk score), to determine which balance measures best correlate with bias in the treatment effect estimate. Study Design and Setting The correlations of multiple common balance measures with bias in the treatment effect estimate produced by weighting by the odds, subclassification on the propensity score, and full matching on the propensity score were calculated. Simulated data were used, based on realistic data settings. Settings included both continuous and binary covariates and continuous covariates only. Results The standardized mean difference in prognostic scores, the mean standardized mean difference, and the mean t-statistic all had high correlations with bias in the effect estimate. Overall, prognostic scores displayed the highest correlations of all the balance measures considered. Prognostic score measure performance was generally not affected by model misspecification and performed well under a variety of scenarios. Conclusion Researchers should consider using prognostic score–based balance measures for assessing the performance of propensity score methods for reducing bias in non-experimental studies. PMID:23849158

[Comparison liver resection with transarterial chemoembolization for Barcelona Clinic Liver Cancer stage B hepatocellular carcinoma patients on long-term survival after SPSS propensity score matching].

PubMed

Ke, Yang; Zhong, Jianhong; Guo, Zhe; Liang, Yongrong; Li, Lequn; Xiang, Bangde

2014-03-18

To compare the long-term survival of patients with Barcelona Clinic Liver Cancer (BCLC) stage B hepatocellular carcinoma (HCC) undergoing either liver resection or transarterial chemoembolization (TACE) after propensity score matching (PSM). One hundred sixty-seven and 70 BCLC-B HCC patients undergoing liver resection and TACE were retrospectively collected. PSM function of SPSS software was conducted to reduce confounding bias between the groups. And then survival analysis was performed for the matched data. Fifty-three pairs of patients were successfully matched. And then survival analysis showed that the median survival periods and their 95% confidence intervals were 35.0 (26.3-43.7)months in the liver resection group versus 20.0(15.0-25.0) months in the TACE group. The 1, 3, 5 and 7-year survival rates were 91.0%, 49.0%, 30.0% and 17.0% in the liver resection group versus 73.0%, 25.0%, 8.0% and 5.0% respectively in the TACE group (P = 0.001). Cox regression analysis revealed that TACE, total bilirubin ≥ 34.2 µmol/L, alpha fetoprotein ≥ 400 ng/ml and tumor number ≥ 3 were independent risk factors of survival (hazard ratio >1, P < 0.05). The balance of covariates may be achieved through PSM. And for patients with BCLC-B HCC, liver resection provides better long-term overall survival than TACE.

Impact of totally laparoscopic combined management of colorectal cancer with synchronous hepatic metastases on severity of complications: a propensity-score-based analysis.

PubMed

Ratti, Francesca; Catena, Marco; Di Palo, Saverio; Staudacher, Carlo; Aldrighetti, Luca

2016-11-01

Thanks to widespread diffusion of minimally invasive approach in the setting of both colorectal and hepatic surgeries, the interest in combined resections for colorectal cancer and synchronous liver metastases (SCLM) by totally laparoscopic approach (TLA) has increased. Aim of this study was to compare outcome of combined resections for SCLM performed by TLA or by open approach, in a propensity-score-based study. All 25 patients undergoing combined TLA for SCLM at San Raffaele Hospital in Milano were compared in a case-matched analysis with 25 out of 91 patients undergoing totally open approach (TOA group). Groups were matched with 1:2 ratio using propensity scores based on covariates representing disease severity. Main endpoints were postoperative morbidity and long-term outcome. The Modified Accordion Severity Grading System was used to quantify complications. The groups resulted comparable in terms of patients and disease characteristics. The TLA group, as compared to the TOA group, had lower blood loss (350 vs 600 mL), shorter postoperative stay (9 vs 12 days), lower postoperative morbidity index (0.14 vs 0.20) and severity score for complicated patients (0.60 vs 0.85). Colonic anastomosis leakage had the highest fractional complication burden in both groups. In spite of comparable long-term overall survival, the TLA group had better recurrence-free survival. TLA for combined resections is feasible, and its indications can be widened to encompass a larger population of patients, provided its benefits in terms of reduced overall risk and severity of complications, rapid functional recovery and favorable long-term outcomes.

Association between spironolactone added to beta-blockers and ACE inhibition and survival in heart failure patients with reduced ejection fraction: a propensity score-matched cohort study.

PubMed

Frankenstein, L; Katus, H A; Grundtvig, M; Hole, T; de Blois, J; Schellberg, D; Atar, D; Zugck, C; Agewall, S

2013-10-01

Heart failure (CHF) guidelines recommend mineralocorticoid receptor antagonists for all symptomatic patients treated with a combination of ACE inhibitors/angiotensin receptor blockers (ARBs) and beta-blockers. As opposed to both eplerenone trials, patients in RALES (spironolactone) received almost no beta-blockers. Since pharmacological properties differ between eplerenone and spironolactone, the prognostic benefit of spironolactone added to this baseline combination therapy needs clarification. We included 4,832 CHF patients with chronic systolic dysfunction from the Norwegian Heart Failure Registry and the heart failure outpatients' clinic of the University of Heidelberg. Propensity scores for spironolactone receipt were calculated for each patient and used for matching to patients without spironolactone. During a total follow-up of 17,869 patient-years, 881 patients (27.0 %) died in the non-spironolactone group and 445 (28.4 %) in the spironolactone group. Spironolactone was not associated with improved survival, neither in the complete sample (HR 0.82; 95 % CI 0.64-1.07; HR 1.03; 95 % CI 0.88-1.20; multivariate and propensity score adjusted respectively), nor in the propensity-matched cohort (HR 0.98; 95 % CI 0.82-1.18). In CHF outpatients we were unable to observe an association between the use of spironolactone and improved survival when administered in addition to a combination of ACE/ARB and beta-blockers.

Second-Line Intraperitoneal Chemotherapy for Recurrent Epithelial Ovarian, Tubal and Peritoneal Cancer: A Propensity Score-Matching Study.

PubMed

Lu, Chien-Hsing; Chang, Yen-Hou; Lee, Wai-Hou; Chang, Yi; Peng, Chia-Wen; Chuang, Chi-Mu

2016-01-01

The superiority of frontline intraperitoneal (IP) over intravenous (IV) chemotherapy is well established in the treatment of epithelial ovarian cancer. However, the role of IP chemotherapy in the second-line setting has rarely been investigated. Consecutive patients diagnosed with recurrent epithelial, tubal and peritoneal cancers between January 2000 and December 2012 were recruited using a propensity score-matching technique to adjust relevant risk factors. In total, 310 patients were included in the final analysis (94 for platinum-refractory/resistant disease and 216 for platinum-sensitive disease). IP chemotherapy demonstrated significantly longer median progression-free survival than IV chemotherapy (4.9 vs. 2.4 months, p < 0.001, for platinum-refractory/resistant disease, and 9.8 vs. 6.9 months, p < 0.001, for platinum-sensitive disease). Second-line IP chemotherapy confers longer progression-free survival than IV chemotherapy. Large-scale clinical trials should be conducted to validate the true efficacy. © 2016 S. Karger AG, Basel.

Increased incidence of clinical hypotension with etomidate compared to ketamine for intubation in septic patients: A propensity matched analysis.

PubMed

Van Berkel, Megan A; Exline, Matthew C; Cape, Kari M; Ryder, Lindsay P; Phillips, Gary; Ali, Naeem A; Doepker, Bruce A

2017-04-01

This study compared the incidence of clinical hypotension between ketamine and etomidate within a 24 hour period following endotracheal intubation. This single-center, retrospective propensity-matched cohort study included septic patients admitted to our medical intensive care unit who received either etomidate or ketamine for intubation. Clinical hypotension was defined as any one of the following: mean arterial pressure (MAP) decrease >40% compared to baseline and MAP <70 mmHg, MAP <60 mmHg, initiation of a vasopressor, or increase to >30% of the initial vasopressor dose. Patients were matched based on propensity scores determined by demographics and baseline characteristics. A total of 384 (200 etomidate and 184 ketamine) patients were included for analysis with 230 patients (115 in each group) matched. Clinical hypotension was less prevalent in patients who received ketamine as compared to etomidate [51.3% vs. 73% (odds ratio=0.39, 95% confidence interval=0.22-0.67, P=.001]. The etomidate group experienced significantly lower MAPs at time periods 6.1-12 hours (65.1 mmHg vs. 69.3 mmHg, P=.01) and 12.1-24 hours (63.9 mmHg vs. 68.4 mmHg, P=.003). Ketamine was associated with a lower incidence of clinical hypotension within the 24 hour period following endotracheal intubation in septic patients. Copyright © 2016 Elsevier Inc. All rights reserved.

Health Services Utilization Among Fee-for-Service Medicare and Medicaid Patients Under Age 65 with Behavioral Health Illness at an Urban Safety Net Hospital.

PubMed

Cancino, Ramon S; Jack, Brian W; Jarvis, John; Cummings, Alice Kate; Cooper, Ellie; Cremieux, Pierre-Yves; Burgess, James F

2017-07-01

In 2011, fee-for-service patients with both Medicare and Medicaid (dual eligible) sustained $319.5 billion in health care costs. To describe the emergency department (ED) use and hospital admissions of adult dual eligible patients aged under 65 years who used an urban safety net hospital. This was a retrospective database analysis of patients aged between 18 and 65 years with Medicare and Medicaid, who used an urban safety net academic health center between January 1, 2011, and December 31, 2011. We compared patients with and without behavioral health illness. The main outcome measures were hospital admission and ED use. Chi-square and Wilcoxon rank-sum tests were used for descriptive statistics on categorical and continuous variables, respectively. Greedy propensity score matching was used to control for confounding factors. Rate ratios (RR) and 95% confidence intervals (CI) were determined after matching and after adjusting for those variables that remained significantly different after matching. In 2011, 10% of all fee-for-service dual eligible patients aged less than 65 years in Massachusetts were seen at Boston Medical Center. Data before propensity score matching showed significant differences in age, sex, race/ethnicity, marital status, education, employment, physical comorbidities, and Charlson Comorbidity Index score between patients with and without behavioral health illness. Analysis after propensity score matching found significant differences in sex, Hispanic race, and other education and employment status. Compared with patients without behavioral health illness, patients with behavioral health illness had a higher RR for hospital admissions (RR = 2.07; 95% CI = 1.81-2.38; P < 0.001) and ED use (RR = 1.61; 95% CI = 1.46-1.77; P < 0.001). Results were robust after adjusting for characteristics that remained statistically significantly different after propensity score matching. Adult dual eligible patients aged less than 65 years with behavioral health illness in the Medicaid fee-for-service plan had significantly higher rates of hospital admission and ED use compared with dual eligible patients without behavioral health illness at the largest urban safety net medical center in New England. Safety net hospitals care for a large proportion of dual eligible patients with behavioral health illness. Further research is needed to elucidate the systems-related and patient-centered factors contributing to the utilization behaviors of this patient population. This research was funded in part by a National Research Service Award (T3HP10028-14-01). The authors have no conflicts of interests to disclose. Cancino had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. Study concept and design were contributed by Cancino, Jack, and Burgess, with assistance from Cremieux. Cancino and Cremieux took the lead in data collection, along with Jack and Burgess, and data interpretation was performed by Jarvis, Cummings, and Cooper, along with the other authors. The manuscript was written primarily by Cancino, along with Jack and Burgess, and revised primarily by Cancino, along with the other authors.

Proton pump inhibitors and functional decline in older adults discharged from acute care hospitals.

PubMed

Corsonello, Andrea; Maggio, Marcello; Fusco, Sergio; Adamo, Bakhita; Amantea, Diana; Pedone, Claudio; Garasto, Sabrina; Ceda, Gian Paolo; Corica, Francesco; Lattanzio, Fabrizia; Antonelli Incalzi, Raffaele

2014-06-01

To investigate the relationship between use of proton pump inhibitors (PPIs) and incident dependency in older adults discharged from acute care hospitals. Prospective observational study. Eleven geriatric and internal medicine acute care wards located throughout Italy. Individuals (mean age 79.2 ± 5.5) who were not completely dependent at the time of discharge from participating wards (N = 401). The outcome of interest was the loss of at least one basic activity of daily living (ADL) from discharge to the end of follow-up (12 months). The relationship between PPI use and functional decline was investigated using logistic regression analysis before and after propensity score matching. Use of PPIs was significantly associated with functional decline before (odds ratio (OR) = 1.75, 95% confidence interval (CI) = 1.17-2.60) and after propensity score matching (OR = 2.44; 95% CI = 1.36-4.41). Other predictors of functional decline were hypoalbuminemia (OR = 3.10, 95% CI = 1.36-7.10 before matching, OR = 2.81, 95% CI = 1.09-7.77 after matching) and cognitive impairment (OR = 4.08, 95% CI = 1.63-10.2 before matching, OR = 6.35, 95% CI = 1.70-24.0 after matching). Use of PPIs is associated with functional decline during 12 months of follow-up in older adults discharged from acute care hospitals. © 2014, Copyright the Authors Journal compilation © 2014, The American Geriatrics Society.

Primary fascial closure with biologic mesh reinforcement results in lesser complication and recurrence rates than bridged biologic mesh repair for abdominal wall reconstruction: A propensity score analysis.

PubMed

Giordano, Salvatore; Garvey, Patrick B; Baumann, Donald P; Liu, Jun; Butler, Charles E

2017-02-01

Previous studies suggest that bridged mesh repair for abdominal wall reconstruction may result in worse outcomes than mesh-reinforced, primary fascial closure, particularly when acellular dermal matrix is used. We compared our outcomes of bridged versus reinforced repair using ADM in abdominal wall reconstruction procedures. This retrospective study included 535 consecutive patients at our cancer center who underwent abdominal wall reconstruction either for an incisional hernia or for abdominal wall defects left after excision of malignancies involving the abdominal wall with underlay mesh. A total of 484 (90%) patients underwent mesh-reinforced abdominal wall reconstruction and 51 (10%) underwent bridged repair abdominal wall reconstruction. Acellular dermal matrix was used, respectively, in 98% of bridged and 96% of reinforced repairs. We compared outcomes between these 2 groups using propensity score analysis for risk-adjustment in multivariate analysis and for 1-to-1 matching. Bridged repairs had a greater hernia recurrence rate (33.3% vs 6.2%, P < .001), a greater overall complication rate (59% vs 30%, P = .001), and worse freedom from hernia recurrence (log-rank P <.001) than reinforced repairs. Bridged repairs also had a greater rate of wound dehiscence (26% vs 14%, P = .034) and mesh exposure (10% vs 1%, P = .003) than mesh-reinforced abdominal wall reconstruction. When the treatment method was adjusted for propensity score in the propensity-score-matched pairs (n = 100), we found that the rates of hernia recurrence (32% vs 6%, P = .002), overall complications (32% vs 6%, P = .002), and freedom from hernia recurrence (68% vs 32%, P = .001) rates were worse after bridged repair. We did not observe differences in wound healing and mesh complications between the 2 groups. In our population of primarily cancer patients at MD Anderson Cancer Center bridged repair for abdominal wall reconstruction is associated with worse outcomes than mesh-reinforced abdominal wall reconstruction. Particularly when employing acellular dermal matrix, reinforced repairs should be used for abdominal wall reconstruction whenever possible. Copyright © 2016 Elsevier Inc. All rights reserved.

Evaluating the effectiveness of flood damage mitigation measures by the application of Propensity Score Matching

NASA Astrophysics Data System (ADS)

Hudson, P.; Botzen, W. J. W.; Kreibich, H.; Bubeck, P.; Aerts, J. C. J. H.

2014-01-01

The employment of damage mitigation measures by individuals is an important component of integrated flood risk management. In order to promote efficient damage mitigation measures, accurate estimates of their damage mitigation potential are required. That is, for correctly assessing the damage mitigation measures' effectiveness from survey data, one needs to control for sources of bias. A biased estimate can occur if risk characteristics differ between individuals who have, or have not, implemented mitigation measures. This study removed this bias by applying an econometric evaluation technique called Propensity Score Matching to a survey of German households along along two major rivers major rivers that were flooded in 2002, 2005 and 2006. The application of this method detected substantial overestimates of mitigation measures' effectiveness if bias is not controlled for, ranging from nearly € 1700 to € 15 000 per measure. Bias-corrected effectiveness estimates of several mitigation measures show that these measures are still very effective since they prevent between € 6700-14 000 of flood damage. This study concludes with four main recommendations regarding how to better apply Propensity Score Matching in future studies, and makes several policy recommendations.

Evaluating the effectiveness of flood damage mitigation measures by the application of propensity score matching

NASA Astrophysics Data System (ADS)

Hudson, P.; Botzen, W. J. W.; Kreibich, H.; Bubeck, P.; Aerts, J. C. J. H.

2014-07-01

The employment of damage mitigation measures (DMMs) by individuals is an important component of integrated flood risk management. In order to promote efficient damage mitigation measures, accurate estimates of their damage mitigation potential are required. That is, for correctly assessing the damage mitigation measures' effectiveness from survey data, one needs to control for sources of bias. A biased estimate can occur if risk characteristics differ between individuals who have, or have not, implemented mitigation measures. This study removed this bias by applying an econometric evaluation technique called propensity score matching (PSM) to a survey of German households along three major rivers that were flooded in 2002, 2005, and 2006. The application of this method detected substantial overestimates of mitigation measures' effectiveness if bias is not controlled for, ranging from nearly EUR 1700 to 15 000 per measure. Bias-corrected effectiveness estimates of several mitigation measures show that these measures are still very effective since they prevent between EUR 6700 and 14 000 of flood damage per flood event. This study concludes with four main recommendations regarding how to better apply propensity score matching in future studies, and makes several policy recommendations.

Stratification for the propensity score compared with linear regression techniques to assess the effect of treatment or exposure.

PubMed

Senn, Stephen; Graf, Erika; Caputo, Angelika

2007-12-30

Stratifying and matching by the propensity score are increasingly popular approaches to deal with confounding in medical studies investigating effects of a treatment or exposure. A more traditional alternative technique is the direct adjustment for confounding in regression models. This paper discusses fundamental differences between the two approaches, with a focus on linear regression and propensity score stratification, and identifies points to be considered for an adequate comparison. The treatment estimators are examined for unbiasedness and efficiency. This is illustrated in an application to real data and supplemented by an investigation on properties of the estimators for a range of underlying linear models. We demonstrate that in specific circumstances the propensity score estimator is identical to the effect estimated from a full linear model, even if it is built on coarser covariate strata than the linear model. As a consequence the coarsening property of the propensity score-adjustment for a one-dimensional confounder instead of a high-dimensional covariate-may be viewed as a way to implement a pre-specified, richly parametrized linear model. We conclude that the propensity score estimator inherits the potential for overfitting and that care should be taken to restrict covariates to those relevant for outcome. Copyright (c) 2007 John Wiley & Sons, Ltd.

Effects of etomidate on complications related to intubation and on mortality in septic shock patients treated with hydrocortisone: a propensity score analysis

PubMed Central

2012-01-01

Introduction Endotracheal intubation in the ICU is associated with a high incidence of complications. Etomidate use is debated in septic shock because it increases the risk of critical illness-related corticosteroid insufficiency, which may impact outcome. We hypothesized that hydrocortisone, administered in all septic shock cases in our ICU, may counteract some negative effects of etomidate. The aim of our study was to compare septic shock patients who received etomidate versus another induction drug both for short-term safety and for long-term outcomes. Methods A single-center observational study was carried out in septic shock patients, treated with hydrocortisone and intubated within the first 48 hours of septic shock. Co-primary end points were life-threatening complications incidence occurring within the first hour after intubation and mortality during the ICU stay. Statistical analyses included unmatched and matched cohorts using a propensity score analysis. P < 0.05 was considered significant. Results Sixty patients in the etomidate cohort and 42 patients in the non-etomidate cohort were included. Critical illness-related corticosteroid insufficiency was 79% in the etomidate cohort and 52% in the non-etomidate cohort (P = 0.01). After intubation, life-threatening complications occurred in 36% of the patients whatever the cohort. After adjustment with propensity score analysis, etomidate was a protective factor for death in the ICU both in unmatched (hazard ratio, 0.33 (0.15 to 0.75); P < 0.01)) and matched cohorts (hazard ratio, 0.33 (0.112 to 0.988); P = 0.04). Conclusion In septic shock patients treated with hydrocortisone, etomidate did not decrease life-threatening complications following intubation, but when associated with hydrocortisone it also did not impair outcome. PMID:23171852

Impact of the branched-chain amino acid to tyrosine ratio and branched-chain amino acid granule therapy in patients with hepatocellular carcinoma: A propensity score analysis.

PubMed

Tada, Toshifumi; Kumada, Takashi; Toyoda, Hidenori; Kiriyama, Seiki; Tanikawa, Makoto; Hisanaga, Yasuhiro; Kanamori, Akira; Kitabatake, Shusuke; Yama, Tsuyoki

2015-09-01

It has been reported that the branched-chain amino acid (BCAA) to tyrosine ratio (BTR) is a useful indicator of liver function and BCAA therapy is associated with a decreased incidence of hepatocellular carcinoma (HCC). However, there has not been sufficient research on the relationship between BTR and the effects of BCAA therapy after initial treatment of HCC. We investigated the impact of BTR and BCAA therapy on survival in patients with HCC. A total of 315 patients with HCC who were treated (n = 66) or not treated (n = 249) with BCAA were enrolled; of these, 66 were selected from each group using propensity score matching. Survival from liver-related mortality was analyzed. In patients who did not receive BCAA therapy (n = 249), multivariate analysis for factors associated with survival indicated that low BTR (≤ 4.4) was independently associated with poor prognosis in patients with HCC (hazard ratio, 1.880; 95% confidence interval, 1.125-3.143; P = 0.016). In addition, among patients selected by propensity score matching (n = 132), multivariate analysis indicated that BCAA therapy was independently associated with good prognosis in patients with HCC (hazard ratio, 0.524; 95% confidence interval, 0.282-0.973; P = 0.041). BTR was not significantly associated with survival. Intervention involving BCAA therapy improved survival in patients with HCC versus untreated controls, regardless of BTR. In addition, low BTR was associated with poor prognosis in patients who did not receive BCAA therapy. © 2015 Journal of Gastroenterology and Hepatology Foundation and Wiley Publishing Asia Pty Ltd.

Bayesian Propensity Score Analysis: Simulation and Case Study

ERIC Educational Resources Information Center

Kaplan, David; Chen, Cassie J. S.

2011-01-01

Propensity score analysis (PSA) has been used in a variety of settings, such as education, epidemiology, and sociology. Most typically, propensity score analysis has been implemented within the conventional frequentist perspective of statistics. This perspective, as is well known, does not account for uncertainty in either the parameters of the…

Measurement of intracranial pressure and short-term outcomes of patients with traumatic brain injury: a propensity-matched analysis

PubMed Central

Ferreira, Cesar Biselli; Bassi, Estevão; Lucena, Lucas; Carreta, Hernandez; Miranda, Leandro Costa; Tierno, Paulo Fernando Guimarães Mazorcchi; Amorim, Robson Luis; Zampieri, Fernando Godinho; Malbouisson, Luis Marcelo Sá

2015-01-01

Objective To assess the impact of intracranial pressure monitoring on the short-term outcomes of traumatic brain injury patients. Methods Retrospective observational study including 299 consecutive patients admitted due to traumatic brain injury from January 2011 through July 2012 at a Level 1 trauma center in São Paulo, Brazil. Patients were categorized in two groups according to the measurement of intracranial pressure (measured intracranial pressure and non-measured intracranial pressure groups). We applied a propensity-matched analysis to adjust for possible confounders (variables contained in the Crash Score prognostic algorithm). Results Global mortality at 14 days (16%) was equal to that observed in high-income countries in the CRASH Study and was better than expected based on the CRASH calculator score (20.6%), with a standardized mortality ratio of 0.77. A total of 28 patients received intracranial pressure monitoring (measured intracranial pressure group), of whom 26 were paired in a 1:1 fashion with patients from the non-measured intracranial pressure group. There was no improvement in the measured intracranial pressure group compared to the non-measured intracranial pressure group regarding hospital mortality, 14-day mortality, or combined hospital and chronic care facility mortality. Survival up to 14 days was also similar between groups. Conclusion Patients receiving intracranial pressure monitoring tend to have more severe traumatic brain injuries. However, after adjusting for multiple confounders using propensity scoring, no benefits in terms of survival were observed among intracranial pressure-monitored patients and those managed with a systematic clinical protocol. PMID:26761468

Measurement of intracranial pressure and short-term outcomes of patients with traumatic brain injury: a propensity-matched analysis.

PubMed

Ferreira, Cesar Biselli; Bassi, Estevão; Lucena, Lucas; Carreta, Hernandez; Miranda, Leandro Costa; Tierno, Paulo Fernando Guimarães Mazorcchi; Amorim, Robson Luis; Zampieri, Fernando Godinho; Malbouisson, Luis Marcelo Sá

2015-01-01

To assess the impact of intracranial pressure monitoring on the short-term outcomes of traumatic brain injury patients. Retrospective observational study including 299 consecutive patients admitted due to traumatic brain injury from January 2011 through July 2012 at a Level 1 trauma center in São Paulo, Brazil. Patients were categorized in two groups according to the measurement of intracranial pressure (measured intracranial pressure and non-measured intracranial pressure groups). We applied a propensity-matched analysis to adjust for possible confounders (variables contained in the Crash Score prognostic algorithm). Global mortality at 14 days (16%) was equal to that observed in high-income countries in the CRASH Study and was better than expected based on the CRASH calculator score (20.6%), with a standardized mortality ratio of 0.77. A total of 28 patients received intracranial pressure monitoring (measured intracranial pressure group), of whom 26 were paired in a 1:1 fashion with patients from the non-measured intracranial pressure group. There was no improvement in the measured intracranial pressure group compared to the non-measured intracranial pressure group regarding hospital mortality, 14-day mortality, or combined hospital and chronic care facility mortality. Survival up to 14 days was also similar between groups. Patients receiving intracranial pressure monitoring tend to have more severe traumatic brain injuries. However, after adjusting for multiple confounders using propensity scoring, no benefits in terms of survival were observed among intracranial pressure-monitored patients and those managed with a systematic clinical protocol.

Steroid Avoidance in Pediatric Heart Transplantation Results in Excellent Graft Survival

PubMed Central

Auerbach, Scott R.; Gralla, Jane; Campbell, David N.; Miyamoto, Shelley D.; Pietra, Biagio A.

2018-01-01

Background Maintenance steroid (MS) use in pediatric heart transplantation (HT) varies across centers. The purpose of this study was to evaluate the impact of steroid-free maintenance immunosuppression (SF) on graft outcomes in pediatric HT. Methods Patients younger than 18 years in the United States undergoing a first HT during 1990 to 2010 were analyzed for conditional 30-day graft loss (death or repeat HT) and death based on MS use by multivariable analysis. A propensity score was then given to each patient using a logistic model, and propensity matching was performed using pre-HT risk factors, induction therapy, and nonsteroid maintenance immunosuppression. Kaplan-Meier graft and patient survival probabilities by MS use were then calculated. Results Of 4894 patients, 3962 (81%) were taking MS and 932 (19%) SF. Of the 4530 alive at 30 days after HT, 3694 (82%) and 836 (18%) were in the MS and SF groups, respectively. Unmatched multivariable analysis showed no difference in 30-day conditional graft survival between MS and SF groups (hazard ratio=1.08, 95% confidence interval=0.93-1.24; P=0.33). Propensity matching resulted in 462 patients in each MS and SF group. Propensity-matched Kaplan-Meier survival analysis showed no difference in graft or patient survival between groups (P=0.3 and P=0.16, respectively). Conclusions We found no difference in graft survival between SF patients and those taking MS. An SF regimen in pediatric HT avoids potential complications of steroid use without compromising graft survival, even after accounting for pre-HT risk factors. PMID:24389908

Do Work Placements Improve Final Year Academic Performance or Do High-Calibre Students Choose to Do Work Placements?

ERIC Educational Resources Information Center

Jones, C. M.; Green, J. P.; Higson, H. E.

2017-01-01

This study investigates whether the completion of an optional sandwich work placement enhances student performance in final year examinations. Using Propensity Score Matching, our analysis departs from the literature by controlling for self-selection. Previous studies may have overestimated the impact of sandwich work placements on performance…

Policy Matters: An Analysis of District-Level Efforts to Increase the Identification of Underrepresented Learners

ERIC Educational Resources Information Center

McBee, Matthew T.; Shaunessy, Elizabeth; Matthews, Michael S.

2012-01-01

Policies delegating control of educational policy to the local level are widespread, yet there has been little examination of the effects of such distributed decision making in the area of advanced education programming. We used propensity score matching to examine the effectiveness of locally developed policies for identifying intellectually…

Potential Pitfalls of Reporting and Bias in Observational Studies With Propensity Score Analysis Assessing a Surgical Procedure: A Methodological Systematic Review.

PubMed

Lonjon, Guillaume; Porcher, Raphael; Ergina, Patrick; Fouet, Mathilde; Boutron, Isabelle

2017-05-01

To describe the evolution of the use and reporting of propensity score (PS) analysis in observational studies assessing a surgical procedure. Assessing surgery in randomized controlled trials raises several challenges. Observational studies with PS analysis are a robust alternative for comparative effectiveness research. In this methodological systematic review, we identified all PubMed reports of observational studies with PS analysis that evaluated a surgical procedure and described the evolution of their use over time. Then, we selected a sample of articles published from August 2013 to July 2014 and systematically appraised the quality of reporting and potential bias of the PS analysis used. We selected 652 reports of observational studies with PS analysis. The publications increased over time, from 1 report in 1987 to 198 in 2013. Among the 129 reports assessed, 20% (n = 24) did not detail the covariates included in the PS and 77% (n = 100) did not report a justification for including these covariates in the PS. The rate of missing data for potential covariates was reported in 9% of articles. When a crossover by conversion was possible, only 14% of reports (n = 12) mentioned this issue. For matched analysis, 10% of articles reported all 4 key elements that allow for reproducibility of a PS-matched analysis (matching ratio, method to choose the nearest neighbors, replacement and method for statistical analysis). Observational studies with PS analysis in surgery are increasing in frequency, but specific methodological issues and weaknesses in reporting exist.

Proton pump inhibitor use and recurrent Clostridium difficile-associated disease: a case-control analysis matched by propensity score.

PubMed

Kim, Yong Gil; Graham, David Y; Jang, Byung Ik

2012-01-01

Clostridium difficile has been increasingly diagnosed in hospitalized patients. An association between proton pump inhibitors (PPIs) use and Clostridium difficile-associated disease (CDAD) and between recurrent CDAD has been suggested. The aim of this study is to investigate whether PPI use is associated with the development of recurrent CDAD. This was a retrospective case-control study of patients with CDAD at Yeungnam University Medical Center, seen from January 2004 to December 2008. C. difficile infection was diagnosed by the presence of C. difficile toxin in the stool. Those with recurrent disease were matched with nonrecurrent controls using multivariate matched sampling methods that incorporated the propensity score. Recurrent CDAD developed in 28 (14.1%) of the 198 patients with diarrhea and positive C. difficile stool toxin assays. Multivariate analysis of the total population of recurrent versus nonrecurrent CDAD revealed that additional use of non-C. difficile antimicrobial therapy (concomitant with the treatment or after or both), poor response to therapy with metronidazole or vancomycin, and recent gastrointestinal surgery were risk factors for recurrent CDAD. We were able to match 21 recurrent CDAD subjects with 21 without recurrent CDAD. Among the matched patients only PPI use was associated with recurrent CDAD (ie, 47.6% vs. 4.8%, P=0.004 for recurrent vs. nonrecurrent CDAD, respectively). Among the matched patient groups, only PPI therapy was associated with recurrent CDAD. Prospective studies are needed to clarify whether avoidance of PPIs or specific cotherapies will reduce the incidence of recurrent C. difficile-associated diarrhea.

Carvedilol Compared With Metoprolol Succinate in the Treatment and Prognosis of Patients With Stable Chronic Heart Failure: Carvedilol or Metoprolol Evaluation Study.

PubMed

Fröhlich, Hanna; Zhao, Jingting; Täger, Tobias; Cebola, Rita; Schellberg, Dieter; Katus, Hugo A; Grundtvig, Morten; Hole, Torstein; Atar, Dan; Agewall, Stefan; Frankenstein, Lutz

2015-09-01

β-Blockers exert a prognostic benefit in the treatment of chronic heart failure. Their pharmacological properties vary. The only substantial comparative trial to date-the Carvedilol or Metoprolol European Trial-has compared carvedilol with short-acting metoprolol tartrate at different dose equivalents. We therefore addressed the relative efficacy of equal doses of carvedilol and metoprolol succinate on survival in multicenter hospital outpatients with chronic heart failure. Four thousand sixteen patients with stable systolic chronic heart failure who were using either carvedilol or metoprolol succinate were identified in the Norwegian Heart Failure Registry and The Heart Failure Registry of the University of Heidelberg, Germany. Patients were individually matched on both the dose equivalents and the respective propensity scores for β-blocker treatment. During a follow-up for 17 672 patient-years, it was found that 304 (27.2%) patients died in the carvedilol group and 1066 (36.8%) in the metoprolol group. In a univariable analysis of the general sample, metoprolol therapy was associated with higher mortality compared with carvedilol therapy (hazard ratio, 1.49; 95% confidence interval, 1.31-1.69; P<0.001). This difference was not seen after multivariable adjustment (hazard ratio, 0.93; 95% confidence interval, 0.57-1.50; P=0.75) and adjustment for propensity score and dose equivalents (hazard ratio, 1.06; 95% confidence interval, 0.94-1.20; P=0.36) or in the propensity and dose equivalent-matched sample (hazard ratio, 1.00; 95% confidence interval, 0.82-1.23; P=0.99). These results were essentially unchanged for all prespecified subgroups. In outpatients with chronic heart failure, no conclusive association between all-cause mortality and treatment with carvedilol or metoprolol succinate was observed after either multivariable adjustment or multilevel propensity score matching. © 2015 American Heart Association, Inc.

Outcomes of subsequent non-muscle-invasive bladder cancer treated with intravesical Bacillus Calmette-Guérin after radical nephroureterectomy for upper urinary tract urothelial carcinoma.

PubMed

Miyake, Makito; Tatsumi, Yoshihiro; Matsumoto, Hiroaki; Nagao, Kazuhiro; Matsuyama, Hideyasu; Inamoto, Teruo; Azuma, Haruhito; Yasumoto, Hiroaki; Shiina, Hiroaki; Fujimoto, Kiyohide

2018-05-01

To describe the clinicopathological characteristics and prognosis of subsequent non-muscle-invasive bladder cancer (NMIBC) after radical nephroureterectomy (RNU) for upper urinary tract urothelial carcinoma (UTUC), and particularly its response to intravesical Bacillus Calmette-Guérin (BCG). An observational study was conducted in 1463 patients with UTUC who had undergone RNU and in 1555 patients with primary NMIBC. Of the 1463 patients with UTUC, 256 (17%) subsequently developed NMIBC (UTUC-NMIBC group) and were available for the analysis. The clinicopathological background and outcomes, including intravesical recurrence-free survival and bladder progression-free survival, were compared between the patients with UTUC-NMIBC and the patients with primary NMIBC treated with intravesical BCG. Propensity score matching was performed to adjust for the potential differences in the backgrounds of the two groups. To validate the utility of the CUETO scoring model in the UTUC-NMIBC group, risk scores were calculated and compared with the published probabilities for recurrence and progression. Compared with the unadjusted primary NMIBC group (n = 352), the UTUC-NMIBC group (n = 75) were found to have a worse prognosis for intravesical recurrence and progression, before propensity score matching. After propensity score matching for potential confounding factors, however, a worse prognosis was observed only for intravesical recurrence. The validation test of the CUETO scoring model for the UTUC-NMIBC group showed a significant difference in the rate of intravesical recurrence and progression for the 0-4 and 5-6 score groups between the UTUC-NMIBC group and the CUETO risk table reference data. Compared with the primary NMIBC group, the UTUC-NMIBC group had a worse prognosis after intravesical BCG, especially with regard to intravesical recurrence. This suggests that patients with UTUC-NMIBC are inherently poor responders to BCG exposure. An optimal treatment strategy and risk scoring model to select patients for adjuvant intravesical BCG, chemotherapy or immediate radical cystectomy should be established. © 2017 The Authors BJU International © 2017 BJU International Published by John Wiley & Sons Ltd.

Less Is More: Results of a Statewide Analysis of the Impact of Blood Transfusion on Coronary Artery Bypass Grafting Outcomes.

PubMed

Crawford, Todd C; Magruder, J Trent; Fraser, Charles; Suarez-Pierre, Alejandro; Alejo, Diane; Bobbitt, Jennifer; Fonner, Clifford E; Canner, Joseph K; Horvath, Keith; Wehberg, Kurt; Taylor, Bradley; Kwon, Christopher; Whitman, Glenn J; Conte, John V; Salenger, Rawn

2018-01-01

Debate persists over the association between blood transfusions, especially those considered discretionary, and outcomes after cardiac operations. Using data from the Maryland Cardiac Surgery Quality Initiative, we sought to determine whether outcomes differed among coronary artery bypass grafting (CABG) patients receiving 1 U of red blood cells (RBCs) vs none. We used a statewide database to review patients who underwent isolated CABG from July 1, 2011, to June 30, 2016, across 10 Maryland cardiac surgery centers. We included patients who received 1 U or fewer of RBCs from the time of the operation through discharge. Propensity scoring, using 20 variables to control for treatment effect, was performed among patients who did and did not receive a transfusion. These two groups were matched 1:1 to assess for differences in our primary outcomes: operative death, prolonged postoperative length of stay (>14 days), and a composite postoperative respiratory complication of pneumonia or reintubation, or both. Of 10,877 patients who underwent CABG, 6,124 (56%) received no RBCs (group 1) during their operative hospitalization, and 981 (9.0%) received 1 U of RBCs (group 2), including 345 of 981 patients (35%) who received a transfusion intraoperatively. Propensity score matching generated 937 well-matched pairs. Compared with group 2, propensity-matched analysis revealed significantly greater 30-day survival in group 1 (99% vs 98%, p = 0.02) and reduced incidence of prolonged length of stay (3.7% vs 4.0%, p < 0.01). Our collaborative statewide analysis demonstrated that even 1 unit of blood was associated with significantly worse survival and longer length of stay after CABG. Multiinstitutional quality initiatives may seek to address discretionary transfusions and possess the potential to improve patient outcomes. Copyright © 2018 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Right anterior mini-thoracotomy vs. conventional sternotomy for aortic valve replacement: a propensity-matched comparison

PubMed Central

Del Giglio, Mauro; Mikus, Elisa; Micari, Antonio; Calvi, Simone; Tripodi, Alberto; Campo, Gianluca; Maietti, Elisa; Castriota, Fausto; Cremonesi, Alberto

2018-01-01

Background Right anterior mini-thoracotomy (MIAVR) is a promising technique for aortic valve replacement. We aimed at comparing its outcomes with those obtained in a propensity-matched group of patients undergoing sternotomy at our two high-volume centers. Methods Main clinical and operative data of patients undergoing aortic valve replacement between January 2010 and May 2016 were retrospectively collected. A total of 678 patients were treated with a standard full sternotomy approach, while MIAVR was performed in 502. Propensity score matching identified 363 patients per each group. Results In-hospital mortality was not significantly different between the propensity-matched groups (1.7% in MIAVR patients vs. 2.2% in conventional sternotomy patients; P=0.79). No significant difference in the incidence of major post-operative complications was observed. Post-operative ventilation times (median 7, range 5–12 hours in MIAVR patients vs. median 7, range 5–12 in conventional sternotomy patients; P=0.72) were not significantly different between the two groups. Cardiopulmonary bypass time (61.0±21.0 vs. 65.9±24.7 min in conventional sternotomy group; P<0.01) and aortic cross-clamping time (48.3±16.7 vs. 53.2±19.6 min in full sternotomy group; P<0.01) were shorter in MIAVR group. EuroSCORE (OR 1.52, 95% CI, 1.12–2.06; P<0.01) was found to be the only independent predictor of intra-hospital mortality in the whole propensity-matched population. Conclusions Our experience shows that mini-access isolated aortic valve surgery is a reproducible, safe and effective procedure with similar outcomes and no longer operative times compared to conventional sternotomy. PMID:29707310

Double-adjustment in propensity score matching analysis: choosing a threshold for considering residual imbalance.

PubMed

Nguyen, Tri-Long; Collins, Gary S; Spence, Jessica; Daurès, Jean-Pierre; Devereaux, P J; Landais, Paul; Le Manach, Yannick

2017-04-28

Double-adjustment can be used to remove confounding if imbalance exists after propensity score (PS) matching. However, it is not always possible to include all covariates in adjustment. We aimed to find the optimal imbalance threshold for entering covariates into regression. We conducted a series of Monte Carlo simulations on virtual populations of 5,000 subjects. We performed PS 1:1 nearest-neighbor matching on each sample. We calculated standardized mean differences across groups to detect any remaining imbalance in the matched samples. We examined 25 thresholds (from 0.01 to 0.25, stepwise 0.01) for considering residual imbalance. The treatment effect was estimated using logistic regression that contained only those covariates considered to be unbalanced by these thresholds. We showed that regression adjustment could dramatically remove residual confounding bias when it included all of the covariates with a standardized difference greater than 0.10. The additional benefit was negligible when we also adjusted for covariates with less imbalance. We found that the mean squared error of the estimates was minimized under the same conditions. If covariate balance is not achieved, we recommend reiterating PS modeling until standardized differences below 0.10 are achieved on most covariates. In case of remaining imbalance, a double adjustment might be worth considering.

Channeling in the Use of Nonprescription Paracetamol and Ibuprofen in an Electronic Medical Records Database: Evidence and Implications.

PubMed

Weinstein, Rachel B; Ryan, Patrick; Berlin, Jesse A; Matcho, Amy; Schuemie, Martijn; Swerdel, Joel; Patel, Kayur; Fife, Daniel

2017-12-01

Over-the-counter analgesics such as paracetamol and ibuprofen are among the most widely used, and having a good understanding of their safety profile is important to public health. Prior observational studies estimating the risks associated with paracetamol use acknowledge the inherent limitations of these studies. One threat to the validity of observational studies is channeling bias, i.e. the notion that patients are systematically exposed to one drug or the other, based on current and past comorbidities, in a manner that affects estimated relative risk. The aim of this study was to examine whether evidence of channeling bias exists in observational studies that compare paracetamol with ibuprofen, and, if so, the extent to which confounding adjustment can mitigate this bias. In a cohort of 140,770 patients, we examined whether those who received any paracetamol (including concomitant users) were more likely to have prior diagnoses of gastrointestinal (GI) bleeding, myocardial infarction (MI), stroke, or renal disease than those who received ibuprofen alone. We compared propensity score distributions between drugs, and examined the degree to which channeling bias could be controlled using a combination of negative control disease outcome models and large-scale propensity score matching. Analyses were conducted using the Clinical Practice Research Datalink. The proportions of prior MI, GI bleeding, renal disease, and stroke were significantly higher in those prescribed any paracetamol versus ibuprofen alone, after adjusting for sex and age. We were not able to adequately remove selection bias using a selected set of covariates for propensity score adjustment; however, when we fit the propensity score model using a substantially larger number of covariates, evidence of residual bias was attenuated. Although using selected covariates for propensity score adjustment may not sufficiently reduce bias, large-scale propensity score matching offers a novel approach to consider to mitigate the effects of channeling bias.

The Association of Statin Use with Age-Related Macular Degeneration Progression: The Age-Related Eye Disease Study 2 Report Number 9.

PubMed

Al-Holou, Shaza N; Tucker, William R; Agrón, Elvira; Clemons, Traci E; Cukras, Catherine; Ferris, Frederick L; Chew, Emily Y

2015-12-01

To evaluate the association of statin use with progression of age-related macular degeneration (AMD). Preplanned, prospective cohort study within a controlled clinical trial of oral supplementation for age-related eye diseases. Age-Related Eye Disease Study 2 (AREDS2) participants, aged 50 to 85 years. Factors, including age, gender, smoking status, aspirin use, and history of diabetes, hypertension, heart disease, angina, and stroke-all known to be associated with statin use-were included in a logistic regression model to estimate propensity scores for each participant. Age-adjusted proportional hazards regression models, with and without propensity score matching, were performed to evaluate the association of statin use with progression to late AMD. Analyses adjusting for the competing risk of death were also performed. Baseline and annual stereoscopic fundus photographs were assessed centrally by masked graders for the development of late AMD, either neovascular AMD or geographic atrophy (GA). Of the 3791 participants (2462 with bilateral large drusen and 1329 with unilateral late AMD at baseline), 1659 (43.8%) were statin users. The overall analysis, with no matching of propensity scores and no adjustment for death as a competing risk, showed that statin use was not associated with progression to late AMD (hazard ratio [HR], 1.08; 95% confidence interval [CI], 0.83-1.41; P = 0.56). When matched for propensity scores and adjusted for death as a competing risk, the result was not statistically significant (HR, 0.81; 95% CI, 0.55-1.20; P = 0.29). Furthermore, subgroup analyses of persons with or without late AMD at baseline and the various components of late AMD (neovascular AMD, central GA, or any GA) also showed no statistically significant association of statin use with progression to AMD. Statin use was not statistically significantly associated with progression to late AMD in the AREDS2 participants, and these findings are consistent with findings in the majority of previous studies. Statins have been demonstrated to reduce the risk of cardiovascular disease, but our data do not provide evidence of a beneficial effect on slowing AMD progression. Published by Elsevier Inc.

Bullying victimization and the social and emotional maladjustment of bystanders: A propensity score analysis.

PubMed

Werth, Jilynn M; Nickerson, Amanda B; Aloe, Ariel M; Swearer, Susan M

2015-08-01

This study investigated how bystanders, who have and have not been bullied, perceive their social and emotional maladjustment depending on the form of bullying (physical or verbal) they witness. Using propensity score matching, equivalent groups of 270 victimized and 270 non-victimized bystander groups were created based on middle school students' responses on the Bully Survey-Student Version (BYS-S; Swearer, 2001). Victimized bystanders experienced higher social maladjustment than non-victimized bystanders. Path analysis results suggest that social and emotional maladjustment as a bystander is related not only to social-emotional maladjustment as victim, but to gender and the form of bullying witnessed. The way in which bystanders are influenced by their personal victimization may be a critical factor in predicting, understanding, and increasing active bystander intervention. Copyright © 2015 Society for the Study of School Psychology. Published by Elsevier Ltd. All rights reserved.

Best (but oft-forgotten) practices: propensity score methods in clinical nutrition research.

PubMed

Ali, M Sanni; Groenwold, Rolf Hh; Klungel, Olaf H

2016-08-01

In observational studies, treatment assignment is a nonrandom process and treatment groups may not be comparable in their baseline characteristics, a phenomenon known as confounding. Propensity score (PS) methods can be used to achieve comparability of treated and nontreated groups in terms of their observed covariates and, as such, control for confounding in estimating treatment effects. In this article, we provide a step-by-step guidance on how to use PS methods. For illustrative purposes, we used simulated data based on an observational study of the relation between oral nutritional supplementation and hospital length of stay. We focused on the key aspects of PS analysis, including covariate selection, PS estimation, covariate balance assessment, treatment effect estimation, and reporting. PS matching, stratification, covariate adjustment, and weighting are discussed. R codes and example data are provided to show the different steps in a PS analysis. © 2016 American Society for Nutrition.

Analysis of Observational Studies in the Presence of Treatment Selection Bias: Effects of Invasive Cardiac Management on AMI Survival Using Propensity Score and Instrumental Variable Methods

PubMed Central

Stukel, Thérèse A.; Fisher, Elliott S; Wennberg, David E.; Alter, David A.; Gottlieb, Daniel J.; Vermeulen, Marian J.

2007-01-01

Context Comparisons of outcomes between patients treated and untreated in observational studies may be biased due to differences in patient prognosis between groups, often because of unobserved treatment selection biases. Objective To compare 4 analytic methods for removing the effects of selection bias in observational studies: multivariable model risk adjustment, propensity score risk adjustment, propensity-based matching, and instrumental variable analysis. Design, Setting, and Patients A national cohort of 122 124 patients who were elderly (aged 65–84 years), receiving Medicare, and hospitalized with acute myocardial infarction (AMI) in 1994–1995, and who were eligible for cardiac catheterization. Baseline chart reviews were taken from the Cooperative Cardiovascular Project and linked to Medicare health administrative data to provide a rich set of prognostic variables. Patients were followed up for 7 years through December 31, 2001, to assess the association between long-term survival and cardiac catheterization within 30 days of hospital admission. Main Outcome Measure Risk-adjusted relative mortality rate using each of the analytic methods. Results Patients who received cardiac catheterization (n=73 238) were younger and had lower AMI severity than those who did not. After adjustment for prognostic factors by using standard statistical risk-adjustment methods, cardiac catheterization was associated with a 50% relative decrease in mortality (for multivariable model risk adjustment: adjusted relative risk [RR], 0.51; 95% confidence interval [CI], 0.50–0.52; for propensity score risk adjustment: adjusted RR, 0.54; 95% CI, 0.53–0.55; and for propensity-based matching: adjusted RR, 0.54; 95% CI, 0.52–0.56). Using regional catheterization rate as an instrument, instrumental variable analysis showed a 16% relative decrease in mortality (adjusted RR, 0.84; 95% CI, 0.79–0.90). The survival benefits of routine invasive care from randomized clinical trials are between 8% and 21 %. Conclusions Estimates of the observational association of cardiac catheterization with long-term AMI mortality are highly sensitive to analytic method. All standard risk-adjustment methods have the same limitations regarding removal of unmeasured treatment selection biases. Compared with standard modeling, instrumental variable analysis may produce less biased estimates of treatment effects, but is more suited to answering policy questions than specific clinical questions. PMID:17227979

Early High-Frequency Oscillatory Ventilation in Pediatric Acute Respiratory Failure. A Propensity Score Analysis.

PubMed

Bateman, Scot T; Borasino, Santiago; Asaro, Lisa A; Cheifetz, Ira M; Diane, Shelley; Wypij, David; Curley, Martha A Q

2016-03-01

The use of high-frequency oscillatory ventilation (HFOV) for acute respiratory failure in children is prevalent despite the lack of efficacy data. To compare the outcomes of patients with acute respiratory failure managed with HFOV within 24-48 hours of endotracheal intubation with those receiving conventional mechanical ventilation (CMV) and/or late HFOV. This is a secondary analysis of data from the RESTORE (Randomized Evaluation of Sedation Titration for Respiratory Failure) study, a prospective cluster randomized clinical trial conducted between 2009 and 2013 in 31 U.S. pediatric intensive care units. Propensity score analysis, including degree of hypoxia in the model, compared the duration of mechanical ventilation and mortality of patients treated with early HFOV matched with those treated with CMV/late HFOV. Among 2,449 subjects enrolled in RESTORE, 353 patients (14%) were ever supported on HFOV, of which 210 (59%) had HFOV initiated within 24-48 hours of intubation. The propensity score model predicting the probability of receiving early HFOV included 1,064 patients (181 early HFOV vs. 883 CMV/late HFOV) with significant hypoxia (oxygenation index ≥ 8). The degree of hypoxia was the most significant contributor to the propensity score model. After adjusting for risk category, early HFOV use was associated with a longer duration of mechanical ventilation (hazard ratio, 0.75; 95% confidence interval, 0.64-0.89; P = 0.001) but not with mortality (odds ratio, 1.28; 95% confidence interval, 0.92-1.79; P = 0.15) compared with CMV/late HFOV. In adjusted models including important oxygenation variables, early HFOV was associated with a longer duration of mechanical ventilation. These analyses make supporting the current approach to HFOV less convincing.

A propensity score matching analysis of the relationship between victim sex and capital juror decision-making in North Carolina.

PubMed

Jennings, Wesley G; Richards, Tara N; Smith, M Dwayne; Bjerregaard, Beth; Fogel, Sondra J

2015-07-01

A small body of prior research has examined the impact of victim sex on jury death penalty decision-making and the majority of this research has demonstrated some evidence of a "female victim effect" such that cases involving a female victim are more likely to receive the death penalty than similarly situated cases with a male victim. However, within this line of research studies have suggested that victim sex may work in conjunction with other case characteristics. In order to further explore this phenomenon, the current study examines a near-population of death penalty cases from North Carolina (n=1069) from 1977-2009 using propensity score matching. Results demonstrate that once cases are matched on more than 50 legal and extralegal case characteristics, there is no statistically significant or substantive link between victim sex and death penalty decision-making. Findings suggest that it is concrete differences in the legal and extralegal factors observed in cases with female victims compared to male victims that shape jury death sentence decisions rather than a direct effect of victim sex (before matching: OR=1.53; 95% CI=1.20-1.95; p<.001/after matching: OR=0.90; 95% CI=0.66-1.24; p=.52). Study limitations and implications are also discussed. Copyright © 2015 Elsevier Inc. All rights reserved.

Establishing equivalence: methodological progress in group-matching design and analysis.

PubMed

Kover, Sara T; Atwoo, Amy K

2013-01-01

This methodological review draws attention to the challenges faced by intellectual and developmental disabilities researchers in the appropriate design and analysis of group comparison studies. We provide a brief overview of matching methodologies in the field, emphasizing group-matching designs used in behavioral research on cognition and language in neurodevelopmental disorders, including autism spectrum disorder, Fragile X syndrome, Down syndrome, and Williams syndrome. The limitations of relying on p values to establish group equivalence are discussed in the context of other existing methods: equivalence tests, propensity scores, and regression-based analyses. Our primary recommendation for advancing research on intellectual and developmental disabilities is the use of descriptive indices of adequate group matching: effect sizes (i.e., standardized mean differences) and variance ratios.

Establishing Equivalence: Methodological Progress in Group-Matching Design and Analysis

PubMed Central

Kover, Sara T.; Atwood, Amy K.

2017-01-01

This methodological review draws attention to the challenges faced by intellectual and developmental disabilities researchers in the appropriate design and analysis of group comparison studies. We provide a brief overview of matching methodologies in the field, emphasizing group-matching designs utilized in behavioral research on cognition and language in neurodevelopmental disorders, including autism spectrum disorder, fragile X syndrome, Down syndrome, and Williams syndrome. The limitations of relying on p-values to establish group equivalence are discussed in the context of other existing methods: equivalence tests, propensity scores, and regression-based analyses. Our primary recommendation for advancing research on intellectual and developmental disabilities is the use of descriptive indices of adequate group matching: effect sizes (i.e., standardized mean differences) and variance ratios. PMID:23301899

Attributable Cost of Clostridium difficile Infection in Pediatric Patients.

PubMed

Mehrotra, Preeti; Jang, Jisun; Gidengil, Courtney; Sandora, Thomas J

2017-12-01

OBJECTIVES The attributable cost of Clostridium difficile infection (CDI) in children is unknown. We sought to determine a national estimate of attributable cost and length of stay (LOS) of CDI occurring during hospitalization in children. DESIGN AND METHODS We analyzed discharge records of patients between 2 and 18 years of age from the Agency for Healthcare Research and Quality (AHRQ) Kids' Inpatient Database. We created a logistic regression model to predict CDI during hospitalization based on demographic and clinical characteristics. Predicted probabilities from the logistic regression model were then used as propensity scores to match 1:2 CDI to non-CDI cases. Charges were converted to costs and compared between patients with CDI and propensity-score-matched controls. In a sensitivity analysis, we adjusted for LOS as a confounder by including it in both the propensity score and a generalized linear model predicting cost. RESULTS We identified 8,527 pediatric hospitalizations (0.53%) with a diagnosis of CDI and 1,597,513 discharges without CDI. In our matched cohorts, the attributable cost of CDI occurring during a hospitalization ranged from $1,917 to $8,317, depending on whether model was adjusted for LOS. When not adjusting for LOS, CDI-associated hospitalizations cost 1.6 times more than non-CDI associated hospitalizations. Attributable LOS of CDI was approximately 4 days. CONCLUSIONS Clostridium difficile infection in hospitalized children is associated with an economic burden similar to adult estimates. This finding supports a continued focus on preventing CDI in children as a priority. Pediatric CDI cost analyses should account for LOS as an important confounder of cost. Infect Control Hosp Epidemiol 2017;38:1472-1477.

Improved Survival After the Ross Procedure Compared With Mechanical Aortic Valve Replacement.

PubMed

Buratto, Edward; Shi, William Y; Wynne, Rochelle; Poh, Chin L; Larobina, Marco; O'Keefe, Michael; Goldblatt, John; Tatoulis, James; Skillington, Peter D

2018-03-27

It is unclear whether the Ross procedure offers superior survival compared with mechanical aortic valve replacement (AVR). This study evaluated experience and compared long-term survival between the Ross procedure and mechanical AVR. Between 1992 and 2016, a total of 392 Ross procedures were performed. These were compared with 1,928 isolated mechanical AVRs performed during the same time period as identified using the University of Melbourne and Australia and New Zealand Society of Cardiac and Thoracic Surgeons' Cardiac Surgery Databases. Only patients between 18 and 65 years of age were included. Propensity-score matching was performed for risk adjustment. Ross procedure patients were younger, and had fewer cardiovascular risk factors. The Ross procedure was associated with longer cardiopulmonary bypass and aortic cross-clamp times. Thirty-day mortality was similar (Ross, 0.3%; mechanical, 0.8%; p = 0.5). Ross procedure patients experienced superior unadjusted long-term survival at 20 years (Ross, 95%; mechanical, 68%; p < 0.001). Multivariable analysis showed the Ross procedure to be associated with a reduced risk of late mortality (hazard ratio: 0.34; 95% confidence internal: 0.17 to 0.67; p < 0.001). Among 275 propensity-score matched pairs, Ross procedure patients had superior survival at 20 years (Ross, 94%; mechanical, 84%; p = 0.018). In this Australian, propensity-score matched study, the Ross procedure was associated with better long-term survival compared with mechanical AVR. In younger patients, with a long life expectancy, the Ross procedure should be considered in centers with sufficient expertise. Crown Copyright © 2018. Published by Elsevier Inc. All rights reserved.

Impact of warm ischaemia time on postoperative renal function after partial nephrectomy for clinical T1 renal cell carcinoma: a propensity score-matched study.

PubMed

Lee, Hakmin; Song, Byung D; Byun, Seok-Soo; Lee, Sang E; Hong, Sung K

2018-01-01

To analyse the effect of prolonged warm ischaemia time (WIT) on long-term renal function after partial nephrectomy (PN), as controversy still exists as to whether prolonged WIT adversely affects the incidence of chronic kidney disease (CKD) after PN. We reviewed data from 1816 patients who underwent PN for a clinical T1 renal tumour. The propensity scores for prolonged WIT were calculated with the shorter WIT group (<30 min) matched to the longer WIT group (≥30 min) in a 2:1 ratio. Multivariate analysis was used to determine independent predictors for occurrence of postoperative CKD [defined as an estimated glomerular filtration rate (eGFR) of <60 mL/min/1.73 m 2 ] and major renal function deterioration (MRFD; defined as an eGFR decrease of ≥25% postoperatively). After propensity score matching, there was no significant difference in CKD-free survival between the two WIT groups (P = 0.787). Furthermore, longer WIT did not show any significant associations with postoperative CKD-free survival [hazard ratio (HR) 1.002, 95% confidence interval (CI) 0.989-1.015; P = 0.765) and MRFD-free survival (HR 1.014, 95% CI 1.000-1.028; P = 0.055). From further subgroup analyses using more specific WIT thresholds (≤20, 21-30, 31-40, 41-50, ≥50 min) and status of preoperative CKD, no significant differences were noted in CKD and MRFD-free survival amongst the subgroups (all P > 0.05). Prolonged WIT was not associated with increased incidence of CKD or MRFD after PN. © 2017 The Authors BJU International © 2017 BJU International Published by John Wiley & Sons Ltd.

Attributable costs of central line-associated bloodstream infections in a pediatric hematology/oncology population.

PubMed

Wilson, Matthew Z; Rafferty, Colleen; Deeter, Deana; Comito, Melanie A; Hollenbeak, Christopher S

2014-11-01

Although several studies have estimated the attributable cost and length of stay (LOS) of central line-associated bloodstream infections (CLABSIs) in the pediatric intensive care unit setting, little is known about the attributable costs and LOS of CLABSIs in the vulnerable pediatric hematology/oncology population. We studied a total of 1562 inpatient admissions for 291 pediatric hematology/oncology patients at a single tertiary care children's hospital in the mid-Atlantic region between January 2008 and May 2011. Costs were normalized to year 2011 dollars. Propensity score matching was used to estimate the effect of CLABSIs on total cost and LOS while controlling for other covariates. Sixty CLABSIs occurred during the 1562 admissions. Compared with the patients without a CLABSI, those who developed a CLABSI tended to be older (9.0 years vs 7.5 years; P = .026) and to have a tunneled catheter (46.7% vs 27.0%) and a peripherally inserted central catheter (20.0% vs 11.2%) as opposed to other types of catheters (P < .0001). Propensity score matching yielded matched groups without significant differences in patient characteristics. In the propensity score analysis, the attributable LOS of a CLABSI was 21.2 days (P < .0001), and the attributable cost of a CLABSI was $69,332 (P < .0001). Among pediatric hematology/oncology patients, CLABSI was associated with an additional LOS of 21 days and increased costs of nearly $70,000. These findings may inform decisions regarding the value of investing in efforts to prevent CLABSIs in this vulnerable population. Copyright © 2014 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Amiodarone use in patients listed for heart transplant is associated with increased 1-year post-transplant mortality.

PubMed

Cooper, Lauren B; Mentz, Robert J; Edwards, Leah B; Wilk, Amber R; Rogers, Joseph G; Patel, Chetan B; Milano, Carmelo A; Hernandez, Adrian F; Stehlik, Josef; Lund, Lars H

2017-02-01

Pre-transplant amiodarone use has been postulated as a risk factor for morbidity and mortality after orthotopic heart transplantation (OHT). We assessed pre-OHT amiodarone use and tested the hypothesis that it is associated with impaired post-OHT outcomes. We performed a retrospective cohort analysis of adult OHT recipients from the registry of the International Society for Heart and Lung Transplantation (ISHLT). All patients had been transplanted between 2005 and 2013 and were stratified by pre-OHT amiodarone use. We derived propensity scores using logistic regression with amiodarone use as the dependent variable, and assessed the associations between amiodarone use and outcomes with Kaplan-Meier analysis after matching patients 1:1 based on propensity score, and with Cox regression with adjustment for propensity score. Of the 14,944 OHT patients in the study cohort, 32% (N = 4,752) received pre-OHT amiodarone. Amiodarone use was higher in recent years (29% in 2005 to 2007, 32% in 2008 to 2010, 35% in 2011 to 2013). Amiodarone-treated patients were older and more frequently had a history of sudden cardiac death (27% vs 13%) and pre-OHT mechanical circulatory support. Key donor characteristics and allograft ischemia times were similar between groups. In propensity-matched analyses, amiodarone-treated patients had higher rates of cardiac reoperation (15% vs 13%) and permanent pacemaker (5% vs 3%) after OHT and before discharge. Amiodarone-treated patients also had higher 1-year mortality (hazard ratio 1.15, 95% confidence interval 1.02 to 1.30), but the risks of early graft failure, retransplantation and rehospitalization were similar between groups. Amiodarone use before OHT was independently associated with increased 1-year mortality. The need for amiodarone therapy should be carefully and continuously assessed in patients awaiting OHT. Copyright © 2016 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

Anterior Versus Posterior Approach for Multilevel Degenerative Cervical Disease: A Retrospective Propensity Score-Matched Study of the MarketScan Database.

PubMed

Cole, Tyler; Veeravagu, Anand; Zhang, Michael; Azad, Tej D; Desai, Atman; Ratliff, John K

2015-07-01

Retrospective 2:1 propensity score-matched analysis on a national longitudinal database between 2006 and 2010. To compare rates of adverse events, revisions procedure rates, and payment differences in anterior cervical fusion procedures compared with posterior laminectomy and fusion procedures with at least 3 levels of instrumentation. The comparative benefits of anterior versus posterior approach to multilevel degenerative cervical disease remain controversial. Recent systematic reviews have reached conflicting conclusions. We demonstrate the comparative economic and clinical outcomes of anterior and posterior approaches for multilevel cervical degenerative disk disease. We identified 13,662 patients in a national billing claims database who underwent anterior or posterior cervical fusion procedures with 3 or more levels of instrumentation. Cohorts were balanced using 2:1 propensity score matching and outcomes were compared using bivariate analysis. With the exception of dysphagia (6.4% in anterior and 1.4% in posterior), overall 30-day complication rates were lower in the anterior approach group. The rate of any complication excluding dysphagia with anterior approaches was 12.3%, significantly lower (P < 0.0001) than that of posterior approaches, 17.8%. Anterior approaches resulted in lower hospital ($18,346 vs. $23,638) and total payments ($28,963 vs. $33,526). Patients receiving an anterior surgical approach demonstrated significantly lower rate of 30-day readmission (5.1% vs. 9.9%, P < 0.0001), were less likely to require revision surgery (12.8% vs. 18.1%, P < 0.0001), and had a shorter length of stay by 1.5 nights (P < 0.0001). Anterior approaches in the surgical management of multilevel degenerative cervical disease provide clinical advantages over posterior approaches, including lower overall complication rates, revision procedure rates, and decreased length of stay. Anterior approach procedures are also associated with decreased overall payments. These findings must be interpreted in light of limitations inherent to retrospective longitudinal studies including absence of subjective and radiographical outcomes. 3.

Within-Cluster and Across-Cluster Matching with Observational Multilevel Data

ERIC Educational Resources Information Center

Kim, Jee-Seon; Steiner, Peter M.; Hall, Courtney; Thoemmes, Felix

2013-01-01

When randomized experiments cannot be conducted in practice, propensity score (PS) techniques for matching treated and control units are frequently used for estimating causal treatment effects from observational data. Despite the popularity of PS techniques, they are not yet well studied for matching multilevel data where selection into treatment…

Bayesian Model Averaging for Propensity Score Analysis

ERIC Educational Resources Information Center

Kaplan, David; Chen, Jianshen

2013-01-01

The purpose of this study is to explore Bayesian model averaging in the propensity score context. Previous research on Bayesian propensity score analysis does not take into account model uncertainty. In this regard, an internally consistent Bayesian framework for model building and estimation must also account for model uncertainty. The…

Effects of dialysate to serum sodium (Na+) alignment in chronic hemodialysis (HD) patients: retrospective cohort study from a quality improvement project.

PubMed

Raimann, Jochen G; Ficociello, Linda H; Usvyat, Len A; Zhang, Hanjie; Pacelli, Lisa; Moore, Sandi; Sheppard, Penny; Xiao, Qingqing; Wang, Yuedong; Mullon, Claudy; Balter, Paul; Sullivan, Terry; Kotanko, Peter

2018-04-02

Evidence indicates favorable effects of dialysate (DNa + ) to serum sodium concentration (SNa + ) alignment, however, results from larger sample populations are needed. For this reason, we conducted a retrospective propensity score-matched cohort study from a quality improvement project to investigate the effects of alignment on population of maintenance hemodialysis patients. At 4 participating hemodialysis (HD) clinics, patients with SNa + lower than the standard DNa + of 137 mEq/L who received HD with DNa + aligned to the average of the last 4 SNa + measurements were evaluated (clinicaltrials.gov # NCT01825590 ). In this retrospective data analysis, an intention-to-treat (primary) and an as-treated "intervention" (secondary) cohort were created. "Aligned" patients from both cohorts (N = 163 for the primary and N = 137 for the secondary) were then propensity-score matched in a 1:1 fashion to "unaligned" patients from the Renal Research Institute database. The propensity score was generated based on age, gender, white race, Hispanic ethnicity, absence or presence of diabetes, hemodialysis vintage, interdialytic weight gain (IDWG; as a percentage of postdialysis body weight), catheter as primary dialysis access, predialysis systolic blood pressure, serum sodium concentration, hospitalization count during baseline. T-Test was employed for group comparisons of changes to the primary (volume-related and hemodynamic parameters) and tertiary outcomes. All-cause and fluid overload-related hospitalization admission rates were compared using Wilcoxon Rank Sum test and Cox regression analysis for repeated events. In the primary analysis, aligned and unaligned subjects showed comparable demographics at baseline. Treatment effects were significant for IDWG [-0.12 (95% CI -0.24 to 0) L] and showed decreasing non-significant trends for pre-dialysis hemodynamic parameters. Count comparison and Cox regression analysis showed no clear advantage of alignment in terms of all-cause and fluid overload-related hospitalization. Results from the largest sodium alignment program to date suggest positive treatment effects on volume-related and hemodynamic parameters, but no clear effect on risk of hospitalization. Well-matched control patients minimized confounding effects. Small effects and lack of significant differences may be explained by a low baseline DNa + limiting the interventional change.

How Socio-Emotional Support Affects Post-Compulsory Education Decisions in Rural China

ERIC Educational Resources Information Center

Yao, Haogen

2017-01-01

This study develops a sequential mixed model of Delphi-Propensity Score Matching to discuss how an NGO's socio-emotional support affects the decisions of dropout, work, and two types of upper secondary schooling in rural China. Data were collected from 6,298 students in 2012 after a subgroup of them were treated. The analysis shows that…

A Cross-National Analysis of the Relations of School Choice and Effectiveness Differences between Private-Dependent and Public Schools

ERIC Educational Resources Information Center

Dronkers, Jaap; Avram, Silvia

2010-01-01

We apply propensity score matching to the estimation of differential school effectiveness between the publicly funded private sector and the public sector in a sample of 26 countries. This technique allows us to distinguish between school choice and school effectiveness processes and thus to account for selectivity issues involved in the…

Parental Empowerment in Mexico: Randomized Experiment of the "Apoyos a La Gestion Escolar (Age)" Program in Rural Primary Schools in Mexico

ERIC Educational Resources Information Center

Gertler, Paul; Patrinos, Harry Anthony; Rodriguez-Oreggia, Eduardo

2012-01-01

Previous evaluations from Mexico are limited. The urban school-based management program, Programa Escuelas de Calidad (PEC), was analyzed using panel data regression analysis and propensity score matching. Participation in PEC is found to lead to decreases in dropout, failure and repetition rates. An evaluation of the rural parental empowerment…

Association Between Subjective Obesity Status and Smoking Behavior Among Normal-Weight Women.

PubMed

Kim, Dae-Hwan

2018-06-01

Smoking and obesity are chief causes of mortality, morbidity, and medical expenditure. However, few studies have investigated the linkage between subjective obesity status and smoking behavior. This study examines whether females in a normal body mass index range who perceive themselves as obese are more likely to smoke than those who do not perceive themselves as obese. Stratifying by age-group, I employed the propensity score matching analysis to control for selection bias. Although body mass index is lower for younger females aged 20 to 39, they are more likely than elder females to consider themselves as obese. Based on a logistic regression, my findings show that younger females who perceive themselves as obese are 21.2% more likely to smoke than females who do not perceive themselves as obese. The positive relationship between perceived obesity status and smoking behavior is also found in the propensity score matching analysis. However, the disparity in smoking prevalence is not detected between elder females who perceive themselves as obese and those who do not. Public education that fosters accurate perception of body shape is imperative in inducing healthy lifestyles and improving social welfare.

Propensity score analysis with partially observed covariates: How should multiple imputation be used?

PubMed

Leyrat, Clémence; Seaman, Shaun R; White, Ian R; Douglas, Ian; Smeeth, Liam; Kim, Joseph; Resche-Rigon, Matthieu; Carpenter, James R; Williamson, Elizabeth J

2017-01-01

Inverse probability of treatment weighting is a popular propensity score-based approach to estimate marginal treatment effects in observational studies at risk of confounding bias. A major issue when estimating the propensity score is the presence of partially observed covariates. Multiple imputation is a natural approach to handle missing data on covariates: covariates are imputed and a propensity score analysis is performed in each imputed dataset to estimate the treatment effect. The treatment effect estimates from each imputed dataset are then combined to obtain an overall estimate. We call this method MIte. However, an alternative approach has been proposed, in which the propensity scores are combined across the imputed datasets (MIps). Therefore, there are remaining uncertainties about how to implement multiple imputation for propensity score analysis: (a) should we apply Rubin's rules to the inverse probability of treatment weighting treatment effect estimates or to the propensity score estimates themselves? (b) does the outcome have to be included in the imputation model? (c) how should we estimate the variance of the inverse probability of treatment weighting estimator after multiple imputation? We studied the consistency and balancing properties of the MIte and MIps estimators and performed a simulation study to empirically assess their performance for the analysis of a binary outcome. We also compared the performance of these methods to complete case analysis and the missingness pattern approach, which uses a different propensity score model for each pattern of missingness, and a third multiple imputation approach in which the propensity score parameters are combined rather than the propensity scores themselves (MIpar). Under a missing at random mechanism, complete case and missingness pattern analyses were biased in most cases for estimating the marginal treatment effect, whereas multiple imputation approaches were approximately unbiased as long as the outcome was included in the imputation model. Only MIte was unbiased in all the studied scenarios and Rubin's rules provided good variance estimates for MIte. The propensity score estimated in the MIte approach showed good balancing properties. In conclusion, when using multiple imputation in the inverse probability of treatment weighting context, MIte with the outcome included in the imputation model is the preferred approach.

Increased Rate of Poor Laryngoscopic Views in Patients Scheduled for Cardiac Surgery Versus Patients Scheduled for General Surgery: A Propensity Score-Based Analysis of 21,561 Cases.

PubMed

Heinrich, Sebastian; Ackermann, Andreas; Prottengeier, Johannes; Castellanos, Ixchel; Schmidt, Joachim; Schüttler, Jürgen

2015-12-01

Former analyses reported an increased rate of poor direct laryngoscopy view in cardiac surgery patients; however, these findings frequently could be attributed to confounding patient characteristics. In most of the reported cardiac surgery cohorts, the rate of well-known risk factors for poor direct laryngoscopy view such as male sex, obesity, or older age, were increased compared with the control groups. Especially in the ongoing debate on anesthesia staff qualification for cardiac interventions outside the operating room a detailed and stratified risk analysis seems necessary. Retrospective, anonymous, propensity score-based, matched-pair analysis. Single-center study in a university hospital. No active participants. Retrospective, anonymous chart analysis. The anesthesia records of patients undergoing cardiac surgery in a period of 6 consecutive years were analyzed retrospectively. The results were compared with those of a control group of patients who underwent general surgery. Poor laryngoscopic view was defined as Cormack and Lehane classification grade 3 or 4. The records of 21,561 general anesthesia procedures were reviewed for the study. The incidence of poor direct laryngoscopic views in patients scheduled for cardiac surgery was significantly increased compared with those of the general surgery cohort (7% v 4.2%). Using propensity score-based matched-pair analysis, equal subgroups were generated of each surgical department, with 2,946 patients showing identical demographic characteristics. After stratifying for demographic characteristics, the rate of poor direct laryngoscopy view remained statistically significantly higher in the cardiac surgery group (7.5% v 5.7%). Even with stratification for demographic risk factors, cardiac surgery patients showed a significantly higher rate of poor direct laryngoscopic view compared with general surgery patients. These results should be taken into account for human resource management and distribution of difficult airway equipment, especially when cardiac interventional programs are implemented in remote hospital locations. Copyright © 2015 Elsevier Inc. All rights reserved.

Total Shoulder Arthroplasty: Is Less Time in the Hospital Better?

PubMed

Duchman, Kyle R; Anthony, Chris A; Westermann, Robert W; Pugely, Andrew J; Gao, Yubo; Hettrich, Carolyn M

2017-01-01

The incidence of total shoulder arthroplasty (TSA) has increased significantly over the last decade. Short-stay protocols for other highvolume procedures have been shown to be safe and effective but have yet to be fully explored for TSA. Our purpose in comparing short-stay and inpatient TSA was to determine: (1) patient demographics and comorbidities, (2) 30-day morbidity, mortality, and readmissions using a matched analysis, and (3) independent predictors of 30-day complications. The American College of Surgeons National Surgical Quality Improvement (ACS NSQIP) database was queried and all patients undergoing elective, primary TSA between 2006 and 2013 were identified. Patients were categorized as short-stay or inpatient based on day of discharge. Propensity score matching was used to adjust for selection bias. Univariate and multivariate statistical analysis was used to compare 30-day morbidity and mortality between the two cohorts. Overall, 4,619 cases were available, with inpatient admission occurring in 65.7% of patients. Prior to propensity score matching, short-stay patients were significantly younger, more frequently male, with fewer comorbid conditions. After matching, inpatient admission was associated with increased rates of urinary tract infection (1.1% vs. 0.1%; p = 0.001), blood transfusion (5.3% vs. 0.8%; p < 0.001), and total complications (4.7% vs. 1.8%; p < 0.001). Multivariate analysis identified inpatient admission as an independent risk factor for 30-day complication following TSA. Short-stay TSA is a safe option for the appropriately selected patient. Inpatient admission was an independent risk factor for complication following TSA. Level of Evidence: III.

Revictimization After Adolescent Dating Violence in a Matched, National Sample of Youth.

PubMed

Exner-Cortens, Deinera; Eckenrode, John; Bunge, John; Rothman, Emily

2017-02-01

To assess if adolescent dating violence was associated with physical intimate partner violence victimization in adulthood, using a comprehensive propensity score to create a matched group of victims and nonvictims. Secondary analysis of waves 1 (1994-1995), 2 (1996), 3 (2001-2002) and 4 (2007-2008) of the National Longitudinal Study of Adolescent to Adult Health, a nationally representative sample of US high schools and middle schools. Individuals aged 12-18 reporting adolescent dating violence between the wave 1 and 2 interviews (n = 732) were matched to nonvictimized participants of the same sex (n = 1,429) using propensity score matching. These participants were followed up approximately 5 (wave 3) and 12 (wave 4) years later. At both follow-up points, physical violence victimization by a current partner was assessed. Data were analyzed using path models. Compared with the matched no victimization group, individuals reporting adolescent dating violence were more likely to experience physical intimate partner violence approximately 12 years later (wave 4), through the experience of 5-year (wave 3) victimization. This path held for males and females. Results from this sample matched on key risk variables suggest that violence first experienced in adolescent relationships may become chronic, confirming adolescent dating violence as an important risk factor for adult partner violence. Findings from this study underscore the critical role of primary and secondary prevention for adolescent dating violence. Copyright © 2016 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Protective Lung Ventilation and Morbidity After Pulmonary Resection: A Propensity Score-Matched Analysis.

PubMed

Amar, David; Zhang, Hao; Pedoto, Alessia; Desiderio, Dawn P; Shi, Weiji; Tan, Kay See

2017-07-01

Protective lung ventilation (PLV) during one-lung ventilation (OLV) for thoracic surgery is frequently recommended to reduce pulmonary complications. However, limited outcome data exist on whether PLV use during OLV is associated with less clinically relevant pulmonary morbidity after lung resection. Intraoperative data were prospectively collected in 1080 patients undergoing pulmonary resection with OLV, intentional crystalloid restriction, and mechanical ventilation to maintain inspiratory peak airway pressure <30 cm H2O. Other ventilator settings and all aspects of anesthetic management were at the discretion of the anesthesia care team. We defined PLV and non-PLV as <8 or ≥8 mL/kg (predicted body weight) mean tidal volume. The primary outcome was the occurrence of pneumonia and/or acute respiratory distress syndrome (ARDS). Propensity score matching was used to generate PLV and non-PLV groups with comparable characteristics. Associations between outcomes and PLV status were analyzed by exact logistic regression, with matching as cluster in the anatomic and nonanatomic lung resection cohorts. In the propensity score-matched analysis, the incidence of pneumonia and/or ARDS among patients who had an anatomic lung resection was 9/172 (5.2%) in the non-PLV compared to the PLV group 7/172 (4.1%; odds ratio, 1.29; 95% confidence interval, 0.48-3.45, P= .62). The incidence of pneumonia and/or ARDS in patients who underwent nonanatomic resection was 3/118 (2.5%) in the non-PLV compared to the PLV group, 1/118 (0.9%; odds ratio, 3.00; 95% confidence interval, 0.31-28.84, P= .34). In this prospective observational study, we found no differences in the incidence of pneumonia and/or ARDS between patients undergoing lung resection with tidal volumes <8 or ≥8 mL/kg. Our data suggest that when fluid restriction and peak airway pressures are limited, the clinical impact of PLV in this patient population is small. Future randomized trials are needed to better understand the benefits of a small tidal volume strategy during OLV on clinically important outcomes.

Estimating Treatment Effects via Multilevel Matching within Homogenous Groups of Clusters

ERIC Educational Resources Information Center

Steiner, Peter M.; Kim, Jee-Seon

2015-01-01

Despite the popularity of propensity score (PS) techniques they are not yet well studied for matching multilevel data where selection into treatment takes place among level-one units within clusters. This paper suggests a PS matching strategy that tries to avoid the disadvantages of within- and across-cluster matching. The idea is to first…

Luminal-like HER2-negative stage IA breast cancer: a multicenter retrospective study on long-term outcome with propensity score analysis

PubMed Central

De Angelis, Carmine; Di Maio, Massimo; Crispo, Anna; Giuliano, Mario; Schettini, Francesco; Bonotto, Marta; Gerratana, Lorenzo; Iacono, Donatella; Cinausero, Marika; Riccardi, Ferdinando; Ciancia, Giuseppe; De Laurentiis, Michelino; Puglisi, Fabio; De Placido, Sabino; Arpino, Grazia

2017-01-01

The benefit of adding chemotherapy (CT) to adjuvant hormone therapy (HT) in stage IA luminal-like HER2-negative breast cancer (BC) is unclear. We retrospectively evaluated predictive factors and clinical outcome of 1,222 patients from 4 oncologic centers. Three hundred and eighty patients received CT and HT (CT-cohort) and 842 received HT alone (HT-cohort). Disease-free survival (DFS) and overall survival (OS) were evaluated with univariate and multivariate analyses. We also applied the propensity score methodology. Compared with the HT-cohort, patients in the CT-cohort were more likely to be younger, have larger tumors of a higher histological grade that were Ki67-positive, and lower estrogen and progesterone receptor expression. At univariate analysis, a higher histological grade and Ki67 were significantly associated to a lower DFS. At multivariable analysis, only histological grade was predictive of DFS. The CT-cohort had a worse outcome than the HT-cohort in terms of DFS and OS, but differences disappeared when matched according to propensity score. In summary, patients with stage IA luminal-like BC had an excellent prognosis, however relapse and mortality were higher in the CT-cohort than in the HT-cohort. Longer use of adjuvant HT or other therapeutic strategies may be needed to improve outcome. PMID:29348868

A Non-bipartite Propensity Score Analysis of the Effects of Teacher-Student Relationships on Adolescent Problem and Prosocial Behavior.

PubMed

Obsuth, Ingrid; Murray, Aja Louise; Malti, Tina; Sulger, Philippe; Ribeaud, Denis; Eisner, Manuel

2017-08-01

Previous research suggests a link between the quality of teacher-student relationships and the students' behavioral outcomes; however, the observational nature of past studies makes it difficult to attribute a causal role to the quality of these relationships. In the current study, therefore, we used a propensity score analysis approach to evaluate whether students who were matched on their propensity to experience a given level of relationship quality but differed on their actual relationship quality diverged on their concurrent and subsequent problem and prosocial behavior. Student/self, teacher, and parent- (only waves 1-3) reported data from 8 waves of the Zurich Project on the Social Development of Children and Youths (z-proso), a longitudinal study of Swiss youth among a culturally diverse sample of 7- to 15-year-olds were utilized. The initial sample included 1483 (49.4 % female) students for whom information relevant for this study was available. The sample represented families from around 80 different countries, from across all the continents; with approximately 42 % of the female primary caregivers having been born in Switzerland. Following successful matching, we found that students who reported better relationships with their teachers and whose teachers reported better relationships with them evidenced fewer problem behaviors concurrently and up to 4 years later. There was also evidence for an analogous effect in predicting prosocial behavior. The implications of these findings are discussed in relation to prevention and intervention practices.

Intermittent chest tube clamping may shorten chest tube drainage and postoperative hospital stay after lung cancer surgery: a propensity score matching analysis.

PubMed

Yan, Shi; Wang, Xing; Wang, Yaqi; Lv, Chao; Wang, Yuzhao; Wang, Jia; Yang, Yue; Wu, Nan

2017-12-01

Postoperative pleural drainage markedly influences the length of hospital stay and the financial costs of medical care. The safety of chest tube clamping before removal has been documented. This study aims to determine if intermittent chest tube clamping shortens the duration of chest tube drainage and hospital stay after lung cancer surgery. We retrospectively analyzed 285 consecutive patients with operable lung cancer treated using lobectomy and systematic mediastinal lymphadenectomy. The chest tube management protocol in our institution was changed in January 2014, and thus, 222 patients (clamping group) were managed with intermittent chest tube clamping, while 63 patients (control group) were managed with a traditional protocol. Propensity score matching at a 1:1 ratio was applied to balance variables potentially affecting the duration of chest tube drainage. Analyses were performed to compare drainage duration and postoperative hospital stay between the two groups in the matched cohort. Multivariate logistic regression analyses were performed to predict the factors associated with chest tube drainage duration. The rates of thoracocentesis after chest tube removal were similar between the clamping and control groups in the whole cohort (0.5% vs. 1.6%, P=0.386). The rates of pyrexia were also comparable in the two groups (2.3% vs. 3.2%, P=0.685). After propensity score matching, 61 cases remained in each group. Both chest tube drainage duration (3.9 vs. 4.8 days, P=0.001) and postoperative stay (5.7 vs. 6.4 days, P=0.025) were significantly shorter in the clamping group than in the control group. Factors significantly associated with shorter chest tube drainage duration were female sex, chest tube clamping, left lobectomy, and video-assisted thoracoscopic surgery (VATS) (P<0.05). Intermittent postoperative chest tube clamping may decrease the duration of chest tube drainage and postoperative hospital stay while maintaining patient safety.

Association between renin-angiotensin system antagonist use and mortality in heart failure with severe renal insufficiency: a prospective propensity score-matched cohort study.

PubMed

Edner, Magnus; Benson, Lina; Dahlström, Ulf; Lund, Lars H

2015-09-07

In heart failure (HF) with reduced ejection fraction (EF), renin-angiotensin receptor (RAS) antagonists reduce mortality. However, severe renal insufficiency was an exclusion criterion in trials. We tested the hypothesis that RAS antagonists are associated with reduced mortality also in HF with severe renal insufficiency. We studied patients with EF ≤39% registered in the prospective Swedish Heart Failure Registry. In patients with creatinine >221 µmol/L or creatinine clearance <30 mL/min, propensity scores for RAS-antagonist use were derived from 36 variables. The association between RAS antagonist use and all-cause mortality was assessed with Cox regression in a cohort matched 1:1 based on age and propensity score. To assess consistency, we performed the same analysis as a 'positive control' in patients without severe renal insufficiency. Between 2000 and 2013, there were 24 283 patients of which 2410 [age, mean (SD), 82 (9), 45% women] had creatinine >221 µmol/L or creatinine clearance <30 mL/min and were treated (n = 1602) or not treated (n = 808) with RAS antagonists. In the matched cohort of 602 vs. 602 patients [age 83 (8), 42% women], RAS antagonist use was associated with 55% [95% confidence interval (CI) 51-59] vs. 45% (41-49) 1-year survival, P < 0.001, with a hazard ratio (HR) for mortality of 0.76 (95% CI 0.67-0.86, P < 0.001). In positive control patients without severe renal insufficiency [n = 21 873; age 71 (12), 27% women], the matched HR was 0.79 (95% CI 0.72-0.86, P < 0.001). In HF with severe renal insufficiency, the use of RAS antagonists was associated with lower all-cause mortality. Prospective randomized trials are needed before these findings can be applied to clinical practice. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

The impacts of speed cameras on road accidents: an application of propensity score matching methods.

PubMed

Li, Haojie; Graham, Daniel J; Majumdar, Arnab

2013-11-01

This paper aims to evaluate the impacts of speed limit enforcement cameras on reducing road accidents in the UK by accounting for both confounding factors and the selection of proper reference groups. The propensity score matching (PSM) method is employed to do this. A naïve before and after approach and the empirical Bayes (EB) method are compared with the PSM method. A total of 771 sites and 4787 sites for the treatment and the potential reference groups respectively are observed for a period of 9 years in England. Both the PSM and the EB methods show similar results that there are significant reductions in the number of accidents of all severities at speed camera sites. It is suggested that the propensity score can be used as the criteria for selecting the reference group in before-after control studies. Speed cameras were found to be most effective in reducing accidents up to 200 meters from camera sites and no evidence of accident migration was found. Copyright © 2013 Elsevier Ltd. All rights reserved.

Empirical Benchmarks of Hidden Bias in Educational Research: Implication for Assessing How well Propensity Score Methods Approximate Experiments and Conducting Sensitivity Analysis

ERIC Educational Resources Information Center

Dong, Nianbo; Lipsey, Mark

2014-01-01

When randomized control trials (RCT) are not feasible, researchers seek other methods to make causal inference, e.g., propensity score methods. One of the underlined assumptions for the propensity score methods to obtain unbiased treatment effect estimates is the ignorability assumption, that is, conditional on the propensity score, treatment…

Aseptic Freeze-Dried versus Sterile Wet-Packaged Human Cadaveric Acellular Dermal Matrix in Immediate Tissue Expander Breast Reconstruction: A Propensity Score Analysis.

PubMed

Hanson, Summer E; Meaike, Jesse D; Selber, Jesse C; Liu, Jun; Li, Liang; Hassid, Victor J; Baumann, Donald P; Butler, Charles E; Garvey, Patrick B

2018-05-01

Although multiple acellular dermal matrix sources exist, it is unclear how its processing impacts complication rates. The authors compared complications between two preparations of human cadaveric acellular dermal matrix (freeze dried and ready-to-use) in immediate tissue expander breast reconstruction to analyze the effect of processing on complications. The authors retrospectively reviewed all alloplastic breast reconstructions with freeze-dried or ready-to-use human acellular dermal matrices between 2006 and 2016. The primary outcome measure was surgical-site occurrence defined as seroma, skin dehiscence, surgical-site infection, or reconstruction failure. The two groups were compared before and after propensity score matching. The authors included 988 reconstructions (freeze-dried, 53.8 percent; ready-to-use, 46.2 percent). Analysis of 384 propensity score-matched pairs demonstrated a slightly higher rate of surgical-site occurrence (21.4 percent versus 16.7 percent; p = 0.10) and surgical-site infection (9.6 percent versus 7.8 percent; p = 0.13) in the freeze-dried group than in the ready-to-use group, but the difference was not significant. However, failure was significantly higher for the freeze-dried versus ready-to-use group (7.8 percent versus 4.4 percent; p = 0.050). This is the largest study comparing the outcomes of alloplastic breast reconstruction using human acellular dermal matrix materials prepared by different methods. The authors demonstrated higher early complications with aseptic, freeze-dried matrix than with sterile ready-to-use matrix; reconstructive failure was the only outcome to achieve statistical significance. The authors conclude that acellular dermal matrix preparation has an independent impact on patient outcomes in their comparison of one company's product. Therapeutic, III.

The significant influence of having children on the postoperative prognosis of patients with nonsmall cell lung cancer: A propensity score-matched analysis.

PubMed

Takamori, Shinkichi; Tagawa, Tetsuzo; Toyokawa, Gouji; Ueo, Hiroki; Shimokawa, Mototsugu; Kinoshita, Fumihiko; Matsubara, Taichi; Kozuma, Yuka; Haratake, Naoki; Akamine, Takaki; Katsura, Masakazu; Takada, Kazuki; Hirai, Fumihiko; Shoji, Fumihiro; Okamoto, Tatsuro; Oda, Yoshinao; Maehara, Yoshihiko

2018-05-29

The aim of this study was to elucidate the relationship between family-associated factors and the postoperative prognosis in patients with nonsmall cell lung cancer (NSCLC). Additionally, we investigated whether having children was associated with the postoperative maintenance of the nutritional status. We selected 438 NSCLC patients who had undergone curative lung resection between 2004 and 2011 at Kyushu University (Fukuoka, Japan), whose family-associated factors were available. Nutritional indices, including the prognostic nutritional index (PNI), were used to estimate the change in the nutritional status for 1 year after surgery. A propensity score analysis was conducted after adjusting the following variables: sex, age, smoking history, performance status, pathological stage, and histological type. Three hundred patients (68.5%) had both children and partners. Forty-nine patients (11.2%) only had children, and 56 (12.8%) patients only had a partner. Thirty-three patients (7.5%) did not have a partner or children. The overall survival (OS) and disease-free survival (DFS) of the partner-present and partner-absent patients did not differ to a statistically significant extent (P = .862 and P = .712, respectively). However, childless patients showed significantly shorter OS and DFS in comparison with patients with children (P = .005 and P = .002, respectively). The postoperative exacerbation of PNI was significantly greater in childless patients than in patients with children (P = .003). These results remained after propensity score matching. Childless patients had a significantly poorer postoperative prognosis than those with children. Surgeons caring for childless NSCLC patients should be aware of the poorer postoperative outcomes in this population. © 2018 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

The Influence of the Japanese Nationwide Cardiovascular Prevention System Health Guidance on Smoking Cessation Among Smokers: A Propensity Score Matching Analysis.

PubMed

Nakamura, Koshi; Watanabe, Makoto; Okuda, Nagako; Yoshita, Katsushi; Kabayama, Mai; Torii, Sayuki; Kuribayashi, Toru; Itai, Kazuyoshi; Kamide, Kei; Miura, Katsuyuki; Okayama, Akira

2018-04-01

We investigated whether 2 types of personalized health guidance (repeated and single counseling) in the Japanese nationwide cardiovascular prevention system promoted smoking cessation among smokers. The study included 47,745 Japanese smokers aged 40 to 74 years classified into 2 personalized health guidance schemes. After a 1-year follow-up, we compared the rates of smoking cessation between individuals who had received counseling ("supported") and those who had not received counseling ("unsupported"). Using propensity score matching analysis, we estimated the average treatment effect (ATE) of each approach on smoking cessation after balancing out the characteristics between the supported and unsupported groups. The propensity score regression model included age, medical insurance type, weight gain since the age of 20 years, exercise, eating habits, alcohol intake, quality of sleep, readiness to modify lifestyle, willingness to receive support, and body mass index. In the repeated counseling scheme, the age-adjusted rates of smoking cessation in the supported and unsupported groups were 8.8% and 6.3% for males, and 9.8% and 9.1% for females respectively. In the single counseling scheme, the corresponding rates were 8.4% and 7.3% for supported and unsupported males, and 11.0% and 11.7% for supported and unsupported females respectively. The ATE of repeated counseling was ＋2.64% (95% confidence interval: ＋1.51% to ＋3.77%) for males and ＋3.11% (－1.85% to ＋8.07%) for females. The ATE of single counseling was ＋0.61% (－1.17% to ＋2.38%) for males and －1.06% (－5.96% to ＋3.85%) for females. In the Japanese cardiovascular prevention system, repeated counseling may promote smoking cessation among male smokers.

A propensity score-matched comparison of the efficacies of OK-432 and talc slurry for pleurodesis for malignant pleural effusion induced by lung adenocarcinoma.

PubMed

Nohara, Kango; Takada, Kazuto; Kojima, Eiji; Ninomiya, Kiyoko; Miyamatsu, Shoko; Shimizu, Takahiro; Sakurai, Tsutomu; Mizuno, Takaaki; Yamashita, Yuuki

2016-09-01

The choice of an optimal sclerosant for pleurodesis for malignant pleural effusion remains controversial. This retrospective clinical study compared the efficacy and safety of two sclerosants; talc slurry (talc-s) and OK-432. We compared the characteristics, 30/90-day success rates, and adverse events in patients with lung adenocarcinoma who underwent pleurodesis by using either OK-432 or talc-s. Propensity score matching was used to compare the two scelrosants. Ninety-four patients (mean age=71.6±9.6 years) were included in this retrospective study, of whom 64 received OK-432 and 30 received talc-s. Seventy-three patients (77.6%) were initially diagnosed with clinical stage IV lung cancer, with a 28.7% epidermal growth factor receptor mutation frequency. The propensity score-matched cohort included 26 patients from each group. The 30-day success rates for OK-432 and talc-s were 80.7% and 76.9%, respectively (odds ratio: 1.26, 95% confidence interval: 0.33-4.77, p=0.73). Neither the overall incidence of adverse events nor the 90-day success rates differed significantly. Multivariate logistic regression revealed that the predictors of 30-day success were lower drainage volume on the previous day, particularly <250mL/day, the presence of full lung expansion, and pre-therapy with an epidermal growth factor receptor-tyrosine kinase inhibitor. The median post-pleurodesis survival time was 6.9 months, which was not significantly different between the study groups. Propensity score-matched analyses showed that pleurodesis using OK-432 and talc-s demonstrated comparable efficacy and safety profiles in patients with lung adenocarcinoma. This indicated that OK-432 could be a viable alternative to talc-s in this procedure. Copyright © 2016. Published by Elsevier B.V.

A comparison of propensity score-based approaches to health service evaluation: a case study of a preoperative physician-led clinic for high-risk surgical patients.

PubMed

Pham, Clarabelle T; Gibb, Catherine L; Mittinty, Murthy N; Fitridge, Robert A; Marshall, Villis R; Karnon, Jonathan D

2016-10-01

A physician-led clinic for the preoperative optimization and management of high-risk surgical patients was implemented in a South Australian public hospital in 2008. This study aimed to estimate the costs and effects of the clinic using a mixed retrospective and prospective observational study design. Alternative propensity score estimation methods were applied to retrospective routinely collected administrative and clinical data, using weighted and matched cohorts. Supplementary survey-based prospective data were collected to inform the analysis of the retrospective data and reduce potential unmeasured confounding. Using weighted cohorts, clinic patients had a significantly longer mean length of stay and higher mean cost. With the matched cohorts, reducing the calliper width resulted in a shorter mean length of stay in the clinic group, but the costs remained significantly higher. The prospective data indicated potential unmeasured confounding in all analyses other than in the most tightly matched cohorts. The application of alternative propensity-based approaches to a large sample of retrospective data, supplemented with a smaller sample of prospective data, informed a pragmatic approach to reducing potential observed and unmeasured confounding in an evaluation of a physician-led preoperative clinic. The need to generate tightly matched cohorts to reduce the potential for unmeasured confounding indicates that significant uncertainty remains around the effects of the clinic. This study illustrates the value of mixed retrospective and prospective observational study designs but also underlines the need to prospectively plan for the evaluation of costs and effects alongside the implementation of significant service innovations. © 2016 John Wiley & Sons, Ltd.

Effects of edaravone on early outcomes in acute ischemic stroke patients treated with recombinant tissue plasminogen activator.

PubMed

Wada, Tomoki; Yasunaga, Hideo; Inokuchi, Ryota; Horiguchi, Hiromasa; Fushimi, Kiyohide; Matsubara, Takehiro; Nakajima, Susumu; Yahagi, Naoki

2014-10-15

We investigated whether edaravone could improve early outcomes in acute ischemic stroke patients treated with recombinant tissue plasminogen activator (rtPA). We conducted a retrospective cohort study using the Japanese Diagnosis Procedure Combination database. We identified patients admitted with a primary diagnosis of ischemic stroke from 1 July 2010 to 31 March 2012 and treated with rtPA on the same day of stroke onset or the following day. Thereafter, we selected those who received edaravone on the same day of rtPA administration (edaravone group), and those who received rtPA without edaravone (control group). The primary outcomes were modified Rankin Scale (mRS) scores at discharge. One-to-one propensity-score matching was performed between the edaravone and control groups. An ordinal logistic regression analysis for mRS scores at discharge was performed with adjustment for possible variables as well as clustering of patients within hospitals using a generalized estimating equation. We identified 6336 eligible patients for inclusion in the edaravone group (n=5979; 94%) and the control group (n=357; 6%) as the total population. In 356 pairs of the propensity-matched population, the ordinal logistic regression analysis showed that edaravone was significantly associated with lower mRS scores of patients at discharge (adjusted odds ratio: 0.74; 95% confidence interval: 0.57-0.96). Edaravone may improve early outcomes in acute ischemic stroke patients treated with rtPA. Copyright © 2014 Elsevier B.V. All rights reserved.

Short-Term Effects of Grade Retention on the Growth Rate of Woodcock-Johnson III Broad Math and Reading Scores

PubMed Central

Wu, Wei; West, Stephen G.; Hughes, Jan N.

2008-01-01

We investigated the effects of grade retention in first grade on the growth of the Woodcock-Johnson broad mathematics and reading scores over three years using linear growth curve modeling on an academically at-risk sample. A large sample (n = 784) of first grade children who were at risk for retention were initially identified based on low literacy scores. Scores representing propensity for retention were constructed based on 72 variables collected in comprehensive baseline testing in first grade. We closely matched 97 pairs of retained and promoted children based on their propensity scores using optimal matching procedures. This procedure adjusted for baseline differences between the retained and promoted children. We found that grade retention decreased the growth rate of mathematical skills but had no significant effect on reading skills. In addition, several potential moderators of the effect of retention on growth of mathematical and reading skills were identified including limited English language proficiency and children's conduct problems. PMID:19083352

Short-term effects of grade retention on the growth rate of Woodcock-Johnson III broad math and reading scores.

PubMed

Wu, Wei; West, Stephen G; Hughes, Jan N

2008-02-01

We investigated the effects of grade retention in first grade on the growth of the Woodcock-Johnson broad mathematics and reading scores over three years using linear growth curve modeling on an academically at-risk sample. A large sample (n=784) of first grade children who were at risk for retention was initially identified based on low literacy scores. Scores representing propensity for retention were constructed based on 72 variables collected in comprehensive baseline testing in first grade. We closely matched 97 pairs of retained and promoted children based on their propensity scores using optimal matching procedures. This procedure adjusted for baseline differences between the retained and promoted children. We found that grade retention decreased the growth rate of mathematical skills but had no significant effect on reading skills. In addition, several potential moderators of the effect of retention on growth of mathematical and reading skills were identified including limited English language proficiency and children's conduct problems.

Bacterial Infections Change Natural History of Cirrhosis Irrespective of Liver Disease Severity.

PubMed

Dionigi, Elena; Garcovich, Matteo; Borzio, Mauro; Leandro, Gioacchino; Majumdar, Avik; Tsami, Aikaterini; Arvaniti, Vasiliki; Roccarina, Davide; Pinzani, Massimo; Burroughs, Andrew K; O'Beirne, James; Tsochatzis, Emmanuel A

2017-04-01

We assessed the prognostic significance of infections in relation to current prognostic scores and explored if infection could be considered per se a distinct clinical stage in the natural history of cirrhosis. We included consecutive patients with cirrhosis admitted to a tertiary referral liver unit for at least 48 h over a 2-year period. Diagnosis of infection was based on positive cultures or strict established criteria. We used competing risk analysis and propensity score matching for data analysis. 501 patients (63% male, 48% alcoholic liver disease, median Model of End-stage Liver Disease (MELD)=17) underwent 781 admissions over the study period. Portal hypertensive bleeding and complicated ascites were the commonest reasons of admission. The incidence of proven bacterial infection was 25.6% (60% community acquired and 40% nosocomial). Survival rates at 3, 6, 12, and 30 months were 83%, 77%, 71%, and 62% in patients without diagnosis of infection, vs. 50%, 46%, 41%, and 34% in patients with diagnosis of infection. Overall survival was independently associated with MELD score (hazards ratio (HR) 1.099), intensive care (ITU) stay (HR 1.967) and bacterial infection (HR 2.226). Bacterial infection was an independent predictor of survival even when patients who died within the first 30 days were excluded from the analysis in Cox regression (HR 2.013) and competing risk Cox models in all patients (HR 1.46) and propensity risk score-matched infected and non-infected patients (HR 1.67). Infection most likely represents a distinct prognostic stage of cirrhosis, which affects survival irrespective of disease severity, even after recovery from the infective episode.

Benefits of Comprehensive Rehabilitation Therapy in Thymectomy for Myasthenia Gravis: A Propensity Score Matching Analysis.

PubMed

Ambrogi, Vincenzo; Mineo, Tommaso Claudio

2017-02-01

To demonstrate the effectiveness of a comprehensive program of rehabilitation therapy in patients undergoing thymectomy for myasthenia gravis (MG). From 2005 to 2010, 46 consecutive patients affected by MG underwent a rehabilitation program both before and after thymectomy. We matched each patient with a "control patient" who underwent thymectomy within the period 1999 to 2004 with no preoperative rehabilitation, who had the closest propensity score matching. All patients but 2 were able to complete the intended program. Eighteen patients (41%) experienced mild fatigue (>25 at MG quantitative score). Propensity score selected a group of 17 patients for the matching process. The group of patients who underwent the rehabilitation program showed significant preoperative improvement associated with a reduced operative risk, a decreased early postoperative morbidity, a lower rate of postoperative intensive care unit needed (12% vs 35%; P = 0.01) and a shorter hospital stay (3 vs 5 days; P = 0.04). After the expected perioperative decline, all major myasthenic outcomes demonstrated a significant faster recovery at 3 months. Complete stable remission did not reveal significant differences. Exercise is not necessarily a contraindication in MG, and rehabilitation can be safely performed before and after thymectomy, reducing operative risks and decreasing recovery time. Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCMECME OBJECTIVES: Upon completion of this article, the reader should be able to do the following: (1) appreciate the benefits of physical therapy in individuals with myasthenia gravis; (2) describe the benefits of physical therapy on postoperative morbidity in myasthenia gravis patients who undergo thymectomy; and (3) incorporate appropriate rehabilitation into the treatment plan of patient with myasthenia gravis. AdvancedACCREDITATION: The Association of Academic Physiatrists is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.The Association of Academic Physiatrists designates this activity for a maximum of 1.5 AMA PRA Category 1 Credit(s)™. Physicians should only claim credit commensurate with the extent of their participation in the activity.

Effectiveness of and Factors Related to Possession of a Mother and Child Health Handbook: An Analysis Using Propensity Score Matching

ERIC Educational Resources Information Center

Kawakatsu, Yoshito; Sugishita, Tomohiko; Oruenjo, Kennedy; Wakhule, Stephen; Kibosia, Kennedy; Were, Eric; Honda, Sumihisa

2015-01-01

Background: Mother and Child Health handbooks (MCH handbooks) serve as useful health education tools for mothers and sources of information that allow health care professionals to understand patient status. Therefore, it is necessary to clarify the effectiveness of and identify the factors related to possession of an MCH handbook among parents in…

Comparing the Effectiveness of Head Start and State Pre-K Using a Propensity-Score Matching Regression Discontinuity Design

ERIC Educational Resources Information Center

Jenkins, Jade Marcus; Farkas, George; Duncan, Greg J.; Burchinal, Margaret; Vandell, Deborah Lowe

2014-01-01

This study is a secondary data analysis of data collected on preschool and kindergarten-aged children in Tulsa, Oklahoma in the fall of 2006 to study the effects of school and community-based public early learning programs on children's cognitive and social-emotional outcomes. Children in the study participated in the state-funded pre-k program,…

Impact of chest radiography for children with lower respiratory tract infection: a propensity score approach.

PubMed

Ecochard-Dugelay, Emmanuelle; Beliah, Muriel; Boisson, Caroline; Perreaux, Francis; de Laveaucoupet, Jocelyne; Labrune, Philippe; Epaud, Ralph; Ducou-Lepointe, Hubert; Bouyer, Jean; Gajdos, Vincent

2014-01-01

Management of acute respiratory tract infection varies substantially despite this being a condition frequently encountered in pediatric emergency departments. Previous studies have suggested that the use of antibiotics was higher when chest radiography was performed. However none of these analyses had considered the inherent indication bias of observational studies. The aim of this work was to assess the relationship between performing chest radiography and prescribing antibiotics using a propensity score analysis to address the indication bias due to non-random radiography assignment. We conducted a prospective study of 697 children younger than 2 years of age who presented during the winter months of 2006-2007 for suspicion of respiratory tract infection at the Pediatric Emergency Department of an urban general hospital in France (Paris suburb). We first determined the individual propensity score (probability of having a chest radiography according to baseline characteristics). Then we assessed the relation between radiography and antibiotic prescription using two methods: adjustment and matching on the propensity score. We found that performing a chest radiography lead to more frequent antibiotic prescription that may be expressed as OR = 2.3, CI [1.3-4.1], or as an increased use of antibiotics of 18.6% [0.08-0.29] in the group undergoing chest radiography. Chest radiography has a significant impact on the management of infants admitted for suspicion of respiratory tract infection in a pediatric emergency department and may lead to unnecessary administration of antibiotics.

Something from nothing: Estimating consumption rates using propensity scores, with application to emissions reduction policies

PubMed Central

Büchs, Milena; Schnepf, Sylke V.

2017-01-01

Consumption surveys often record zero purchases of a good because of a short observation window. Measures of distribution are then precluded and only mean consumption rates can be inferred. We show that Propensity Score Matching can be applied to recover the distribution of consumption rates. We demonstrate the method using the UK National Travel Survey, in which c.40% of motorist households purchase no fuel. Estimated consumption rates are plausible judging by households’ annual mileages, and highly skewed. We apply the same approach to estimate CO2 emissions and outcomes of a carbon cap or tax. Reliance on means apparently distorts analysis of such policies because of skewness of the underlying distributions. The regressiveness of a simple tax or cap is overstated, and redistributive features of a revenue-neutral policy are understated. PMID:29020029

Effects of sugammadex vs. pyridostigmine-glycopyrrolate on post-operative nausea and vomiting: propensity score matching.

PubMed

Lee, O H; Choi, G J; Kang, H; Baek, C W; Jung, Y H; Woo, Y C; Oh, J; Park, Y H

2017-01-01

Sugammadex is a new agent that reverses neuromuscular blockade by aminosteroid neuromuscular blocker. This retrospective study compared the effects of sugammadex on post-operative nausea and vomiting (PONV) with those of a pyridostigmine-glycopyrrolate mixture. We reviewed the electronic medical records of 7179 patients who had received fentanyl-based, intravenous, patient-controlled analgesia (IV-PCA) at Chung-Ang University Hospital between January 1, 2010 and December 31, 2015. We categorized the patients into two groups on the basis of the type of reversal agent to neuromuscular blockade that was used: a traditional reversal agent (pyridostigmine-glycopyrrolate mixture; Group R; n = 7059) and sugammadex (Group S; n = 120). The propensity score matching method was then used to select 408 subjects in Group R and 115 subjects in Group S; on the basis of their covariates, these subjects were then matched with a counterpart in the other group. After propensity score matching, the two groups were well balanced with respect to all baseline covariates. In Group S, the numeric rating scale of nausea on day 0, as well as the number of patients who vomited on day 0, was lower than that in group R. Furthermore, Group S used fewer rescue antiemetics on day 0 and had a higher complete response on day 0. Sugammadex might be more beneficial for PONV compared to pyridostigmine-glycopyrrolate mixture for patients who have received opioid-based IV-PCA. © 2016 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Functional outcome after primary endovascular therapy or IV thrombolysis alone for stroke. An observational, comparative effectiveness study.

PubMed

Abilleira, Sònia; Ribera, Aida; Dávalos, Antonio; Ribó, Marc; Chamorro, Angel; Cardona, Pere; Molina, Carlos A; Martínez-Yélamos, Antonio; Urra, Xabier; Dorado, Laura; Roquer, Jaume; Martí-Fàbregas, Joan; Aja, Lucía; Tomasello, Alejandro; Castaño, Carlos; Blasco, Jordi; Cánovas, David; Castellanos, Mar; Krupinski, Jerzy; Guimaraens, Leopoldo; Perendreu, Joan; Ustrell, Xavier; Purroy, Francisco; Gómez-Choco, Manuel; Baiges, Joan Josep; Cocho, Dolores; Saura, Júlia; Gallofré, Miquel

2014-01-01

Among the acute ischemic stroke patients with large vessel occlusions and contraindications for the use of IV thrombolysis, mainly on oral anticoagulation or presenting too late, primary endovascular therapy is often performed as an alternative to the standard therapy even though evidence supporting the use of endovascular reperfusion therapies is not yet established. Using different statistical approaches, we compared the functional independence rates at 3 months among patients undergoing primary endovascular therapy and patients treated only with IV thrombolysis. We used data from a prospective, government-mandated and externally audited registry of reperfusion therapies for ischemic stroke (January 2011 to November 2012). Patients were selected if treated with either IV thrombolysis alone (n = 1,582) or primary endovascular thrombectomy (n = 250). A series of exclusions were made to homogenize the clinical characteristics among the two groups. We then carried out multivariate logistic regression and propensity score matching analyses on the final study sample (n = 1,179) to compare functional independence at 3 months, as measured by the modified Rankin scale scores 0-2, between the two groups. The unadjusted likelihood of good outcome was poorer among the endovascular group (OR: 0.69; 95% CI: 0.47-1.0). After adjustment, no differences by treatment modality were seen (OR: 1.51; 95% CI: 0.93-2.43 for primary endovascular therapy). Patients undergoing endovascular thrombectomy within 180-270 min (OR: 2.89; 95% CI: 1.17-7.15) and patients with severe strokes (OR: 1.84; 95% CI: 1.02-3.35) did better than their intravenous thrombolysis counterparts. The propensity score-matched analyses with and without adjustment by additional covariates showed that endovascular thrombectomy was as effective as intravenous thrombolysis alone in achieving functional independence (OR for unadjusted propensity score matched: 1.35; 95% CI: 0.9-2.02, OR for adjusted propensity score matched: 1.45; 95% CI: 0.91-2.32). This comparative effectiveness study shows that in ischemic stroke patients with contraindications for IV thrombolysis, primary endovascular treatment might be an alternative therapy at least as effective as IV thrombolysis alone. Randomized controlled trials are urgently needed. © 2014 S. Karger AG, Basel.

Statistical primer: propensity score matching and its alternatives.

PubMed

Benedetto, Umberto; Head, Stuart J; Angelini, Gianni D; Blackstone, Eugene H

2018-06-01

Propensity score (PS) methods offer certain advantages over more traditional regression methods to control for confounding by indication in observational studies. Although multivariable regression models adjust for confounders by modelling the relationship between covariates and outcome, the PS methods estimate the treatment effect by modelling the relationship between confounders and treatment assignment. Therefore, methods based on the PS are not limited by the number of events, and their use may be warranted when the number of confounders is large, or the number of outcomes is small. The PS is the probability for a subject to receive a treatment conditional on a set of baseline characteristics (confounders). The PS is commonly estimated using logistic regression, and it is used to match patients with similar distribution of confounders so that difference in outcomes gives unbiased estimate of treatment effect. This review summarizes basic concepts of the PS matching and provides guidance in implementing matching and other methods based on the PS, such as stratification, weighting and covariate adjustment.

Effect of plasma exchange on in-hospital mortality in patients with pulmonary hemorrhage secondary to antineutrophil cytoplasmic antibody-associated vasculitis: A propensity-matched analysis using a nationwide administrative database.

PubMed

Uechi, Eishi; Okada, Masato; Fushimi, Kiyohide

2018-01-01

Secondary pulmonary hemorrhage increases the risk of mortality in patients with antineutrophil cytoplasmic antibody-associated vasculitis (AAV); plasma exchange therapy may improve outcomes in these patients. We conducted a retrospective cohort study to investigate the effect of plasma exchange therapy on short-term prognoses in patients with pulmonary hemorrhage secondary to AAV. This study utilized the Diagnosis Procedure Combination database, which is a nationwide inpatient database in Japan. We checked the abstract data and medical actions and identified the patients with pulmonary hemorrhage secondary to AAV who required proactive treatment between 2009 and 2014. To compare the in-hospital mortality, we performed propensity score matching between the plasma exchange and non-plasma exchange groups at a ratio of 1:1. Of the 52,932 patients with AAV, 940 developed pulmonary hemorrhage as a complication. A total of 249 patients from 194 hospitals were eligible for the study. Propensity score matching at a ratio of 1:1 was performed, and 59 pairs were formed (plasma exchange group, n = 59; non-plasma exchange group, n = 59). A statistically significant difference was found in the all-cause in-hospital mortality between the plasma exchange and non-plasma exchange groups (35.6% vs. 54.2%; p = 0041; risk difference, -18.6; 95% confidence interval (CI), -35.4% to -0.67%). Thus, plasma exchange therapy was associated with improved in-hospital mortality in patients with pulmonary hemorrhage secondary to AAV.

Preoperative Angiotensin Blocking Drug Therapy Is not Associated with Atrial Fibrillation after Cardiac Surgery

PubMed Central

Rader, Florian; Van Wagoner, David R.; Gillinov, A. Marc; Blackstone, Eugene H.

2010-01-01

Background Preoperative use of angiotensin blocking drug therapy (ABDT) with ACE-inhibitors or Angiotensin II receptor blockers (ARBs) and its link to occurrence of postoperative atrial fibrillation (POAF), a common marker of poor outcomes after cardiac surgery, remains controversial. Methods From 1997-2003 10,552 patients underwent coronary artery bypass grafting (CABG) with or without valve surgery. To adjust for differences of clinical characteristics between patients receiving ABDT within 24 hours prior to surgery compared to those who did not, propensity score analyses were conducted. Results ABDT was prescribed in 4,795 (45%) prior to surgery of which 1,725 (36%) developed POAF prior to discharge vs. 1908 (33%) of 5,757 patients who have not received ABDT (unadjusted odds ratio [OR] of 1.13 (95% Confidence Interval [CI] 1.05-1.25, p<0.01). In 6744 propensity score matched patients with well balanced co-morbidity profiles, ABDT was not associated with POAF (OR 1.05, CI 0.95-1.16, p=0.38). Stratified analysis within quintiles of propensity score and propensity-adjusted logistic multivariable regression confirmed these findings. Conclusions In this large observational study we found no evidence of an association between preoperative angiotensin blockade and the occurrence of postoperative atrial fibrillation. Adequately powered randomized studies are needed to clarify the best strategy of perioperative angiotensin blocking drug therapy in patients with and without guideline-based indications. PMID:20691840

Thromboembolic and Major Bleeding Events With Rivaroxaban Versus Warfarin Use in a Real-World Setting.

PubMed

Russo-Alvarez, Giavanna; Martinez, Kathryn A; Valente, Megan; Bena, James; Hu, Bo; Luxenburg, Jennifer; Chaitoff, Alexander; Ituarte, Catherine; Brateanu, Andrei; Rothberg, Michael B

2018-01-01

Although randomized trials demonstrate the noninferiority of rivaroxaban compared with warfarin in the context of nonvalvular atrial fibrillation (AF), little is known about how these drugs compare in practice. To assess the relative effectiveness and safety of rivaroxaban versus warfarin in a large health system and to evaluate this association by time in therapeutic range (TTR). We conducted a retrospective cohort study with propensity matching in the Cleveland Clinic Health System. The study included patients initiated on warfarin or rivaroxaban for thromboembolic prevention in nonvalvular AF between January 2012 and July 2016. The main outcomes were thromboembolic events and major bleeds. Analyses were stratified by warfarin patients' TTR. The cohort consisted of 472 propensity-matched pairs. The mean age was 73.6 years (SD = 11.7), and the mean CHADS 2 score was 1.8. The median TTR for warfarin patients was 64%. In the propensity-matched analysis, there was no significant difference in thromboembolic or major bleeding events between groups. Among warfarin patients with a TTR <64% and their matched rivaroxaban pairs, there was also no significant difference in thromboembolic or major bleeding events. Under real-world conditions, warfarin and rivaroxaban were associated with similar safety and effectiveness, even among those with suboptimal therapeutic control. Individualized decision making, taking into account the nontherapeutic tradeoffs associated with these medications (eg, monitoring, half-life, cost) is warranted.

The use of propensity scores to assess the generalizability of results from randomized trials

PubMed Central

Stuart, Elizabeth A.; Cole, Stephen R.; Bradshaw, Catherine P.; Leaf, Philip J.

2014-01-01

Randomized trials remain the most accepted design for estimating the effects of interventions, but they do not necessarily answer a question of primary interest: Will the program be effective in a target population in which it may be implemented? In other words, are the results generalizable? There has been very little statistical research on how to assess the generalizability, or “external validity,” of randomized trials. We propose the use of propensity-score-based metrics to quantify the similarity of the participants in a randomized trial and a target population. In this setting the propensity score model predicts participation in the randomized trial, given a set of covariates. The resulting propensity scores are used first to quantify the difference between the trial participants and the target population, and then to match, subclassify, or weight the control group outcomes to the population, assessing how well the propensity score-adjusted outcomes track the outcomes actually observed in the population. These metrics can serve as a first step in assessing the generalizability of results from randomized trials to target populations. This paper lays out these ideas, discusses the assumptions underlying the approach, and illustrates the metrics using data on the evaluation of a schoolwide prevention program called Positive Behavioral Interventions and Supports. PMID:24926156

Oral intradialytic nutritional supplement use and mortality in hemodialysis patients.

PubMed

Weiner, Daniel E; Tighiouart, Hocine; Ladik, Vladimir; Meyer, Klemens B; Zager, Philip G; Johnson, Douglas S

2014-02-01

Hemodialysis patients have high mortality rates, potentially reflecting underlying comorbid conditions and ongoing catabolism. Intradialytic oral nutritional supplements may reduce this risk. Retrospective propensity-matched cohort. Maintenance hemodialysis patients treated at Dialysis Clinic Inc facilities who were initiated on a nutritional supplement protocol in September to October 2010 were matched using a propensity score to patients at facilities at which the protocol was not used. Prescription of the protocol, whereby hemodialysis patients with serum albumin levels ≤3.5g/dL would initiate oral protein supplementation during the dialysis procedure. Sensitivity analyses matched on actual supplement intake during the first 3 study months. Covariates included patient and facility characteristics, which were used to develop the propensity scores and adjust multivariable models. All-cause mortality, ascertained though March 2012. Of 6,453 eligible patients in 101 eligible hemodialysis facilities, the protocol was prescribed to 2,700, and 1,278 of these were propensity matched to controls. Mean age was 61 ± 15 (SD) years and median dialysis vintage was 34 months. There were 258 deaths among protocol assignees versus 310 among matched controls during a mean follow-up of 14 months. In matched analyses, protocol prescription was associated with a 29% reduction in the hazard of all-cause mortality (HR, 0.71; 95% CI, 0.58-0.86); adjustment had minimal impact on models. In time-dependent models incorporating change in albumin level, protocol status remained significant but was attenuated in models incorporating a 30-day lag. Similar results were seen in sensitivity analyses of 439 patients receiving supplements who were propensity-matched to controls, with 116 deaths among supplement users versus 140 among controls (HR, 0.79; 95% CI, 0.60-1.05), achieving statistical significance in adjusted models. Observational design, potential residual confounding. Prescription of an oral nutritional supplement protocol and use of oral protein nutritional supplements during hemodialysis are associated with reduced mortality among in-center maintenance hemodialysis patients, an effect likely not mediated by change in serum albumin levels. Copyright © 2014 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

Effects of Internet and Smartphone Addictions on Depression and Anxiety Based on Propensity Score Matching Analysis.

PubMed

Kim, Yeon-Jin; Jang, Hye Min; Lee, Youngjo; Lee, Donghwan; Kim, Dai-Jin

2018-04-25

The associations of Internet addiction (IA) and smartphone addiction (SA) with mental health problems have been widely studied. We investigated the effects of IA and SA on depression and anxiety while adjusting for sociodemographic variables. In this study, 4854 participants completed a cross-sectional web-based survey including socio-demographic items, the Korean Scale for Internet Addiction, the Smartphone Addiction Proneness Scale, and the subscales of the Symptom Checklist 90 Items-Revised. The participants were classified into IA, SA, and normal use (NU) groups. To reduce sampling bias, we applied the propensity score matching method based on genetics matching. The IA group showed an increased risk of depression (relative risk 1.207; p < 0.001) and anxiety (relative risk 1.264; p < 0.001) compared to NUs. The SA group also showed an increased risk of depression (relative risk 1.337; p < 0.001) and anxiety (relative risk 1.402; p < 0.001) compared to NCs. These findings show that both, IA and SA, exerted significant effects on depression and anxiety. Moreover, our findings showed that SA has a stronger relationship with depression and anxiety, stronger than IA, and emphasized the need for prevention and management policy of the excessive smartphone use.

Case matching and the reduction of selection bias in quasi-experiments: The relative importance of pretest measures of outcome, of unreliable measurement, and of mode of data analysis.

PubMed

Cook, Thomas D; Steiner, Peter M

2010-03-01

In this article, we note the many ontological, epistemological, and methodological similarities between how Campbell and Rubin conceptualize causation. We then explore 3 differences in their written emphases about individual case matching in observational studies. We contend that (a) Campbell places greater emphasis than Rubin on the special role of pretest measures of outcome among matching variables; (b) Campbell is more explicitly concerned with unreliability in the covariates; and (c) for analyzing the outcome, only Rubin emphasizes the advantages of using propensity score over regression methods. To explore how well these 3 factors reduce bias, we reanalyze and review within-study comparisons that contrast experimental and statistically adjusted nonexperimental causal estimates from studies with the same target population and treatment content. In this context, the choice of covariates counts most for reducing selection bias, and the pretest usually plays a special role relative to all the other covariates considered singly. Unreliability in the covariates also influences bias reduction but by less. Furthermore, propensity score and regression methods produce comparable degrees of bias reduction, though these within-study comparisons may not have met the theoretically specified conditions most likely to produce differences due to analytic method.

One-millimeter cancer-free margin is curative for colorectal liver metastases: a propensity score case-match approach.

PubMed

Hamady, Zaed Z R; Lodge, J Peter A; Welsh, Fenella K; Toogood, Giles J; White, Alan; John, Timothy; Rees, Myrddin

2014-03-01

To investigate the influence of clear surgical resection margin width on disease recurrence rate after intentionally curative resection of colorectal liver metastases. There is consensus that a histological positive resection margin is a predictor of disease recurrence after resection of colorectal liver metastases. The dispute, however, over the width of cancer-free resection margin required is ongoing. Analysis of observational prospectively collected data for 2715 patients who underwent primary resection of colorectal liver metastases from 2 major hepatobiliary units in the United Kingdom. Histological cancer-free resection margin was classified as positive (if cancer cells present at less than 1 mm from the resection margin) or negative (if the distance between the cancer and the margin is 1 mm or more). The negative margin was further classified according to the distance from the tumor in millimeters. Predictors of disease-free survival were analyzed in univariate and multivariate analyses. A case-match analysis by a propensity score method was undertaken to reduce bias. A 1-mm cancer-free resection margin was sufficient to achieve 33% 5-year overall disease-free survival. Extra margin width did not add disease-free survival advantage (P > 0.05). After the propensity case-match analysis, there is no statistical difference in disease-free survival between patients with negative narrow and wider margin clearance [hazard ratio (HR) 1.0; 95% (confidence interval) CI: 0.9-1.2; P = 0.579 at 5-mm cutoff and HR 1.1; 95% CI: 0.96-1.3; P = 0.149 at 10-mm cutoff]. Patients with extrahepatic disease and positive lymph node primary tumor did not have disease-free survival advantage despite surgical margin clearance (9 months for <1-mm vs 12 months for ≥1-mm margin clearance; P = 0.062). One-mm cancer-free resection margin achieved in patients with colorectal liver metastases should now be considered the standard of care.

Teen trauma without the drama: outcomes of adolescents treated at Ohio adult versus pediatric trauma centers.

PubMed

Walther, Ashley E; Pritts, Timothy A; Falcone, Richard A; Hanseman, Dennis J; Robinson, Bryce R H

2014-07-01

The optimal treatment facility for adolescent trauma patients is controversial. We sought to investigate risk-adjusted outcomes of adolescents treated at adult-only trauma centers (ATCs) versus pediatric-only trauma centers (PTCs) in a state system with legislated American College of Surgeons-verified institutions to determine ideal prehospital referral patterns. The Ohio Trauma Registry was queried for patients 15 years to 19 years with a length of stay (LOS) greater than 1 day at ATC (Level 1) or PTC (Levels 1 and 2) from 2008 to 2012. Race, sex, emergency department vital signs, Injury Severity Score (ISS), computed tomography, and ultrasound imaging were reviewed. Outcomes by mechanism of injury included ventilator days, intensive care unit LOS, hospital LOS, and mortality. Statistical analysis was performed using χ test, t test, and Wilcoxon rank-sum test. Propensity score-based risk adjustment matching was used to compare groups (propensity score within 0.01, ISS within 5). Of 5,793 adolescents examined, (84% blunt, 16% penetrating) 66% were treated at an ATC. In unmatched comparisons, age, ISS, vital signs, and mortality differed significantly between centers (p < 0.01). For adolescents with blunt injury, more males (71.6% vs. 66.3%, p < 0.01) and nonwhites (19.2% vs. 15.8%, p < 0.01) were seen at PTCs. For penetrating trauma, more males (88.6% vs. 50.8%, p < 0.01) and nonwhites (66.4% vs. 34.3%, p < 0.01) were admitted to ATCs. In 873 propensity-matched pairs for blunt trauma and 95 propensity-matched pairs of penetrating injuries, no differences were seen in a priori outcomes. Imaging (blunt, head computed tomography and abdominal ultrasound, p < 0.01; penetrating, abdominal ultrasound, p = 0.02) was more common at ATCs. Major outcome differences for injured adolescents do not exist between ATCs and PTCs, regardless of injury pattern. Imaging remains more prevalent at ATCs. In a state system with mandatory American College of Surgeons-verified centers, injury patterns need not dictate triage decisions for adolescents. Epidemiologic study, level III.

Propensity score matching for selection of local areas as controls for evaluation of effects of alcohol policies in case series and quasi case-control designs.

PubMed

de Vocht, F; Campbell, R; Brennan, A; Mooney, J; Angus, C; Hickman, M

2016-03-01

Area-level public health interventions can be difficult to evaluate using natural experiments. We describe the use of propensity score matching (PSM) to select control local authority areas (LAU) to evaluate the public health impact of alcohol policies for (1) prospective evaluation of alcohol policies using area-level data, and (2) a novel two-stage quasi case-control design. Ecological. Alcohol-related indicator data (Local Alcohol Profiles for England, PHE Health Profiles and ONS data) were linked at LAU level. Six LAUs (Blackpool, Bradford, Bristol, Ipswich, Islington, and Newcastle-upon-Tyne) as sample intervention or case areas were matched to two control LAUs each using PSM. For the quasi case-control study a second stage was added aimed at obtaining maximum contrast in outcomes based on propensity scores. Matching was evaluated based on average standardized absolute mean differences (ASAM) and variable-specific P-values after matching. The six LAUs were matched to suitable control areas (with ASAM < 0.20, P-values >0.05 indicating good matching) for a prospective evaluation study that sought areas that were similar at baseline in order to assess whether a change in intervention exposure led to a change in the outcome (alcohol related harm). PSM also generated appropriate matches for a quasi case-control study--whereby the contrast in health outcomes between cases and control areas needed to be optimized in order to assess retrospectively whether differences in intervention exposure were associated with the outcome. The use of PSM for area-level alcohol policy evaluation, but also for other public health interventions, will improve the value of these evaluations by objective and quantitative selection of the most appropriate control areas. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Neutrophil-to-lymphocyte ratio as an independent predictor for survival in patients with localized clear cell renal cell carcinoma after radiofrequency ablation: a propensity score matching analysis.

PubMed

Chang, Xiaofeng; Zhang, Fan; Liu, Tieshi; Wang, Wei; Guo, Hongqian

2017-06-01

To investigate the role of neutrophil-to-lymphocyte ratio as a prognostic indicator in patients with localized clear cell renal cell carcinoma treated with radiofrequency ablation. We retrospectively analyzed data from patients with renal cell carcinoma who underwent radiofrequency ablation from 2006 to 2013. The Kaplan-Meier method was used to generate the survival curves according to different categories of neutrophil-to-lymphocyte ratio. Relationships between preoperative neutrophil-to-lymphocyte ratio or the change of neutrophil-to-lymphocyte ratio and survival were evaluated with multivariable Cox proportional hazards regression analysis. A propensity score matching analysis was carried out to avoid confounding bias. A total of 185 patients were included in present study. When stratified by preoperative neutrophil-to-lymphocyte ratio cutoff value of 2.79, 5-year recurrence-free survival, 5-year disease-free survival, and 5-year overall survival rates of neutrophil-to-lymphocyte ratio <2.79 versus ≥2.79 were 100, 98.5, and 99.2% versus 80.5, 72.6, and 90.6%, respectively (P < 0.001, P < 0.001, P = 0.003). In terms of propensity score matching analysis, 5-year recurrence-free survival, 5-year disease-free survival, and 5-year overall survival rates of neutrophil-to-lymphocyte ratio <2.79 versus ≥2.79 were 100, 97.9, and 100% versus 82.3, 73.4, and 89.4%, respectively (P = 0.003, P = 0.001, P = 0.022). When combining preoperative neutrophil-to-lymphocyte ratio with the change of neutrophil-to-lymphocyte ratio, patients with both preoperative neutrophil-to-lymphocyte ratio ≥2.79 and the change of neutrophil-to-lymphocyte ratio ≥0.40 had the worst disease-free survival. Results of multivariable analysis showed that preoperative neutrophil-to-lymphocyte ratio and the change of neutrophil-to-lymphocyte ratio correlated with cancer relapse remarkably. High preoperative neutrophil-to-lymphocyte ratio and elevated postoperative neutrophil-to-lymphocyte ratio are associated with significant increase in risk of local recurrence as well as distant metastasis. The combination of neutrophil-to-lymphocyte ratio with the other prognostic indicators can be applied in the evaluation of relapse risk in patients with clear cell renal cell carcinoma after radiofrequency ablation.

Antegrade versus retrograde cerebral perfusion for hemiarch replacement with deep hypothermic circulatory arrest: Does it matter? A propensity-matched analysis

PubMed Central

Ganapathi, Asvin M.; Hanna, Jennifer M.; Schechter, Matthew A.; Englum, Brian R.; Castleberry, Anthony W.; Gaca, Jeffrey G.; Hughes, G. Chad

2015-01-01

Objective The choice of cerebral perfusion strategy for aortic arch surgery has been debated, and the superiority of antegrade (ACP) or retrograde (RCP) cerebral perfusion has not been shown. We examined the early and late outcomes for ACP versus RCP in proximal (hemi-) arch replacement using deep hypothermic circulatory arrest (DHCA). Methods A retrospective analysis of a prospectively maintained database was performed for all patients undergoing elective and nonelective hemiarch replacement at a single referral institution from June 2005 to February 2013. Total arch cases were excluded to limit the analysis to shorter DHCA times and a more uniform patient population for whom clinical equipoise regarding ACP versus RCP exists. A total of 440 procedures were identified, with 360 (82%) using ACP and 80 (18%) using RCP. The endpoints included 30-day/in-hospital and late outcomes. A propensity score with 1:1 matching of 40 pre- and intraoperative variables was used to adjust for differences between the 2 groups. Results All 80 RCP patients were propensity matched to a cohort of 80 similar ACP patients. The pre- and intra-operative characteristics were not significantly different between the 2 groups after matching. No differences were found in 30-day/in-hospital mortality or morbidity outcomes. The only significant difference between the 2 groups was a shorter mean operative time in the RCP cohort (P = .01). No significant differences were noted in late survival (P = .90). Conclusions In proximal arch operations using DHCA, equivalent early and late outcomes can be achieved with RCP and ACP, although the mean operative time is significantly less with RCP, likely owing to avoidance of axillary cannulation. Questions remain regarding comparative outcomes with straight DHCA and lesser degrees of hypothermia. PMID:24908350

Effectiveness of Cetuximab in Combination with Concurrent Chemoradiotherapy in Locoregionally Advanced Nasopharyngeal Carcinoma: A 1:2 Propensity Score-matched Analysis.

PubMed

Wu, Li-Rong; Zhu, Huan-Feng; Xu, Jianhua; Jiang, Xue-Song; Yin, Li; Jiang, Ning; Zong, Dan; Wang, Fei-Jiang; Huang, Sheng-Fu; Bian, Xiu-Hua; Wu, Jian-Feng; Song, Dan; Guo, Wen-Jie; Liu, Ju-Ying; He, Xia

2018-01-01

Background : This study aimed to compare concurrent chemoradiotherapy (CCRT) plus cetuximab (C) with CCRT alone in locoregionally advanced nasopharyngeal carcinoma(NPC). Methods : A total of 682 locoregionally advanced NPC patients who had undergone chemoradiotherapy with or without cetuximab were included. Propensity score-matching method was used to match patients. Progression-free survival (PFS), overall survival (OS), locoregional relapse-free survival (LRFS), and distant metastasis-free survival (DMFS) were compared between the two treatment arms. Results : After matching, 225 patients were identified for the analysis. Compared to CCRT, CCRT plus C was associated with significantly improved 3-year PFS (83.7% vs 71.9%, P = 0.036), LRFS (98.6% vs 90.2%, P = 0.034) but not OS (91.4% vs 85.4%, P = 0.117). Among patients with T4 and/or N3 category, CCRT plus C significantly prolonged 3-year PFS (81.0% vs 61.4%, P = 0.022) and increased 3-year OS (88.0% vs 77.9%, P = 0.086). No significant differences were observed between CCRT plus C and CCRT alone groups with regard to 3-year PFS, OS, LRFS and DMFS rates in stage III patients. Acute oral and oropharyngeal mucositis during radiotherapy were more common in the CCRT plus C than that in CCRT, but late toxicities were comparable. Conclusions: This study reveals that patients with locoregionally advanced NPC could benefit from the addition of cetuximab to CCRT, and this therapeutic gain mainly originated from T4 and/or N3 subgroup although suffering more acute moderate to severe toxicities.

Mediastinal micro-vessels clipping during lymph node dissection may contribute to reduce postoperative pleural drainage

PubMed Central

Yan, Shi; Wang, Xing; Lv, Chao; Phan, Kevin; Wang, Yuzhao; Wang, Jia; Yang, Yue

2016-01-01

Background Postoperative pleural drainage markedly influences the length of postoperative stay and financial costs of medical care. The aim of this study is to retrospectively investigate potentially predisposing factors related to pleural drainage after curative thoracic surgery and to explore the impact of mediastinal micro-vessels clipping on pleural drainage control after lymph node dissection. Methods From February 2012 to November 2013, 322 consecutive cases of operable non-small cell lung cancers (NSCLC) undergoing lobectomy and mediastinal lymph node dissection with or without application of clipping were collected. Total and daily postoperative pleural drainage were recorded. Propensity score matching (1:2) was applied to balance variables potentially impacting pleural drainage between group clip and group control. Analyses were performed to compare drainage volume, duration of chest tube and postoperative hospital stay between the two groups. Variables linked with pleural drainage in whole cohort were assessed using multivariable logistic regression analysis. Results Propensity score matching resulted in 197 patients (matched cohort). Baseline patient characteristics were matched between two groups. Group clip showed less cumulative drainage volume (P=0.020), shorter duration of chest tube (P=0.031) and postoperative hospital stay (P=0.022) compared with group control. Risk factors significantly associated with high-output drainage in multivariable logistic regression analysis were being male, age >60 years, bilobectomy/sleeve lobectomy, pleural adhesion, the application of clip applier, duration of operation ≥220 minutes and chylothorax (P<0.05). Conclusions This study suggests that mediastinal micro-vessels clipping during lymph node dissection may reduce postoperative pleural drainage and thus shorten hospital stay. PMID:27076936

Sinus Bradycardia in Habitual Cocaine Users.

PubMed

Franklin, Sona M; Thihalolipavan, Sudarone; Fontaine, John M

2017-05-15

Common physiological manifestations of cocaine are related to its adrenergic effects, due to inhibition of dopamine and norepinephrine uptake at the postsynaptic terminal. Few studies have documented bradycardia secondary to cocaine use, representing the antithesis of its adrenergic effects. We assessed the prevalence of sinus bradycardia (SB) in habitual cocaine users and postulated a mechanism for this effect. One hundred sixty-two patients with a history of cocaine use were analyzed and compared with age- and gender-matched controls. SB was defined as a rate of <60 beats/min and habitual cocaine use as 2 or more documented uses >30 days apart. Propensity score-matching analysis was applied to balance covariates between cocaine users and nonusers and reduce selection bias. Patients with a history of bradycardia, hypothyroidism, or concomitant beta-blocker use were excluded. Mean age of study patients was 44 ± 8 years. SB was observed in 43 of 162 (27%) cocaine users and in 9 of 149 (6%) nonusers (p = 0.0001). Propensity score-matching analysis matched 218 patients from both groups. Among matched patients SB was observed in 25 of 109 (23%) cocaine users and in 5 of 109 (5%) nonusers (p = 0.0001). Habitual cocaine use was an independent predictor of SB and associated with a sevenfold increase in the risk of SB (95% CI 2.52 to 19.74, p = 0.0002). In conclusion, habitual cocaine use is a strong predictor of SB and was unrelated to recency of use. A potential mechanism for SB may be related to cocaine-induced desensitization of the beta-adrenergic receptor secondary to continuous exposure. Symptomatic SB was not observed; thus, pacemaker therapy was not indicated. Copyright © 2017 Elsevier Inc. All rights reserved.

Medication persistence and discontinuation of rivaroxaban and dabigatran etexilate among patients with non-valvular atrial fibrillation.

PubMed

Nelson, Winnie W; Song, Xue; Thomson, Erin; Smith, David M; Coleman, Craig I; Damaraju, C V; Schein, Jeffrey R

2015-01-01

To compare real-world persistence and discontinuation among non-valvular atrial fibrillation (NVAF) patients on rivaroxaban and dabigatran in the US. A large nationally representative US claims database was used to conduct a retrospective cohort analysis of patients with NVAF on rivaroxaban or dabigatran between October 2010 and March 2013. The index date was the date of the first prescription of rivaroxaban or dabigatran. All patients had ≥6 months of data prior to the index date and were followed until the earliest of inpatient death, end of continuous enrollment, or end of the study period. Rivaroxaban patients were matched 1:1 with dabigatran patients using the propensity score matching technique. Cox proportional hazards models were employed to estimate the adjusted hazard ratios (aHRs) of non-persistence and discontinuation. Persistence was defined as absence of a refill gap of ≥60 days. Discontinuation was defined as no additional refill for at least 90 days and until the end of follow-up. A total of 30,337 NVAF patients on rivaroxaban or dabigatran met the study criteria. All 7259 rivaroxaban patients were matched 1:1 to dabigatran patients. Compared with dabigatran users, rivaroxaban patients were 11% less likely to become non-persistent with therapy (aHR: 0.89, 95% CI 0.84-0.95) and 29% less likely to discontinue therapy (aHR: 0.71, 95% CI 0.66-0.77). Claims data are subject to miscoding and inaccuracies. Refill data may not fully reflect actual medication taken. Confounding may remain even after propensity score matching and additional adjustments in model. Longer follow-up may produce more precise estimates of persistence and discontinuation. This matched cohort analysis indicated that, compared to dabigatran, rivaroxaban was associated with better persistence and lower rates of discontinuation.

Comparison of the survival between coronary artery bypass graft surgery versus percutaneous coronary intervention in patients with poor left ventricular function (ejection fraction <30%): a propensity-matched analysis.

PubMed

Shah, Shaneel; Benedetto, Umberto; Caputo, Massimo; Angelini, Gianni D; Vohra, Hunaid A

2018-06-22

Existing evidence comparing the outcomes of coronary artery bypass graft (CABG) surgery versus percutaneous coronary intervention (PCI) in patients with poor left ventricular function (LVF) is sparse and flawed. This is largely due to patients with poor LVF being underrepresented in major research trials and the outdated nature of some studies that do not consider drug-eluting stent PCI. Following strict inclusion criteria, 717 patients who underwent revascularization by CABG or PCI between 2002 and 2015 were enrolled. All patients had poor LVF (defined by ejection fraction <30%). By employing a propensity score analysis, 134 suitable matches (67 CABG and 67 PCI) were identified. Several outcomes were evaluated, in the matched population, using data extracted from national registry databases. CABG patients required a longer length of hospital stay post-revascularization compared to PCI in the propensity-matched population, 7 days (lower-upper quartile; 6-12) and 2 days (lower-upper quartile; 1-6), respectively (Mood's median test, P = 0.001). Stratified Cox-regression proportional-hazards analysis of the propensity-matched population found that PCI patients experienced a higher adjusted 8-year mortality rate (hazard ratio 3.291, 95% confidence interval 1.776-6.101; P < 0.001). This trend was consistent amongst urgent cases of revascularization: patients with 3 or more vessels with coronary artery disease and patients where complete revascularization was achieved. Although sub-analyses found no difference between survival distributions of on-pump versus off-pump CABG (log-rank P = 0.726), both modes of CABG were superior to PCI (stratified log-rank P = 0.002). Despite a longer length of hospital stay, patients with impaired LVF requiring intervention for coronary artery disease experienced a greater post-procedural survival benefit if they received CABG compared to PCI. We have demonstrated this at 30 days, 90 days, 1 year, 3 years, 5 years and 8 years following revascularization. At present, CABG remains a superior revascularization modality to PCI in patients with poor LVF.

Evaluation of dystonia in children and adolescents treated with atomoxetine within the Truven MarketScan database: a retrospective cohort study.

PubMed

Meyers, Kristin J; Upadhyaya, Himanshu P; Goodloe, Robert; Kryzhanovskaya, Ludmila A; Liles-Burden, Marie A; Kellier-Steele, Nicole A; Mancini, Michele

2018-05-01

Atomoxetine is a non-stimulant drug indicated for the treatment of attention-deficit/hyperactivity disorder in children aged ≥6 years, adolescents, and adults. In this retrospective cohort study, the incidence and risk of dystonia in children and adolescents treated with atomoxetine was compared to a propensity score-matched cohort of stimulant users. Data between 1 January 2006 and 31 December 2014 from patients aged 6-17 years in the Truven Health Analytics MarketScan database were used to generate two cohorts of patients: (1) atomoxetine users and (2) stimulant (methylphenidates or amphetamines) users. A Cox proportional hazards regression model was used to compare incidence of dystonia across propensity score-matched cohorts. Of the 70,657 atomoxetine users, 70,655 users were propensity score-matched to a stimulant user. In the atomoxetine- and stimulant-treated cohorts, the crude incidence rates of dystonia were 54.9 (95% CI: 27.1-82.7) and 77.9 (95% CI: 49.1-106.8) per 100,000 person-years, respectively. The hazard ratio for occurrence of dystonia with atomoxetine use relative to stimulant use was 0.68 (95% CI: 0.36 - 1.28; P = 0.23). In this large retrospective cohort study, there was no significant difference in incidence or risk of dystonia among patients treated with atomoxetine compared to stimulants.

Spironolactone Treatment and Effect on Survival in Chronic Heart Failure Patients with Reduced Renal Function: A Propensity-Matched Study

PubMed Central

Stubnova, Viera; Os, Ingrid; Grundtvig, Morten; Atar, Dan; Waldum-Grevbo, Bård

2017-01-01

Background/Aims Spironolactone may be hazardous in heart failure (HF) patients with renal dysfunction due to risk of hyperkalemia and worsened renal function. We aimed to evaluate the effect of spironolactone on all-cause mortality in HF outpatients with renal dysfunction in a propensity-score-matched study. Methods A total of 2,077 patients from the Norwegian Heart Failure Registry with renal dysfunction (eGFR <60 mL/min/1.73 m2) not treated with spironolactone at the first visit at the HF clinic were eligible for the study. Patients started on spironolactone at the outpatient HF clinics (n = 206) were propensity-score-matched 1:1 with patients not started on spironolactone, based on 16 measured baseline characteristics. Kaplan-Meier and Cox regression analyses were used to investigate the independent effect of spironolactone on 2-year all-cause mortality. Results Propensity score matching identified 170 pairs of patients, one group receiving spironolactone and the other not. The two groups were well matched (mean age 76.7 ± 8.1 years, 66.4% males, and eGFR 46.2 ± 10.2 mL/min/1.73 m2). Treatment with spironolactone was associated with increased potassium (delta potassium 0.31 ± 0.55 vs. 0.05 ± 0.41 mmol/L, p < 0.001) and decreased eGFR (delta eGFR −4.12 ± 12.2 vs. −0.98 ± 7.88 mL/min/1.73 m2, p = 0.006) compared to the non-spironolactone group. After 2 years, 84% of patients were alive in the spironolactone group and 73% of patients in the non-spironolactone group (HR 0.59, 95% CI 0.37-0.92, p = 0.020). Conclusion In HF outpatients with renal dysfunction, treatment with spironolactone was associated with improved 2-year survival compared to well-matched patients not treated with spironolactone. Favorable survival was observed despite worsened renal function and increased potassium in the spironolactone group. PMID:28611786

Prognostic significance of pre-resection albumin/fibrinogen ratio in patients with non-small cell lung cancer: A propensity score matching analysis.

PubMed

Chen, Shuaishuai; Yan, Haixi; Du, Juping; Li, Jun; Shen, Bo; Ying, Haijian; Zhang, Ying; Chen, Shiyong

2018-07-01

Nutrition and coagulation play important roles in cancer progression. This study was aimed to investigate the value of the albumin/fibrinogen ratio (AFR) in non-small cell lung cancer (NSCLC) patients, through a propensity score matching (PSM) method. We retrospectively analyzed 529 NSCLC patients underwent surgical resection from 2010 to 2015. PSM was used to eliminate possible biases. A Cox proportional hazards regression model was performed to evaluate the prognostic value of AFR in NSCLC. The optimal value was 9.67 for the AFR by ROC (receiver operating characteristic) curve. The AFR was statistically significantly associated with age, sex, smoking history, histological subtype, tumor size, pathological stage and adjuvant therapy (p < 0.05). Multivariate analysis indicated that the pathological stage and pre-resection AFR were independent prognostic factors for patients with NSCLC. Additionally, elevated AFR indicated a better outcome, and patients with higher AFR had lower risk for overall death (OS) (HR 0.512, 95% CI 0.316-0.829, p = 0.006) as well as disease-free death (DFS) (HR 0.561, 95% CI 0.399-0.787, p = 0.001). The propensity score model identified 120 patients from each group that were balanced for age, sex, smoking history, histological subtype, tumor size, stage distribution and adjuvant therapy. In multivariable regression analysis of PSM groups, the result indicated that the AFR was predictive for OS (HR 0.392, 95% CI 0.225-0.683, p < 0.001) and DFS (HR 0.526, 95% CI 0.344-0.805, p = 0.003). Pre-resection AFR can be considered as an independent prognostic factor in NSCLC patients, and higher AFR may enhance OS and DFS of NSCLC patients. Copyright © 2018 Elsevier B.V. All rights reserved.

Validating the EXCEL hypothesis: a propensity score matched 3-year comparison of percutaneous coronary intervention versus coronary artery bypass graft in left main patients with SYNTAX score ≤32.

PubMed

Capodanno, Davide; Caggegi, Anna; Capranzano, Piera; Cincotta, Glauco; Miano, Marco; Barrano, Gionbattista; Monaco, Sergio; Calvo, Francesco; Tamburino, Corrado

2011-06-01

The aim of this study is to verify the study hypothesis of the EXCEL trial by comparing percutaneous coronary intervention (PCI) and coronary artery bypass graft (CABG) in an EXCEL-like population of patients. The upcoming EXCEL trial will test the hypothesis that left main patients with SYNTAX score ≤ 32 experience similar rates of 3-year death, myocardial infarction (MI), or cerebrovascular accidents (CVA) following revascularization by PCI or CABG. We compared the 3-year rates of death/MI/CVA and death/MI/CVA/target vessel revascularization (MACCE) in 556 patients with left main disease and SYNTAX score ≤ 32 undergoing PCI (n = 285) or CABG (n = 271). To account for confounders, outcome parameters underwent extensive statistical adjustment. The unadjusted incidence of death/MI/CVA was similar between PCI and CABG (12.7% vs. 8.4%, P = 0.892), while MACCE were higher in the PCI group compared to the CABG group (27.0% vs. 11.8%, P < 0.001). After propensity score matching, PCI was not associated with a significant increase in the rate of death/MI/CVA (11.8% vs. 10.7%, P = 0.948), while MACCE were more frequently noted among patients treated with PCI (28.8% vs. 14.1%, P = 0.002). Adjustment by means of SYNTAX score and EUROSCORE, covariates with and without propensity score, and propensity score alone did not change significantly these findings. In an EXCEL-like cohort of patients with left main disease, there seems to be a clinical equipoise between PCI and CABG in terms of death/MI/CVA. However, even in patients with SYNTAX score ≤ 32, CABG is superior to PCI when target vessel revascularization is included in the combined endpoint. Copyright © 2011 Wiley-Liss, Inc.

The Association of Statin Use with Age-Related Macular Degeneration Progression The Age-Related Eye Disease Study 2 Report Number 9

PubMed Central

Al-Holou, Shaza N.; Tucker, William R.; Agrón, Elvira; Clemons, Traci E.; Cukras, Catherine; Ferris, Frederick L.; Chew, Emily Y.

2015-01-01

Objective/purpose To evaluate the association of statin use with progression of age-related macular degeneration (AMD). Design Preplanned, prospective cohort study within a controlled clinical trial of oral supplementation for age-related eye diseases. Subjects Age-Related Eye Disease Study 2 participants, aged 50 to 85 years. Methods Factors, including age, gender, smoking status, aspirin use, and history of diabetes, hypertension, heart disease, angina, and stroke, all known to be associated with statin use, were included in a logistic regression model to estimate propensity scores for each participant. Age-adjusted proportional hazards regression models, with and without propensity score matching, were performed to evaluate the association of statin use with progression to late AMD. Analyses were also performed adjusting for the competing risk of death. Main Outcome Measures Baseline and annual stereoscopic fundus photographs were assessed centrally by masked graders for the development of late AMD, either neovascular AMD or geographic atrophy (GA). Results Of the 3791 participants (2462 with bilateral large drusen and 1329 with unilateral late AMD at baseline), 1659 (43.8%) were statin users. The overall analysis, with no matching of propensity scores and no adjustment for death as a competing risk, showed that statin use was not associated with progression to late AMD (hazard ratios [HR] of 1.08, 95% confidence intervals [CI] of 0.83–1.41, P=0.56). When matched for propensity scores and adjusted for death as a competing risk, the result was not statistically significant with HR: 0.81, 95% CI: 0.55–1.20, P=0.29. Further subgroup analyses of persons with or without late AMD at baseline to the various components of late AMD (neovascular, central geographic atrophy, or any geographic atrophy) also showed no statistically significant association of statin use with progression to AMD. Conclusions Statin use was not statistically significantly associated with the progression to late AMD in the AREDS2 participants, and these findings are consistent with the findings in the majority of previous studies. Statins have been demonstrated to reduce the risks of cardiovascular disease, but our data do not provide evidence of a beneficial effect on slowing AMD progression. PMID:26435335

Effect of Retention in First Grade on Children's Achievement Trajectories over 4 Years: A Piecewise Growth Analysis Using Propensity Score Matching

ERIC Educational Resources Information Center

Wu, Wei; West, Stephen G.; Hughes, Jan N.

2008-01-01

The authors investigated the relatively short-term and longer term effects of grade retention in 1st grade on the growth of mathematics and reading achievement over 4 years. The authors initially identified a large multiethnic sample (n = 784) of children who were below the median in literacy at school entrance. From this sample, the authors…

The relationship between inotrope exposure, six-hour postoperative physiological variables, hospital mortality and renal dysfunction in patients undergoing cardiac surgery.

PubMed

Shahin, Jason; DeVarennes, Benoit; Tse, Chun Wing; Amarica, Dan-Alexandru; Dial, Sandra

2011-07-07

Acute haemodynamic complications are common after cardiac surgery and optimal perioperative use of inotropic agents, typically guided by haemodynamic variables, remains controversial. The aim of this study was to examine the relationship of inotrope use to hospital mortality and renal dysfunction. A retrospective cohort study of 1,326 cardiac surgery patients was carried out at two university-affiliated ICUs. Multivariable logistic regression analysis and propensity matching were performed to evaluate whether inotrope exposure was independently associated with mortality and renal dysfunction. Patients exposed to inotropes had a higher mortality rate than those not exposed. After adjusting for differences in Parsonnet score, left ventricular ejection fraction, perioperative intraaortic balloon pump use, bypass time, reoperation and cardiac index, inotrope exposure appeared to be independently associated with increased hospital mortality (adjusted odds ratio (OR) 2.3, 95% confidence interval (95% CI) 1.2 to 4.5) and renal dysfunction (adjusted OR 2.7, 95% CI 1.5 to 4.6). A propensity score-matched analysis similarly demonstrated that death and renal dysfunction were significantly more likely to occur in patients exposed to inotropes (P = 0.01). Postoperative inotrope exposure was independently associated with worse outcomes in this cohort study. Further research is needed to better elucidate the appropriate use of inotropes in cardiac surgery.

Longer-term Baerveldt to Trabectome glaucoma surgery comparison using propensity score matching.

PubMed

Kostanyan, Tigran; Shazly, Tarek; Kaplowitz, Kevin B; Wang, Steven Z; Kola, Sushma; Brown, Eric N; Loewen, Nils A

2017-12-01

To apply propensity score matching to compare Baerveldt glaucoma drainage implant (BGI) to Trabectome-mediated ab interno trabeculectomy (AIT). Recent data suggests that AIT can produce results similar to BGI which is traditionally reserved for more severe glaucoma. BGI and AIT patients with at least 1 year of follow-up were included. The primary outcome measures were intraocular pressure (IOP), number of glaucoma medications, and a Glaucoma Index (GI) score. GI reflected glaucoma severity based on visual field, the number of preoperative medications, and preoperative IOP. Score matching used a genetic algorithm consisting of age, gender, type of glaucoma, concurrent phacoemulsification, baseline number of medications, and baseline IOP. Patients with neovascular glaucoma, with prior glaucoma surgery, or without a close match were excluded. Of 353 patients, 30 AIT patients were matched to 29 BGI patients. Baseline characteristics including, IOP, the number of glaucoma medications, type of glaucoma, the degree of VF loss and GI were not significantly different between AIT and BGI. BGI had a preoperative IOP of 21.6 ± 6.3 mmHg compared to 21.5 ± 7.4 for AIT on 2.8 ± 1.1 medications and 2.5 ± 2.3 respectively. At 30 months, the mean IOP was 15.0 ± 3.9 mmHg for AIT versus 15.0 ± 5.7 mmHg for BGI (p > 0.05), while the number of drops was 1.5 ± 1.3 for AIT (change: p = 0.001) versus 2.4 ± 1.2 for BGI (change: p = 0.17; AIT vs BGI: 0.007). Success, defined as IOP < 21 mmHg, < 20% reduction and no reoperation, was achieved at 1 year in 56% of AIT versus 55% of BGI (p > 0.05) and 50% versus 52% at 2.5 years. A propensity score matched comparison of AIT and BGI demonstrated a similar IOP reduction through 1 year. AIT required fewer medications.

Quantifying the causal effects of 20mph zones on road casualties in London via doubly robust estimation.

PubMed

Li, Haojie; Graham, Daniel J

2016-08-01

This paper estimates the causal effect of 20mph zones on road casualties in London. Potential confounders in the key relationship of interest are included within outcome regression and propensity score models, and the models are then combined to form a doubly robust estimator. A total of 234 treated zones and 2844 potential control zones are included in the data sample. The propensity score model is used to select a viable control group which has common support in the covariate distributions. We compare the doubly robust estimates with those obtained using three other methods: inverse probability weighting, regression adjustment, and propensity score matching. The results indicate that 20mph zones have had a significant causal impact on road casualty reduction in both absolute and proportional terms. Copyright © 2016 Elsevier Ltd. All rights reserved.

Simultaneous Pure Laparoscopic Resection of Primary Colorectal Cancer and Synchronous Liver Metastases: A Single Institution Experience with Propensity Score Matching Analysis.

PubMed

Ivanecz, Arpad; Krebs, Bojan; Stozer, Andraz; Jagric, Tomaz; Plahuta, Irena; Potrc, Stojan

2018-03-01

The aim of the study was to compare the outcome of pure laparoscopic and open simultaneous resection of both the primary colorectal cancer and synchronous colorectal liver metastases (SCLM). From 2000 to 2016 all patients treated by simultaneous resection were assessed for entry in this single center, clinically nonrandomized trial. A propensity score matching was used to compare the laparoscopic group (LAP) to open surgery group (OPEN). Primary endpoints were perioperative and oncologic outcomes. Secondary endpoints were overall survival (OS) and disease-free survival (DFS). Of the 82 patients identified who underwent simultaneous liver resection for SCLM, 10 patients underwent LAP. All these consecutive patients from LAP were matched to 10 comparable OPEN. LAP reduced the length of hospital stay (P = 0.044) and solid food oral intake was faster (P = 0.006) in this group. No patient undergoing the laparoscopic procedure experienced conversion to the open technique. No difference was observed in operative time, blood loss, transfusion rate, narcotics requirement, clinical risk score, resection margin, R0 resections rate, morbidity, mortality and incisional hernias rate. The two groups did not differ significantly in terms of the 3-year OS rate (90 vs. 75%; P = 0.842) and DFS rate (60 vs. 57%; P = 0.724). LAP reduced the length of hospital stay and offers faster solid food oral intake. Comparable oncologic and survival outcomes can be achieved. LAP is beneficial for well selected patients in high volume centers with appropriate expertise.

Prevalence and Distribution of Coronary Artery Calcification in Asymptomatic United States and Korean Adults　- Cross-Sectional Propensity-Matched Analysis.

PubMed

Han, Donghee; Ó Hartaigh, Bríain; Gransar, Heidi; Lee, Ji Hyun; Choi, Su-Yeon; Chun, Eun Ju; Sung, Jidong; Han, Hae-Won; Park, Sung Hak; Callister, Tracy; Lin, Fay Y; Min, James K; Chang, Hyuk-Jae

2016-10-25

The incidence of coronary artery disease (CAD) varies depending on ethnicity, but the precise differences remain to be firmly established. This study therefore evaluated the disparity in coronary artery calcification (CAC), as a marker of CAD, in asymptomatic US and Korean adults.Methods and Results:CAC score was compared between asymptomatic Korean (n=15,128) and US (n=7,533) adults. Propensity score matching was performed according to age, gender, hypertension, diabetes, dyslipidemia, and current smoking, which generated 2 cohorts of 5,427 matched pairs. Both cohorts were categorized according to age group: 45-54, 55-64, and 65-74 years. Overall, the prevalence of CAC score >0, >100, and >400 in Korean adults was lower than in US adults (P<0.001, all). According to increasing age groups, the likelihood of CAC was most often lower in Korean adults, especially in Korean women. The odds of having CAC >400 in Korean adults aged 65-74 years was 0.66 (95% CI: 0.48-0.91) overall, 0.78 (95% CI: 0.52-1.19) in men, and 0.50 (95% CI: 0.29-0.86) in women, compared with US counterparts. Korean adults have a lower prevalence and severity of atherosclerotic burden as assessed on CAC, compared with US adults, but the disparity in CAC according to ethnicity may decline with older age. (Circ J 2016; 80: 2349-2355).

Optimal case-control matching in practice.

PubMed

Cologne, J B; Shibata, Y

1995-05-01

We illustrate modern matching techniques and discuss practical issues in defining the closeness of matching for retrospective case-control designs (in which the pool of subjects already exists when the study commences). We empirically compare matching on a balancing score, analogous to the propensity score for treated/control matching, with matching on a weighted distance measure. Although both methods in principle produce balance between cases and controls in the marginal distributions of the matching covariates, the weighted distance measure provides better balance in practice because the balancing score can be poorly estimated. We emphasize the use of optimal matching based on efficient network algorithms. An illustration is based on the design of a case-control study of hepatitis B virus infection as a possible confounder and/or effect modifier of radiation-related primary liver cancer in atomic bomb survivors.

Trainee-associated outcomes in laparoscopic colectomy for cancer: propensity score analysis accounting for operative time, procedure complexity and patient comorbidity.

PubMed

Kasten, Kevin R; Celio, Adam C; Trakimas, Lauren; Manwaring, Mark L; Spaniolas, Konstantinos

2018-02-01

Surgical trainee association with operative outcomes is controversial. Studies are conflicting, possibly due to insufficient control of confounding variables such as operative time, case complexity, and heterogeneous patient populations. As operative complications worsen long-term outcomes in oncologic patients, understanding effect of trainee involvement during laparoscopic colectomy for cancer is of utmost importance. Here, we hypothesized that resident involvement was associated with worsened 30-day mortality and 30-day overall morbidity in this patient population. Patients undergoing laparoscopic colectomy for oncologic diagnosis from 2005 to 2012 were assessed using the American College of Surgeons National Surgical Quality Improvement Program dataset. Propensity score matching accounted for demographics, comorbidities, case complexity, and operative time. Attending only cases were compared to junior, middle, chief resident, and fellow level cohorts to assess primary outcomes of 30-day mortality and 30-day overall morbidity. A total of 13,211 patients met inclusion criteria, with 4075 (30.8%) cases lacking trainee involvement and 9136 (69.2%) involving a trainee. Following propensity matching, junior (PGY 1-2) and middle level (PGY 3-4) resident involvement was not associated with worsened outcomes. Chief (PGY 5) resident involvement was associated with worsened 30-day overall morbidity (15.5 vs. 18.6%, p = 0.01). Fellow (PGY > 5) involvement was associated with worsened 30-day overall morbidity (16.0 vs. 21.0%, p < 0.001), serious morbidity (9.3 vs. 13.5%, p < 0.001), minor morbidity (9.8 vs. 13.1%, p = 0.002), and surgical site infection (7.9 vs. 10.5%, p = 0.006). No differences were seen in 30-day mortality for any resident level. Following propensity-matched analysis of cancer patients undergoing laparoscopic colectomy, chief residents, and fellows were associated with worsened operative outcomes compared to attending along cases, while junior and mid-level resident outcomes were no different. Further study is necessary to determine what effect the PGY surgical trainee level has on post-operative morbidity in cancer patients undergoing laparoscopic colectomy in the context of multiple collinear factors.

Effect of dextran-70 on outcome in severe sepsis; a propensity-score matching study.

PubMed

Bentzer, Peter; Broman, Marcus; Kander, Thomas

2017-07-06

Albumin may be beneficial in patients with septic shock but availability is limited and cost is high. The objective of the present study was to investigate if the use of dextran-70 in addition to albumin and crystalloids influences organ failure or mortality in patients with severe sepsis or septic shock. Patients with severe sepsis or septic shock (n = 778) admitted to a university hospital intensive care unit (ICU) between 2007 and 2015 that received dextran-70 during resuscitation were propensity score matched to controls at a 1 to 1 ratio. Outcomes were highest acute kidney injury network (AKIN) score the first 10 days in the ICU, use of renal replacement therapy, days alive and free of organ support the first 28 days after admission to ICU, mortality and events of severe bleeding. Outcomes were assessed using paired hypothesis testing. Propensity score matching resulted in two groups of patients with 245 patients in each group. The dextran group received a median volume of 1483 ml (interquartile range, 1000-2000 ml) of dextran-70 during the ICU stay. Highest AKIN score did not differ between the control- and dextran groups (1 (0-3) versus 2 (0-3), p = 0.06). Incidence of renal replacement therapy in the control- and dextran groups was similar (19% versus 22%, p = 0.42, absolute risk reduction -2.9% [95% CI: -9.9 to 4.2]). Days alive and free of renal replacement, vasopressors and mechanical ventilation did not differ between the control- and dextran groups. The 180-day mortality was 50.2% in the control group and 41.6% in the dextran group (p = 0.046, absolute risk reduction 8.6% [-0.2 to 17.4]). Fraction of patients experiencing a severe bleeding in the first 10 days in the ICU did not differ between the control and dextran groups (14% versus 18%, p = 0.21). There is a paucity of high quality data regarding effects of dextran solutions on outcome in sepsis. In the present study, propensity score matching was used in attempt to reduce bias. No evidence to support a detrimental effect of dextran-70 on mortality or on organ failures in patients with severe sepsis or septic shock could be detected.

Do family dinners reduce the risk for early adolescent substance use? A propensity score analysis.

PubMed

Hoffmann, John P; Warnick, Elizabeth

2013-01-01

The risks of early adolescent substance use on health and well-being are well documented. In recent years, several experts have claimed that a simple preventive measure for these behaviors is for families to share evening meals. In this study, we use data from the 1997 National Longitudinal Study of Youth (n = 5,419) to estimate propensity score models designed to match on a set of covariates and predict early adolescent substance use frequency and initiation. The results indicate that family dinners are not generally associated with alcohol or cigarette use or with drug use initiation. However, a continuous measure of family dinners is modestly associated with marijuana frequency, thus suggesting a potential causal impact. These results show that family dinners may help prevent one form of substance use in the short term but do not generally affect substance use initiation or alcohol and cigarette use.

The impact of confounder selection in propensity scores when applied to prospective cohort studies in pregnancy.

PubMed

Xu, Ronghui; Hou, Jue; Chambers, Christina D

2018-06-01

Our work was motivated by small cohort studies on the risk of birth defects in infants born to pregnant women exposed to medications. We controlled for confounding using propensity scores (PS). The extremely rare events setting renders the matching or stratification infeasible. In addition, the PS itself may be formed via different approaches to select confounders from a relatively long list of potential confounders. We carried out simulation experiments to compare different combinations of approaches: IPW or regression adjustment, with 1) including all potential confounders without selection, 2) selection based on univariate association between the candidate variable and the outcome, 3) selection based on change in effects (CIE). The simulation showed that IPW without selection leads to extremely large variances in the estimated odds ratio, which help to explain the empirical data analysis results that we had observed. Copyright © 2018 Elsevier Inc. All rights reserved.

Comparison of Laparoscopic Discoid Resection and Segmental Resection for Colorectal Endometriosis Using a Propensity Score Matching Analysis.

PubMed

Jayot, Aude; Nyangoh Timoh, Krystel; Bendifallah, Sofiane; Ballester, Marcos; Darai, Emile

Our primary endpoint was to compare the intra- and postoperative complications, whereas secondary endpoints were the occurrence of voiding dysfunction and evaluation of the quality or life of segmental and discoid resection in patients with colorectal endometriosis. Retrospective study (Canadian Task Force classification II-2). Tenon University Hospital in Paris. Thirty-one 31 patients who underwent a conservative surgery and 31 patients who underwent. The 2 groups were compared using propensity score matching (PSM) analysis, with a median follow-up of 247 days (8.2 months). Discoid colorectal resection was associated with a shorter operating time (155 vs 180 minutes, p = .03) and hospital stay (7 vs 8 days, p = .002) than segmental colorectal resection; however, a similar intra- and postoperative complication rate was found. A higher rate of postoperative voiding dysfunction was observed in the segmental resection group (19% vs 45%, p = .03) as well as duration of voiding dysfunction requiring bladder self-catheterization longer than 30 days (0 vs 22%, p = .005). Our PSM analysis suggests the advantages of discoid resection because it results in a similar surgical complication rate to segmental resection but with advantages in operating time, hospital stay, and voiding dysfunction. Copyright © 2017 American Association of Gynecologic Laparoscopists. Published by Elsevier Inc. All rights reserved.

The Utility of Therapeutic Hypothermia for Post-Cardiac Arrest Syndrome Patients With an Initial Nonshockable Rhythm.

PubMed

Perman, Sarah M; Grossestreuer, Anne V; Wiebe, Douglas J; Carr, Brendan G; Abella, Benjamin S; Gaieski, David F

2015-12-01

Therapeutic hypothermia (TH) attenuates reperfusion injury in comatose survivors of cardiac arrest. The utility of TH in patients with nonshockable initial rhythms has not been widely accepted. We sought to determine whether TH improved neurological outcome and survival in postarrest patients with nonshockable rhythms. We identified 519 patients after in- and out-of-hospital cardiac arrest with nonshockable initial rhythms from the Penn Alliance for Therapeutic Hypothermia (PATH) registry between 2000 and 2013. Propensity score matching was used. Patient and arrest characteristics used to estimate the propensity to receive TH were age, sex, location of arrest, witnessed arrest, and duration of arrest. To determine the association between TH and outcomes, we created 2 multivariable logistic models controlling for confounders. Of 201 propensity score-matched pairs, mean age was 63 ± 17 years, 51% were male, and 60% had an initial rhythm of pulseless electric activity. Survival to hospital discharge was greater in patients who received TH (17.6% versus 28.9%; P < 0.01), as was a discharge Cerebral Performance Category of 1 to 2 (13.7% versus 21.4%; P = 0.04). In adjusted analyses, patients who received TH were more likely to survive (odds ratio, 2.8; 95% confidence interval, 1.6-4.7) and to have better neurological outcome (odds ratio, 3.5; 95% confidence interval, 1.8-6.6) than those that did not receive TH. Using propensity score matching, we found that patients with nonshockable initial rhythms treated with TH had better survival and neurological outcome at hospital discharge than those who did not receive TH. Our findings further support the use of TH in patients with initial nonshockable arrest rhythms. © 2015 American Heart Association, Inc.

Evaluation of a disease management program for COPD using propensity matched control group

PubMed Central

George, Pradeep Paul; Heng, Bee Hoon; Lim, Tow Keang; Abisheganaden, John; Ng, Alan Wei Keong; Lim, Fong Seng

2016-01-01

Background Disease management programs (DMPs) have proliferated recently as a means of improving the quality and efficiency of care for patients with chronic illness. These programs include education about disease, optimization of evidence-based medications, information and support from case managers, and institution of self-management principles. Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality in Singapore and worldwide. DMP aims to reduce mortality, hospitalizations, and average length of stay in such patients. This study assesses the outcomes of the DMP, comparing the propensity score matched DMP patients with controls. Methods DMP patients were compared with the controls, who were COPD patients fulfilling the DMP’s inclusion criteria but not included in the program. Control patients were identified from Operations Data Store (ODS) database. The outcomes of interest were average length of stay, number of days admitted to hospital per 100 person days, readmission, and mortality rates per person year. The risk of death and readmission was estimated using Cox, and competing risk regression respectively. Propensity score was estimated to identify the predictors of DMP enrolment. DMP patients and controls were matched on their propensity score. Results There were 170 matched DMP patients and control patients having 287 and 207 hospitalizations respectively. Program patient had lower mortality than the controls (0.12 vs. 0.27 per person year); cumulative 1-year survival was 91% among program patient and 76% among the control patients. Readmission, and hospital days per 100 person-days was higher for the program patients (0.36 vs. 0.17 per person year), and (2.19 vs. 1.88 per person year) respectively. Conclusions Participation in “DMP” was associated with lower all-cause mortality when compared to the controls. This survival gain in the program patients was paradoxically associated with an increase in readmission rate and total hospital days. PMID:27499955

Evaluation of a disease management program for COPD using propensity matched control group.

PubMed

George, Pradeep Paul; Heng, Bee Hoon; Lim, Tow Keang; Abisheganaden, John; Ng, Alan Wei Keong; Verma, Akash; Lim, Fong Seng

2016-07-01

Disease management programs (DMPs) have proliferated recently as a means of improving the quality and efficiency of care for patients with chronic illness. These programs include education about disease, optimization of evidence-based medications, information and support from case managers, and institution of self-management principles. Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality in Singapore and worldwide. DMP aims to reduce mortality, hospitalizations, and average length of stay in such patients. This study assesses the outcomes of the DMP, comparing the propensity score matched DMP patients with controls. DMP patients were compared with the controls, who were COPD patients fulfilling the DMP's inclusion criteria but not included in the program. Control patients were identified from Operations Data Store (ODS) database. The outcomes of interest were average length of stay, number of days admitted to hospital per 100 person days, readmission, and mortality rates per person year. The risk of death and readmission was estimated using Cox, and competing risk regression respectively. Propensity score was estimated to identify the predictors of DMP enrolment. DMP patients and controls were matched on their propensity score. There were 170 matched DMP patients and control patients having 287 and 207 hospitalizations respectively. Program patient had lower mortality than the controls (0.12 vs. 0.27 per person year); cumulative 1-year survival was 91% among program patient and 76% among the control patients. Readmission, and hospital days per 100 person-days was higher for the program patients (0.36 vs. 0.17 per person year), and (2.19 vs. 1.88 per person year) respectively. Participation in "DMP" was associated with lower all-cause mortality when compared to the controls. This survival gain in the program patients was paradoxically associated with an increase in readmission rate and total hospital days.

Smartphone-based reminder system to promote pelvic floor muscle training for the management of postnatal urinary incontinence: historical control study with propensity score-matched analysis.

PubMed

Kinouchi, Kaori; Ohashi, Kazutomo

2018-01-01

The purpose of this study was to evaluate the efficacy of a smartphone-based reminder system in promoting pelvic floor muscle training (PFMT) to help postpartum women manage urinary incontinence (UI). Forty-nine and 212 postpartum women in the intervention and control groups, respectively, received PFMT guidance using a leaflet and verbal instruction as the standard care at an obstetrics clinic in Japan. Women in the intervention group also received PFMT support using the smartphone-based reminder system between January and August 2014. For analysis, they were compared with historical controls between February 2011 and January 2012, who did not receive such support and were chosen by propensity score matching. The outcomes examined were PFMT adherence and UI prevalence. The former consisted of implementation rate (i.e., the percentage of women who reported performing PFMT during the intervention period), training intensity (i.e., the number of pelvic floor muscle contractions (PFMCs) per day), and training frequency (i.e., the number of days PFMT was performed per week); the latter consisted of self-reported UI prevalence at baseline and at the end of the eight-week intervention period. Propensity score matching resulted in 58 postpartum women ( n  = 29 per group). The intervention group exhibited better PFMT adherence than the control group, in terms of PFMT implementation rate (69 vs. 31%, p  = 0.008), median training intensity (15 vs. 1 PFMC reps/day, p  = 0.006), and training frequency (7 vs. 3 days/week, p  < 0.001). UI prevalence was not different between the groups at baseline, but was significantly reduced in the intervention group at eight weeks (0 vs. 24%, p  = 0.004). Our smartphone-based reminder system appears promising in enhancing PFMT adherence and managing postpartum UI in postpartum women. By enhancing PFMT adherence and improving women's ability to manage the condition, the reminder system could improve the health-related quality of life of postpartum women with UI.

Splash M-knife versus Flush Knife BT in the technical outcomes of endoscopic submucosal dissection for early gastric cancer: a propensity score matching analysis.

PubMed

Esaki, Mitsuru; Suzuki, Sho; Hayashi, Yasuyo; Yokoyama, Azusa; Abe, Shuichi; Hosokawa, Taizo; Ogino, Haruei; Akiho, Hirotada; Ihara, Eikichi; Ogawa, Yoshihiro

2018-02-27

Endoscopic submucosal dissection (ESD) is a standard treatment for early gastric cancer. A new multi-functional ESD device was developed to achieve complete ESD with a single device. A metal plate attached to its distal sheath achieves better hemostasis during the procedure than the other needle-knife device, Flush Knife BT®, that has been conventionally used. The aim of this study was to compare the technical outcomes of ESD for early gastric cancer using the Splash M-Knife® with those using the Flush Knife BT. We conducted a retrospective review of the case records of 149 patients with early gastric cancer treated with ESD using the needle-type ESD knives between January 2012 and August 2016 at Kitakyushu Municipal Medical Center. Lesions treated with ESD using the Splash M-knife (ESD-M) and the Flush Knife BT (ESD-F) were compared. Multivariate analyses and propensity score matching were used to compensate for the differences in age, gender, underlying disease, antithrombotic drug use, lesion location, lesion position, macroscopic type, tumor size, presence of ulceration, operator level and types of electrosurgical unit used. The primary endpoint was the requirement to use hemostatic forceps in the two groups. The secondary endpoints of procedure time, en bloc and complete resection rates, and adverse events rates were evaluated for the two groups. There were 73 patients in the ESD-M group, and 76 patients in the ESD-F group. Propensity score matching analysis created 45 matched pairs. Adjusted comparisons between the two groups showed a significantly lower usage rate of hemostatic forceps in the ESD-M group than in the ESD-F group (6.7% vs 84.4%, p < 0.001). Treatment outcomes showed an en bloc resection rate of 100% in both groups; complete resection rate of 95.6% vs 100%, p = 0.49; median procedure time of 74.0 min vs 71.0 min, p = 0.90; post-procedure bleeding of 2.2% vs 2.2%, p = 1, in the ESD-M and ESD-F groups, respectively. There were no perforations in either group. ESD-M appeared to reduce the usage of hemostatic forceps during ESD for early gastric cancer without increasing the adverse effects. Thus, it may contribute to a reduction in the total ESD cost.

Prehospital antiplatelet use and functional status on admission of patients with non-haemorrhagic moyamoya disease: a nationwide retrospective cohort study (J-ASPECT study)

PubMed Central

Onozuka, Daisuke; Hagihara, Akihito; Nishimura, Kunihiro; Kada, Akiko; Nakagawara, Jyoji; Ogasawara, Kuniaki; Ono, Junichi; Shiokawa, Yoshiaki; Aruga, Toru; Miyachi, Shigeru; Nagata, Izumi; Toyoda, Kazunori; Matsuda, Shinya; Suzuki, Akifumi; Kataoka, Hiroharu; Nakamura, Fumiaki; Kamitani, Satoru; Nishimura, Ataru; Kurogi, Ryota; Sayama, Tetsuro; Iihara, Koji

2016-01-01

Objectives To elucidate the association between antiplatelet use in patients with non-haemorrhagic moyamoya disease before hospital admission and good functional status on admission in Japan. Design Retrospective, multicentre, non-randomised, observational study. Setting Nationwide registry data in Japan. Participants A total of 1925 patients with non-haemorrhagic moyamoya disease admitted between 1 April 2012 and 31 March 2014 in Japan. Main outcome measure We performed propensity score-matched analysis to examine the association between prehospital antiplatelet use and no significant disability on hospital admission, as defined by a modified Rankin Scale score of 0 or 1. Results Propensity-matched patients who received prehospital antiplatelet drugs were associated with a good outcome on hospital admission (OR adjusted for all covariates, 3.82; 95% CI 1.22 to 11.99) compared with those who did not receive antiplatelet drugs prior to hospital admission. Conclusions Prehospital antiplatelet use was significantly associated with good functional status on hospital admission among patients with non-haemorrhagic moyamoya disease in Japan. Our results suggest that prehospital antiplatelet use should be considered when evaluating outcomes of patients with non-haemorrhagic moyamoya disease. PMID:27008684

The Impact of Relative Poverty on Norwegian Adolescents’ Subjective Health: A Causal Analysis with Propensity Score Matching

PubMed Central

Elstad, Jon Ivar; Pedersen, Axel West

2012-01-01

Studies have revealed that relative poverty is associated with ill health, but the interpretations of this correlation vary. This article asks whether relative poverty among Norwegian adolescents is causally related to poor subjective health, i.e., self-reported somatic and mental symptoms. Data consist of interview responses from a sample of adolescents (N = 510) and their parents, combined with register data on the family’s economic situation. Relatively poor adolescents had significantly worse subjective health than non-poor adolescents. Relatively poor adolescents also experienced many other social disadvantages, such as parental unemployment and parental ill health. Comparisons between the relatively poor and the non-poor adolescents, using propensity score matching, indicated a negative impact of relative poverty on the subjective health among those adolescents who lived in families with relatively few economic resources. The results suggest that there is a causal component in the association between relative poverty and the symptom burden of disadvantaged adolescents. Relative poverty is only one of many determinants of adolescents’ subjective health, but its role should be acknowledged when policies for promoting adolescent health are designed. PMID:23249858

Gender differences in the association between cohabitation with parents and stress among married adults: A propensity score-matched analysis from the Korean National Health and Nutrition Examination Survey (KNHANES).

PubMed

Kim, Dae-Hwan; Mak, Kwok-Kei

2016-01-01

This study examined the gender-specific associations between cohabitation with parents and stress using an econometric approach. A total of 13,565 (41.7% men and 58.3% women) Korean adults aged 20-59 years from the Korean National Health and Nutrition Examination Survey (KNHANES) 2008 to 2011 were pooled. They reported their gender, age, marital status, education level, employment status, income, home ownership, and cohabitation status with their parents. The association of living with parents and stress, as well as the gender difference in the association, was investigated using propensity score matching and the average treatment effect on the treated. Adults with higher education and income, not owning a house, or living in larger cities were less likely to live with parents. Stress was associated with having children and participating in the labor market for both married men and women. Moreover, living with parents was a protective factor for stress among husbands, but a risk factor for wives in Korea. Gender differences existed in the association between cohabitation with parents and stress. Greater stress was related to cohabiting with parents and working for married women.

Propensity score matching analysis to evaluate the comparative effectiveness of daratumumab versus real-world standard of care therapies for patients with heavily pretreated and refractory multiple myeloma.

PubMed

Kumar, Shaji; Durie, Brian; Nahi, Hareth; Vij, Ravi; Dimopoulos, Meletios A; Kastritis, Efstathios; Terpos, Evangelos; Leleu, Xavier; Beksac, Meral; Goldschmidt, Hartmut; Hillengass, Jens; Su, Zhuo; Hutton, Brian; Cameron, Chris; Khan, Imran; Lam, Annette

2018-05-09

Daratumumab is a CD38-directed monoclonal antibody approved for treating multiple myeloma (MM). Propensity score matching (PSM) based on individual patient data (IPD) was conducted to compare overall survival (OS) and progression-free survival (PFS) for daratumumab versus real-world standard of care (SOC). IPD for patients with relapsed and refractory (RR) MM treated with daratumumab monotherapy were from the GEN501 and SIRIUS studies; IPD for patients treated with SOC were from an International Myeloma Working Group (IMWG) chart review of patients with RRMM. Prior to PSM, patients treated with daratumumab had significantly longer OS (median 20.1 vs. 10.1 months, hazard ratio [HR] = 0.51 [0.39-0.67]) and PFS (median 4.0 vs. 2.8 months, HR = 0.73 [0.58-0.92]) than patients treated with SOC therapies. After PSM, daratumumab maintained a significantly prolonged OS (19.9 vs. 9.2 months, HR = 0.44 [0.31-0.63]) and PFS (3.9 vs. 1.6 months, HR = 0.56 [0.42-0.74]) compared with SOC.

Macrolide therapy is associated with reduced mortality in acute respiratory distress syndrome (ARDS) patients.

PubMed

Simonis, Fabienne D; de Iudicibus, Gianfranco; Cremer, Olaf L; Ong, David S Y; van der Poll, Tom; Bos, Lieuwe D; Schultz, Marcus J

2018-01-01

Macrolides have been associated with favorable immunological effects in various inflammatory disease states. We investigated the association between macrolide therapy and mortality in patients with the acute respiratory distress syndrome (ARDS). This was an unplanned secondary analysis of patients with ARDS within a large prospective observational study of critically ill patients in the intensive care units (ICUs) of two university-affiliated hospitals in the Netherlands. The exposure of interest was low-dose macrolide use prescribed for another reason than infection; we excluded patients who received high-dose macrolides for an infection. The primary endpoint was 30-day mortality. The association between macrolide therapy and mortality was determined in the whole cohort, as well as in a propensity score matched cohort; the association was compared between pulmonary versus non-pulmonary ARDS, and between two biological phenotypes based on plasma levels of 20 biomarkers. In total, 873 patients with ARDS were analyzed, of whom 158 patients (18%) received macrolide therapy during stay in ICU for a median duration of 3 (interquartile range, 1-4) days. Erythromycin was the most frequent prescribed macrolide (97%). Macrolide therapy was associated with reduced 30-day mortality in the whole cohort [22.8% vs. 31.6%; crude odds ratio (OR), 0.64 (interquartile range, 0.43-0.96), P=0.03]. The association in the propensity score matched cohort remained significant [22.8% vs. 32.9%; OR, 0.62 (interquartile range, 0.39-0.96), P=0.03]. Propensity matched associations with mortality were different in patients with non-pulmonary ARDS vs. pulmonary ARDS and also varied by biological phenotype. These data together show that low-dose macrolide therapy prescribed for another reason than infection is associated with decreased mortality in patients with ARDS.

Macrolide therapy is associated with reduced mortality in acute respiratory distress syndrome (ARDS) patients

PubMed Central

de Iudicibus, Gianfranco; Cremer, Olaf L.; Ong, David S. Y.; van der Poll, Tom; Bos, Lieuwe D.; Schultz, Marcus J.

2018-01-01

Background Macrolides have been associated with favorable immunological effects in various inflammatory disease states. We investigated the association between macrolide therapy and mortality in patients with the acute respiratory distress syndrome (ARDS). Methods This was an unplanned secondary analysis of patients with ARDS within a large prospective observational study of critically ill patients in the intensive care units (ICUs) of two university-affiliated hospitals in the Netherlands. The exposure of interest was low-dose macrolide use prescribed for another reason than infection; we excluded patients who received high-dose macrolides for an infection. The primary endpoint was 30-day mortality. The association between macrolide therapy and mortality was determined in the whole cohort, as well as in a propensity score matched cohort; the association was compared between pulmonary versus non-pulmonary ARDS, and between two biological phenotypes based on plasma levels of 20 biomarkers. Results In total, 873 patients with ARDS were analyzed, of whom 158 patients (18%) received macrolide therapy during stay in ICU for a median duration of 3 (interquartile range, 1–4) days. Erythromycin was the most frequent prescribed macrolide (97%). Macrolide therapy was associated with reduced 30-day mortality in the whole cohort [22.8% vs. 31.6%; crude odds ratio (OR), 0.64 (interquartile range, 0.43–0.96), P=0.03]. The association in the propensity score matched cohort remained significant [22.8% vs. 32.9%; OR, 0.62 (interquartile range, 0.39–0.96), P=0.03]. Propensity matched associations with mortality were different in patients with non-pulmonary ARDS vs. pulmonary ARDS and also varied by biological phenotype. Conclusions These data together show that low-dose macrolide therapy prescribed for another reason than infection is associated with decreased mortality in patients with ARDS. PMID:29430441

Effect of intravenous immunoglobulin for fulminant myocarditis on in-hospital mortality: propensity score analyses.

PubMed

Isogai, Toshiaki; Yasunaga, Hideo; Matsui, Hiroki; Tanaka, Hiroyuki; Horiguchi, Hiromasa; Fushimi, Kiyohide

2015-05-01

Fulminant myocarditis (FM) is a rare but life-threatening disease. Intravenous immunoglobulin (IVIG) is not recommended for acute or chronic myocarditis in Western nations owing to the lack of rigorous evidence, but it is widely used in other countries, including Japan. This nationwide retrospective cohort study focused on evaluating the effect of IVIG in FM patients. Using the Diagnosis Procedure Combination database in Japan, we identified 603 FM patients aged ≥16 years who received mechanical circulatory support within 7 days after admission. We performed propensity score analyses to compare the in-hospital mortality and total costs between IVIG users (n = 220; 36.5%) and nonusers (n = 383; 63.5%). Among propensity score-matched patients (164 pairs), there was no significant difference in in-hospital mortality between IVIG users and nonusers (36.6% vs 37.2%; P = .909). A multivariable logistic regression analysis showed no significant association between IVIG use and in-hospital mortality (adjusted odds ratio 0.91; 95% confidence interval 0.52 to 1.58; P = .733). The median total costs were significantly higher for IVIG users than for nonusers (US $44,226 vs $33,280; P < .001). IVIG for FM was not significantly associated with a decrease in in-hospital mortality. Copyright © 2015 Elsevier Inc. All rights reserved.

Adjuvant treatment for resected rectal cancer: impact of standard and intensified postoperative chemotherapy on disease-free survival in patients undergoing preoperative chemoradiation-a propensity score-matched analysis of an observational database.

PubMed

Garlipp, Benjamin; Ptok, Henry; Benedix, Frank; Otto, Ronny; Popp, Felix; Ridwelski, Karsten; Gastinger, Ingo; Benckert, Christoph; Lippert, Hans; Bruns, Christiane

2016-12-01

Adjuvant chemotherapy for resected rectal cancer is widely used. However, studies on adjuvant treatment following neoadjuvant chemoradiotherapy (CRT) and total mesorectal excision (TME) have yielded conflicting results. Recent studies have focused on adding oxaliplatin to both preoperative and postoperative therapy, making it difficult to assess the impact of adjuvant oxaliplatin alone. This study was aimed at determining the impact of (i) any adjuvant treatment and (ii) oxaliplatin-containing adjuvant treatment on disease-free survival in CRT-pretreated, R0-resected rectal cancer patients. Patients undergoing R0 TME following 5-fluorouracil (5FU)-only-based CRT between January 1, 2008, and December 31, 2010, were selected from a nationwide registry. After propensity score matching (PSM), comparison of disease-free survival (DFS) using Kaplan-Meier analysis and log-rank test was performed in (i) patients receiving no vs. any adjuvant treatment and (ii) patients treated with adjuvant 5FU/capecitabine without vs. with oxaliplatin. Out of 1497 patients, 520 matched pairs were generated for analysis of no vs. any adjuvant treatment. Mean DFS was significantly prolonged with adjuvant treatment (81.8 ± 2.06 vs. 70.1 ± 3.02 months, p < 0.001). One hundred forty-eight matched pairs were available for analysis of adjuvant therapy with or without oxaliplatin, showing no improvement in DFS in patients receiving oxaliplatin (76.9 ± 4.12 vs. 79.3 ± 4.44 months, p = 0.254). Local recurrence rate was not significantly different between groups in either analysis. In this cohort of rectal cancer patients treated with neoadjuvant CRT and TME surgery under routine conditions, adjuvant chemotherapy significantly improved DFS. No benefit was observed for the addition of oxaliplatin to adjuvant chemotherapy in this setting.

Surgery or stereotactic body radiotherapy for elderly stage I lung cancer? A propensity score matching analysis.

PubMed

Miyazaki, Takuro; Yamazaki, Takuya; Nakamura, Daisuke; Sato, Shuntaro; Yamasaki, Naoya; Tsuchiya, Tomoshi; Matsumoto, Keitaro; Kamohara, Ryotaro; Hatachi, Go; Nagayasu, Takeshi

2017-12-01

The aim of this study was to compare the outcomes of surgery and stereotactic body radiotherapy (SBRT) for elderly clinical stage I non-small cell lung cancer (NSCLC) patients. Patients ≥80 years of age with clinical stage I NSCLC between August 2008 and December 2014 were treated either surgery or SBRT. Propensity score matching was performed to reduce bias in various clinicopathological factors. Surgery was performed in 57 cases and SBRT in 41 cases. In the surgery group, the operations included 34 lobectomies and 23 sublobar resections. In the SBRT group, 27 cases were given 48 Gy in 4 fractions, and 14 were given 60 Gy in 10 fractions. Similar characteristics were identified in age (82 years), gender (male:female ratio 2:1), tumor size (2.2 cm), carcinoembryonic antigen (3.6 ng/ml), Charlson comorbidity index (1), Glasgow prognostic scale (0), and forced expiratory volume in 1 s (1.7 L) after matching. Before matching, the 5-year overall survival (OS) in surgery (68.3%) was significantly better than that in SBRT (47.4%, p = 0.02), and the 5-year disease-specific survival (DSS) (94.1%, 78.2%, p = 0.17) was not significantly different between the groups. The difference in the 5-year OS became non-significant between the matched pairs (57.0%, 49.1%, p = 0.56). The outcomes of surgery and SBRT for elderly patients with the early stage NSCLC were roughly the same.

The Association of Individual and Regional Socioeconomic Status on Initial Peritonitis and Outcomes in Peritoneal Dialysis Patients: A Propensity Score-Matched Cohort Study.

PubMed

Wang, Qin; Hu, Ke-Jie; Ren, Ye-Ping; Dong, Jie; Han, Qing-Feng; Zhu, Tong-Ying; Chen, Jiang-Hua; Zhao, Hui-Ping; Chen, Meng-Hua; Xu, Rong; Wang, Yue; Hao, Chuan-Ming; Zhang, Xiao-Hui; Wang, Mei; Tian, Na; Wang, Hai-Yan

2016-01-01

♦ Research indicates that the socioeconomic status (SES) of individuals and the area where they live are related to initial peritonitis and outcomes in peritoneal dialysis (PD). We conducted a retrospective, multi-center cohort study in China to examine these associations. ♦ Data on 2,171 PD patients were collected from 7 centers, including baseline demographic, socioeconomic, and laboratory data. We explored the potential risk factors for initial peritonitis and outcomes using univariate Cox regression and unadjusted binary logistic regression. Then, we used propensity score matching to balance statistically significant risk factors for initial peritonitis and outcomes, and Kaplan-Meier survival analysis to compare differences in peritonitis-free rates between different groups of participants after matching. ♦ A total of 563 (25.9%) initial episodes of peritonitis occurred during the study period. The Kaplan-Meier peritonitis-free rate curve showed high-income patients had a significantly lower risk than low-income patients (p = 0.007) after matching for age, hemoglobin, albumin, and regional SES and PD center. The risk of treatment failure was significantly lower in the high-income than the low-income group after matching for the organism causing peritonitis and PD center: odds ratio (OR) = 0.27 (0.09 - 0.80, p = 0.018). Regional SES and education were not associated with initial peritonitis and outcomes. ♦ Our study demonstrates low individual income is a risk factor for the initial onset of peritonitis and treatment failure after initial peritonitis. Copyright © 2016 International Society for Peritoneal Dialysis.

Empirical and targeted therapy of candidemia with fluconazole versus echinocandins: a propensity score-derived analysis of a population-based, multicentre prospective cohort.

PubMed

López-Cortés, L E; Almirante, B; Cuenca-Estrella, M; Garnacho-Montero, J; Padilla, B; Puig-Asensio, M; Ruiz-Camps, I; Rodríguez-Baño, J

2016-08-01

We compared the clinical efficacy of fluconazole and echinocandins in the treatment of candidemia in real practice. The CANDIPOP study is a prospective, population-based cohort study on candidemia carried out between May 2010 and April 2011 in 29 Spanish hospitals. Using strict inclusion criteria, we separately compared the impact of empirical and targeted therapy with fluconazole or echinocandins on 30-day mortality. Cox regression, including a propensity score (PS) for receiving echinocandins, stratified analysis on the PS quartiles and PS-based matched analyses, were performed. The empirical and targeted therapy cohorts comprised 316 and 421 cases, respectively; 30-day mortality was 18.7% with fluconazole and 33.9% with echinocandins (p 0.02) in the empirical therapy group and 19.8% with fluconazole and 27.7% with echinocandins (p 0.06) in the targeted therapy group. Multivariate Cox regression analysis including PS showed that empirical therapy with fluconazole was associated with better prognosis (adjusted hazard ratio 0.38; 95% confidence interval 0.17-0.81; p 0.01); no differences were found within each PS quartile or in cases matched according to PS. Targeted therapy with fluconazole did not show a significant association with mortality in the Cox regression analysis (adjusted hazard ratio 0.77; 95% confidence interval 0.41-1.46; p 0.63), in the PS quartiles or in PS-matched cases. The results were similar among patients with severe sepsis and septic shock. Empirical or targeted treatment with fluconazole was not associated with increased 30-day mortality compared to echinocandins among adults with candidemia. Copyright © 2016 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

The search for causal inferences: using propensity scores post hoc to reduce estimation error with nonexperimental research.

PubMed

Tumlinson, Samuel E; Sass, Daniel A; Cano, Stephanie M

2014-03-01

While experimental designs are regarded as the gold standard for establishing causal relationships, such designs are usually impractical owing to common methodological limitations. The objective of this article is to illustrate how propensity score matching (PSM) and using propensity scores (PS) as a covariate are viable alternatives to reduce estimation error when experimental designs cannot be implemented. To mimic common pediatric research practices, data from 140 simulated participants were used to resemble an experimental and nonexperimental design that assessed the effect of treatment status on participant weight loss for diabetes. Pretreatment participant characteristics (age, gender, physical activity, etc.) were then used to generate PS for use in the various statistical approaches. Results demonstrate how PSM and using the PS as a covariate can be used to reduce estimation error and improve statistical inferences. References for issues related to the implementation of these procedures are provided to assist researchers.

Statins and musculoskeletal conditions, arthropathies, and injuries.

PubMed

Mansi, Ishak; Frei, Christopher R; Pugh, Mary Jo; Makris, Una; Mortensen, Eric M

2013-07-22

Statin use may be associated with increased musculoskeletal adverse events, especially in physically active individuals. To determine whether statin use is associated with musculoskeletal conditions, including arthropathy and injury, in a military health care system. A retrospective cohort study with propensity score matching. San Antonio Military Multi-Market. Tricare Prime/Plus beneficiaries evaluated from October 1, 2003, to March 1, 2010. Statin use during fiscal year 2005. On the basis of medication fills, patients were divided into 2 groups: statin users (received a statin for at least 90 days) and nonusers (never received a statin throughout the study period). Using patients' baseline characteristics, we generated a propensity score that was used to match statin users and nonusers; odds ratios (ORs) were determined for each outcome measure. Secondary analyses determined adjusted ORs for all patients who met study criteria and a subgroup of patients with no comorbidities identified using the Charlson Comorbidity Index. Sensitivity analysis further determined adjusted ORs for a subgroup of patients with no musculoskeletal diseases at baseline and a subgroup of patients who continued statin therapy for 2 years or more. The occurrence of musculoskeletal conditions was determined using prespecified groups of International Classification of Diseases, Ninth Revision, ClinicalModification codes: Msk1, all musculoskeletal diseases; Msk1a, arthropathies and related diseases; Msk1b, injury-related diseases (dislocation, sprain, strain); and Msk2, drug-associated musculoskeletal pain. A total of 46 249 individuals met study criteria (13 626 statin users and 32 623 nonusers). Of these, we propensity score-matched 6967 statin users with 6967 nonusers. Among matched pairs, statin users had a higher OR for Msk1 (OR, 1.19; 95% CI, 1.08-1.30), Msk1b (1.13; 1.05-1.21), and Msk2 (1.09; 1.02-1.18); the OR for Msk1a was 1.07 (0.99-1.16; P = .07). Secondary and sensitivity analyses revealed higher adjusted ORs for statin users in all outcome groups. Musculoskeletal conditions, arthropathies, injuries, and pain are more common among statin users than among similar nonusers. The full spectrum of statins' musculoskeletal adverse events may not be fully explored, and further studies are warranted, especially in physically active individuals.

Strengths-Based Advising Approaches: Benefits for First-Year Undergraduates

ERIC Educational Resources Information Center

Soria, Krista M.; Laumer, Nicole L.; Morrow, Dale J.; Marttinen, Garrett

2017-01-01

We explored the benefits of strengths-based academic advising approaches for first-year students (N = 1,228). We used propensity score matching techniques to create matched pairs of students who did and did not engage in strengths-based advising conversations with an advisor. First-year students who experienced strengths-based conversations had…

Blood transfusion and coagulopathy in geriatric trauma patients.

PubMed

Mador, Brett; Nascimento, Bartolomeu; Hollands, Simon; Rizoli, Sandro

2017-03-29

Trauma resuscitation has undergone a paradigm shift with new emphasis on the early use of blood products and increased proportions of plasma and platelets. However, it is unclear how this strategy is applied or how effective it is in the elderly population. The study aim is to identify differences in transfusion practices and the coagulopathy of trauma in the elderly. Data was prospectively collected on all consecutive patients that met trauma activation criteria at a Level I trauma centre. Data fields included patient demographics, co-morbidities, injury and resuscitation data, laboratory values, thromboelastography (TEG) results, and outcome measures. Elderly patients were defined as those 55 and older. Propensity-score matched analysis was completed for patients receiving blood product transfusion. Patients were matched by gender, mechanism, injury severity score (ISS), head injury, and time from injury. Total of 628 patients were included, of which 142 (23%) were elderly. Elderly patients were more likely to be female (41% vs. 24%), suffer blunt mechanism of trauma (96% vs. 80%), have higher ISS scores (mean 25.4 vs. 21.6) and mortality (19% vs. 8%). Elderly patients were significantly more likely to receive a blood transfusion (42% vs. 30%), specifically for red cells and plasma. Propensity-matched analysis resulted in no difference in red cell transfusion or mortality. Despite the broad similarities between the matched cohorts, trauma coagulopathy as measured by TEG was less commonly observed in the elderly. Our results suggest that elderly trauma patients are more likely to receive blood products when admitted to a trauma centre, though this may be attributed to under-triage. The results also suggest an altered coagulopathic response to traumatic injury which is partially influenced by increased anticoagulant and antiplatelet medication use in the geriatric population. It is not clear whether the acute coagulopathy of trauma is equivalent in geriatric patients, and further study is therefore warranted.

Oncologic and surgical outcomes in colorectal cancer patients with liver cirrhosis: A propensity-matched study.

PubMed

Han, Eon Chul; Ryoo, Seung-Bum; Park, Ji Won; Yi, Jin Wook; Oh, Heung-Kwon; Choe, Eun Kyung; Ha, Heon-Kyun; Park, Byung Kwan; Moon, Sang Hui; Jeong, Seung-Yong; Park, Kyu Joo

2017-01-01

The management of colorectal cancer in patients with liver cirrhosis requires a thorough understanding of both diseases. This study evaluated the effect of liver cirrhosis on oncologic and surgical outcomes and prognostic factors in colorectal cancer patients. Fifty-five consecutive colorectal cancer patients with liver cirrhosis underwent colorectal resection (LC group). Using a prospectively maintained database, these patients were matched 1:4 using propensity scoring with R programming language, package "MatchIt" and "optmatch" by sex, age, cancer location, and tumor stage with 220 patients without liver cirrhosis (non-LC group), resulting in 275 patients. The 5-year overall survival (OS) was significantly worse in the LC group than in the non-LC group (46.7% vs. 76.2% respectively, P < 0.001); however, the 5-year proportion of recurrence free (PRF) rates were similar (73.1% vs. 84.5% respectively, P = 0.094). On multivariate analysis of the LC group, tumor-node-metastasis (TNM) stage ≥III disease, venous invasion, and a model for end-stage liver disease plus serum sodium (MELD-Na) score >10 were prognostic factors for OS. However, the OS was not different between the LC group with MELD-Na score ≤10 and the non-LC group (5-year OS rate, TNM stage ≤II, 85.7 vs 89.5%, p = 0.356; TNM stage ≥III, 41.1 vs 66.2%, p = 0.061). Colorectal cancer patients with liver cirrhosis have poorer OS compared to those without liver cirrhosis; however, the PRF rates are similar. It might be due to the mortality from the liver, and surgical treatment should be actively considered for patients with MELD-Na score <10.

Pure laparoscopic living donor left lateral sectionectomy in pediatric transplantation: A Propensity score analysis on 220 consecutive cases.

PubMed

Broering, Dieter C; Elsheikh, Yasser; Shagrani, Mohammed; Abaalkhail, Faisal; Troisi, Roberto I

2018-02-28

Left lateral sectionectomy for donor hepatectomy is a well-established alternative to deceased donor pediatric liver transplantation. However, very little is available on the laparoscopic approach (L-LLS). With the aim to assess safety, reproducibility under proctorship and outcomes following LDLT in children, a comparative single center series using the propensity score matching (PSM) to evaluate open (O-LLS) vs. L-LLS was carried out in a relatively short time period in a high volume pediatric transplant center. A retrospective, observational, single-center, propensity score matched study was conducted on 220 consecutive living donor hepatectomies from January 2011 to April 2017. The variables considered for PSM were: year of operation, recipient age, indication for transplant, recipient weight, donor gender, donor age and donor body mass index. After matching, 72 O-LLS were fit to be compared with 72 L-LLS. Operative time and warm ischemia time were significantly longer in L-LLS whereas blood loss and overall donor complication rates were significantly lower. Postoperative day 1 and 4 pain scores were significantly less in the L-LLS group (p=0.015 and 0.003, respectively). The length of hospital stay was significantly shorter in L-LLS (4.6 vs 4.1 days) (p=0.014). Overall donor biliary complications were 9(12.5%) and 1(1.3%), respectively for O-LLS and L-LLS (p=0.022). Vascular complications occurred in 3(4.2%) children without graft loss in the laparoscopic group. The 1-3 and 5-year overall patient survival were 98.5%, 90.9% and 90.9% in the O-LLS group and in the L-LLS group 94.3%, 92.7% and 86.8% (p=0.280). Laparoscopic left lateral sectionectomy for donor hepatectomy is a safe and reproducible technique yielding better donors' perioperative outcomes respect to the conventional approach with similar recipients' outcomes. This article is protected by copyright. All rights reserved. © 2018 by the American Association for the Study of Liver Diseases.

Thrombocytopenia after aortic valve replacement with freedom solo bioprosthesis: a propensity study.

PubMed

Piccardo, Alessandro; Rusinaru, Dan; Petitprez, Benoit; Marticho, Paul; Vaida, Ioana; Tribouilloy, Christophe; Caus, Thierry

2010-05-01

The incidence of postoperative thrombocytopenia after aortic valve replacement with the Freedom Solo bioprosthesis remains unclear. This propensity-matched study was carried out to evaluate the incidence and clinical impact of thrombocytopenia in patients receiving the Freedom Solo bioprosthesis. Patients who underwent aortic valve replacement with a Freedom Solo or Carpentier-Edwards Perimount pericardial prosthesis at our institution between 2006 and 2008 were screened retrospectively. Exclusion criteria included double valve replacement, redo surgery, and active endocarditis. Two hundred six patients were considered eligible for this analysis. Using propensity scores 36 matched pairs of patients with a Freedom Solo or Perimount bioprosthesis were obtained. The primary end point was the occurrence of postoperative thrombocytopenia. Secondary end points were postoperative thromboembolic or hemorrhagic events and 30-day mortality. Before matching, severe thrombocytopenia (<30 x 10(9) platelets/L) occurred in 22% of patients with a Freedom Solo bioprosthesis and 1% with a Perimount bioprosthesis (p < 0.0001), thromboembolic or hemorrhagic events occurred in 3% and 2%, respectively (p = 0.37), and 30-day mortality was 4% and 6%, respectively (p = 0.48). Multivariate analysis identified preoperative platelet count (p = 0.01) and Freedom Solo (p < 0.0001) as independent risk factors for severe postoperative thrombocytopenia. After matching, severe thrombocytopenia occurred in 25% and 3% of patients with Freedom Solo and Perimount bioprostheses, respectively (p < 0.0001), thromboembolic or hemorrhagic events occurred in 0%, and 30-day mortality was 3% and 6%, respectively (p = 0.99). The risk of thrombocytopenia was high after Freedom Solo implantation. However, this complication was not related to any deleterious events in our study population. Copyright (c) 2010 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Distal anastomotic vein adjunct usage in infrainguinal prosthetic bypasses.

PubMed

McPhee, James T; Goodney, Philip P; Schanzer, Andres; Shaykevich, Shimon; Belkin, Michael; Menard, Matthew T

2013-04-01

Single-segment saphenous vein remains the optimal conduit for infrainguinal revascularization. In its absence, prosthetic conduit may be used. Existing data regarding the significance of anastomotic distal vein adjunct (DVA) usage with prosthetic grafts are based on small series. This is a retrospective cohort analysis derived from the regional Vascular Study Group of New England as well as the Brigham and Women's hospital database. A total of 1018 infrainguinal prosthetic bypass grafts were captured in the dataset from 73 surgeons at 15 participating institutions. Propensity scoring and 3:1 matching was performed to create similar exposure groups for analysis. Outcome measures of interest included: primary patency, freedom from major adverse limb events (MALEs), and amputation free survival at 1 year as a function of vein patch utilization. Time to event data were compared with the log-rank test; multivariable Cox proportional hazard models were used to evaluate the adjusted association between vein cuff usage and the primary end points. DVA was defined as a vein patch, cuff, or boot in any configuration. Of the 1018 bypass operations, 94 (9.2%) had a DVA whereas 924 (90.8%) did not (no DVA). After propensity score matching, 88 DVAs (25%) and 264 no DVAs (75%) were analyzed. On univariate analysis of the matched cohort, the DVA and no DVA groups were similar in terms of mean age (70.0 vs 69.0; P = .55), male sex (58.0% vs 58.3%; P > .99), and preoperative characteristics such as living at home (93.2% vs 94.3%; P = .79) and independent ambulatory status (72.7% vs 75.7%; P = .64). The DVA and no DVA groups had similar rates of major comorbidities such as hypertension chronic obstructive pulmonary disease, diabetes mellitus, coronary artery disease, and dialysis dependence (P > .05 for all). Likewise, they had similar rates of distal origin grafts (13.6% vs 12.5%; P = .85), critical limb ischemia indications (P = .53), and prior arterial bypass (58% vs 47%; P = .08). The DVA group had a higher rate of completion angiogram performed (55.7% vs 37.5%; P =.002) and were more likely to be discharged on coumadin (53.4% vs 37.1%; P =.01). By multivariable analysis, use of a distal DVA was protective against MALEs (hazard ratio, 0.36; 95% confidence interval, 0.14-0.90; P = .03). This contemporary multi-institutional propensity-matched study demonstrates that patients that receive distal anastomotic vein adjuncts as part of infrainguinal prosthetic bypass operations in general have more extreme comorbidities and more technically challenging operations based on level of target vessel and prior bypass attempts. After propensity-matched analysis, the use of a DVA may protect against MALEs in prosthetic bypass surgery and should be considered when feasible. Copyright © 2013 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.

Medication persistence and discontinuation of rivaroxaban versus warfarin among patients with non-valvular atrial fibrillation.

PubMed

Nelson, Winnie W; Song, Xue; Coleman, Craig I; Thomson, Erin; Smith, David M; Damaraju, C V; Schein, Jeffrey R

2014-12-01

To compare real-world persistence and discontinuation among non-valvular atrial fibrillation (NVAF) patients on rivaroxaban and warfarin in the US. A large nationally representative US claims database was used to conduct a retrospective cohort analysis of patients with NVAF treated with rivaroxaban or warfarin from 1 July 2010 through 31 March 2013. Index date was the date of the first prescription of rivaroxaban or warfarin. All patients were followed until the earliest of inpatient death, end of continuous enrollment, or end of study period. Rivaroxaban patients were matched 1:1 by propensity scores. Medication persistence was defined as absence of refill gap of ≥ 60 days. Discontinuation was defined as no additional refill for at least 90 days and until the end of follow-up. Cox proportional hazards models were estimated to examine the adjusted hazard ratios (aHRs) of rivaroxaban vs. warfarin on non-persistence and discontinuation. A total of 32,886 NVAF patients on rivaroxaban or warfarin met the study inclusion criteria. Each of the 7259 rivaroxaban patients identified were matched 1:1 to warfarin patients. Patients on rivaroxaban had a significantly better rate of persistence (aHR: 0.63, 95% CI 0.59-0.68) and lower rate of discontinuation (aHR: 0.54, 95% CI 0.49-0.58) compared to warfarin recipients. Claims data may have contained inaccuracies and miscoding. Confounding may remain even after propensity score matching and additional adjustments in model. Refill data may not fully reflect actual medication use. Longer follow-up may produce more precise estimates of persistence and discontinuation. This matched cohort analysis indicated that rivaroxaban was associated with significantly higher medication persistence and lower discontinuation rates compared to warfarin.

The Adverse Survival Implications of Bland Thrombus in Renal Cell Carcinoma With Venous Tumor Thrombus.

PubMed

Hutchinson, Ryan; Rew, Charles; Chen, Gong; Woldu, Solomon; Krabbe, Laura-Maria; Meissner, Matthew; Sheth, Kunj; Singla, Nirmish; Shakir, Nabeel; Master, Viraj A; Karam, Jose A; Matin, Surena F; Borregales, Leonardo D; Wood, Christopher; Masterson, Timothy; Thompson, R Houston; Boorjian, Stephen A; Leibovich, Bradley C; Abel, E Jason; Bagrodia, Aditya; Margulis, Vitaly

2018-05-01

To characterize the presence of bland (nontumor) thrombus in advanced renal cell carcinoma and assess the impact of this finding on cancer-specific survival. A multi-institutional database of patients treated with nephrectomy with caval thrombectomy for locally-advanced renal tumors was assembled from 5 tertiary care medical centers. Using clinicopathologic variables including patient age, body mass index, Eastern Cooperative Oncology Group performance status, tumor stage, grade, nodal status and histology, and nearest-neighbor and multiple-matching propensity score matched cohorts of bland thrombus vs nonbland thrombus patients were assessed. Multivariable analysis for predictors of cancer-specific survival was performed. From an initial cohort of 579 patients, 446 met inclusion criteria (174 with bland thrombus, 272 without). At baseline, patients with bland thrombus had significantly worse performance status, higher tumor stage, higher prevalence of regional nodal metastases and higher nuclear grade (P < .01 for all). In both nearest-neighbor and multiple-matching propensity score matched cohorts, the presence of bland thrombus presence was associated with inferior median cancer-specific survival (28.1 months vs 156.8 months, and 28.1 months vs 76.7 months, P < .001 for both). The presence of bland thrombus remained independently associated with an increased risk of cancer-specific mortality on multivariable analysis (hazard ratio 4.33, 95% confidence interval 2.79-6.73, P < .001). Presence of bland thrombus is associated with adverse survival outcomes in patients treated surgically for renal tumors with venous tumor thrombus. These findings may have important implications in patient counseling, selection for surgery and inclusion in clinical trials. Copyright © 2018 Elsevier Inc. All rights reserved.

Prior Radiotherapy Does Not Affect Abdominal Wall Reconstruction Outcomes: Evidence from Propensity Score Analysis.

PubMed

Giordano, Salvatore; Garvey, Patrick B; Baumann, Donald P; Liu, Jun; Butler, Charles E

2017-03-01

Prior abdominal wall radiotherapy (XRT) adversely affects wound healing, but data are limited on how prior XRT may affect abdominal wall reconstruction (AWR) outcomes. The purpose of this study was to determine whether prior abdominal wall radiotherapy is associated with a higher incidence of complications following AWR for a hernia or oncologic resection defect. We performed a retrospective study of consecutive patients who underwent complex AWR using acellular dermal matrix (ADM) at a single center. We compared outcomes between patients who underwent prior XRT that directly involved the abdominal wall and those who did not receive XRT. Propensity score match-paired and multivariate analyses were performed. A total of 511 patients (130 [25.4 %] with prior XRT; 381 [74.6 %] without prior XRT) underwent AWR with ADM for repair of a complex hernia or oncologic resection defect. Mean follow-up was 31.4 months, mean XRT dose was 48.9 Gy, and mean time between XRT and reconstruction was 19.2 months. XRT AWR patients underwent more flap reconstructions (14.6 vs. 5.0 %, P < 0.001) but fewer component separations (61.5 vs. 71.4 %; P = 0.036) than non-XRT AWR patients. The two groups had similar rates of hernia recurrence (8.5 vs. 9.4 %; P = 0.737) and surgical site occurrence (25.4 vs. 23.4 %; P = 0.640). In the propensity score-matched subgroups, there were no differences in hernia recurrence, surgical site occurrence, and wound healing complication rates. Prior XRT does not adversely affect outcomes in AWR. However, surgeons should be aware of the higher likelihood of needing a soft tissue flap reconstruction for soft tissue replacement when performing AWR after XRT.

Impact of Colic Pain as a Significant Factor for Predicting the Stone Free Rate of One-Session Shock Wave Lithotripsy for Treating Ureter Stones: A Bayesian Logistic Regression Model Analysis

PubMed Central

Chung, Doo Yong; Cho, Kang Su; Lee, Dae Hun; Han, Jang Hee; Kang, Dong Hyuk; Jung, Hae Do; Kown, Jong Kyou; Ham, Won Sik; Choi, Young Deuk; Lee, Joo Yong

2015-01-01

Purpose This study was conducted to evaluate colic pain as a prognostic pretreatment factor that can influence ureter stone clearance and to estimate the probability of stone-free status in shock wave lithotripsy (SWL) patients with a ureter stone. Materials and Methods We retrospectively reviewed the medical records of 1,418 patients who underwent their first SWL between 2005 and 2013. Among these patients, 551 had a ureter stone measuring 4–20 mm and were thus eligible for our analyses. The colic pain as the chief complaint was defined as either subjective flank pain during history taking and physical examination. Propensity-scores for established for colic pain was calculated for each patient using multivariate logistic regression based upon the following covariates: age, maximal stone length (MSL), and mean stone density (MSD). Each factor was evaluated as predictor for stone-free status by Bayesian and non-Bayesian logistic regression model. Results After propensity-score matching, 217 patients were extracted in each group from the total patient cohort. There were no statistical differences in variables used in propensity- score matching. One-session success and stone-free rate were also higher in the painful group (73.7% and 71.0%, respectively) than in the painless group (63.6% and 60.4%, respectively). In multivariate non-Bayesian and Bayesian logistic regression models, a painful stone, shorter MSL, and lower MSD were significant factors for one-session stone-free status in patients who underwent SWL. Conclusions Colic pain in patients with ureter calculi was one of the significant predicting factors including MSL and MSD for one-session stone-free status of SWL. PMID:25902059

Evaluation of a hepatitis C clinical care coordination programme's effect on treatment initiation and cure: A surveillance-based propensity score matching approach.

PubMed

Deming, R; Ford, M M; Moore, M S; Lim, S; Perumalswami, P; Weiss, J; Wyatt, B; Shukla, S; Litwin, A; Reynoso, S; Laraque, F

2018-05-14

Hepatitis C (HCV) is a viral infection that if left untreated can severely damage the liver. Project INSPIRE was a 3 year HCV care coordination programme in New York City (NYC) that aimed to address barriers to treatment initiation and cure by providing patients with supportive services and health promotion. We examined whether enrolment in Project INSPIRE was associated with differences in HCV treatment and cure compared with a demographically similar group not enrolled in the programme. INSPIRE participants in 2015 were matched with a cohort of HCV-infected persons identified in the NYC surveillance registry, using full optimal matching on propensity scores and stratified by INSPIRE enrolment status. Conditional logistic regression was used to assess group differences in the two treatment outcomes. Two follow-up sensitivity analyses using individual pair-matched sets and the full unadjusted cohort were also conducted. Treatment was initiated by 72% (790/1130) of INSPIRE participants and 36% (11 960/32 819) of study-eligible controls. Among initiators, 65% (514/790) of INSPIRE participants compared with 47% (5641/11 960) of controls achieved cure. In the matched analysis, enrolment in INSPIRE increased the odds of treatment initiation (OR: 5.25, 95% CI: 4.47-6.17) and cure (OR: 2.52, 95% CI: 2.00-3.16). Results from the sensitivity analyses showed agreement with the results from the full optimal match. Participation in the HCV care coordination programme significantly increased the probability of treatment initiation and cure, demonstrating that care coordination for HCV-infected individuals improves treatment outcomes. © 2018 John Wiley & Sons Ltd.

Can Palliative Home Care Reduce 30-Day Readmissions? Results of a Propensity Score Matched Cohort Study

PubMed Central

Ranganathan, Anjana; Dougherty, Meredith; Waite, David

2013-01-01

Abstract Objective This study examined the impact of palliative home nursing care on rates of hospital 30-day readmissions. Methods The electronic health record based retrospective cohort study was performed within home care and palliative home care programs. Participants were home care patients discharged from one of three urban teaching hospitals. Outcome measures were propensity score matched rates of hospital readmissions within 30 days of hospital discharge. Results Of 406 palliative home care patients, matches were identified for 392 (96%). Of 15,709 home care patients, 890 were used at least once as a match for palliative care patients, for a total final sample of 1282. Using the matched sample we calculated the average treatment effect for treated patients. In this sample, palliative care patients had a 30-day readmission probability of 9.1% compared to a probability of 17.4% in the home care group (mean ATT: 8.3%; 95% confidence interval [CI] 8.0%–8.6%). This effect persisted after adjustment for visit frequency. Conclusions Palliative home care may offer benefits to health systems by allowing patients to remain at home and thereby avoiding 30-day rehospitalizations. PMID:24007348

Analysis of the North Carolina long-term care polypharmacy initiative: a multiple-cohort approach using propensity-score matching for both evaluation and targeting.

PubMed

Trygstad, Troy K; Christensen, Dale B; Wegner, Steve E; Sullivan, Rob; Garmise, Jennifer M

2009-09-01

The high cost and undesirable consequences of polypharmacy are well-recognized problems among elderly long-term care (LTC) residents. Despite the implementation of the 1987 Omnibus Budget Reconciliation Act, which requires pharmacist review of drug regimens in this setting, medical and drug costs for LTC residents have continued to increase. This study evaluates the North Carolina Long-Term Care Polypharmacy Initiative, a large-scale medication therapy management program (MTMP) that combined drug utilization review activities with drug regimen review techniques. This was a prospective records-based study that used a difference-in-difference model with both historical and nonintervention group controls. To ensure equivalence among subjects, propensity scoring was used to match study subjects from participating LTC facilities with comparison subjects from nonparticipating facilities. Residents with interventions were grouped for analysis by intervention type-retrospective only, prospective only, or dual type (residents with both prospective and retrospective interventions)-and by intervention stage-review, recommendation, and drug change-plus an all-inclusive "all types" grouping that aggregated groups by intervention type, for a total of 10 total cohorts. In the overall population of 5255 study subjects identified, a US $21.63 per member per month drug-cost savings was observed. Although only 1 of 10 cohorts had a change in the number of drug fills, substantial reductions in 2 of 5 types of drug alerts were observed in all 10 cohorts. A reduction in the relative risk for hospitalization (0.84 [95% CI, 0.71-1.00]) was observed in the cohort of residents receiving a retrospective review. This Initiative suggests that an MTMP can be quickly launched in a large number of LTC facility residents to produce monetary drug-cost savings and improved health outcomes. Additionally, the evaluation of this program illustrates the utility of using propensity scoring techniques to target future intervention groups in a cost-effective manner.

Nebulized heparin for patients under mechanical ventilation: an individual patient data meta-analysis.

PubMed

Glas, Gerie J; Serpa Neto, Ary; Horn, Janneke; Cochran, Amalia; Dixon, Barry; Elamin, Elamin M; Faraklas, Iris; Dissanaike, Sharmila; Miller, Andrew C; Schultz, Marcus J

2016-12-01

Pulmonary coagulopathy is a characteristic feature of lung injury including ventilator-induced lung injury. The aim of this individual patient data meta-analysis is to assess the effects of nebulized anticoagulants on outcome of ventilated intensive care unit (ICU) patients. A systematic search of PubMed (1966-2014), Scopus, EMBASE, and Web of Science was conducted to identify relevant publications. Studies evaluating nebulization of anticoagulants in ventilated patients were screened for inclusion, and corresponding authors of included studies were contacted to provide individual patient data. The primary endpoint was the number of ventilator-free days and alive at day 28. Secondary endpoints included hospital mortality, ICU- and hospital-free days at day 28, and lung injury scores at day seven. We constructed a propensity score-matched cohort for comparisons between patients treated with nebulized anticoagulants and controls. Data from five studies (one randomized controlled trial, one open label study, and three studies using historical controls) were included in the meta-analysis, compassing 286 patients. In all studies unfractionated heparin was used as anticoagulant. The number of ventilator-free days and alive at day 28 was higher in patients treated with nebulized heparin compared to patients in the control group (14 [IQR 0-23] vs. 6 [IQR 0-22]), though the difference did not reach statistical significance (P = 0.459). The number of ICU-free days and alive at day 28 was significantly higher, and the lung injury scores at day seven were significantly lower in patients treated with nebulized heparin. In the propensity score-matched analysis, there were no differences in any of the endpoints. This individual patient data meta-analysis provides no convincing evidence for benefit of heparin nebulization in intubated and ventilated ICU patients. The small patient numbers and methodological shortcomings of included studies underline the need for high-quality well-powered randomized controlled trials.

A reappraisal of the benefit-risk profile of hydroxyurea in polycythemia vera: A propensity-matched study.

PubMed

Barbui, Tiziano; Vannucchi, Alessandro Maria; Finazzi, Guido; Finazzi, Maria Chiara; Masciulli, Arianna; Carobbio, Alessandra; Ghirardi, Arianna; Tognoni, Gianni

2017-11-01

The use of hydroxyurea (HU) as first line therapy in polycythemia vera (PV) has been criticized because no solid demonstration that this drug prevents thrombosis or prolongs survival has been so far produced. Here we present the outcomes of a large cohort of patients with PV included in the European Collaborative Low-dose Aspirin (ECLAP) study. We selected 1,042 patients who, during the follow-up, had received only phlebotomy (PHL) or HU to maintain the hematocrit level < 45%. To assure comparability, we conducted a propensity score matching analysis. The two groups (PHL n = 342 and HU n = 681) were well balanced for the parameters included in the propensity score (overall balance: χ 2  = 2.44, P = 0.964). Over a comparable period of follow-up (PHL = 29.9 vs. HU = 34.7 months), we documented an advantage of HU over PHL consistently significant with respect to the incidence of fatal/non-fatal cardiovascular (CV) events (5.8 vs. 3.0 per 100 person-years in PHL vs. HU group, P = 0.002) and myelofibrosis transformation that was only experienced by patients of PHL group. Evolution to acute leukemia was registered in three patients (two in PHL and one in HU group). The excess of mortality and total CV events in the PHL patients was restricted to the high-risk group, and, compared with HU cases, was significant higher in the PHL patients who failed to reach the hematocrit target < 0.45% (P = 0.000). In conclusion, this analysis provides reliable and qualified estimates of the therapeutic profile of HU and PHL treatments for future experimental studies and for the management of PV in clinical practice. © 2017 Wiley Periodicals, Inc.

Improved knowledge of and difficulties in palliative care among physicians during 2008 and 2015 in Japan: Association with a nationwide palliative care education program.

PubMed

Nakazawa, Yoko; Yamamoto, Ryo; Kato, Masashi; Miyashita, Mitsunori; Kizawa, Yoshiyuki; Morita, Tatsuya

2018-02-01

Palliative care education for health care professionals is a key element in improving access to quality palliative care. The Palliative Care Emphasis Program on Symptom Management and Assessment for Continuous Medical Education (PEACE) was designed to provide educational opportunities for all physicians in Japan. As of 2015, 57,764 physicians had completed it. The objective of this study was to estimate the effects of the program. This study was an analysis of 2 nationwide observational studies from 2008 and 2015. We conducted 2 questionnaire surveys for representative samples of physicians. The measurements used were the Palliative Care Knowledge Test (range, 0-100) and the Palliative Care Difficulties Scale (range, 1-4). Comparisons were made with the unpaired Student t test and with a multivariate linear regression model using 2 cohorts and a propensity score-matched sample. This study analyzed a total of 48,487 physicians in 2008 and a total of 2720 physicians in 2015. Between 2008 and 2015, physicians' knowledge and difficulties significantly improved on the Palliative Care Knowledge Test with total scores of 68 and 78, respectively (P < .001; effect size, 0.40) and on the Palliative Care Difficulties Scale with total scores of 2.65 and 2.49, respectively (P < .001; effect size, 0.29). Propensity-score matching resulted in 619 untrained physicians matched to 619 trained physicians, and physicians who trained with the PEACE program had a higher knowledge score (74 vs 86; P < .001; effect size, 0.64) and a lower difficulties score (2.6 vs 2.3; P < .001; effect size, 0.42). Physicians' knowledge of and difficulties with palliative care improved on a national level. The PEACE program may have contributed to these improvements. Cancer 2018;124:626-35. © 2017 American Cancer Society. © 2017 American Cancer Society.

Robotic Versus Laparoscopic Colorectal Cancer Surgery in Elderly Patients: A Propensity Score Match Analysis.

PubMed

de'Angelis, Nicola; Abdalla, Solafah; Bianchi, Giorgio; Memeo, Riccardo; Charpy, Cecile; Petrucciani, Niccolo; Sobhani, Iradj; Brunetti, Francesco

2018-05-31

Minimally invasive surgery in elderly patients with colorectal cancer remains controversial. The study aimed to compare the operative, postoperative, and oncologic outcomes of robotic (robotic colorectal resection surgery [RCRS]) versus laparoscopic colorectal resection surgery (LCRS) in elderly patients with colorectal cancer. Propensity score matching (PSM) was used to compare patients aged 70 years and more undergoing elective RCRS or LCRS for colorectal cancer between 2010 and 2017. Overall, 160 patients underwent elective curative LCRS (n = 102) or RCRS (n = 58) for colorectal cancer. Before PSM, the mean preoperative Charlson score and the tumor size were significantly lower in the robotic group. After matching, 43 RCRSs were compared with 43 LCRSs. The RCRS group showed longer operative times (300.6 versus 214.5 min, P = .03) compared with LCRS, but all other operative variables were comparable between the two groups. No differences were found for postoperative morbidity, mortality, time to flatus, return to regular diet, and length of hospital stay. R0 resection was obtained in 95.3% of procedures. The overall and disease-free survival rates at 1, 2, and 3 years were similar between RCRS and LCRS patients. The presence of more than one comorbidity before surgery was significantly associated with the incidence of postoperative complications. In patients aged 70 years or more, robotic colorectal surgery showed operative and oncologic outcomes similar to those obtained by laparoscopy, despite longer operative times. Randomized trials are awaited to reliably assess the clinical and oncological noninferiority and the costs/benefits ratio of robotic colorectal surgery in elderly populations.

Impact of Private Secondary Schooling on Cognitive Skills: Evidence from India

ERIC Educational Resources Information Center

Azam, Mehtabul; Kingdon, Geeta; Wu, Kin Bing

2016-01-01

We examine the effect of attending private secondary school on educational achievement, as measured by students' scores in a comprehensive standardized math test, in two Indian states: Orissa and Rajasthan. We use propensity score matching (PSM) to control for any systematic differences between students attending private secondary schools and…

The effects of breastfeeding on childhood BMI: a propensity score matching approach.

PubMed

Gibson, Laura A; Hernández Alava, Mónica; Kelly, Michael P; Campbell, Michael J

2017-12-01

Many studies have found a statistical association between breastfeeding and childhood adiposity. This paper investigates whether breastfeeding has an effect on subsequent childhood body mass index (BMI) using propensity scores to account for confounding. We use data from the Millennium Cohort Study, a nationally representative UK cohort survey, which contains detailed information on infant feeding and childhood BMI. Propensity score matching is used to investigate the mean BMI in children breastfed exclusively and partially for different durations of time. We find statistically significant influences of breastfeeding on childhood BMI, particularly in older children, when breastfeeding is prolonged and exclusive. At 7 years, children who were exclusively breastfed for 16 weeks had a BMI 0.28 kg/m2 (95% confidence interval 0.07 to 0.49) lower than those who were never breastfed, a 2% reduction from the mean BMI of 16.6 kg/m2. For this young cohort, even small effects of breastfeeding on BMI could be important. In order to reduce BMI, breastfeeding should be encouraged as part of wider lifestyle intervention. This evidence could help to inform public health bodies when creating public health guidelines and recommendations. © The Author 2016. Published by Oxford University Press on behalf of Faculty of Public Health.

Comparison and limitations of DVH-based NTCP models derived from 3D-CRT and IMRT data for prediction of gastrointestinal toxicities in prostate cancer patients by using propensity score matched pair analysis.

PubMed

Troeller, Almut; Yan, Di; Marina, Ovidiu; Schulze, Derek; Alber, Markus; Parodi, Katia; Belka, Claus; Söhn, Matthias

2015-02-01

This study compared normal tissue complication probability (NTCP) modeling of chronic gastrointestinal toxicities following prostate cancer treatment for 2 treatment modalities. Possible factors causing discrepancies in optimal NTCP model parameters between 3-dimensional conformal radiation therapy (3D-CRT) and intensity modulated RT (IMRT) were analyzed and discussed, including the impact of patient characteristics, image guidance, toxicity scoring bias, and NTCP model limitations. Rectal wall dose-volume histograms of 1115 patients treated for prostate cancer under an adaptive radiation therapy protocol were used to model gastrointestinal toxicity grade ≥2 (according to Common Terminology Criteria for Adverse Events). A total of 457 patients were treated with 3D-CRT and 658 with IMRT. 3D-CRT patients were matched to IMRT patients based on various patient characteristics, using a propensity score-based algorithm. Parameters of the Lyman equivalent uniform dose and cut-off dose logistic regression NTCP models were estimated for the 2 matched treatment modalities and the combined group. After they were matched, the 3D-CRT and IMRT groups contained 275 and 550 patients with a large discrepancy of 28.7% versus 7.8% toxicities, respectively (P<.001). For both NTCP models, optimal parameters found for the 3D-CRT groups did not fit the IMRT patients well and vice versa. Models developed for the combined data overestimated NTCP for the IMRT patients and underestimated NTCP for the 3D-CRT group. Our analysis did not reveal a single definitive cause for discrepancies of model parameters between 3D-CRT and IMRT. Patient characteristics and bias in toxicity scoring, as well as image guidance alone, are unlikely causes of the large discrepancy of toxicities. Whether the cause was inherent to the specific NTCP models used in this study needs to be verified by future investigations. Because IMRT is increasingly used clinically, it is important that appropriate NTCP model parameters are determined for this treatment modality. Copyright © 2015 Elsevier Inc. All rights reserved.

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2011-05-27

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The relationship between inotrope exposure, six-hour postoperative physiological variables, hospital mortality and renal dysfunction in patients undergoing cardiac surgery

PubMed Central

2011-01-01

Introduction Acute haemodynamic complications are common after cardiac surgery and optimal perioperative use of inotropic agents, typically guided by haemodynamic variables, remains controversial. The aim of this study was to examine the relationship of inotrope use to hospital mortality and renal dysfunction. Material and methods A retrospective cohort study of 1,326 cardiac surgery patients was carried out at two university-affiliated ICUs. Multivariable logistic regression analysis and propensity matching were performed to evaluate whether inotrope exposure was independently associated with mortality and renal dysfunction. Results Patients exposed to inotropes had a higher mortality rate than those not exposed. After adjusting for differences in Parsonnet score, left ventricular ejection fraction, perioperative intraaortic balloon pump use, bypass time, reoperation and cardiac index, inotrope exposure appeared to be independently associated with increased hospital mortality (adjusted odds ratio (OR) 2.3, 95% confidence interval (95% CI) 1.2 to 4.5) and renal dysfunction (adjusted OR 2.7, 95% CI 1.5 to 4.6). A propensity score-matched analysis similarly demonstrated that death and renal dysfunction were significantly more likely to occur in patients exposed to inotropes (P = 0.01). Conclusions Postoperative inotrope exposure was independently associated with worse outcomes in this cohort study. Further research is needed to better elucidate the appropriate use of inotropes in cardiac surgery. PMID:21736726

Clinical presentation of acute coronary syndrome in patients previously treated with nitrates.

PubMed

Latour-Pérez, Jaime; Gómez-Tello, Vicente; Fuset-Cabanes, María Paz; Balsa, Eva de Miguel; Sáez, Frutos Del Nogal; Orts, Francisco Javier Coves; Rodríguez, Carmen Martín; Pino-Izquierdo, Karel; Pesquera, María de la Concepción Pavía; Rodríguez, Antonio José Montón

2013-11-01

Several reports have suggested that nitrates limit acute ischaemic damage by a mechanism similar to preconditioning. This study aims to evaluate the effect of chronic oral nitrates on the clinical presentation and short-term outcomes of patients admitted with acute coronary syndrome (ACS). A retrospective cohort study was conducted in patients with ACS admitted to 62 acute care units from 2010 to 2011. A propensity score-matched samples analysis was performed. We analysed 3171 consecutive patients, of whom 298 (9.4%) were chronically treated with nitrates. Patients previously treated with nitrates had higher comorbidity and disease severity at admission, lower prevalence of ACS with ST elevation, lower troponin elevation, higher prevalence of initial Killip class 2-4 and higher hospital mortality. The propensity score-matched analysis confirmed that previous use of nitrates is independently associated with a lower prevalence of ST-elevation ACS [odds ratio (OR) 0.53, 95% confidence interval (CI) 0.36-0.78; P = 0.0014] and a lower troponin elevation (OR 0.61, 95% CI 0.41-0.92) but not with Killip class on admission (OR 1.18, 95% CI 0.83-1.67, P = 0.3697) or mortality (OR 0.71, 95% CI 0.37-1.38, P = 0.3196). The results support the hypothesis that nitrates have a protective effect on acute ischaemic injury.

Outcomes following Kidney transplantation in IgA nephropathy: a UNOS/OPTN analysis.

PubMed

Kadiyala, Aditya; Mathew, Anna T; Sachdeva, Mala; Sison, Cristina P; Shah, Hitesh H; Fishbane, Steven; Jhaveri, Kenar D

2015-10-01

This study updates assessment of post-transplant outcomes in IgAN patients in the modern era of immunosuppression. Using UNOS/OPTN data, patients ≥18 yr of age with first kidney transplant (1/1/1999 to 12/31/2008) were analyzed. Multivariable Cox regression models and propensity score-based matching techniques were used to estimate hazard ratios (HRs) for death-censored allograft survival (DCGS) and patient survival in IgAN compared to non-IgAN. Results of multivariable regression were stratified by donor type (living vs. deceased). A total of 107, 747 recipients were included (4589 with IgAN and 103 158 with non-IgAN). Adjusted HR for DCGS showed no significant difference between IgAN and non-IgAN. IgAN had higher patient survival compared to non-IgAN (HR 0.54, 95% CI 0.47-0.62, p < 0.0001 for deceased donors; HR 0.42, 95% CI 0.33-0.54, p < 0.0001 for living donors). Propensity score-matched analysis was similar, with no significant difference in DCGS between matched groups and higher patient survival in IgAN patients compared to non-IgAN group (HR 0.54, 95% CI 0.47, 0.63; p-value <0.0001). IgAN patients with first kidney transplant have superior patient survival and similar graft survival compared to non-IgAN recipients. Results can be used in prognostication and informed decision-making about kidney transplantation in patients with IgAN. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Does Certification as Bariatric Surgery Center and Volume Influence the Outcome in RYGB-Data Analysis of German Bariatric Surgery Registry.

PubMed

Stroh, Christine; Köckerling, F; Lange, V; Wolff, S; Knoll, C; Bruns, C; Manger, Th

2017-02-01

To examine the association between the certification as bariatric surgery center and volume and patient outcome, data collected in the German Bariatric Surgery Registry were evaluated. All data were registered prospectively in cooperation with the Institute of Quality Assurance in Surgery at Otto-von-Guericke University Magdeburg. Data collection began in 2005 for all bariatric procedures in an online database. Participation in the quality assurance study is required for all certified bariatric surgery centers in Germany. Descriptive evaluation and matched pairs analysis were performed. Patients were matched via propensity score taking into account BMI, age, and incidence of comorbidities. During the period from 2005 to 2013, 3083 male and 10,639 female patients were operated on with the RYGB primary approach. In Centers of Competence (77.2 %) and non-accredited hospitals (76.3 %), the proportion of female patients was significantly lower than in Centers of Reference/Excellence (78.7 %; p = 0.002). The mean age in Centers of Reference/Excellence (41.2 years) was significantly lower than in Centers of Competence (43.2 years; p < 0.05). Propensity score analysis was performed to compare matched patients with regard to BMI, age, and incidence of comorbidities. The rate of general and surgical postoperative complications and mortality rate was significantly lower in certified Centers of Reference/Excellence compared to Centers of Competence with 29 and non-certified hospitals. There is evidence of improved patient outcome in certified bariatric surgery centers with higher volume. The study supports the concept of certification. There are different factors which can and cannot be preoperatively modified and influence the perioperative outcome.

The Association Between Mild Intraoperative Hypotension and Stroke in General Surgery Patients.

PubMed

Hsieh, Jason K; Dalton, Jarrod E; Yang, Dongsheng; Farag, Ehab S; Sessler, Daniel I; Kurz, Andrea M

2016-10-01

Intraoperative hypotension may contribute to perioperative strokes. We therefore tested the hypothesis that intraoperative hypotension is associated with perioperative stroke. After institutional review board approval for this case-control study, we identified patients who had nonneurological, noncardiac, and noncarotid surgery under general anesthesia at the Cleveland Clinic between 2005 and 2011 and experienced a postoperative stroke. Control patients not experiencing postoperative stroke were matched in a 4-to-1 ratio using propensity scores and restriction to the same procedure type as stroke patients. The association between intraoperative hypotension, measured as time-integrated area under a mean arterial pressure (MAP) of 70 mm Hg, and postoperative stroke was assessed using zero-inflated negative binomial regression. Among 106 337 patients meeting inclusion criteria, we identified 120 who had confirmed postoperative stroke events based on manual chart review. Four-to-one propensity matching yielded a final matched sample of 104 stroke cases and 398 controls. There was no association between stroke and intraoperative hypotension. Stroke patients were not more likely than controls to have been hypotensive (odds ratio, 0.49 [0.18-1.38]), and among patients with intraoperative hypotension, stroke patients did not experience a greater degree of hypotension than controls (ratio of geometric means, 1.07 [0.76-1.53]). In our propensity score-matched case-control study, we did not find an association between intraoperative hypotension, defined as MAP < 70 mm Hg, and postoperative stroke.

Provisional vs. two-stent technique for unprotected left main coronary artery disease after ten years follow up: A propensity matched analysis.

PubMed

D'Ascenzo, Fabrizio; Iannaccone, Mario; Giordana, Francesca; Chieffo, Alaide; Connor, Stephen O; Napp, L Christian; Chandran, SujaySubash; de la Torre Hernández, José María; Chen, Shao-Liang; Varbella, Ferdinando; Omedè, Pierluigi; Taha, Salma; Meliga, Emanuele; Kawamoto, Hiroyoshi; Montefusco, Antonio; Chong, Mervyn; Garot, Philippe; Sin, Lin; Gasparetto, Valeria; Abdirashid, Mohamed; Cerrato, Enrico; Biondi-Zoccai, Giuseppe; Gaita, Fiorenzo; Escaned, Javier; Hiddick Smith, David; Lefèvre, Thierry; Colombo, Antonio; Sheiban, Imad; Moretti, Claudio

2016-05-15

There is uncertainty on which stenting approach confers the best long-term outlook for unprotected left main (ULM) bifurcation disease. This is a non-randomized, retrospective study including all consecutive patients with 50% stenosis of the left main involving at least 1 of the arteries stemming from the left main treated with drug-eluting stents (DES) in 9 European centers between 2002 and 2004. Patients were divided into two groups: those treated with provisional stentings vs. those treated with two stent strategy. The outcomes of interest were 10-year rates of target lesion revascularization (TLR), major adverse cardiac events (MACE), and their components (cardiovascular death, myocardial infarction [MI], or repeat revascularization), along with stent thrombosis (ST). A total of 285 patients were included, 178 (62.5%) in the provisional stenting group and 87 (37.5%) in the two stent group. After 10 years, no differences in TLR were found at unadjusted analysis (19% vs 25%, p>0.05) nor after propensity score matching (25% vs 28%, p>0.05). Similar rates of MACE (60% vs 66%, p>0.05), death (34% vs 43%, p>0.05), MI (9% vs 14%, p>0.05) and ST were also disclosed at propensity-based analysis. Even after 10 year follow-up, patients treated with provisional stenting on left main showed comparable rates of target lesion revascularization compared to two stent strategy. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Effects of a german asthma disease management program using sickness fund claims data.

PubMed

Windt, Roland; Glaeske, Gerd

2010-08-01

The purpose of this study was to assess outcomes of a nationwide asthma disease management (DM) program in Germany. A retrospective observational study with propensity-score matching was performed using claims data of sickness funds exclusively. Effects were analyzed on the basis of a match of 317 program participants and nonparticipants with similar propensity score and age. Hospitalization or oral corticosteroid user rates were comparable in both groups, whereas there are significantly more subjects in the DM group with a prescription of an inhaled corticosteroid and fewer with a prescription of a cromolyn/reproterol combination. There are also less "doctor hoppers" in the DM group, defined as subjects with antiasthmatic drug prescriptions of at least three physicians. The results suggest that the impact of a nationwide disease management program for asthma is weak in respect of clinically relevant endpoints, but there are indications that medication in a DM program approximates asthma guidelines more closely.

A propensity score matching study of participation in community activities: a path to positive outcomes for youth in New Zealand?

PubMed

O'Connor, Seini; Jose, Paul E

2012-11-01

Extracurricular activities are important in many young people's lives and have been associated with positive academic, psychological, and social outcomes. However, most previous research has been limited to school-based activities in the North American context. This study expands existing literature by analyzing longitudinal data from more than 1,300 young Māori and European New Zealanders, using propensity score matching techniques to control for selection effects. Results suggest that youth participating in community-based activities experienced greater social support than nonparticipants. For Māori youth, participating in nonsports activities was associated with later benefits, while for New Zealand European youth, benefits were associated with sports activities. Participants of different ages reported different types of benefits. These findings highlight points of similarity and difference between New Zealand and North American youth and provide a better understanding of the positive impacts of community-based activities for young people.

Survival outcomes of radical prostatectomy and external beam radiotherapy in clinically localized high-risk prostate cancer: a population-based, propensity score matched study

PubMed Central

Gu, Xiaobin; Gao, Xianshu; Cui, Ming; Xie, Mu; Ma, Mingwei; Qin, Shangbin; Li, Xiaoying; Qi, Xin; Bai, Yun; Wang, Dian

2018-01-01

Objective This study was aimed to compare survival outcomes in high-risk prostate cancer (PCa) patients receiving external beam radiotherapy (EBRT) or radical prostatectomy (RP). Materials and methods The Surveillance, Epidemiology, and End Results (SEER) database was used to identify PCa patients with high-risk features who received RP alone or EBRT alone from 2004 to 2008. Propensity-score matching (PSM) was performed. Kaplan–Meier survival analysis was used to compare cancer-specific survival (CSS) and overall survival (OS). Multivariate Cox regression analysis was used to identify independent prognostic factors. Results A total of 24,293 patients were identified, 14,460 patients receiving RP and 9833 patients receiving EBRT. Through PSM, 3828 patients were identified in each group. The mean CSS was 128.6 and 126.7 months for RP and EBRT groups, respectively (P<0.001). The subgroup analyses showed that CSS of the RP group was better than that of the EBRT group for patients aged <65 years (P<0.001), White race (P<0.001), and married status (P<0.001). However, there was no significant difference in CSS for patients aged ≥65 years, Black race, other race, and unmarried status. Similar trends were observed for OS. Multivariate analysis showed that EBRT treatment modality, T3–T4 stage, Gleason score 8–10, and prostate-specific antigen >20 ng/mL were significant risk factors for both CSS and OS. Conclusion This study suggested that survival outcomes might be better with RP than EBRT in high-risk PCa patients aged <65 years; however, RP and EBRT provided equivalent survival outcomes in older patients, which argues for primary radiotherapy in this older cohort.

Acute kidney injury is associated with higher morbidity and resource utilization in pediatric patients undergoing heart surgery.

PubMed

Tóth, Roland; Breuer, Tamás; Cserép, Zsuzsanna; Lex, Dániel; Fazekas, Levente; Sápi, Erzsébet; Szatmári, András; Gál, János; Székely, Andrea

2012-06-01

The RIFLE (risk, injury, failure, loss, and end-stage renal disease) classification system was developed to standardize the definition of acute kidney injury (AKI) in adults. We hypothesized that AKI was associated with increased mortality and morbidity. Acute kidney injury was defined as a decrease in the amount of estimated creatinine clearance based on pediatric-modified RIFLE (pRIFLE) criteria. Using propensity score analysis, 325 patients who had AKI were matched to 325 patients who did not have AKI from a database of 1,510 consecutive pediatric patients who underwent cardiac surgery between January 2004 and December 2008 at a single center. The association between AKI and outcome was analyzed after propensity score matching of perioperative variables. Four hundred eighty-one patients (31.9%) had AKI according to the RIFLE categories. Of those 1,510, 173 (11.5%) reached pRIFLE criteria for risk; 26 (1.7%) reached the criteria for injury; and 282 (18.7%) reached the criteria for failure. Fifty-five patients (3.6%) died. The 2 matched groups were well balanced in terms of measured perioperative variables. Mortality rate was 5.2% in the AKI and 2.5% in the matched control group (p=0.09). Occurrence of low cardiac output syndrome (p=0.002), need for dialysis (p<0.001), and infection (p=0.03) were significantly higher, and duration of mechanical ventilation (p<0.001) and length of intensive care unit stay (p<0.001) were significantly longer compared with the matched control group. Acute kidney injury was independently associated with an increased occurrence of postoperative complications but not with mortality after pediatric cardiac surgery. Copyright © 2012 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Employment during pregnancy and obstetric intervention without medical reason: labor induction and cesarean delivery

PubMed Central

Kozhimannil, Katy Backes; Attanasio, Laura B.; Johnson, Pamela Jo; Gjerdingen, Dwenda K.; McGovern, Patricia M.

2014-01-01

Background Rising rates of labor induction and cesarean delivery, especially when used without a medical reason, have generated concern among clinicians, women, and policymakers. Whether employment status affects pregnant women's childbirth-related care is not known. We estimated the relationship between prenatal employment and obstetric procedures, distinguishing whether women reported that the induction or cesarean was performed for medical reasons. Methods Using data from a nationally-representative sample of women who gave birth in U.S. hospitals (N=1,573), we used propensity score matching to reduce potential bias from non-random selection into employment. Outcomes were cesarean delivery and labor induction, with and without a self-reported medical reason. Exposure was prenatal employment status (full-time employment, not employed). We conducted separate analyses for unmatched and matched cohorts using multivariable regression models. Findings There were no differences in labor induction based on employment status. In unmatched analyses, employed women had higher odds of cesarean delivery overall (adjusted odds ratio (AOR) = 1.45, p=0.046) and cesarean delivery without medical reason (AOR=1.94, p=0.024). Adding an interaction term between employment and college education revealed no significant effects on cesarean without medical reason. There were no significant differences in cesarean delivery by employment status in the propensity score matched analysis. Conclusions Full-time prenatal employment is associated with higher odds of cesarean delivery, but this association was not explained by socio-economic status and no longer existed after accounting for socio-demographic differences by matching women employed full-time with similar women not employed during pregnancy. PMID:25213740

Practice-Based Research: Ex Post Facto Evaluation of Evidence-Based Police Practices Implemented in Residential Burglary Micro-Time Hot Spots.

PubMed

Santos, Roberto G; Santos, Rachel Boba

2015-10-01

Police agencies around the country are implementing various strategies to reduce crime in their communities that need to be evaluated. These strategies are often based on systematic crime analysis and are focused on crime occurring in hot spots, which are areas of disproportionate amounts of crime. This article takes a practice-based research approach to evaluate whether evidence-based police strategies implemented by one police agency as its normal everyday crime reduction practice are effective in reducing residential burglary incidents in micro-time hot spots. A quasi-experimental ex post facto design is employed using 5 years of data from one police agency that has institutionalized the identification and response to micro-time hot spots into its day-to-day practices. Propensity score matching is used to match 54 pairs of micro-time hot spots using logistic regression to compute the propensity scores and greedy 1 to 1 matching with a caliper width of 0.5 of the standard deviation of the logit to match the cases. Independent t-tests show that tactical police response to micro-time hot spots can lead to significant reductions in residential burglary incidents without the spatial displacement of crime. Tactical police responses that seek to achieve short-term reductions in crime appear to be well suited for micro-time hot spots since they are, by nature, short term. Importantly, the conclusions are based on the evaluation of an agency's systematic implementation of the evidence-based practices as its normal practices and not for the sake of research. © The Author(s) 2015.

Employment during pregnancy and obstetric intervention without medical reason: labor induction and cesarean delivery.

PubMed

Kozhimannil, Katy Backes; Attanasio, Laura B; Johnson, Pamela Jo; Gjerdingen, Dwenda K; McGovern, Patricia M

2014-01-01

Rising rates of labor induction and cesarean delivery, especially when used without a medical reason, have generated concern among clinicians, women, and policymakers. Whether employment status affects pregnant women's childbirth-related care is not known. We estimated the relationship between prenatal employment and obstetric procedures, distinguishing whether women reported that the induction or cesarean was performed for medical reasons. Using data from a nationally representative sample of women who gave birth in U.S. hospitals (n = 1,573), we used propensity score matching to reduce potential bias from nonrandom selection into employment. Outcomes were cesarean delivery and labor induction, with and without a self-reported medical reason. Exposure was prenatal employment status (full-time employment, not employed). We conducted separate analyses for unmatched and matched cohorts using multivariable regression models. There were no differences in labor induction based on employment status. In unmatched analyses, employed women had higher odds of cesarean delivery overall (adjusted odds ratio [AOR], 1.45; p = .046) and cesarean delivery without medical reason (AOR, 1.94; p = .024). Adding an interaction term between employment and college education revealed no effects on cesarean delivery without medical reason. There were no differences in cesarean delivery by employment status in the propensity score-matched analysis. Full-time prenatal employment is associated with higher odds of cesarean delivery, but this association was not explained by socioeconomic status and no longer existed after accounting for sociodemographic differences by matching women employed full time with similar women not employed during pregnancy. Copyright © 2014 Jacobs Institute of Women's Health. Published by Elsevier Inc. All rights reserved.

Antegrade versus retrograde cerebral perfusion for hemiarch replacement with deep hypothermic circulatory arrest: does it matter? A propensity-matched analysis.

PubMed

Ganapathi, Asvin M; Hanna, Jennifer M; Schechter, Matthew A; Englum, Brian R; Castleberry, Anthony W; Gaca, Jeffrey G; Hughes, G Chad

2014-12-01

The choice of cerebral perfusion strategy for aortic arch surgery has been debated, and the superiority of antegrade (ACP) or retrograde (RCP) cerebral perfusion has not been shown. We examined the early and late outcomes for ACP versus RCP in proximal (hemi-) arch replacement using deep hypothermic circulatory arrest (DHCA). A retrospective analysis of a prospectively maintained database was performed for all patients undergoing elective and nonelective hemiarch replacement at a single referral institution from June 2005 to February 2013. Total arch cases were excluded to limit the analysis to shorter DHCA times and a more uniform patient population for whom clinical equipoise regarding ACP versus RCP exists. A total of 440 procedures were identified, with 360 (82%) using ACP and 80 (18%) using RCP. The endpoints included 30-day/in-hospital and late outcomes. A propensity score with 1:1 matching of 40 pre- and intraoperative variables was used to adjust for differences between the 2 groups. All 80 RCP patients were propensity matched to a cohort of 80 similar ACP patients. The pre- and intraoperative characteristics were not significantly different between the 2 groups after matching. No differences were found in 30-day/in-hospital mortality or morbidity outcomes. The only significant difference between the 2 groups was a shorter mean operative time in the RCP cohort (P = .01). No significant differences were noted in late survival (P = .90). In proximal arch operations using DHCA, equivalent early and late outcomes can be achieved with RCP and ACP, although the mean operative time is significantly less with RCP, likely owing to avoidance of axillary cannulation. Questions remain regarding comparative outcomes with straight DHCA and lesser degrees of hypothermia. Copyright © 2014 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

ESTIMATING TREATMENT EFFECTS ON HEALTHCARE COSTS UNDER EXOGENEITY: IS THERE A ‘MAGIC BULLET’?

PubMed Central

Polsky, Daniel; Manning, Willard G.

2011-01-01

Methods for estimating average treatment effects, under the assumption of no unmeasured confounders, include regression models; propensity score adjustments using stratification, weighting, or matching; and doubly robust estimators (a combination of both). Researchers continue to debate about the best estimator for outcomes such as health care cost data, as they are usually characterized by an asymmetric distribution and heterogeneous treatment effects,. Challenges in finding the right specifications for regression models are well documented in the literature. Propensity score estimators are proposed as alternatives to overcoming these challenges. Using simulations, we find that in moderate size samples (n= 5000), balancing on propensity scores that are estimated from saturated specifications can balance the covariate means across treatment arms but fails to balance higher-order moments and covariances amongst covariates. Therefore, unlike regression model, even if a formal model for outcomes is not required, propensity score estimators can be inefficient at best and biased at worst for health care cost data. Our simulation study, designed to take a ‘proof by contradiction’ approach, proves that no one estimator can be considered the best under all data generating processes for outcomes such as costs. The inverse-propensity weighted estimator is most likely to be unbiased under alternate data generating processes but is prone to bias under misspecification of the propensity score model and is inefficient compared to an unbiased regression estimator. Our results show that there are no ‘magic bullets’ when it comes to estimating treatment effects in health care costs. Care should be taken before naively applying any one estimator to estimate average treatment effects in these data. We illustrate the performance of alternative methods in a cost dataset on breast cancer treatment. PMID:22199462

Efficacy and safety in pharmacological cardioversion of recent-onset atrial fibrillation: a propensity score matching to compare amiodarone vs class IC antiarrhythmic drugs.

PubMed

Bonora, Antonio; Turcato, Gianni; Franchi, Elena; Taioli, Gabriele; Dilda, Alice; Zerman, Germana; Maccagnani, Antonio; Pistorelli, Claudio; Olivieri, Oliviero

2017-09-01

The acute management of recent-onset (<48 h) atrial fibrillation (AF) is still debated. Aim of our study was to compare efficacy and safety of intravenously administered class IC antidysrhythmic agents vs amiodarone in a propensity score matched series of patients acutely treated for AF in the emergency department. During a 3-year period, we retrospectively evaluated all episodes of recent-onset (<48 h) AF pharmacologically treated for sinus rhythm restoration in the emergency department. By means of a propensity score matching considering the main statistically different covariates, we selected two accurately matched treatment groups. We analysed the differences between amiodarone and class IC group in terms of efficacy and safety that is conversion to sinus rhythm rates within 12 and 48 h after starting treatment, time to conversion, and adverse drug effects. An overall number of 817 episodes of recent-onset AF were collected (amiodarone group = 406, class IC group = 411). After matching, we obtained 358 episodes equally divided (amiodarone group = 179 and class IC group = 179). Conversion rates within 12 h were 139 (53.1 %) in amiodarone group and 95 (72.6 %) in class IC group (p < 0.05). Median time for cardioversion was 420 min (331.6-508.3 CI 95 %) in amiodarone and 55 min (44.9-65.1 CI 95 %) in class IC group (p < 0.05). The incidence of adverse events in both groups was very low and equally distributed (p = ns). Intravenously administration of class IC agents, when compared with amiodarone, proved to be more rapid and effective, and equally safe in the acute management of recent-onset AF.

Bias reduction in repeated-measures observational studies by the use of propensity score: the case of enteral sedation for critically ill patients.

PubMed

Umbrello, Michele; Mistraletti, Giovanni; Corbella, Davide; Cigada, Marco; Salini, Silvia; Morabito, Alberto; Iapichino, Gaetano

2012-12-01

Within the evidence-based medicine paradigm, randomized controlled trials represent the "gold standard" to produce reliable evidence. Indeed, planning and implementing randomized controlled trials in critical care medicine presents limitations because of intrinsic and structural problems. As a consequence, observational studies still occur frequently. In these cases, propensity score (PS) (probability of receiving a treatment conditional on observed covariates) is an increasingly used technique to adjust the results. Few studies addressed the specific issue of a PS correction of repeated-measures designs. Three techniques for correcting the analysis of nonrandomized designs (matching, stratification, regression adjustment) are presented in a tutorial form and applied to a real case study: the comparison between intravenous and enteral sedative therapy in the intensive care unit setting. After showing the results before and after the use of PS, we suggest that such a tool allows to partially overcoming the bias associated with the observational nature of the study. It permits to correct the estimates for any observed covariate, while unobserved confounders cannot be controlled for. Propensity score represents a useful additional tool to estimate the effects of treatments in nonrandomized studies. In the case study, an enteral sedation approach was equally effective to an intravenous regime, allowing for a lower level of sedation and spare of resources. Copyright © 2012 Elsevier Inc. All rights reserved.

Psychological autopsy study comparing suicide decedents, suicide ideators, and propensity score matched controls: results from the study to assess risk and resilience in service members (Army STARRS).

PubMed

Nock, M K; Dempsey, C L; Aliaga, P A; Brent, D A; Heeringa, S G; Kessler, R C; Stein, M B; Ursano, R J; Benedek, D

2017-11-01

The suicide rate has increased significantly among US Army soldiers over the past decade. Here we report the first results from a large psychological autopsy study using two control groups designed to reveal risk factors for suicide death among soldiers beyond known sociodemographic factors and the presence of suicide ideation. Informants were next-of-kin and Army supervisors for: 135 suicide cases, 137 control soldiers propensity-score-matched on known sociodemographic risk factors for suicide and Army history variables, and 118 control soldiers who reported suicide ideation in the past year. Results revealed that most (79.3%) soldiers who died by suicide have a prior mental disorder; mental disorders in the prior 30-days were especially strong risk factors for suicide death. Approximately half of suicide decedents tell someone that they are considering suicide. Virtually all of the risk factors identified in this study differed between suicide cases and propensity-score-matched controls, but did not significantly differ between suicide cases and suicide ideators. The most striking difference between suicides and ideators was the presence in the former of an internalizing disorder (especially depression) and multi-morbidity (i.e. 3+ disorders) in the past 30 days. Most soldiers who die by suicide have identifiable mental disorders shortly before their death and tell others about their suicidal thinking, suggesting that there are opportunities for prevention and intervention. However, few risk factors distinguish between suicide ideators and decedents, pointing to an important direction for future research.

The “Dry-Run” Analysis: A Method for Evaluating Risk Scores for Confounding Control

PubMed Central

Wyss, Richard; Hansen, Ben B.; Ellis, Alan R.; Gagne, Joshua J.; Desai, Rishi J.; Glynn, Robert J.; Stürmer, Til

2017-01-01

Abstract A propensity score (PS) model's ability to control confounding can be assessed by evaluating covariate balance across exposure groups after PS adjustment. The optimal strategy for evaluating a disease risk score (DRS) model's ability to control confounding is less clear. DRS models cannot be evaluated through balance checks within the full population, and they are usually assessed through prediction diagnostics and goodness-of-fit tests. A proposed alternative is the “dry-run” analysis, which divides the unexposed population into “pseudo-exposed” and “pseudo-unexposed” groups so that differences on observed covariates resemble differences between the actual exposed and unexposed populations. With no exposure effect separating the pseudo-exposed and pseudo-unexposed groups, a DRS model is evaluated by its ability to retrieve an unconfounded null estimate after adjustment in this pseudo-population. We used simulations and an empirical example to compare traditional DRS performance metrics with the dry-run validation. In simulations, the dry run often improved assessment of confounding control, compared with the C statistic and goodness-of-fit tests. In the empirical example, PS and DRS matching gave similar results and showed good performance in terms of covariate balance (PS matching) and controlling confounding in the dry-run analysis (DRS matching). The dry-run analysis may prove useful in evaluating confounding control through DRS models. PMID:28338910

Propensity score-matched analysis comparing the therapeutic efficacies of cefazolin and extended-spectrum cephalosporins as appropriate empirical therapy in adults with community-onset Escherichia coli, Klebsiella spp. and Proteus mirabilis bacteraemia.

PubMed

Hsieh, Chih-Chia; Lee, Chung-Hsun; Hong, Ming-Yuan; Hung, Yuan-Pin; Lee, Nan-Yao; Ko, Wen-Chien; Lee, Ching-Chi

2016-12-01

In this study, the therapeutic efficacy of cefazolin was compared with that of extended-spectrum cephalosporins (ESCs) (cefotaxime, ceftriaxone and ceftazidime) as appropriate empirical therapy in adults with community-onset monomicrobial bacteraemia caused by Escherichia coli, Klebsiella spp. or Proteus mirabilis (EKP). Compared with cefazolin-treated patients (n = 135), significantly higher proportions of patients in the ESC treatment group (n = 456) had critical illness at bacteraemia onset (Pitt bacteraemia score ≥4) and fatal co-morbidities (McCabe classification). Of the 591 patients, 121 from each group were matched using propensity score matching (PSM) based on the following independent predictors of 28-day mortality: fatal co-morbidities (McCabe classification); Pitt bacteraemia score ≥4 at bacteraemia onset; initial syndrome of septic shock; and bacteraemia due to pneumonia. After appropriate PSM, no significant differences were observed in the early clinical failure rate (10.7% vs. 7.4%; P = 0.37), the proportion of critical illness (Pitt bacteraemia score ≥4) (0% vs. 0%; P = 1.00) and defervescence (52.6% vs. 42.6%; P = 0.13) on Day 3 between the cefazolin and ESC treatment groups. Similarly, no significant differences were observed in the mean of time to defervescence (4.1 days vs. 4.9 days; P = 0.15), late clinical failure rate (18.2% vs. 10.7%; P = 0.10) and 28-day crude mortality rate (0.8% vs. 3.3%; P = 0.37) between the two groups. These data suggest that the efficacy of cefazolin is similar to that of ESCs when used as appropriate empirical antimicrobial treatment for community-onset EKP bacteraemia. Copyright © 2016 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

Using propensity scores to estimate the effects of insecticides on stream invertebrates from observational data

USGS Publications Warehouse

Lester L. Yuan,; Amina I. Pollard,; Carlisle, Daren M.

2009-01-01

Analyses of observational data can provide insights into relationships between environmental conditions and biological responses across a broader range of natural conditions than experimental studies, potentially complementing insights gained from experiments. However, observational data must be analyzed carefully to minimize the likelihood that confounding variables bias observed relationships. Propensity scores provide a robust approach for controlling for the effects of measured confounding variables when analyzing observational data. Here, we use propensity scores to estimate changes in mean invertebrate taxon richness in streams that have experienced insecticide concentrations that exceed aquatic life use benchmark concentrations. A simple comparison of richness in sites exposed to elevated insecticides with those that were not exposed suggests that exposed sites had on average 6.8 fewer taxa compared to unexposed sites. The presence of potential confounding variables makes it difficult to assert a causal relationship from this simple comparison. After controlling for confounding factors using propensity scores, the difference in richness between exposed and unexposed sites was reduced to 4.1 taxa, a difference that was still statistically significant. Because the propensity score analysis controlled for the effects of a wide variety of possible confounding variables, we infer that the change in richness observed in the propensity score analysis was likely caused by insecticide exposure.

Using propensity scores to estimate the effects of insecticides on stream invertebrates from observational data

USGS Publications Warehouse

Yuan, L.L.; Pollard, A.I.; Carlisle, D.M.

2009-01-01

Analyses of observational data can provide insights into relationships between environmental conditions and biological responses across a broader range of natural conditions than experimental studies, potentially complementing insights gained from experiments. However, observational data must be analyzed carefully to minimize the likelihood that confounding variables bias observed relationships. Propensity scores provide a robust approach for controlling for the effects of measured confounding variables when analyzing observational data. Here, we use propensity scores to estimate changes in mean invertebrate taxon richness in streams that have experienced insecticide concentrations that exceed aquatic life use benchmark concentrations. A simple comparison of richness in sites exposed to elevated insecticides with those that were not exposed suggests that exposed sites had on average 6.8 fewer taxa compared to unexposed sites. The presence of potential confounding variables makes it difficult to assert a causal relationship from this simple comparison. After controlling for confounding factors using propensity scores, the difference in richness between exposed and unexposed sites was reduced to 4.1 taxa, a difference that was still statistically significant. Because the propensity score analysis controlled for the effects of a wide variety of possible confounding variables, we infer that the change in richness observed in the propensity score analysis was likely caused by insecticide exposure. ?? 2009 SETAC.

A Cross-Sectional Cohort Study of a Large, Statewide Medicaid Home and Community-Based Services Autism Waiver Program

ERIC Educational Resources Information Center

Eskow, Karen Goldrich; Chasson, Gregory S.; Summers, Jean Ann

2015-01-01

State-specific 1915(c) Medicaid Home and Community-Based Services waiver programs have become central in the provision of services specifically tailored to children with autism spectrum disorders (ASD). Using propensity score matching, 130 families receiving waiver services for a child with ASD were matched with and compared to 130 families…

An Analysis of Surgical Treatment for the Spontaneous Rupture of Hepatocellular Carcinoma.

PubMed

Sada, Haruki; Ohira, Masahiro; Kobayashi, Tsuyoshi; Tashiro, Hirotaka; Chayama, Kazuaki; Ohdan, Hideki

2016-01-01

The prognosis of spontaneous rupture of hepatocellular carcinoma (HCC) remains unclear. We investigated the prognosis of patients with ruptured HCC based on the treatments and prognostic factors associated with long-term survival. The prognoses of 64 consecutive patients treated for ruptured HCC from 1986 to 2013 were analyzed according to their methods of treatment. The prognostic factors of 16 surgical patients were identified, and their overall survival (OS) and recurrence rates were compared to 1,157 surgical patients who underwent surgery for non-ruptured HCC. The surgical outcomes were also compared using a propensity score matching method. Surgery was associated with a better OS. Curative resection was the only independent prognostic factor in surgical patients with ruptured HCC (p = 0.040). Although the OS of surgical patients with non-ruptured HCC was found to be significantly better than that of the patients with ruptured HCC, no significant difference in OS was observed after propensity score matching. A curative resection should be the objective of treatment, assuming the suitability of the patient's clinical condition. When the liver function reserve and tumor extension of patients with ruptured and non-ruptured HCC are similar, then their surgical outcomes may not be significantly different. © 2015 S. Karger AG, Basel.

Fully laparoscopic left hepatectomy - a technical reference proposed for standard practice compared to the open approach: a retrospective propensity score model.

PubMed

Valente, Roberto; Sutcliffe, Robert; Levesque, Eric; Costa, Mara; De' Angelis, Nicola; Tayar, Claude; Cherqui, Daniel; Laurent, Alexis

2018-04-01

Laparoscopic left hemihepatectomy (LLH) may be an alternative to open (OLH). There are several original variations in the technical aspects of LLH, and no accepted standard. The aim of this study is to assess the safety and effectiveness of the technique developed at Henri Mondor Hospital since 1996. The technique of LLH was conceived for safety and training of two mature generations of lead surgeons. The technique includes full laparoscopy, ventral approach to the common trunk, extrahepatic pedicle dissection, CUSA ® parenchymal transection, division of the left hilar plate laterally to the Arantius ligament, and ventral transection of the left hepatic vein. The outcomes of LLH and OLH were compared. Perioperative analysis included intra- and postoperative, and histology variables. Propensity Score Matching was undertaken of background covariates including age, ASA, BMI, fibrosis, steatosis, tumour size, and specimen weight. 17 LLH and 51 OLH were performed from 1996 to 2014 with perioperative mortality rates of 0% and 6%, respectively. In the LLH group, two patients underwent conversion to open surgery. Propensity matching selected 10 LLH/OLH pairs. The LLH group had a higher proportion of procedures for benign disease. LLH was associated with longer operating time and less blood loss. Perioperative complications occurred in 30% (LLH) and 10% (OLH) (p = 1). Mortality and ITU stay were similar. This technique is recommended as a possible technical reference for standard LLH. Copyright © 2017 International Hepato-Pancreato-Biliary Association Inc. Published by Elsevier Ltd. All rights reserved.

Revascularization of Left Coronary System Using a Skeletonized Left Internal Mammary Artery　- Sequential vs. Separate Grafting.

PubMed

Ji, Qiang; Shi, YunQing; Xia, LiMin; Ma, RunHua; Shen, JinQiang; Lai, Hao; Ding, WenJun; Wang, ChunSheng

2017-12-25

To evaluate in-hospital and mid-term outcomes of sequential vs. separate grafting of in situ skeletonized left internal mammary artery (LIMA) to the left coronary system in a single-center, propensity-matched study.Methods and Results:After propensity score-matching, 120 pairs of patients undergoing first scheduled isolated coronary artery bypass grafting (CABG) with in situ skeletonized LIMA grafting to the left anterior descending artery (LAD) territory were entered into a sequential group (sequential grafting of LIMA to the diagonal artery and then to the LAD) or a control group (separate grafting of LIMA to the LAD). The in-hospital and follow-up clinical outcomes and follow-up LIMA graft patency were compared. Both propensity score-matched groups had similar in-hospital and follow-up clinical outcomes. Sequential LIMA grafting was not found to be an independent predictor of adverse events. During a follow-up period of 27.0±7.3 months, 99.1% patency for the diagonal site and 98.3% for the LAD site were determined by coronary computed tomographic angiography after sequential LIMA grafting, both of which were similar with graft patency of separate grafting of in situ skeletonized LIMA to the LAD. Revascularization of the left coronary system using a skeletonized LIMA resulted in excellent in-hospital and mid-term clinical outcomes and graft patency using sequential grafting.

[Revascularization of left anterior descending artery area using a skeletonized left internal mammary artery: a comparison between sequential and separate grafting].

PubMed

Shen, J Q; Ji, Q; Ding, W J; Xia, L M; Wei, L; Wang, C S

2018-03-13

Objective: To evaluate in-hospital and mid-term outcomes of sequential versus separate grafting of in situ skeletonized left internal mammary artery (LIMA) to the left coronary system in a single-center, propensity-matched study. Methods: After propensity score matching, 120 pairs of patients undergoing first, scheduled, isolated coronary artery bypass grafting (CABG) with in situ skeletonized LIMA grafting to the left anterior descending artery (LAD) territory were entered into a sequential group (sequential grafting of LIMA to the diagonal artery and then to the LAD) or a control group (separate grafting of LIMA to the LAD). The in-hospital and follow-up clinical outcomes and follow-up LIMA graft patency were compared. Results: The two propensity score-matched groups had similar in-hospital and follow-up clinical outcomes. The number of bypass conduits ranged from 3 to 6 (with a mean of 3.5), and 91.3%(219/240)of the included patients received off-pump CABG surgery. No significant differences were found between the two propensity score-matched groups in the in-hospital outcomes, including in-hospital death and the incidence of complications associated with CABG (prolonged ventilation, peroperative stroke, re-operation before discharge, and deep sternal wound infection). During follow-up, 9 patients (4 patients from the sequential group and 5 patients from the control group) died, and the all-cause mortality rate was 3.9%. No significant difference was found in the all-cause mortality rate between the 2 groups[3.4% (4/116) vs 4.3% (5/115), P =0.748]. During follow-up period, 99.1% (115/116) patency for the diagonal site and 98.3% (114/116) for the LAD site were determined by coronary computed tomographic angiography after sequential LIMA grafting, both of which were similar with graft patency of separate grafting of in situ skeletonized LIMA to the LAD. Conclusions: Revascularization of the left coronary system using a skeletonized LIMA resulted in excellent in-hospital and mid-term clinical outcomes and graft patency using sequential grafting.

On the use and misuse of scalar scores of confounders in design and analysis of observational studies.

PubMed

Pfeiffer, R M; Riedl, R

2015-08-15

We assess the asymptotic bias of estimates of exposure effects conditional on covariates when summary scores of confounders, instead of the confounders themselves, are used to analyze observational data. First, we study regression models for cohort data that are adjusted for summary scores. Second, we derive the asymptotic bias for case-control studies when cases and controls are matched on a summary score, and then analyzed either using conditional logistic regression or by unconditional logistic regression adjusted for the summary score. Two scores, the propensity score (PS) and the disease risk score (DRS) are studied in detail. For cohort analysis, when regression models are adjusted for the PS, the estimated conditional treatment effect is unbiased only for linear models, or at the null for non-linear models. Adjustment of cohort data for DRS yields unbiased estimates only for linear regression; all other estimates of exposure effects are biased. Matching cases and controls on DRS and analyzing them using conditional logistic regression yields unbiased estimates of exposure effect, whereas adjusting for the DRS in unconditional logistic regression yields biased estimates, even under the null hypothesis of no association. Matching cases and controls on the PS yield unbiased estimates only under the null for both conditional and unconditional logistic regression, adjusted for the PS. We study the bias for various confounding scenarios and compare our asymptotic results with those from simulations with limited sample sizes. To create realistic correlations among multiple confounders, we also based simulations on a real dataset. Copyright © 2015 John Wiley & Sons, Ltd.

The Trauma of Commercial Sexual Exploitation of Youth: A Comparison of CSE Victims to Sexual Abuse Victims in a Clinical Sample.

PubMed

Cole, Jennifer; Sprang, Ginny; Lee, Robert; Cohen, Judith

2016-01-01

This study examined the demographic features, trauma profiles, clinical severity indicators, problem behaviors, and service utilization characteristics of youth victims of commercial sexual exploitation (CSE) compared with a matched sample of sexually abused/assaulted youth who were not exploited in commercial sex. Secondary data analysis and propensity score matching were used to select a sample of 215 help-seeking youth who were exploited in prostitution (n = 43) or who were sexually abused/assaulted but not exploited in prostitution (n = 172) from the National Child Traumatic Stress Network Core Data Set (NCTSN CDS). Propensity Score Matching was used to select a comparison sample based on age, race, ethnicity, and primary residence. Statistically significant differences were noted between the groups on standardized (e.g., UCLA Posttraumatic Stress Disorder Reaction Index [PTSD-RI], Child Behavior Checklist [CBCL]) and other measures of emotional and behavioral problems (e.g., avoidance and hyperarousal symptoms, dissociation, truancy, running away, conduct disorder, sexualized behaviors, and substance abuse). This study provides useful insight into the symptom and service utilization profiles of youth exploited in commercial sex as compared with youth with other types of sexually exploitive experiences. Targeted screening and event-sensitive measures are recommended to more accurately identify youth exploited in commercial sex. More research is needed to determine if and what modifications to trauma therapies may be required to address the more severe symptomatology and behavior problems associated with youth exploited in commercial sex. © The Author(s) 2014.

Cystic Fibrosis Associated with Worse Survival After Liver Transplantation.

PubMed

Black, Sylvester M; Woodley, Frederick W; Tumin, Dmitry; Mumtaz, Khalid; Whitson, Bryan A; Tobias, Joseph D; Hayes, Don

2016-04-01

Survival in cystic fibrosis patients after liver transplantation and liver-lung transplantation is not well studied. To discern survival rates after liver transplantation and liver-lung transplantation in patients with and without cystic fibrosis. The United Network for Organ Sharing database was queried from 1987 to 2013. Univariate Cox proportional hazards, multivariate Cox models, and propensity score matching were performed. Liver transplant and liver-lung transplant were performed in 212 and 53 patients with cystic fibrosis, respectively. Univariate Cox proportional hazards regression identified lower survival in cystic fibrosis after liver transplant compared to a reference non-cystic fibrosis liver transplant cohort (HR 1.248; 95 % CI 1.012, 1.541; p = 0.039). Supplementary analysis found graft survival was similar across the 3 recipient categories (log-rank test: χ(2) 2.68; p = 0.262). Multivariate Cox models identified increased mortality hazard among cystic fibrosis patients undergoing liver transplantation (HR 2.439; 95 % CI 1.709, 3.482; p < 0.001) and liver-lung transplantation (HR 2.753; 95 % CI 1.560, 4.861; p < 0.001). Propensity score matching of cystic fibrosis patients undergoing liver transplantation to non-cystic fibrosis controls identified a greater mortality hazard in the cystic fibrosis cohort using a Cox proportional hazards model stratified on matched pairs (HR 3.167; 95 % CI 1.265, 7.929, p = 0.014). Liver transplantation in cystic fibrosis is associated with poorer long-term patient survival compared to non-cystic fibrosis patients, although the difference is not due to graft survival.

Liver Transplantation Using Grafts From Donors After Circulatory Death: A Propensity Score-Matched Study From a Single Center.

PubMed

Laing, R W; Scalera, I; Isaac, J; Mergental, H; Mirza, D F; Hodson, J; Wilkin, R J W; Perera, M T P R; Muiesan, P

2016-06-01

The use of livers from donation after circulatory death (DCD) is increasing, but concerns exist regarding outcomes following use of grafts from "marginal" donors. To compare outcomes in transplants using DCD and donation after brain death (DBD), propensity score matching was performed for 973 patients with chronic liver disease and/or malignancy who underwent primary whole-liver transplant between 2004 and 2014 at University Hospitals Birmingham NHS Foundation Trust. Primary end points were overall graft and patient survival. Secondary end points included postoperative, biliary and vascular complications. Over 10 years, 234 transplants were carried out using DCD grafts. Of the 187 matched DCDs, 82.9% were classified as marginal per British Transplantation Society guidelines. Kaplan-Meier analysis of graft and patient survival found no significant differences for either outcome between the paired DCD and DBD patients (p = 0.162 and p = 0.519, respectively). Aspartate aminotransferase was significantly higher in DCD recipients until 48 h after transplant (p < 0.001). The incidences of acute kidney injury and ischemic cholangiopathy were greater in DCD recipients (32.6% vs. 15% [p < 0.001] and 9.1% vs. 1.1% [p < 0.001], respectively). With appropriate recipient selection, the use of DCDs, including those deemed marginal, can be safe and can produce outcomes comparable to those seen using DBD grafts in similar recipients. © Copyright 2016 The American Society of Transplantation and the American Society of Transplant Surgeons.

Propensity score estimation: machine learning and classification methods as alternatives to logistic regression

PubMed Central

Westreich, Daniel; Lessler, Justin; Funk, Michele Jonsson

2010-01-01

Summary Objective Propensity scores for the analysis of observational data are typically estimated using logistic regression. Our objective in this Review was to assess machine learning alternatives to logistic regression which may accomplish the same goals but with fewer assumptions or greater accuracy. Study Design and Setting We identified alternative methods for propensity score estimation and/or classification from the public health, biostatistics, discrete mathematics, and computer science literature, and evaluated these algorithms for applicability to the problem of propensity score estimation, potential advantages over logistic regression, and ease of use. Results We identified four techniques as alternatives to logistic regression: neural networks, support vector machines, decision trees (CART), and meta-classifiers (in particular, boosting). Conclusion While the assumptions of logistic regression are well understood, those assumptions are frequently ignored. All four alternatives have advantages and disadvantages compared with logistic regression. Boosting (meta-classifiers) and to a lesser extent decision trees (particularly CART) appear to be most promising for use in the context of propensity score analysis, but extensive simulation studies are needed to establish their utility in practice. PMID:20630332

Effects of cognitive behavioral therapy in patients with depressive disorder and comorbid insomnia: A propensity score-matched outcome study.

PubMed

Hsu, Hui-Min; Chou, Kuei-Ru; Lin, Kuan-Chia; Chen, Kuan-Yu; Su, Shu-Fang; Chung, Min-Huey

2015-10-01

We evaluated the effects of cognitive behavioral therapy for insomnia (CBT-I) in inpatients with a diagnosis of depression and comorbid insomnia. This study used a prospective, parallel-group design. The experimental group received CBT-I for no more than 90 min once weekly for 6 weeks and the control group only have health education manuals for insomnia. The following questionnaires were administered at baseline: the Hamilton Rating Scale for Depression (HAM-D), Dysfunctional Beliefs and Attitudes about Sleep (DBAS), Presleep Arousal Scale (PSAS), Sleep Hygiene Practice (SHP), and Pittsburgh Sleep Quality Index. The questionnaires were readministered after the completion of the 6-wk CBT-I intervention and 1 month following the completion of CBT-I, to determine the effects of the CBT-I intervention over time. The analysis of Generalized Estimation Equations was identified the difference between the experimental group and the control group by controlling for the variables in BZD dose and propensity score of gender, age, and the scores for the DBAS-16, PSAS, SHPS, and HAM-D. Consequently, the significant difference in the PSQI scores was observed at the 1-month follow-up assessment however, no significant intergroup difference in the PSQI scores was found at the completion of the CBT-I intervention between two groups. As a conclusion, we found that overall sleep quality significantly improved in patients who received CBT-I after we controlled for the BZD dose and propensity score, which suggests that CBT-I may represent a useful clinical strategy for improving sleep quality in patients with depression and comorbid insomnia. Copyright © 2015 Elsevier Ltd. All rights reserved.

Propensity scores-potential outcomes framework to incorporate severity probabilities in the highway safety manual crash prediction algorithm.

PubMed

Sasidharan, Lekshmi; Donnell, Eric T

2014-10-01

Accurate estimation of the expected number of crashes at different severity levels for entities with and without countermeasures plays a vital role in selecting countermeasures in the framework of the safety management process. The current practice is to use the American Association of State Highway and Transportation Officials' Highway Safety Manual crash prediction algorithms, which combine safety performance functions and crash modification factors, to estimate the effects of safety countermeasures on different highway and street facility types. Many of these crash prediction algorithms are based solely on crash frequency, or assume that severity outcomes are unchanged when planning for, or implementing, safety countermeasures. Failing to account for the uncertainty associated with crash severity outcomes, and assuming crash severity distributions remain unchanged in safety performance evaluations, limits the utility of the Highway Safety Manual crash prediction algorithms in assessing the effect of safety countermeasures on crash severity. This study demonstrates the application of a propensity scores-potential outcomes framework to estimate the probability distribution for the occurrence of different crash severity levels by accounting for the uncertainties associated with them. The probability of fatal and severe injury crash occurrence at lighted and unlighted intersections is estimated in this paper using data from Minnesota. The results show that the expected probability of occurrence of fatal and severe injury crashes at a lighted intersection was 1 in 35 crashes and the estimated risk ratio indicates that the respective probabilities at an unlighted intersection was 1.14 times higher compared to lighted intersections. The results from the potential outcomes-propensity scores framework are compared to results obtained from traditional binary logit models, without application of propensity scores matching. Traditional binary logit analysis suggests that the probability of occurrence of severe injury crashes is higher at lighted intersections compared to unlighted intersections, which contradicts the findings obtained from the propensity scores-potential outcomes framework. This finding underscores the importance of having comparable treated and untreated entities in traffic safety countermeasure evaluations. Copyright © 2014 Elsevier Ltd. All rights reserved.

New steps of robot-assisted radical prostatectomy using the extraperitoneal approach: a propensity-score matched comparison between extraperitoneal and transperitoneal approach in Japanese patients.

PubMed

Kurokawa, Satoshi; Umemoto, Yukihiro; Mizuno, Kentaro; Okada, Atsushi; Nakane, Akihiro; Nishio, Hidenori; Hamamoto, Shuzo; Ando, Ryosuke; Kawai, Noriyasu; Tozawa, Keiichi; Hayashi, Yutaro; Yasui, Takahiro

2017-11-21

Robot-assisted radical prostatectomy (RARP) is commonly performed using the transperitoneal (TP) approach with six trocars over an 8-cm distance in the steep Trendelenburg position. In this study, we investigated the feasibility and the benefit of using the extraperitoneal (EP) approach with six trocars over a 4-cm distance in a flat or 5° Trendelenburg position. We also introduced four new steps to the surgical procedure and compared the surgical results and complications between the EP and TP approach using propensity score matching. Between August 2012 and August 2016, 200 consecutive patients without any physical restrictions underwent RARP with the EP approach in a less than 5° Trendelenburg position, and 428 consecutive patients underwent RARP with the TP approach in a steep Trendelenburg position. Four new steps to RARP using the EP approach were developed: 1) arranging six trocars; 2) creating the EP space using laparoscopic forceps; 3) holding the separated prostate in the EP space outside the robotic view; and 4) preventing a postoperative inguinal hernia. Clinicopathological results and complications were compared between the EP and TP approaches using propensity score matching. Propensity scores were calculated for each patient using multivariate logistic regression based on the preoperative covariates. All 200 patients safely underwent RARP using the EP approach. The mean volume of estimated blood loss and duration of indwelling urethral catheter use were significantly lower with the EP approach than the TP approach (139.9 vs 184.9 mL, p = 0.03 and 5.6 vs 7.7 days, p < 0.01, respectively). No significant differences in the positive surgical margin were observed. None of the patients developed an inguinal hernia postoperatively after we introduced this technique. The EP approach to RARP was safely performed regardless of patient physique or contraindications to a steep Trendelenburg position. Our method, which involved using the EP approach to perform RARP, can decrease the amount of perioperative blood loss, the duration of indwelling urethral catheter use, and the incidence of postoperative inguinal hernia development.

Sublobar resection versus lobectomy in patients aged ≤35 years with stage IA non-small cell lung cancer: a SEER database analysis.

PubMed

Gu, Chang; Wang, Rui; Pan, Xufeng; Huang, Qingyuan; Zhang, Yangyang; Yang, Jun; Shi, Jianxin

2017-11-01

Sublobar resection has been increasingly adopted in elderly patients with stage IA non-small cell lung cancer (NSCLC), but the equivalency of sublobar resection versus lobectomy among young patients with stage IA NSCLC is unknown. Using the Surveillance, Epidemiology, and End Results (SEER) registry, we identified patients aged ≤35 years who were diagnosed between 2004 and 2013 with pathological stage IA NSCLC and treated with sublobar resection or lobectomy. We used propensity-score matching to minimize the effect of potential confounders that existed in the baseline characteristics of patients in different treatment groups. The overall survival (OS) and lung cancer-specific survival (LCSS) rates of patients who underwent sublobar resection or lobectomy were compared in stratification analysis. Overall, we identified 188 patients who had stage IA disease, 32 (17%) of whom underwent sublobar resection. We did not identify any difference in OS/LCSS between patients who received sublobar resection versus lobectomy before (log-rank p = 0.6354) or after (log-rank p = 0.5305) adjusting for propensity scores. Similarly, we still could not recognize different OS/LCSS rates among stratified T stage groups or stratified lymph node-removed groups before or after adjusting for propensity scores. Sublobar resection is not inferior to lobectomy for young patients with stage IA NSCLC. Considering sublobar resection better preserves lung function and has reduced overall morbidity, sublobar resection may be preferable for the treatment of young patients with stage IA NSCLC.

Tubeless percutaneous nephrolithotomy with non-absorbable hemostatic sealant (Quikclot®) versus nephrostomy tube placement: a propensity score-matched analysis.

PubMed

Koo, Kyo Chul; Park, Sang Un; Jang, Ho Sung; Hong, Chang-Hee

2015-11-01

The purpose of this study was to determine the efficacy and safety of tubeless percutaneous nephrolithotomy (PNL) using a non-absorbable hemostatic sealant (Quikclot(®)) as an adjunct compared to nephrostomy tube placement in patients exhibiting significant parenchymal bleeding following PNL. We identified 113 PNL cases performed between May 2011 and October 2014. For patients with insignificant parenchymal bleeding following stone removal, defined as a clear visualization of the surgical field at full irrigation of the nephroscope, tubeless PNL was performed. For patients with significant parenchymal bleeding, we introduced the tubeless Quikclot(®) technique as of September 2013 and have performed it ever since. Formerly, nephrostomy placement PNL was performed. In this study, 40 Quikclot(®) applied PNL cases were matched with an equal number of nephrostomy placement cases by propensity scoring based on body mass index, stone size, and Guy's stone score. The mean postoperative drop in hematocrit was comparative between the Quikclot(®) group and the nephrostomy group on both postoperative days 1 (p = 0.459) and 2 (p = 0.325). Quikclot(®) application was associated with lower VAS scores throughout the postoperative period, lower cumulative analgesic requirement (p = 0.025), and with shorter hospitalization (p = 0.002). Complication rates were comparable with no need for blood transfusions in any patients. Tubeless Quikclot(®) PNL was safe and provided effective hemostasis of significant parenchymal bleeding. By avoiding nephrostomy placement, we were able to reduce postoperative pain, analgesic requirements, and hospitalization. Application of Quikclot(®) may be considered prior to nephrostomy placement in patients with significant parenchymal bleeding.

The Clinical Outcomes of Lower Gastrointestinal Bleeding Are Not Better than Those of Upper Gastrointestinal Bleeding.

PubMed

Kwak, Min Seob; Cha, Jae Myung; Han, Yong Jae; Yoon, Jin Young; Jeon, Jung Won; Shin, Hyun Phil; Joo, Kwang Ro; Lee, Joung Il

2016-10-01

The incidence of lower gastrointestinal bleeding (LGIB) is increasing; however, predictors of outcomes for patients with LGIB are not as well defined as those for patients with upper gastrointestinal bleeding (UGIB). The aim of this study was to identify the clinical outcomes and the predictors of poor outcomes for patients with LGIB, compared to outcomes for patients with UGIB. We identified patients with LGIB or UGIB who underwent endoscopic procedures between July 2006 and February 2013. Propensity score matching was used to improve comparability between LGIB and UGIB groups. The clinical outcomes and predictors of 30-day rebleeding and mortality rate were analyzed between the two groups. In total, 601 patients with UGIB (n = 500) or LGIB (n = 101) were included in the study, and 202 patients with UGIB and 101 patients with LGIB were analyzed after 2:1 propensity score matching. The 30-day rebleeding and mortality rates were 9.9% and 4.5% for the UGIB group, and 16.8% and 5.0% for LGIB group, respectively. After logistic regression analysis, the Rockall score (P = 0.013) and C-reactive protein (CRP; P = 0.047) levels were significant predictors of 30-day mortality in patients with LGIB; however, we could not identify any predictors of rebleeding in patients with LGIB. The clinical outcomes for patients with LGIB are not better than clinical outcomes for patients with UGIB. The clinical Rockall score and serum CRP levels may be used to predict 30-day mortality in patients with LGIB.

Renal function on admission modifies prognostic impact of diuretics in acute heart failure: a propensity score matched and interaction analysis.

PubMed

Matsue, Yuya; Shiraishi, Atsushi; Kagiyama, Nobuyuki; Yoshida, Kazuki; Kume, Teruyoshi; Okura, Hiroyuki; Suzuki, Makoto; Matsumura, Akihiko; Yoshida, Kiyoshi; Hashimoto, Yuji

2016-12-01

Although intravenous diuretics have been mainstay drugs in patients with acute heart failure (AHF), they have been suggested to have some deleterious effects on prognosis. We postulated that renal function may modify their deleterious effects in AHF patients. The study population consisted of 1094 AHF patients from three hospitals. Renal dysfunction (RD) was defined as estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m 2 on admission, and the cohort was divided into a high-dose furosemide (≥100 mg/48 h) and low-dose furosemide group according to the amount of intravenous furosemide used within 48 h from admission. In the whole cohort, in-hospital mortality rate was higher in the high-dose furosemide group than the low-dose furosemide group (12.5 vs. 6.6 %, respectively, P = 0.001). However, this difference in the in-hospital mortality rates was significant only in the RD subgroup (15.6 vs. 7.0 %, respectively, P < 0.001), and not in the non-RD subgroup (2.5 vs. 5.9 %, respectively, P = 0.384). Propensity score-matched analysis was performed to evaluate the impact of high-dose furosemide on prognosis. After propensity score matching, high-dose furosemide was not associated with in-hospital mortality (OR 1.25, 95 % CI 0.73-2.16, P = 0.408). However, there was a qualitative difference in OR for in-hospital mortality between AHF with RD (OR 1.77, 95 % CI 0.96-3.28, P = 0.068) and without RD (OR 0.23, 95 % CI 0.05-1.10, P = 0.064), and there was a significant interaction between eGFR and prognostic impact of high-dose furosemide (P for OR interaction = 0.013). An inverse relationship was observed between eGFR and OR for in-hospital death in the group treated with high-dose furosemide (decreasing OR with better eGFR). The deleterious effect of diuretics was significantly modified with renal function in AHF. This association may be one reason for poorer prognosis of AHF patients complicated with renal impairment.

Propensity score analysis of recurrence for neutrophil-to-lymphocyte ratio in colorectal cancer.

PubMed

Balde, Alpha I; Fang, Suzhen; He, Linyun; Cai, Zhai; Han, Shuai; Wang, Weiwei; Li, Zhou; Kang, Liang

2017-11-01

The perioperative serum neutrophil-to-lymphocyte ratio (NLR) has been proposed to predict adverse prognosis in colorectal cancer (CRC). However, its interpretation remains unclear. The present study aimed to clarify the prognostic value of NLR in predicting survival among CRC patients. A single-centre, retrospective, propensity score-matched study of adenocarcinoma patients who underwent D3 lymphadenectomy via laparoscopic or open surgery between 2010 and 2016 was conducted. A cutoff of 3.5 was used based on the receiver operating characteristic curve. To overcome selection biases, we performed a 1:1 match using six covariates. The high-preoperative NLR group had a higher recurrence rate than the low group (P < 0.001). Univariate analysis showed that increased NLR (P < 0.001), N1 (P = 0.016), and N2 (P < 0.001) were associated with worse recurrence-free survival (RFS). Multivariate analysis showed that N2 (hazard ratio [HR], 2.492; P = 0.008) was an adverse prognostic factor for RFS. Univariate analysis for overall survival (OS) revealed that high perioperative NLR (P = 0.001), N1 (P = 0.01), N2 (P < 0.001), and distant metastasis (P < 0.001) were adverse prognostic factors. Subsequent multivariate analysis showed that M1 (HR, 3.973; P < 0.001) and N2 (HR, 2.381; P = 0.013) were highly adverse factors for OS. Clinical assessments performed during a 21.14 (±16.20)-mo follow-up revealed that OS (P = 0.001) and RFS (P < 0.001) were worse in the high-perioperative group than in the low group between the matched groups. An elevated preoperative NLR is a strong predictor of worse RFS and OS in CRC patients. Copyright © 2017 Elsevier Inc. All rights reserved.

Enteral Nutrition for TBI Patients in the Rehabilitation Setting: Associations with Patient Pre-injury and Injury Characteristics and Outcomes

PubMed Central

Horn, Susan D.; Kinikini, Merin; Moore, Linda W.; Hammond, Flora M.; Brandstater, Murray E.; Smout, Randall J.; Barrett, Ryan S.

2015-01-01

Objective To determine the association of enteral nutrition (EN) with patient pre-injury and injury characteristics and outcomes for patients receiving inpatient brain injury rehabilitation. Design Prospective observational study using propensity scores to isolate the effect of EN Setting 9 rehabilitation centers in the US Participants Patients (n=1701) admitted for first full inpatient rehabilitation after a TBI index injury Interventions Not applicable Main Outcome Measures Functional Independence Measure (FIM) at rehabilitation discharge, length of stay (LOS), weight loss, and presence of infections. Results There were many significant differences in pre-injury and injury characteristics for patients who received EN compared to patients who did not. After matching patients with a propensity score >40% for the likely use of EN, patients with greater than 25% of their rehabilitation stay receiving EN with either standard or high protein formulas (greater than 20% of calories coming from protein) had better FIM Motor and FIM Cognitive scores at rehabilitation discharge and less weight loss than similar patients not receiving EN. Conclusions For patients receiving inpatient rehabilitation following TBI and matched on a propensity to use EN of >40%, clinicians should strongly consider, when possible, EN for at least 25% of the patient’s stay and especially with a formula that contains at least 20% protein rather than a standard formula. PMID:26212401

Association between dietary patterns and metabolic syndrome in Chinese adults: a propensity score-matched case-control study.

PubMed

Xia, Yang; Gu, Yeqing; Yu, Fei; Zhang, Qing; Liu, Li; Meng, Ge; Wu, Hongmei; Du, Huanmin; Shi, Hongbin; Guo, Xiaoyan; Liu, Xing; Li, Chunlei; Han, Peipei; Dong, Renwei; Wang, Xiuyang; Bao, Xue; Su, Qian; Fang, Liyun; Liu, Fangfang; Yang, Huijun; Kang, Li; Ma, Yixuan; Yu, Bin; Sun, Shaomei; Wang, Xing; Zhou, Ming; Jia, Qiyu; Guo, Qi; Wu, Yuntang; Song, Kun; Huang, Guowei; Wang, Guolin; Niu, Kaijun

2016-10-06

Previous studies indicated that dietary patterns were associated with metabolic syndrome (MS), but little is known in Chinese. We design this case-control study to evaluate the associations between dietary patterns and MS in Chinese adults. In this study, 1492 participants with MS were matched with 1492 controls using the 1:1 ratio propensity score matching methods. Dietary intake was assessed using a valid self-administered food frequency questionnaire, and MS was defined in accordance with the criteria of the American Heart Association scientific statement of 2009. Higher scores for the high-protein/cholesterol pattern were associated with higher prevalence of MS. Compared with the participants in the lowest quartile, the odds ratio (OR) for the extreme quartile was 1.36 (95% confidence interval (CI), 1.10-1.68) and the P for trend <0.01 after adjusted for the other two dietary pattern scores. We also found a moderate consumption of the balanced pattern was associated with the lowest prevalence of MS. The ORs across quartiles of the balanced pattern were 1 (reference), 0.83 (95% CI, 0.68-1.02), 0.69 (95% CI, 0.56-0.85), and 0.84 (95% CI, 0.68-1.04) after adjustment. Our study demonstrates that there is a strong association between a diet rich in animal offal, animal blood, meat, and sausage and a higher prevalence of MS.

Long term use of analgesics and risk of osteoarthritis progressions and knee replacement: propensity score matched cohort analysis of data from the Osteoarthritis Initiative.

PubMed

Hafezi-Nejad, N; Guermazi, A; Roemer, F W; Eng, J; Zikria, B; Demehri, S

2016-04-01

To determine the association between the long-term use of analgesics and progression of osteoarthritis (OA) as evidenced by up to 3-years follow-up worsening of radiographic Kellgren-Lawrence (KL) grade and incidence of knee replacement (KR). Using nearest neighbor matching of the propensity scores with caliper in the Osteoarthritis Initiative (OAI) cohort, 173 index (Analgesic +) and 173 referent (Analgesic -) subjects were included. Analgesic + and - subjects had analgesics in all and none of their visits, respectively. Analgesic + and - subjects were balanced in their demographics, baseline, first, second and third year body mass index (BMI), Western Ontario and McMaster (WOMAC) total score, Physical and Mental health summary scales (SF-12), Physical Activity Scale for the Elderly (PASE) and Charleston Comorbidity Scale. Analgesic + and - subjects were also matched for baseline radiographic KL grade. Interval increase in the KL grade and incidence of KR were defined as the outcome. Included subjects had average 6.5 years of follow-up. By the third year, 44 subjects had an interval increase in the KL grade; 29 in Analgesic + and 15 among Analgesic - subjects (P = 0.024). By the eighth-year, 41 subjects had their first KR; 29 in Analgesic + and 12 among Analgesic - subjects (P = 0.005). Hazard Ratio (HR) of OA progression and KR for Analgesic + subjects was 1.91 (1.02-3.57) and 2.57 (1.31-5.04), respectively. Long-term use of analgesics may be associated with radiographic progression of knee OA and increased risk of future KR. Copyright © 2015 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Effectiveness of early administration of tranexamic acid in patients with severe trauma.

PubMed

Shiraishi, A; Kushimoto, S; Otomo, Y; Matsui, H; Hagiwara, A; Murata, K

2017-05-01

A reduction in mortality with the early use of tranexamic acid has been demonstrated in severely injured patients who are bleeding. However, the modest treatment effect with no reduction in blood transfusion has raised concerns. The aim of the present study was to estimate the effectiveness of regular use of tranexamic acid in severely injured patients. This multicentre observational study used retrospectively collected data from consecutive injured patients (Injury Severity Score at least 16) treated in 15 Japanese academic institutions in 2012. A propensity score-matched analysis compared patients who did or did not receive tranexamic acid administration within 3 h of injury. Study outcomes included 28-day all-cause and cause-specific mortality, and need for blood transfusion. Of 796 eligible subjects, 281 were treated with tranexamic acid. Propensity score matching selected a total of 500 matched subjects (250 in each group). Tranexamic acid administration was associated with lower 28-day mortality (10·0 versus 18·4 per cent; difference -8·4 (95 per cent c.i. -14·5 to -2·3) per cent) and lower 28-day mortality from primary brain injury (6·0 versus 13·2 per cent; difference -7·2 (-12·3 to -2·1) per cent). However, there was no significant difference between groups in the need for blood transfusion (33·2 versus 34·8 per cent; difference -1·6 (-9·9 to 6·7) per cent). Early tranexamic acid use was associated with reduced mortality in severely injured patients, in particular those with a primary brain injury. © 2017 BJS Society Ltd Published by John Wiley & Sons Ltd.

Jugular venous valved conduit (Contegra) matches allograft performance in infant truncus arteriosus repair.

PubMed

Hickey, Edward J; McCrindle, Brian W; Blackstone, Eugene H; Yeh, Thomas; Pigula, Frank; Clarke, David; Tchervenkov, Christo I; Hawkins, John

2008-05-01

Limited availability and durability of allograft conduits require that alternatives be considered. We compared bovine jugular venous valved (JVV) and allograft conduit performance in 107 infants who survived truncus arteriosus repair. Children were prospectively recruited between 2003 and 2007 from 17 institutions. The median z-score for JVV (n=27, all 12 mm) was +2.1 (range +1.2 to +3.2) and allograft (n=80, 9-15mm) was +1.7 (range -0.4 to +3.6). Propensity-adjusted comparison of conduit survival was undertaken using parametric risk-hazard analysis and competing risks techniques. All available echocardiograms (n=745) were used to model deterioration of conduit function in regression equations adjusted for repeated measures. Overall conduit survival was 64+/-9% at 3 years. Conduit replacement was for conduit stenosis (n=16) and/or pulmonary artery stenosis (n=18) or regurgitation (n=1). The propensity-adjusted 3-year freedom from replacement for in-conduit stenosis was 96+/-4% for JVV and 69+/-8% for allograft (p=0.05). The risk of intervention or replacement for branch pulmonary artery stenosis was similar for JVV and allograft. Smaller conduit z-score predicted poor conduit performance (p<0.01) with best outcome between +1 and +3. Although JVV conduits were a uniform diameter, their z-score more consistently matched this ideal. JVV exhibited a non-significant trend towards slower progression of conduit regurgitation and peak right ventricular outflow tract (RVOT) gradient. In addition, catheter intervention was more successful at slowing subsequent gradient progression in children with JVV versus those with allograft (p<0.01). JVV does match allograft performance and may be advantageous. It is an appropriate first choice for repair of truncus arteriosus, and perhaps other small infants requiring RVOT reconstruction.

5A.01: CORONARY ATHEROSCLEROSIS AND ADVERSE OUTCOME IN HYPERTENSIVE PATIENTS WITH RECENT-ONSET ATRIAL FIBRILLATION AND TROPONIN RISE.

PubMed

Conti, A; Angeli, E; Trausi, F; Grifoni, C; Lazzeretti, D; Bianchi, S; Catarzi, S; Covelli, A; Perrotta, M E; Lencioni, A M; Pisani, N; Bertolini, L

2015-06-01

Atrial fibrillation (AF), the most common cardiac-arrhythmia in critical-care, has reached a high prevalence in hypertensive patients. Prevention of systemic-embolism is mandatory; unfortunately, evidence to support the treatment of comorbidities as coronary artery disease (CAD) that contribute to excess mortality is lacking, and the mechanism underlying the troponin-rise during AF without acute coronary syndrome (ACS) is unclear. This study investigates the relationship between CAD, stroke and outcomes in patients with troponin-rise and AF. Patients with a recent-onset AF and without severe comorbidities were enrolled. Baseline characteristics in those with troponin-rise versus those without were adjusted with propensity-score-matching for possible confounders. SPSS-software allowed estimation of the propensity-score using logistic-regression and specifying nearest-neighbor matching in prior-stroke, heart-rate, hypertension, TIMI-risk-score, GRACE-score, CHA2DS2Vasc-score. Patients with a troponin-rise or cardiovascular event (CVE) were considered for angiography. The primary endpoint was the composite of ACS, revascularization (with critical CAD>/ = 70%) and cardiac-death at the follow-up; the secondary endpoint was stroke. Out of 6203 AF patients without severe comorbidities, 3541 with recent-onset AF completed the study; 202(6%) showed a troponin-rise, 91(3%) a CVE. After matching no difference existed in baseline characteristics. On multivariate analysis, in the entire cohort, troponin-rise, know-CAD and hypertension were predictors of the endpoint, whereas only troponin-rise (Odd Ratio, OR: 10, Confidence Interval 95%, CI: 4-22, p < 0.001) and TIMI-score > 2 (OR 4, CI 2-9, p < 0.001) in the matching cohort, suggesting the role of CAD in poor outcomes. Patients with or without troponin-rise achieved the endpoint in 38(19%) and 43(1%), respectively (p < 0.001). Stroke occurred in 4(2%) and 20 (1%), respectively (p = 0.018). Critical CAD account for 23(12%) and 15(1%), respectively (p < 0,001). In the matching cohort, only stroke did not reach the statistical significance. Interestingly, the best cut/off troponin level for decision-making was 0.30 ng/L which, on Receiver Operator Curve analysis, was associated with 68% of sensitivity and 60% specificity; the value > 0.50 ng/L with 55% and 75%, respectively. Patients with a recent-onset AF and troponin-rise showed a high prevalence of CVE but not stroke, thus CAD might have a role in poor outcomes.

Quasi-Experimental Designs for Causal Inference

ERIC Educational Resources Information Center

Kim, Yongnam; Steiner, Peter

2016-01-01

When randomized experiments are infeasible, quasi-experimental designs can be exploited to evaluate causal treatment effects. The strongest quasi-experimental designs for causal inference are regression discontinuity designs, instrumental variable designs, matching and propensity score designs, and comparative interrupted time series designs. This…

Propensity Score-Matched Analysis of Clinical and Financial Outcomes After Robotic and Laparoscopic Colorectal Resection.

PubMed

Al-Mazrou, Ahmed M; Baser, Onur; Kiran, Ravi P

2018-06-01

The study aims to evaluate the clinical and financial outcomes of the use of robotic when compared to laparoscopic colorectal surgery and any changes in these over time. From the Premier Perspective database, patients who underwent elective laparoscopic and robotic colorectal resections from 2012 to 2014 were included. Laparoscopic colorectal resections were propensity score matched to robotic cases for patient, disease, procedure, surgeon specialty, and hospital type and volume. The two groups were compared for conversion, hospital stay, 30-day post-discharge readmission, mortality, and complications. Direct, cumulative, and total (including 30-day post-discharge) costs were evaluated. Clinical and financial outcomes were also separately assessed for each of the included years. Of 36,701 patients, 32,783 (89.3%) had laparoscopic colorectal resection and 3918 (10.7%) had robotic colorectal resection; 4438 procedures (2219 in each group) were propensity score matched. For the entire period, conversion to open approach (4.7 vs. 3.7%, p = 0.1) and hospital stay (mean days [SD] 6 [5.3] vs. 5 [4.6], p = 0.2) were comparable between robotic and laparoscopic procedures. Surgical and medical complications were also the same for the two groups. However, the robotic approach was associated with lower readmission (6.3 vs. 4.8%, p = 0.04). Wound or abdominal infection (4.7 vs. 2.3%, p = 0.01) and respiratory complications (7.4 vs. 4.7%, p = 0.02) were significantly lower for the robotic group in the final year of inclusion, 2014. Direct, cumulative, and total (including 30-day post-discharge) costs were significantly higher for robotic surgery. The difference in costs between the two approaches reduced over time (direct cost difference: 2012, $2698 vs. 2013, $2235 vs. 2014, $1402). Robotic colorectal surgery can be performed with comparable clinical outcomes to laparoscopy. With greater use of the technology, some further recovery benefits may be evident. The robotic approach is more expensive but cost differences have been diminishing over time.

Robot-assisted laparoscopic versus open partial nephrectomy in patients with chronic kidney disease: A propensity score-matched comparative analysis of surgical outcomes.

PubMed

Takagi, Toshio; Kondo, Tsunenori; Tachibana, Hidekazu; Iizuka, Junpei; Omae, Kenji; Kobayashi, Hirohito; Yoshida, Kazuhiko; Tanabe, Kazunari

2017-07-01

To compare surgical outcomes between robot-assisted laparoscopic partial nephrectomy and open partial nephrectomy in patients with chronic kidney disease. Of 550 patients who underwent partial nephrectomy between 2012 and 2015, 163 patients with T1-2 renal tumors who had an estimated glomerular filtration rate between 30 and 60 mL/min/1.73 m 2 , and underwent robot-assisted laparoscopic partial nephrectomy or open partial nephrectomy were retrospectively analyzed. To minimize selection bias between the two surgical methods, patient variables were adjusted by 1:1 propensity score matching. The present study included 75 patients undergoing robot-assisted laparoscopic partial nephrectomy and 88 undergoing open partial nephrectomy. After propensity score matching, 40 patients were included in each operative group. The mean preoperative estimated glomerular filtration rate was 49 mL/min/1.73 m 2 . The mean ischemia time was 21 min in robot-assisted laparoscopic partial nephrectomy (warm ischemia) and 35 min in open partial nephrectomy (cold ischemia). Preservation of the estimated glomerular filtration rate 3-6 months postoperatively was not significantly different between robot-assisted laparoscopic partial nephrectomy and open partial nephrectomy (92% vs 91%, P = 0.9348). Estimated blood loss was significantly lower in the robot-assisted laparoscopic partial nephrectomy group than in the open partial nephrectomy group (104 vs 185 mL, P = 0.0025). The postoperative length of hospital stay was shorter in the robot-assisted laparoscopic partial nephrectomy group than in the open partial nephrectomy group (P < 0.0001). The prevalence of Clavien-Dindo grade 3 complications and a negative surgical margin status were not significantly different between the two groups. In our experience, robot-assisted laparoscopic partial nephrectomy and open partial nephrectomy provide similar outcomes in terms of functional preservation and perioperative complications among patients with chronic kidney disease. However, a lower estimated blood loss and shorter postoperative length of hospital stay can be obtained with robot-assisted laparoscopic partial nephrectomy. © 2017 The Japanese Urological Association.

Prediction and analysis of protein solubility using a novel scoring card method with dipeptide composition

PubMed Central

2012-01-01

Background Existing methods for predicting protein solubility on overexpression in Escherichia coli advance performance by using ensemble classifiers such as two-stage support vector machine (SVM) based classifiers and a number of feature types such as physicochemical properties, amino acid and dipeptide composition, accompanied with feature selection. It is desirable to develop a simple and easily interpretable method for predicting protein solubility, compared to existing complex SVM-based methods. Results This study proposes a novel scoring card method (SCM) by using dipeptide composition only to estimate solubility scores of sequences for predicting protein solubility. SCM calculates the propensities of 400 individual dipeptides to be soluble using statistic discrimination between soluble and insoluble proteins of a training data set. Consequently, the propensity scores of all dipeptides are further optimized using an intelligent genetic algorithm. The solubility score of a sequence is determined by the weighted sum of all propensity scores and dipeptide composition. To evaluate SCM by performance comparisons, four data sets with different sizes and variation degrees of experimental conditions were used. The results show that the simple method SCM with interpretable propensities of dipeptides has promising performance, compared with existing SVM-based ensemble methods with a number of feature types. Furthermore, the propensities of dipeptides and solubility scores of sequences can provide insights to protein solubility. For example, the analysis of dipeptide scores shows high propensity of α-helix structure and thermophilic proteins to be soluble. Conclusions The propensities of individual dipeptides to be soluble are varied for proteins under altered experimental conditions. For accurately predicting protein solubility using SCM, it is better to customize the score card of dipeptide propensities by using a training data set under the same specified experimental conditions. The proposed method SCM with solubility scores and dipeptide propensities can be easily applied to the protein function prediction problems that dipeptide composition features play an important role. Availability The used datasets, source codes of SCM, and supplementary files are available at http://iclab.life.nctu.edu.tw/SCM/. PMID:23282103

The Use of Vedolizumab in Preventing Postoperative Recurrence of Crohn's Disease.

PubMed

Yamada, Akihiro; Komaki, Yuga; Patel, Nayan; Komaki, Fukiko; Pekow, Joel; Dalal, Sushila; Cohen, Russell D; Cannon, Lisa; Umanskiy, Konstantin; Smith, Radhika; Hurst, Roger; Hyman, Neil; Rubin, David T; Sakuraba, Atsushi

2018-02-15

Clinical and endoscopic recurrence are common after surgery in Crohn's disease (CD). Vedolizumab has been increasingly used to treat CD, however, its effectiveness in preventing postoperative recurrence remains unknown. We aimed to investigate the use of vedolizumab in the postoperative setting and compare the risk of recurrence between patients receiving vedolizumab and anti-tumor necrosis factor (TNF)-α agents. Medical records of CD patients who underwent surgery between April 2014 and June 2016 were reviewed. We first analyzed how frequently vedolizumab is used to prevent postoperative recurrence and compared the patient characteristics with those being treated with other therapies. Furthermore, the rates of endoscopic remission, defined as a simple endoscopic score for CD of 0, at 6-12 months after surgery were compared between patients receiving vedolizumab and anti-TNF-α agents. Clinical, biological, and histologic outcomes such as Harvey-Bradshaw index, C-reactive protein, and histologic inflammation also were compared between the 2 groups. Risks of recurrence were assessed by univariate, multivariate, and propensity score-matched analyses. Among 203 patients that underwent a CD related surgery, 22 patients received vedolizumab as postoperative treatment. There were 58, 38, and 16 patients who received anti-TNF-α agents, immunomodulators, and metronidazole, respectively, whereas 69 patients were monitored without any medication. Patients receiving vedolizumab were young and frequently had perianal disease. Patients postoperatively treated with vedolizumab or anti-TNF-α agents were mostly treated with the same agent pre- and postoperatively. Rate of endoscopic remission at 6-12 months in the vedolizumab group was 25%, which was significantly lower as compared to anti-TNF-α agent group (66%, P = 0.01). Vedolizumab use was the only factor that was associated with an increased risk of endoscopic recurrence on both univariate (odds ratio (OR) 5.58, 95% confidence interval (CI) 1.51-24.3, P = 0.005) and multivariate analysis (OR 5.77, 95%CI 1.71-19.4, P = 0.005). The results were supported by a propensity score-matched analysis demonstrating lower rates of endoscopic remission (25 vs 69%, P = 0.03) in patients treated with vedolizumab as compared to anti-TNF-α agents. In the present retrospective cohort study of real-world experience, vedolizumab was shown to be commonly used as postoperative treatment for CD especially in high risk patients. Multivariate and propensity score-matched analyses showed that postoperative endoscopic recurrence in CD was higher with vedolizumab than with anti-TNF-α agents, but further investigation including controlled trials is required before determining the utility of vedolizumab in preventing postoperative recurrence of CD.

Down syndrome and postoperative complications after paediatric cardiac surgery: a propensity-matched analysis.

PubMed

Tóth, Roland; Szántó, Péter; Prodán, Zsolt; Lex, Daniel J; Sápi, Erzsébet; Szatmári, András; Gál, János; Szántó, Tamás; Székely, Andrea

2013-10-01

The incidence of congenital heart disease is ~50%, mostly related to endocardial cushion defects. The aim of our study was to investigate the postoperative complications that occur after paediatric cardiac surgery. Our perioperative data were analysed in paediatric patients with Down syndrome undergoing cardiac surgery. We retrospectively analysed the data from 2063 consecutive paediatric patients between January 2003 and December 2008. After excluding the patients who died or had missing data, the analysed database (before propensity matching) contained 129 Down patients and 1667 non-Down patients. After propensity matching, the study population comprised 222 patients and 111 patients had Down syndrome. Before propensity matching, the occurrences of low output syndrome (21.2 vs 32.6%, P = 0.003), pulmonary complication (14 vs 28.7%, P < 0.001) and severe infection (11.9 vs 22.5%, P = 0.001) were higher in the Down group. Down patients were more likely to have prolonged mechanical ventilation [median (interquartile range) 22 (9-72) h vs 49 (24-117) h, P = 0.007]. The total intensive care unit length of stay [6.9 (4.2-12.4) days vs 8.3 (5.3-13.2) days, P = 0.04] and the total hospital length of stay [17.3 (13.3-23.2) days vs 18.3 (15.1-23.6) days, P = 0.05] of the Down patients were also longer. Mortality was similar in the two groups before (3.58 vs 3.88%, P = 0.86) and after (5.4 vs 4.5%, P = 1.00) propensity matching. After propensity matching, there was no difference in the occurrence of adverse events. After propensity matching Down syndrome was not associated with increased mortality or complication rate following congenital cardiac surgery.

Assessing the short term impact of air pollution on mortality: a matching approach.

PubMed

Baccini, Michela; Mattei, Alessandra; Mealli, Fabrizia; Bertazzi, Pier Alberto; Carugno, Michele

2017-02-10

The opportunity to assess short term impact of air pollution relies on the causal interpretation of the exposure-response association. However, up to now few studies explicitly faced this issue within a causal inference framework. In this paper, we reformulated the problem of assessing the short term impact of air pollution on health using the potential outcome approach to causal inference. We considered the impact of high daily levels of particulate matter ≤10 μm in diameter (PM 10 ) on mortality within two days from the exposure in the metropolitan area of Milan (Italy), during the period 2003-2006. Our research focus was the causal impact of a hypothetical intervention setting daily air pollution levels under a pre-fixed threshold. We applied a matching procedure based on propensity score to estimate the total number of attributable deaths (AD) during the study period. After defining the number of attributable deaths in terms of difference between potential outcomes, we used the estimated propensity score to match each high exposure day, namely each day with a level of exposure higher than 40 μg/m 3 , with a day with similar background characteristics but a level of exposure lower than 40 μg/m 3 . Then, we estimated the impact by comparing mortality between matched days. During the study period daily exposures larger than 40 μg/m 3 were responsible for 1079 deaths (90% CI: 116; 2042). The impact was more evident among the elderly than in the younger age classes. Exposures ≥ 40 μg/m 3 were responsible, among the elderly, for 1102 deaths (90% CI: 388, 1816), of which 797 from cardiovascular causes and 243 from respiratory causes. Clear evidence of an impact on respiratory mortality was found also in the age class 65-74, with 87 AD (90% CI: 11, 163). The propensity score matching turned out to be an appealing method to assess historical impacts in this field, which guarantees that the estimated total number of AD can be derived directly as sum of either age-specific or cause-specific AD, unlike the standard model-based procedure. For this reason, it is a promising approach to perform surveillance focusing on very specific causes of death or diseases, or on susceptible subpopulations. Finally, the propensity score matching is free from issues concerning the exposure-confounders-mortality modeling and does not involve extrapolation. On the one hand this enhances the internal validity of our results; on the other, it makes the approach scarcely appropriate for estimating future impacts.

Transarterial Chemoembolization within First 3 Months of Sorafenib Initiation Improves Overall Survival in Hepatocellular Carcinoma: A Retrospective, Multi-Institutional Study with Propensity Matching.

PubMed

Kaplan, David E; Mehta, Rajni; D'Addeo, Kathryn; Gade, Terence P; Taddei, Tamar H

2018-04-01

The impact of transarterial chemoembolization after initiation of sorafenib (SOR) has not been prospectively compared with SOR alone in unresectable hepatocellular carcinoma (HCC). The objective of this study was to assess whether SOR + transarterial chemoembolization provides benefit over SOR alone in this setting. A retrospective cohort study with propensity matching using data from patients prescribed SOR for HCC at Veterans Health Administration hospitals from 2007 to 2015. The primary outcome was overall survival from the time of SOR prescription and stratified by receipt of transarterial chemoembolization within 90 days of SOR initiation. A total of 4,896 patients received SOR for HCC, of whom 232 (4.7%) underwent transarterial chemoembolization within 90 days. Patients receiving transarterial chemoembolization + SOR were highly selected, being younger and with less significant hepatic dysfunction, earlier Barcelona Clinic Liver Cancer stage (P < .0001), and fewer tumors with lower rates of macrovascular invasion (MVI) and metastases (all P < .0001) than SOR-alone patients. In unadjusted analysis, SOR + transarterial chemoembolization was associated with reduced mortality (hazard ratio [HR] 0.61, 95% confidence interval [CI] 0.53-0.71; P < .0001). After propensity matching, SOR + transarterial chemoembolization continued to show significant associations with reduced mortality with HR 0.75 (95% CI 0.62-0.92; P = .0005). Subgroup analysis suggests that the addition of transarterial chemoembolization to SOR improves outcomes in most patients, particularly those with Model for End-Stage Liver Disease score <15, platelets >50,000/μL, and >3 tumors with or without macrovascular invasion, without local invasion or metastases. Patients with unresectable HCC started on systemic therapy with SOR appear to benefit from adjuvant transarterial chemoembolization. Optimal application of multimodal therapy in this setting should be prospectively investigated. Published by Elsevier Inc.

Atypical Antipsychotic Drugs and the Risk of Sudden Cardiac Death

PubMed Central

Ray, Wayne A.; Chung, Cecilia P.; Murray, Katherine T.; Hall, Kathi; Stein, C. Michael

2009-01-01

Background Users of typical antipsychotics have increased risk of serious ventricular arrhythmias and sudden cardiac death. However, less is known regarding the cardiac safety of the atypical antipsychotic drugs, which have largely replaced the older agents in clinical practice. Methods We calculated the adjusted incidence of sudden cardiac death among current users of antipsychotics in a retrospective cohort of Tennessee Medicaid enrollees. The primary analysis included 44,218 and 46,089 baseline users of single typical and atypical drugs, respectively, and 186,600 matched nonuser controls. To assess residual confounding related to antipsychotic indication, we performed a secondary analysis of antipsychotic users with no baseline diagnosis of schizophrenia or related psychoses, propensity-score matched with nonusers. Results Current users of both typical and atypical antipsychotics had greater rates of sudden cardiac death than did nonusers of any antipsychotic, with adjusted incidence-rate ratios (IRRs) of 2.00 (95% CI, 1.69–2.35) and 2.27 (1.89–2.73), respectively. Former antipsychotic users had no significantly increased risk (IRR = 1.13 [0.98–1.30]). For both classes of drugs, the risk for current users increased significantly with dose. For typical antipsychotics the IRRs increased from 1.31 (0.97–1.77) for low doses to 2.42 (1.91–3.06) for high doses (p<.001). For atypical agents the IRRs increased from 1.59 (1.03–2.46) for low doses to 2.86 (2.25–3.65) for high doses (p=.015). The IRR for atypical vs typical antipsychotics was 1.14 (.93–1.39). Similar findings were present in the propensity-score matched cohort. Conclusion Current users of both typical and atypical antipsychotics had a similar, dose-related increased risk of sudden cardiac death. PMID:19144938

Comparative analysis of lactic acidosis induced by linezolid and vancomycin therapy using cohort and case-control studies of incidence and associated risk factors.

PubMed

Mori, Nobuaki; Kamimura, Yoshio; Kimura, Yuki; Hirose, Shoko; Aoki, Yasuko; Bito, Seiji

2018-04-01

Lactic acidosis is a rare complication of linezolid (LZD) therapy, and its incidence and risk factors remain unknown. This study aimed to compare the incidence of LZD-associated lactic acidosis (LALA) and vancomycin (VAN)-associated lactic acidosis (VALA) and investigate the risk factors for LALA. We performed a retrospective cohort study using propensity score-matched analyses comparing the incidence of lactic acidosis between LZD and VAN therapy. We included adult patients administered LZD or VAN between April 2014 and March 2016 and extracted patient baseline data. In a case-control study, we identified the risk factors of lactic acidosis in patients treated with LZD. We identified 94 and 313 patients who were administered LZD and VAN, respectively. The incidence of lactic acidosis after LZD and VAN therapy was 10.6 and 0.3%, respectively. After propensity score-matched analyses, the incidence of lactic acidosis with LZD therapy was significantly higher than that with VAN therapy [10.0% (8/80) vs. 0% (0/80), respectively; risk difference, 0.1; 95% confidence interval (CI), 0.03-0.17; p = 0.004]. In a case-control study, 10 patients with LALA were matched to 20 non-lactic acidosis patients by age and sex. Patients with LALA were more likely to have renal insufficiency than non-lactic acidosis patients that were in the univariate analysis (odds ratio, 7.4; 95% CI, 1.0-84.4; p = 0.02). This study indicates that LALA occurs more frequently than VALA does and is associated with renal insufficiency. Therefore, close monitoring of kidney function and serum lactate is recommended during LZD therapy.

Trauma injury in adult underweight patients

PubMed Central

Hsieh, Ching-Hua; Lai, Wei-Hung; Wu, Shao-Chun; Chen, Yi-Chun; Kuo, Pao-Jen; Hsu, Shiun-Yuan; Hsieh, Hsiao-Yun

2017-01-01

Abstract The aim of this study was to investigate and compare the injury characteristics, severity, and outcome between underweight and normal-weight patients hospitalized for the treatment of all kinds of trauma injury. This study was based on a level I trauma center Taiwan. The detailed data of 640 underweight adult trauma patients with a body mass index (BMI) of <18.5 kg/m2 and 6497 normal-weight adult patients (25 > BMI ≥ 18.5 kg/m2) were retrieved from the Trauma Registry System between January 1, 2009, and December 31, 2014. Pearson's chi-square test, Fisher's exact test, and independent Student's t-test were performed to compare the differences. Propensity score matching with logistic regression was used to evaluate the effect of underweight on mortality. Underweight patients presented a different bodily injury pattern and a significantly higher rate of admittance to the intensive care unit (ICU) than did normal-weight patients; however, no significant differences in the Glasgow Coma Scale (GCS) score, injury severity score (ISS), in-hospital mortality, and hospital length of stay were found between the two groups. However, further analysis of the patients stratified by two major injury mechanisms (motorcycle accident and fall injury) revealed that underweight patients had significantly lower GCS scores (13.8 ± 3.0 vs 14.5 ± 2.0, P = 0.020), but higher ISS (10.1 ± 6.9 vs 8.4 ± 5.9, P = 0.005), in-hospital mortality (odds ratio, 4.4; 95% confidence interval, 1.69–11.35; P = 0.006), and ICU admittance rate (24.1% vs 14.3%, P = 0.007) than normal-weight patients in the fall accident group, but not in the motorcycle accident group. However, after propensity score matching, logistic regression analysis of well-matched pairs of patients with either all trauma, motorcycle accident, or fall injury did not show a significant influence of underweight on mortality. Exploratory data analysis revealed that underweight patients presented a different bodily injury pattern from that of normal-weight patients, specifically a higher incidence of pneumothorax in those with penetrating injuries and of femoral fracture in those with struck on/against injuries; however, the injury severity and outcome of underweight patients varied depending on the injury mechanism. PMID:28272241

A Comparison of State Test Performances of Public Schools and a Charter School System in Old and New Testing in Texas

ERIC Educational Resources Information Center

Sahin, Alpaslan; Almus, Kadir; Willson, Victor

2017-01-01

This study examined the high schools' state tests performances in mathematics, reading, and science of an open-enrollment STEM-focused charter school system,Harmony Public Schools(HPS), between 2010 and 2013, and compared them with the performance of matched traditional public schools (TPS) in Texas. After propensity score matching, 12 HPS schools…

Comparison of outcome and cost among open, laparoscopic, and robotic surgical treatments for rectal cancer: A propensity score matched analysis of nationwide inpatient sample data.

PubMed

Chen, Szu-Ta; Wu, Meng-Che; Hsu, Tzu-Chun; Yen, Debra W; Chang, Chia-Na; Hsu, Wan-Ting; Wang, Chia-Chun; Lee, Matthew; Liu, Shing-Hwa; Lee, Chien-Chang

2018-03-01

Population-based studies evaluating outcomes of different approaches for rectal cancer are scarce. We conducted a retrospective cohort study using the Nationwide Inpatient Sample database between 2008 and 2012. We compared the outcomes and costs among rectal cancer patients undergoing robotic, laparoscopic, or open surgeries using propensity scores for adjusted and matched analysis. We identified 194 957 rectal cancer patients. Over the 5-year period, the annual admission number decreased by 13.9%, the in-hospital mortality rate decreased by 32.2%, while the total hospitalization cost increased by 13.6%. Compared with laparoscopic surgery, robotic surgery had significantly lower length of stay (LOS) (OR 0.69, 95%CI 0.57-0.84), comparable wound complications (OR 1.08, 95%CI 0.70-1.65) and higher cost (OR 1.42, 95%CI 1.13-1.79), while open surgery had significantly longer LOS (OR 1.38, 95%CI 1.19-1.59), more wound complications (OR 1.49, 95%CI 1.08-1.79), and comparable cost (OR 0.92, 95%CI 0.79-1.07). There were no difference in in-hospital mortality among three approaches. Laparoscopic surgery was associated with better outcomes than open surgery. Robotic surgery was associated with higher cost, but no advantage over laparoscopic surgery in terms of mortality and complications. Studies on cost-effectiveness of robotic surgery may be warranted. © 2017 Wiley Periodicals, Inc.

Alloimmune responses and atherosclerotic disease after kidney transplantation.

PubMed

Ducloux, Didier; Courivaud, Cécile; Bamoulid, Jamal; Bisaccia, Vincent; Roubiou, Caroline; Crepin, Thomas; Gaugler, Béatrice; Laheurte, Caroline; Rebibou, Jean-Michel; Chalopin, Jean-Marc; Saas, Philippe

2015-01-01

Chronic exposure to exogenous antigens causes accumulation of proinflammatory CD57(+)CD28(-) hyperactivated CD8(+) T cells that may promote atherosclerosis. We hypothesized that persistent alloimmune responses may induce immune activation and contribute to posttransplant atherosclerosis. This hypothesis was tested in a single-center cohort of 577 kidney transplant patients. Propensity score analysis was performed to address potential confounding variables by indication. Immune exhaustion was studied in subcohort of 103 patients. Five hundred seventy-seven consecutive renal transplant recipients were included. Seventy-seven atherosclerotic events (AE) (12.3%) occurred during a mean follow-up of 7 years. The cumulative incidence of AE increased with the number of human leukocyte antigen (HLA) mismatches (18%, 10%, and 5% in patients with 5-6, 3-4, and 0-2 mismatches, respectively; P=0.012). Human leukocyte antigen mismatch number (hazards ratio, 1.35; 95% confidence interval, 1.10-1.66, for each supplementary mismatch; P=0.005) was an independent risk factor for AE. In the propensity score match analysis, having received a well-matched kidney conferred a reduced risk of AE (hazards ratio, 0.22; 95% confidence interval, 0.05-0.95; P=0.044). We observed a significant correlation between HLA mismatch numbers and circulating CD57(+)CD28(-) CD8(+) T cells (R=0.31; P=0.017). These CD8(+) T cells were more frequent in patients with more HLA mismatches (P<0.0001). Overall, our results suggest that chronic allogeneic stimulation participates to accelerated atherosclerosis observed after transplantation.

Warfarin Use in Patients With Atrial Fibrillation Undergoing Hemodialysis: A Nationwide Population-Based Study.

PubMed

Yoon, Chang-Yun; Noh, Juhwan; Jhee, Jong Hyun; Chang, Tae Ik; Kang, Ea Wha; Kee, Youn Kyung; Kim, Hyoungnae; Park, Seohyun; Yun, Hae-Ryong; Jung, Su-Young; Oh, Hyung Jung; Park, Jung Tak; Han, Seung Hyeok; Kang, Shin-Wook; Kim, Changsoo; Yoo, Tae-Hyun

2017-09-01

The aim of this study is to elucidate the effects of warfarin use in patients with atrial fibrillation undergoing dialysis using a population-based Korean registry. Data were extracted from the Health Insurance Review and Assessment Service, which is a nationwide, mandatory social insurance database of all Korean citizens enrolled in the National Health Information Service between 2009 and 2013. Thromboembolic and hemorrhagic outcomes were analyzed according to warfarin use. Overall and propensity score-matched cohorts were analyzed by Cox proportional hazards models. Among 9974 hemodialysis patients with atrial fibrillation, the mean age was 66.6±12.2 years, 5806 (58.2%) were men, and 2921 (29.3%) used warfarin. After propensity score matching to adjust for all described baseline differences, 5548 subjects remained, and differences in baseline variables were distributed equally between warfarin users and nonusers. During a mean follow-up duration of 15.9±11.1 months, ischemic and hemorrhagic stroke occurred in 678 (6.8%) and 227 (2.3%) patients, respectively. In a multiple Cox model, warfarin use was significantly associated with an increased risk of hemorrhagic stroke (hazard ratio, 1.44; 95% confidence interval, 1.09-1.91; P =0.010) in the overall cohort. Furthermore, a significant relationship between warfarin use and hemorrhagic stroke was found in propensity-matched subjects (hazard ratio, 1.56; 95% confidence interval, 1.10-2.22; P =0.013). However, the ratios for ischemic stroke were not significantly different in either the propensity-matched (hazard ratio, 0.95; 95% confidence interval, 0.78-1.15; P =0.569) or overall cohort (hazard ratio, 1.06; 95% confidence interval, 0.90-1.26; P =0.470). Our findings suggest that warfarin should be used carefully in hemodialysis patients, given the higher risk of hemorrhagic events and the lack of ability to prevent thromboembolic complications. © 2017 American Heart Association, Inc.

Risk of Postoperative Complications Among Inflammatory Bowel Disease Patients Treated Preoperatively With Vedolizumab.

PubMed

Yamada, Akihiro; Komaki, Yuga; Patel, Nayan; Komaki, Fukiko; Aelvoet, Arthur S; Tran, Anthony L; Pekow, Joel; Dalal, Sushila; Cohen, Russell D; Cannon, Lisa; Umanskiy, Konstantin; Smith, Radhika; Hurst, Roger; Hyman, Neil; Rubin, David T; Sakuraba, Atsushi

2017-09-01

Vedolizumab is increasingly used to treat patients with ulcerative colitis (UC) and Crohn's disease (CD), however, its safety during the perioperative period remains unclear. We compared the 30-day postoperative complications among patients treated preoperatively with vedolizumab, anti-tumor necrosis factor (TNF)-α agents or non-biological therapy. The retrospective study cohort was comprised of patients receiving vedolizumab, anti-TNF-α agents or non-biological therapy within 4 weeks of surgery. The rates of 30-day postoperative complications were compared between groups using univariate and multivariate analysis. Propensity score-matched analysis was performed to compare the outcome between groups. Among 443 patients (64 vedolizumab, 129 anti-TNF-α agents, and 250 non-biological therapy), a total of 144 patients experienced postoperative complications (32%). In multivariate analysis, age >65 (odds ratio (OR) 3.56, 95% confidence interval (CI) 1.30-9.76) and low-albumin (OR 2.26, 95% CI 1.28-4.00) were associated with increased risk of 30-day postoperative complications. For infectious complications, steroid use (OR 3.67, 95% CI 1.57-8.57, P=0.003) and low hemoglobin (OR 3.03, 95% CI 1.32-6.96, P=0.009) were associated with increased risk in multivariate analysis. Propensity score matched analysis demonstrated that the risks of postoperative complications were not different among patients preoperatively receiving vedolizumab, anti-TNF-α agents or non-biological therapy (UC, P=0.40; CD, P=0.35). In the present study, preoperative vedolizumab exposure did not affect the risk of 30-day postoperative complications in UC and CD. Further, larger studies are required to confirm our findings.

Use of recombinant factor VIIa in US military casualties for a five-year period.

PubMed

Wade, Charles E; Eastridge, Brian J; Jones, John A; West, Susan A; Spinella, Philip C; Perkins, Jeremy G; Dubick, Michael A; Blackbourne, Lorne H; Holcomb, John B

2010-08-01

Two prospective randomized trauma trials have shown recombinant factor VIIa (rFVIIa) to be safe and to decrease transfusion requirements. rFVIIa is presently used in 22% of massively transfused civilian trauma patients. The US Military has used rFVIIa in combat trauma patients for five years, and two small studies of massively transfused patients described an association with improved outcomes. This study was undertaken to assess how deployed physicians are using rFVIIa and its impact on casualty outcomes. US combat casualties (n = 2,050) receiving any blood transfusion from 2003 to 2009 were reviewed to compare patients receiving rFVIIa (n = 506) with those who did not (n = 1,544). Propensity-score matching (primary analysis) and multivariable logistic regression were used to compare outcomes. Differences were determined at p < 0.05. Twenty-five percent of patients received rFVIIa. Significant differences were noted between groups in indices of injury severity (Injury Severity Score, Abbreviated Injury Scale score, and Glasgow Coma Scale score), admission physiology (systolic blood pressure, diastolic blood pressure, heart rate, temperature, base deficit, hemoglobin, and international normalization ratio), and use of blood products, indicating that patients treated with rFVIIa were more severely injured, in shock, and coagulopathic. For propensity-score matching, factors associated with death were used: Injury Severity Score, Glasgow Coma Scale score, heart rate, systolic blood pressure, diastolic blood pressure, Hgb, and total packed red blood cell. A total of 266 patients per group were matched; 52% of the rFVIIa group. After pairing, there were no significant differences in any of the demographics, including incidence of massive transfusion (53% vs. 51%). There was no difference in the rate of complications (21% vs. 21%) or mortality (14% vs. 20%) for patients not treated or receiving rFVIIa, respectively. In military casualties, rFVIIa is used in the most severely injured patients based on physician selection rather than on guideline criteria. Use of rFVIIa is not associated with an improvement in survival or an increase in complications. The undetected bias of physician selection of patients for treatment with rFVIIa, likely, has an impact on case matching to achieve equivalence similar to that of randomized control studies. This inability to match populations, thus, prevents definitive interpretation of this study and others studies of similar design. This problem emphasizes the need to develop entry criteria to identify patients who could potentially benefit from use of rFVIIa and the need to subsequently perform efficacy studies.

Long-term results after lung transplantation using organs from circulatory death donors: a propensity score-matched analysis†.

PubMed

Sabashnikov, Anton; Patil, Nikhil P; Popov, Aron-Frederik; Soresi, Simona; Zych, Bartlomiej; Weymann, Alexander; Mohite, Prashant N; García Sáez, Diana; Zeriouh, Mohamed; Wahlers, Thorsten; Choi, Yeong-Hoon; Wippermann, Jens; Wittwer, Thorsten; De Robertis, Fabio; Bahrami, Toufan; Amrani, Mohamed; Simon, André R

2016-01-01

Due to organ shortage in lung transplantation (LTx), donation after circulatory death (DCD) has been implemented in several countries, contributing to an increasing number of organs transplanted. We sought to assess long-term outcomes after LTx with organs procured following circulatory death in comparison with those obtained from donors after brain death (DBD). Between January 2007 and November 2013, 302 LTxs were performed in our institution, whereby 60 (19.9%) organs were retrieved from DCD donors. We performed propensity score matching (DCD:DBD = 1:2) based on preoperative donor and recipient factors that were significantly different in univariate analysis. After propensity matching, there were no statistically significant differences between the groups in terms of demographics and preoperative donor and recipient characteristics. There were no significant differences regarding intraoperative variables and total ischaemic time. Patients from the DCD group had significantly higher incidence of primary graft dysfunction grade 3 at the end of the procedure (P = 0.014), and significantly lower pO2/FiO2 ratio during the first 24 h after the procedure (P = 0.018). There was a trend towards higher incidence of the need for postoperative extracorporeal life support in the DCD group. Other postoperative characteristics were comparable. While the overall cumulative survival was not significantly different, the DCD group had significantly poorer results in terms of bronchiolitis obliterans syndrome (BOS)-free survival in the long-term follow-up. Long-term results after LTx with organs procured following DCD are in general comparable with those obtained after DBD LTx. However, patients transplanted using organs from DCD donors have a predisposition for development of BOS in the longer follow-up. © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Anti-hypertensive treatment prolongs tPA door-to-treatment time: Secondary analysis of the INSTINCT trial.

PubMed Central

Skolarus, Lesli E.; Scott, Phillip A.; Burke, James F.; Adelman, Eric E.; Frederiksen, Shirley M.; Kade, Allison M.; Kalbfleisch, Jack D.; Ford, Andria L.; Meurer, William J.

2012-01-01

Background/Purpose Identifying modifiable tPA treatment delays may improve stroke outcomes. We hypothesized that pre-thrombolytic anti-hypertensive treatment (AHT) may prolong door-to-treatment time (DTT). Methods Analysis of consecutive tPA-treated patients at 24 randomly selected community hospitals in the INSTINCT trial between 2007-2010. DTTs among stroke patients who received pre-thrombolytic AHT were compared to those that did not receive pre-thrombolytic AHT. We then calculated a propensity score for the probability of receiving pre-thrombolytic AHT using logistic regression with demographics, stroke risk factors, home medications, stroke severity (NIHSS), onset-to-door time, admission glucose, pretreatment blood pressure, EMS transport and location at time of stroke as independent variables. A paired t-test was performed to compare the DTTs between the propensity matched groups. Results Of 534 tPA treated stroke patients analyzed, 95 received pre-thrombolytic AHT. In the unmatched cohort, patients who received pre-thrombolytic AHT had a longer DTT (mean increase 9 minutes; 95% confidence interval (CI) 2-16 minutes) than patients who did not. After propensity matching, patients who received pre-thrombolytic AHT had a longer DTT (mean increase 10.4 minutes, 95% CI 1.9 - 18.8) than patients who did not receive pre-thrombolytic AHT. Conclusion Pre-thrombolytic AHT is associated with modest delays in DTT. This represents a potential target for quality improvement initiatives. Further research evaluating optimum pre-thrombolytic hypertension management is warranted. PMID:23033348

Antihypertensive treatment prolongs tissue plasminogen activator door-to-treatment time: secondary analysis of the INSTINCT trial.

PubMed

Skolarus, Lesli E; Scott, Phillip A; Burke, James F; Adelman, Eric E; Frederiksen, Shirley M; Kade, Allison M; Kalbfleisch, Jack D; Ford, Andria L; Meurer, William J

2012-12-01

Identifying modifiable tissue plasminogen activator treatment delays may improve stroke outcomes. We hypothesized that prethrombolytic antihypertensive treatment (AHT) may prolong door-to-treatment time (DTT). We performed an analysis of consecutive tissue plasminogen activator-treated patients at 24 randomly selected community hospitals in the Increasing Stroke Treatment through Interventional Behavior Change Tactics (INSTINCT) trial between 2007 and 2010. DTT among stroke patients who received prethrombolytic AHT were compared with those who did not receive prethrombolytic AHT. We then calculated a propensity score for the probability of receiving prethrombolytic AHT using logistic regression with demographics, stroke risk factors, home medications, stroke severity (National Institutes of Health Stroke Scale), onset-to-door time, admission glucose, pretreatment blood pressure, emergency medical service transport, and location at time of stroke as independent variables. A paired t test was performed to compare the DTT between the propensity-matched groups. Of 534 tissue plasminogen activator-treated stroke patients analyzed, 95 received prethrombolytic AHT. In the unmatched cohort, patients who received prethrombolytic AHT had a longer DTT (mean increase, 9 minutes; 95% confidence interval, 2-16 minutes) than patients who did not. After propensity matching, patients who received prethrombolytic AHT had a longer DTT (mean increase, 10.4 minutes; 95% confidence interval, 1.9-18.8) than patients who did not receive prethrombolytic AHT. Prethrombolytic AHT is associated with modest delays in DTT. This represents a potential target for quality-improvement initiatives. Further research evaluating optimum prethrombolytic hypertension management is warranted.

Long-Term Outcomes After Percutaneous Lower Extremity Arterial Interventions With Atherectomy vs. Balloon Angioplasty　- Propensity Score-Matched Registry.

PubMed

Janas, Adam; Buszman, Piotr P; Milewski, Krzysztof P; Wiernek, Szymon; Janas, Ksenia; Pruski, Maciej; Wojakowski, Wojciech; Błachut, Aleksandra; Picheta, Wojciech; Buszman, Pawel; Kiesz, Stefan

2017-02-24

The impact of endovascular revascularization of the lower extremity arteries with atherectomy (AT) compared with percutaneous transluminal angioplasty (PTA) is still unclear. Therefore, the aim of the study was to compare long-term outcomes after percutaneous PTA and AT in patients requiring endovascular revascularization.Methods and Results:This was a single-center, retrospective registry of obstructive and symptomatic PAD patients who underwent endovascular revascularization. PTA was performed in 215 patients, and AT in 204 (Silver Hawk, EV3, n=125; CSI 360°, n=66; Pathway Medical Technologies, n=13). There were no significant between-group differences in baseline characteristics except for increased CAD, dialysis and CLI prevalence in the PTA group. Following propensity score analysis 131 well-matched pairs were included in analysis. Bail-out stenting was more frequent in the reference group (PTA, 6.1% vs. AT, 0%; P=0.004). At 6- and 12-month follow-up there were no differences in TLR between the groups (PTA, 8.3% vs. AT, 5.3%; P=0.47; and PTA, 16.7% vs. AT, 13.7%; P=0.73, respectively). The difference was in favor of AT at 24-month follow-up (PTA, 29.0% vs. AT, 16.7%; P=0.05). No difference was observed in amputation rate (PTA, 0.7% vs AT, 1.5%; P=0.62). On Kaplan-Meier analysis there were no significant differences between groups in time to TLR, amputation or death. AT was associated with lower risk of TLR, and this should be confirmed in randomized controlled trials.

Chemoradiotherapy versus chemotherapy as adjuvant treatment for localized gastric cancer: a propensity score-matched analysis.

PubMed

Girardi, Daniel M; de Lima, Mariana A; Pereira, Gabriel C B; Negrão, Marcelo V; López, Rossana V M; Capareli, Fernanda C; Sabbaga, Jorge; Hoff, Paulo Marcelo G

2018-04-03

Treatment of localized gastric cancer (LGC) consists of surgical resection followed by adjuvant treatment. Both chemoradiation (CRT) and chemotherapy (CT) regimens have shown benefit in survival outcomes versus observation. However, there are few data comparing these approaches. This study included consecutive patients with LGC treated at Instituto do Cancer do Estado de Sao Paulo (ICESP) from 2012 to 2015. CRT was based on the INT-0116 regimen and CT consisted of a platinum and fluoropyrimidine doublet. Treatment choice was based on physician preference. Toxicity was evaluated for every cycle. Overall survival (OS) analysis was performed by Kaplan-Meier. A propensity score-matched analysis was performed to minimize selection bias. A total of 309 patients were evaluated, 227 in CRT group and 82 in CT group. The most prevalent grade 3/4 toxicities in CRT and CT groups were: nausea/vomiting (9.25 vs 4.9%), fatigue (9.3% vs 2.4%), mucositis (4.4% vs 1.2%), neutropenia (37.8% vs 20.9%), febrile neutropenia (3.9% vs 0%), anemia (4.3% vs 6.1%), thrombocytopenia (2.6% vs 4.9%), neuropathy (0 vs 2.4%) and hand-foot syndrome (0.4% vs 2.4%). Two grade 5 toxicities (febrile neutropenia and anemia) occurred in CRT group. There was no difference in the pattern of recurrence. After a median follow-up of 23.5 months (CRT) and 20.6 months (CT), there was no difference in OS between groups. CT and CRT present similar efficacy and tolerability as adjuvant treatment for LGC.

Household Financial Management and Women's Experiences of Intimate Partner Violence in the Philippines: A Study Using Propensity Score Methods.

PubMed

Tsai, Laura Cordisco

2016-04-27

This study explores the causal impact of independent management of household finances upon women's experiences of intimate partner violence (IPV) in the Philippines. Propensity score matching is used to generate a casual estimate of the impact of women's roles as household financial managers on their experiences of IPV. Findings demonstrate that managing household finances independently significantly increased the severity of IPV women experienced from their partners compared with women who managed finances jointly with partners. Findings reinforce the importance of explicit attention to intrahousehold power dynamics and gender norms in the implementation of microfinance interventions intended to empower women. © The Author(s) 2016.

Comparison and Limitations of DVH-Based NTCP Models Derived From 3D-CRT and IMRT Data for Prediction of Gastrointestinal Toxicities in Prostate Cancer Patients by Using Propensity Score Matched Pair Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Troeller, Almut; Department of Radiotherapy and Radiation Oncology, Ludwig-Maximilians-Universität, Munich; Yan, Di, E-mail: dyan@beaumont.edu

2015-02-01

Purpose: This study compared normal tissue complication probability (NTCP) modeling of chronic gastrointestinal toxicities following prostate cancer treatment for 2 treatment modalities. Possible factors causing discrepancies in optimal NTCP model parameters between 3-dimensional conformal radiation therapy (3D-CRT) and intensity modulated RT (IMRT) were analyzed and discussed, including the impact of patient characteristics, image guidance, toxicity scoring bias, and NTCP model limitations. Methods and Materials: Rectal wall dose-volume histograms of 1115 patients treated for prostate cancer under an adaptive radiation therapy protocol were used to model gastrointestinal toxicity grade ≥2 (according to Common Terminology Criteria for Adverse Events). A total ofmore » 457 patients were treated with 3D-CRT and 658 with IMRT. 3D-CRT patients were matched to IMRT patients based on various patient characteristics, using a propensity score–based algorithm. Parameters of the Lyman equivalent uniform dose and cut-off dose logistic regression NTCP models were estimated for the 2 matched treatment modalities and the combined group. Results: After they were matched, the 3D-CRT and IMRT groups contained 275 and 550 patients with a large discrepancy of 28.7% versus 7.8% toxicities, respectively (P<.001). For both NTCP models, optimal parameters found for the 3D-CRT groups did not fit the IMRT patients well and vice versa. Models developed for the combined data overestimated NTCP for the IMRT patients and underestimated NTCP for the 3D-CRT group. Conclusions: Our analysis did not reveal a single definitive cause for discrepancies of model parameters between 3D-CRT and IMRT. Patient characteristics and bias in toxicity scoring, as well as image guidance alone, are unlikely causes of the large discrepancy of toxicities. Whether the cause was inherent to the specific NTCP models used in this study needs to be verified by future investigations. Because IMRT is increasingly used clinically, it is important that appropriate NTCP model parameters are determined for this treatment modality.« less

Dual antiplatelet therapy reduces stroke but increases bleeding at the time of carotid endarterectomy.

PubMed

Jones, Douglas W; Goodney, Philip P; Conrad, Mark F; Nolan, Brian W; Rzucidlo, Eva M; Powell, Richard J; Cronenwett, Jack L; Stone, David H

2016-05-01

Controversy persists regarding the perioperative management of clopidogrel among patients undergoing carotid endarterectomy (CEA). This study examined the effect of preoperative dual antiplatelet therapy (aspirin and clopidogrel) on in-hospital CEA outcomes. Patients undergoing CEA in the Vascular Quality Initiative were analyzed (2003-2014). Patients on clopidogrel and aspirin (dual therapy) were compared with patients taking aspirin alone preoperatively. Study outcomes included reoperation for bleeding and thrombotic complications defined as transient ischemic attack (TIA), stroke, or myocardial infarction. Secondary outcomes were in-hospital death and composite stroke/death. Univariate and multivariable analyses assessed differences in demographics and operative factors. Propensity score-matched cohorts were derived to control for subgroup heterogeneity. Of 28,683 CEAs, 21,624 patients (75%) were on aspirin and 7059 (25%) were on dual therapy. Patients on dual therapy were more likely to have multiple comorbidities, including coronary artery disease (P < .001), congestive heart failure (P < .001), and diabetes (P < .001). Patients on dual therapy were also more likely to have a drain placed (P < .001) and receive protamine during CEA (P < .001). Multivariable analysis showed that dual therapy was independently associated with increased reoperation for bleeding (odds ratio [OR], 1.71; 95% confidence interval [CI], 1.20-2.42; P = .003) but was protective against TIA or stroke (OR, 0.61; 95% CI, 0.43-0.87; P = .007), stroke (OR, 0.63; 95% CI, 0.41-0.97; P = .03), and stroke/death (OR, 0.66; 95% CI, 0.44-0.98; P = .04). Propensity score matching yielded two groups of 4548 patients and showed that patients on dual therapy were more likely to require reoperation for bleeding (1.3% vs 0.7%; P = .004) but less likely to suffer TIA or stroke (0.9% vs 1.6%; P = .002), stroke (0.6% vs 1.0%; P = .04), or stroke/death (0.7% vs 1.2%; P = .03). Within the propensity score-matched groups, patients on dual therapy had increased rates of reoperation for bleeding regardless of carotid symptom status. However, asymptomatic patients on dual therapy demonstrated reduced rates of TIA or stroke (0.6% vs 1.5%; P < .001), stroke (0.4% vs 0.9%; P = .01), and composite stroke/death (0.5% vs 1.0%; P = .02). Among propensity score-matched patients with symptomatic carotid disease, these differences were not statistically significant. Preoperative dual antiplatelet therapy was associated with a 40% risk reduction for neurologic events but also incurred a significant increased risk of reoperation for bleeding after CEA. Given its observed overall neurologic protective effect, continued dual antiplatelet therapy throughout the perioperative period is justified. Initiating dual therapy in all patients undergoing CEA may lead to decreased neurologic complication rates. Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Clinical benefit of ertapenem compared to flomoxef for the treatment of cefotaxime-resistant Enterobacteriaceae bacteremia

PubMed Central

Lee, Chen-Hsiang; Chen, I-Ling; Li, Chia-Chin; Chien, Chun-Chih

2018-01-01

Objectives Cefotaxime-resistant Enterobacteriaceae (CE) infections are intractable, with limited treatment options. Though carbapenems are frequently prescribed for CE infections, the emergence of carbapenem-resistant Enterobacteriaceae is of huge concern. Flomoxef is effective against CE in vitro, and some clinical data on its demonstrated effectiveness against CE bloodstream infections (BSIs) exists. Patients and methods We conducted a retrospective study on adults with BSI caused by flomoxef-susceptible CE to investigate the efficacy of flomoxef compared with that of ertapenem. The outcome was evaluated with propensity score-based matching and logistic regression analysis. Results Demographic and clinical characteristics of patients treated with flomoxef (n = 58) or ertapenem (n = 188) were compared. In the multivariate analysis, severe sepsis (adjusted odds ratio [AOR] = 3.84; 95% confidence interval [CI], 1.16–12.78; p = 0.03), high BSI mortality score (AOR = 5.59; 95% CI, 2.37–13.21; p < 0.01), ultimately or rapidly fatal comorbidity (AOR = 10.60; 95% CI, 3.43–32.75; p < 0.01), and pneumonia (AOR = 10.11; 95% CI, 3.43–29.81; p < 0.01) were independently associated with 28-day mortality. Using propensity scores, 58 flomoxef-treated patients were matched to 116 ertapenem-treated patients. There were no intergroup differences in BSI severity, comorbidity, or BSI sources. The 28-day mortality rates (20.7% vs 13.8%, p = 0.28) did not differ significantly. However, hospitalization length was shorter in the ertapenem group (10.2 ± 8.5 vs. 14.6 ± 9.4 days, p < 0.01). Conclusion Although similar outcomes were observed between the groups, ertapenem therapy was associated with a shorter hospitalization time in adults after CE BSI. PMID:29503575

Clinical benefit of ertapenem compared to flomoxef for the treatment of cefotaxime-resistant Enterobacteriaceae bacteremia.

PubMed

Lee, Chen-Hsiang; Chen, I-Ling; Li, Chia-Chin; Chien, Chun-Chih

2018-01-01

Cefotaxime-resistant Enterobacteriaceae (CE) infections are intractable, with limited treatment options. Though carbapenems are frequently prescribed for CE infections, the emergence of carbapenem-resistant Enterobacteriaceae is of huge concern. Flomoxef is effective against CE in vitro, and some clinical data on its demonstrated effectiveness against CE bloodstream infections (BSIs) exists. We conducted a retrospective study on adults with BSI caused by flomoxef-susceptible CE to investigate the efficacy of flomoxef compared with that of ertapenem. The outcome was evaluated with propensity score-based matching and logistic regression analysis. Demographic and clinical characteristics of patients treated with flomoxef (n = 58) or ertapenem (n = 188) were compared. In the multivariate analysis, severe sepsis (adjusted odds ratio [AOR] = 3.84; 95% confidence interval [CI], 1.16-12.78; p = 0.03), high BSI mortality score (AOR = 5.59; 95% CI, 2.37-13.21; p < 0.01), ultimately or rapidly fatal comorbidity (AOR = 10.60; 95% CI, 3.43-32.75; p < 0.01), and pneumonia (AOR = 10.11; 95% CI, 3.43-29.81; p < 0.01) were independently associated with 28-day mortality. Using propensity scores, 58 flomoxef-treated patients were matched to 116 ertapenem-treated patients. There were no intergroup differences in BSI severity, comorbidity, or BSI sources. The 28-day mortality rates (20.7% vs 13.8%, p = 0.28) did not differ significantly. However, hospitalization length was shorter in the ertapenem group (10.2 ± 8.5 vs. 14.6 ± 9.4 days, p < 0.01). Although similar outcomes were observed between the groups, ertapenem therapy was associated with a shorter hospitalization time in adults after CE BSI.

Effect of rescue breathing by lay rescuers for out-of-hospital cardiac arrest caused by respiratory disease: a nationwide, population-based, propensity score-matched study.

PubMed

Fukuda, Tatsuma; Ohashi-Fukuda, Naoko; Kondo, Yutaka; Sera, Toshiki; Yahagi, Naoki

2017-06-01

The importance of respiratory care in cardiopulmonary resuscitation may vary depending on the cause of cardiac arrest. No previous study has investigated the effects of rescue breathing performed by a lay rescuer on the outcomes of patients with out-of-hospital cardiac arrest (OHCA) caused by intrinsic respiratory diseases. The aim of this study was to investigate whether rescue breathing performed by a lay rescuer is associated with outcomes after respiratory disease-related OHCA. In a nationwide, population-based, propensity score-matched study in Japan, among adult patients with OHCA caused by respiratory disease who received bystander cardiopulmonary resuscitation from January 1, 2005 to December 31, 2010, we compared patients with rescue breathing to those without rescue breathing. The primary outcome was neurologically favorable survival 1 month after OHCA. Of the eligible 14,781 patients, 4970 received rescue breathing from a lay rescuer and 9811 did not receive rescue breathing. In a propensity score-matched cohort (4897 vs. 4897 patients), the neurologically favorable survival rate was similar between patients with and without rescue breathing from a lay rescuer [0.9 vs. 0.7 %; OR 1.23 (95 % CI 0.79-1.93)]. Additionally, in subgroup analyses, rescue breathing was not associated with neurological outcome regardless of the type of rescuer [family member: adjusted OR 0.83 (95 % CI 0.39-1.70); or non-family member: adjusted OR 1.91 (95 % CI 0.79-5.35)]. Even among patients with OHCA caused by respiratory disease, rescue breathing performed by a lay rescuer was not associated with neurological outcomes, regardless of the type of lay rescuer.

Residential proximity to electromagnetic field sources and birth weight: Minimizing residual confounding using multiple imputation and propensity score matching.

PubMed

de Vocht, Frank; Lee, Brian

2014-08-01

Studies have suggested that residential exposure to extremely low frequency (50 Hz) electromagnetic fields (ELF-EMF) from high voltage cables, overhead power lines, electricity substations or towers are associated with reduced birth weight and may be associated with adverse birth outcomes or even miscarriages. We previously conducted a study of 140,356 singleton live births between 2004 and 2008 in Northwest England, which suggested that close residential proximity (≤ 50 m) to ELF-EMF sources was associated with reduced average birth weight of 212 g (95%CI: -395 to -29 g) but not with statistically significant increased risks for other adverse perinatal outcomes. However, the cohort was limited by missing data for most potentially confounding variables including maternal smoking during pregnancy, which was only available for a small subgroup, while also residual confounding could not be excluded. This study, using the same cohort, was conducted to minimize the effects of these problems using multiple imputation to address missing data and propensity score matching to minimize residual confounding. Missing data were imputed using multiple imputation using chained equations to generate five datasets. For each dataset 115 exposed women (residing ≤ 50 m from a residential ELF-EMF source) were propensity score matched to 1150 unexposed women. After doubly robust confounder adjustment, close proximity to a residential ELF-EMF source remained associated with a reduction in birth weight of -116 g (95% confidence interval: -224:-7 g). No effect was found for proximity ≤ 100 m compared to women living further away. These results indicate that although the effect size was about half of the effect previously reported, close maternal residential proximity to sources of ELF-EMF remained associated with suboptimal fetal growth. Copyright © 2014 Elsevier Ltd. All rights reserved.

What is the effect of unemployment on all-cause mortality? A cohort study using propensity score matching.

PubMed

Clemens, Tom; Popham, Frank; Boyle, Paul

2015-02-01

There is a strong association between unemployment and mortality, but whether this relationship is causal remains debated. This study utilizes population-level administrative data from Scotland within a propensity score framework to explore whether the association between unemployment and mortality may be causal. The study examined a sample of working men and women aged 25-54 in 1991. Subsequent employment status in 2001 was observed (in work or unemployed) and the relative all-cause mortality risk of unemployment between 2001 and 2010 was estimated. To account for potential selection into unemployment of those in poor health, a propensity score matching approach was used. Matching variables were observed prior to unemployment and included health status up to the year of unemployment (hospital admissions and self-reported limiting long-term illness), as well as measures of socioeconomic position. Unemployment was associated with a significant all-cause mortality risk relative to employment for men (hazard ratio [HR] 1.85; 95% confidence interval [CI] 1.33-2.55). This effect was robust to controlling for prior health and sociodemographic characteristics. Effects for women were smaller and statistically insignificant (HR 1.51; 95% CI 0.68-3.37). For men, the findings support the notion that the often-observed association between unemployment and mortality may contain a significant causal component; although for women, there is less support for this conclusion. However, female employment status, as recorded in the census, is more complex than for men and may have served to underestimate any mortality effect of unemployment. Future work should examine this issue further. © The Author 2014. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

Increased Risk of Venous Thromboembolism in Women with Uterine Leiomyoma: A Nationwide, Population-Based Case-Control Study

PubMed Central

Huang, Hung-Kai; Kor, Chew-Teng; Chen, Ching-Pei; Chen, Hung-Te; Yang, Po-Ta; Tsai, Chen-Dao; Huang, Ching-Hui

2018-01-01

Background Venous thromboembolism (VTE) is a sex-specific disease that has different presentations between men and women. Women with uterine leiomyoma can present with VTE without exhibiting the traditional risk factors. We investigated the relationship between a history of uterine leiomyoma and the risk of VTE using the National Health Insurance Research Database (NHIRD). Methods We conducted a retrospective, nationwide, population-based case-control study using the NHIRD. We identified 2,282 patients with diagnosed VTE and 392,635 subjects without VTE from 2000 to 2013. After development of an age and index diagnosis year frequency-matched model and propensity score-matched model, 2 models with a case-to-control ratio of 1 to 4 were established. Using the diagnosis of uterine leiomyoma as the exposure factor, conditional logistic regression was performed to examine the association between uterine leiomyoma and VTE. Multiple logistic regression analysis was used to investigate the joint effect of uterine leiomyoma and comorbid diseases on the risk of VTE. Results A strong association was observed between uterine leiomyoma and VTE in the overall patient model, frequency-matched model and propensity score-matched model [p < 0.0001, odds ratio (OR): 1.547; p = 0.0005, OR: 1.486; p = 0.0405, OR: 1.26, respectively]. In the subgroup analyses, women with uterine leiomyoma who were ≥ 45 years old were less likely to experience VTE, but women with uterine leiomyoma and anemia, cancer, coronary artery disease or heart failure were more likely to experience VTE. Conclusions Women with uterine leiomyomas have an increased risk of developing VTE, especially during reproductive periods or in the presence of specific diseases. PMID:29375226

Patient satisfaction with health-care professionals and structure is not affected by longer hospital stay and complications after lung resection: a case-matched analysis.

PubMed

Pompili, Cecilia; Tiberi, Michela; Salati, Michele; Refai, Majed; Xiumé, Francesco; Brunelli, Alessandro

2015-02-01

The objective of this investigation was to assess satisfaction with care of patients with long hospital stay (LHS) or complications after pulmonary resection in comparison with case-matched counterparts with a regular postoperative course. This is a prospective observational analysis on 171 consecutive patients submitted to pulmonary resections (78 wedges, 8 segmentectomies, 83 lobectomies, 3 pneumonectomies) for benign (35), primary (93) or secondary malignant (43) diseases. A hospital stay >7 days was defined as long (LHS). Major cardiopulmonary complications were defined according to the ESTS database. Patient satisfaction was assessed by the administration of the EORTC IN-PATSAT32 module at discharge. The questionnaire is a 32-item self-administered survey including different scales, reflecting the perceived level of satisfaction about the care provided by doctors, nurses and other personnel. To minimize selection bias, propensity score case-matching technique was applied to generate two sets of matched patients: patients with LHS with counterparts without it; patients with complications with counterparts without it. Median length of postoperative stay was 4 days (range 2-43). Forty-one patients (24%) had a hospital stay>7 days and 21 developed cardiopulmonary complications (12%). Propensity score yielded two well-matched groups of 41 patients with and without LHS. There were no significant differences in any patient satisfaction scale between the two groups. The comparison of the results of the patient satisfaction questionnaire between the two matched groups of 21 patients with and without complications did not show significant differences in any scale. Patients experiencing poor outcomes such as long hospital stay or complications have similar perception of quality of care compared with those with regular outcomes. Patient-reported outcome measures are becoming increasingly important in the evaluation of the quality of care and may complement more traditional objective indicators such as morbidity or length of stay. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

A Propensity Score–Matched Analysis of Robotic vs Open Pancreatoduodenectomy on Incidence of Pancreatic Fistula

PubMed Central

McMillan, Matthew T.; Zureikat, Amer H.; Hogg, Melissa E.; Kowalsky, Stacy J.; Zeh, Herbert J.; Sprys, Michael H.

2016-01-01

Importance The adoption of robotic pancreatoduodenectomy (RPD) is gaining momentum; however, its impact on major outcomes, including pancreatic fistula, has yet to be adequately compared with open pancreatoduodenectomy (OPD). Objective To demonstrate that use of RPD does not increase the incidence of clinically relevant pancreatic fistula (CR-POPF) compared with OPD. Design, Setting, and Participants Data were accrued from 2846 patients who underwent pancreatoduodenectomies (OPDs, n = 2661; RPDs, n = 185), performed by 51 surgeons at 17 institutions worldwide (2003-2015). All RPDs were conducted at a high-volume, academic, pancreatic surgery specialty center—in a standardized fashion—by surgeons who had surpassed the RPD learning curve. Propensity score matching was used to minimize bias from nonrandomized treatment assignment. The RPD and OPD cohorts were matched by propensity scores accounting for factors significantly associated with either undergoing robotic surgery or CR-POPF occurrence on logistic regression analysis. These variables included pancreatic gland texture, pancreatic duct diameter, intraoperative blood loss, pathologic findings of disease, and intraoperative drain placement. Interventions Use of RPD or OPD. Main Outcomes and Measures The major outcome of interest was CR-POPF occurrence, which is the most common and morbid complication following pancreatoduodenectomy. Results The overall cohort was 51.5% male, with a median age of 64 years (interquartile range, 56-72 years). The propensity score–matched cohort comprised 152 RPDs and 152 OPDs; all covariate imbalances were alleviated. After adjusting for potential confounders, undergoing RPD was associated with a reduced risk for CR-POPF incidence (OR, 0.4 [95% CI, 0.2-0.7]; P = .002) relative to OPD. Other predictors of risk-adjusted CR-POPF occurrence included soft pancreatic parenchyma (OR, 4.7 [95% CI, 3.4-6.6]; P < .001), pathologic findings of high-risk disease (OR, 1.4 [95% CI, 1.1-1.9]; P = .01), small pancreatic duct diameter (vs ≥5 mm: 2 mm, OR, 2.1 [95% CI, 1.4-3.1]; P < .001; ≤1 mm, OR, 1.8 [95% CI, 1.0-3.0]; P = .03), elevated intraoperative blood loss (vs ≤400 mL: 401-700 mL, OR, 1.5 [95% CI, 1.1-2.0]; P = .01; >1000 mL, OR, 2.1 [95% CI, 1.4-2.9]; P < .001), omission of intraoperative drain(s) (OR, 0.5 [95% CI, 0.3-0.8]; P = .005), and octreotide prophylaxis (OR, 3.1 [95% CI, 2.3-4.0]; P < .001). Patients undergoing RPD demonstrated similar CR-POPF rates compared with patients in the OPD cohort (6.6% vs 11.2%; P = .23). This relationship held for both grade B (6.6% vs 9.2%; P = .52) and grade C (0% vs 2.0%; P = .25) POPFs. Robotic pancreatoduodenectomy was also noninferior to OPD in terms of the occurrence of any complication (73.7% vs 66.4%; P = .21), severe complications (Accordion grade ≥3, 23.05% vs 23.7%; P > .99), hospital stay (median: 8 vs 8.5 days; P = .31), 30-day readmission (22.4% vs 21.7%; P > .99), and 90-day mortality (3.3% vs 1.3%; P = .38). Conclusions and Relevance To our knowledge, this is the first propensity score–matched analysis of robotic vs open pancreatoduodenectomy to date, and it demonstrates that RPD is noninferior to OPD in terms of pancreatic fistula development and other major postoperative outcomes. PMID:28030724

Hand grip strength and chronic obstructive pulmonary disease in Korea: an analysis in KNHANES VI.

PubMed

Lee, Su Hwan; Kim, Soo Jung; Han, Yeji; Ryu, Yon Ju; Lee, Jin Hwa; Chang, Jung Hyun

2017-01-01

Muscle mass is known to be associated with mortality in elderly adults. Because hand grip strength (HGS) is known as a simple assessment tool for muscular strength, many researchers have studied the association between HGS and disease. However, empirical evidence for the relationship between chronic obstructive pulmonary disease (COPD) and HGS is still controversial. The aim of this study was to evaluate the association between COPD and HGS, using Korean population data. This was a population-based cross-sectional study. Data were obtained from the sixth Korean National Health and Nutrition Examination Survey, which was conducted from 2013 to 2015. To reduce the effects of HGS-related factors and potential confounding factors, propensity score matching was used to match subjects with and without COPD. Among 14,930 subjects, 832 were enrolled in each group (non-COPD and COPD) after propensity score matching. COPD subjects did not have lower HGS than non-COPD subjects (non-COPD vs COPD, male, 38.0±7.0 vs 38.9±7.0 kg, P =0.044, female, 23.8±4.6 vs 24.2±4.9 kg, P =0.342). Lung function was classified by Global Initiative for Chronic Obstructive Lung Disease stages and was not significantly associated with HGS. For male COPD subjects, there was a significant correlation between HGS and the EuroQol Five-Dimension Questionnaire (EQ5D) utility score index, which is an indicator of quality of life that adjusts for age and body mass index ( r =0.201, P <0.001). The correlation was absent for female subjects ( r =0.098, P =0.170). COPD subjects did not have lower HGS than non-COPD subjects. HGS did not associate with lung function. However, the HGS of male COPD subjects was positively associated with EQ5D utility score index, an indicator of quality of life. HGS may be helpful as an additional method to the evaluation of quality of life in male COPD patients.

Propensity score estimation: neural networks, support vector machines, decision trees (CART), and meta-classifiers as alternatives to logistic regression.

PubMed

Westreich, Daniel; Lessler, Justin; Funk, Michele Jonsson

2010-08-01

Propensity scores for the analysis of observational data are typically estimated using logistic regression. Our objective in this review was to assess machine learning alternatives to logistic regression, which may accomplish the same goals but with fewer assumptions or greater accuracy. We identified alternative methods for propensity score estimation and/or classification from the public health, biostatistics, discrete mathematics, and computer science literature, and evaluated these algorithms for applicability to the problem of propensity score estimation, potential advantages over logistic regression, and ease of use. We identified four techniques as alternatives to logistic regression: neural networks, support vector machines, decision trees (classification and regression trees [CART]), and meta-classifiers (in particular, boosting). Although the assumptions of logistic regression are well understood, those assumptions are frequently ignored. All four alternatives have advantages and disadvantages compared with logistic regression. Boosting (meta-classifiers) and, to a lesser extent, decision trees (particularly CART), appear to be most promising for use in the context of propensity score analysis, but extensive simulation studies are needed to establish their utility in practice. Copyright (c) 2010 Elsevier Inc. All rights reserved.

Non-ST-Segment-Elevation Myocardial Infarction Among Patients With Chronic Kidney Disease: A Propensity Score-Matched Comparison of Percutaneous Coronary Intervention Versus Conservative Management.

PubMed

Bhatia, Subir; Arora, Shilpkumar; Bhatia, Sravya M; Al-Hijji, Mohammed; Reddy, Yogesh N V; Patel, Parshva; Rihal, Charanjit S; Gersh, Bernard J; Deshmukh, Abhishek

2018-03-10

Chronic kidney disease (CKD) remains an independent predictor of cardiovascular morbidity and mortality. CKD complicates referral for percutaneous coronary intervention (PCI) in non-ST-segment-elevation myocardial infarction (NSTEMI) patients because of the risk for acute kidney injury and the need for dialysis, with American College of Cardiology/American Heart Association guidelines underscoring the limited data on these patients. Using the National Inpatient Sample to analyze hospitalizations in the United States from 2004 to 2014, we sought to assess PCI utilization and in-hospital outcomes in NSTEMI admissions with CKD. NSTEMI admissions were identified by International Classification of Diseases, Ninth Edition, Clinical Modification (ICD-9-CM) code 410.7. CKD admissions were identified by ICD-9-CM code 585. Propensity score-matched cohorts of patients with NSTEMI were matched for age, sex, comorbidities, race, median household income, primary payer status, and hospital characteristics. Of 4 488 795 hospitalizations for NSTEMI, 31% underwent PCI. Overall, 89% of admissions had no CKD. In addition, 32% of NSTEMI admissions with no CKD and 23%, 14%, and 22% with CKD stages 3, 4, and 5 underwent PCI, respectively. Hospitalized NSTEMI patients with CKD stages 4 and 5 had 41% and 20% less likelihood, respectively, of undergoing PCI compared with those with no CKD. Among hospitalized NSTEMI patients with no CKD or CKD stage 3, 4, or 5, PCI-treated groups had 63%, 57%, 39%, and 59% lower likelihood, respectively, of all-cause, in-hospital mortality compared with propensity score-matched medically managed groups. PCI use decreased among hospitalized NSTEMI patients as CKD severity increased, and all-cause, in-hospital mortality was greater for NSTEMI patients admitted with more severe CKD regardless of treatment strategy. © 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Freedom Solo® versus Trifecta® bioprostheses: clinical and haemodynamic evaluation after propensity score matching.

PubMed

Cerqueira, Rui J; Raimundo, Renata; Moreira, Soraia; Saraiva, Francisca A; Andrade, Marta; Salgueiro, Elson; Almeida, Jorge; Amorim, Mário Jorge; Pinho, Paulo; Lourenço, André P; Leite-Moreira, Adelino

2018-01-16

The goal of this study was to compare the stentless Freedom Solo® (FS) and the stented Trifecta® (TF) aortic bioprostheses with regard to haemodynamic profile, left ventricular mass regression and early and late postoperative outcomes and survival. A longitudinal cohort study of consecutive patients undergoing aortic valve replacement (2009-16) with either the FS or TF at 1 centre was performed. Local databases and national records were queried. Prosthesis haemodynamics and left ventricular dimensions were obtained from postoperative echocardiograms. After propensity score matching (21 covariates), the Kaplan-Meier and competing risk analyses were performed for survival and the combined outcome of structural valve deterioration and endocarditis, respectively. Haemodynamics and mass regression were assessed by a mixed-effects model including propensity score as a covariate. From a total sample of 397 patients with the FS and 525 TF bioprostheses with a median follow-up time of 4.0 (2.2-6.0) and 2.4 (1.4-3.7) years, respectively, a matched sample of 329 pairs was obtained. Matched groups showed no differences in survival (hazard ratio = 1.04, 95% confidence interval = 0.69-1.56) or cumulative hazards of combined outcome (subdistribution hazard ratio = 0.54, 95% confidence interval = 0.21-1.39). Although the TF showed an improved haemodynamic profile, no difference was found in mass regression. Patients with TF bioprostheses had higher rates of prolonged mechanical ventilation, whereas patients with the FS bioprosthesis showed higher rates of thrombocytopenia. The TF showed an improved haemodynamic profile compared to the FS, but this did not translate into further reverse remodelling. Postoperative outcomes and survival rates were comparable for both bioprostheses. Long-term follow-up is needed for comparisons with classical bioprosthesis models. © The Author(s) 2018. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

The District-Wide Effectiveness of the Achieve3000 Program: A Quasi-Experimental Study

ERIC Educational Resources Information Center

Borman, Geoffrey D.; Park, So Jung; Min, Sookweon

2015-01-01

The purpose of this study was to evaluate the impact of Achieve3000, a differentiated online literacy curriculum, on students' scores on the California State Test (CST). In the 2011-12 school year, 1,957 students in Chula Vista began using Achieve3000's solutions in 3rd through 8th grade. Using a form of propensity score matching called Inverse…

Cost Attributable to Nosocomial Bacteremia. Analysis According to Microorganism and Antimicrobial Sensitivity in a University Hospital in Barcelona.

PubMed

Riu, Marta; Chiarello, Pietro; Terradas, Roser; Sala, Maria; Garcia-Alzorriz, Enric; Castells, Xavier; Grau, Santiago; Cots, Francesc

2016-01-01

To calculate the incremental cost of nosocomial bacteremia caused by the most common organisms, classified by their antimicrobial susceptibility. We selected patients who developed nosocomial bacteremia caused by Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, or Pseudomonas aeruginosa. These microorganisms were analyzed because of their high prevalence and they frequently present multidrug resistance. A control group consisted of patients classified within the same all-patient refined-diagnosis related group without bacteremia. Our hospital has an established cost accounting system (full-costing) that uses activity-based criteria to analyze cost distribution. A logistic regression model was fitted to estimate the probability of developing bacteremia for each admission (propensity score) and was used for propensity score matching adjustment. Subsequently, the propensity score was included in an econometric model to adjust the incremental cost of patients who developed bacteremia, as well as differences in this cost, depending on whether the microorganism was multidrug-resistant or multidrug-sensitive. A total of 571 admissions with bacteremia matched the inclusion criteria and 82,022 were included in the control group. The mean cost was € 25,891 for admissions with bacteremia and € 6,750 for those without bacteremia. The mean incremental cost was estimated at € 15,151 (CI, € 11,570 to € 18,733). Multidrug-resistant P. aeruginosa bacteremia had the highest mean incremental cost, € 44,709 (CI, € 34,559 to € 54,859). Antimicrobial-susceptible E. coli nosocomial bacteremia had the lowest mean incremental cost, € 10,481 (CI, € 8,752 to € 12,210). Despite their lower cost, episodes of antimicrobial-susceptible E. coli nosocomial bacteremia had a major impact due to their high frequency. Adjustment of hospital cost according to the organism causing bacteremia and antibiotic sensitivity could improve prevention strategies and allow their prioritization according to their overall impact and costs. Infection reduction is a strategy to reduce resistance.

Cost Attributable to Nosocomial Bacteremia. Analysis According to Microorganism and Antimicrobial Sensitivity in a University Hospital in Barcelona

PubMed Central

Riu, Marta; Chiarello, Pietro; Terradas, Roser; Sala, Maria; Garcia-Alzorriz, Enric; Castells, Xavier; Grau, Santiago; Cots, Francesc

2016-01-01

Aim To calculate the incremental cost of nosocomial bacteremia caused by the most common organisms, classified by their antimicrobial susceptibility. Methods We selected patients who developed nosocomial bacteremia caused by Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, or Pseudomonas aeruginosa. These microorganisms were analyzed because of their high prevalence and they frequently present multidrug resistance. A control group consisted of patients classified within the same all-patient refined-diagnosis related group without bacteremia. Our hospital has an established cost accounting system (full-costing) that uses activity-based criteria to analyze cost distribution. A logistic regression model was fitted to estimate the probability of developing bacteremia for each admission (propensity score) and was used for propensity score matching adjustment. Subsequently, the propensity score was included in an econometric model to adjust the incremental cost of patients who developed bacteremia, as well as differences in this cost, depending on whether the microorganism was multidrug-resistant or multidrug-sensitive. Results A total of 571 admissions with bacteremia matched the inclusion criteria and 82,022 were included in the control group. The mean cost was € 25,891 for admissions with bacteremia and € 6,750 for those without bacteremia. The mean incremental cost was estimated at € 15,151 (CI, € 11,570 to € 18,733). Multidrug-resistant P. aeruginosa bacteremia had the highest mean incremental cost, € 44,709 (CI, € 34,559 to € 54,859). Antimicrobial-susceptible E. coli nosocomial bacteremia had the lowest mean incremental cost, € 10,481 (CI, € 8,752 to € 12,210). Despite their lower cost, episodes of antimicrobial-susceptible E. coli nosocomial bacteremia had a major impact due to their high frequency. Conclusions Adjustment of hospital cost according to the organism causing bacteremia and antibiotic sensitivity could improve prevention strategies and allow their prioritization according to their overall impact and costs. Infection reduction is a strategy to reduce resistance. PMID:27055117

The role of implantable cardioverter defibrillators in patients bridged to transplantation with a continuous-flow left ventricular assist device: A propensity score matched analysis.

PubMed

Clerkin, Kevin J; Topkara, Veli K; Mancini, Donna M; Yuzefpolskaya, Melana; Demmer, Ryan T; Dizon, Jose M; Takeda, Koji; Takayama, Hiroo; Naka, Yoshifumi; Colombo, Paolo C; Garan, A Reshad

2017-06-01

Implantable cardioverter defibrillators (ICDs) provide a significant mortality benefit for appropriately selected patients with advanced heart failure. ICDs are associated with a mortality benefit when used in patients with a pulsatile left ventricular assist device (LVAD). It is unclear whether patients with a continuous-flow LVAD (CF-LVAD) derive the same benefit. We sought to determine if the presence of an ICD provided a mortality benefit during CF-LVAD support as a bridge to transplantation. Patients were identified in the United Network for Organ Sharing (UNOS) registry who underwent LVAD implantation as bridge to transplantation between May 2004 and April 2014, with follow-up through June 2014. Primary outcome was freedom from death while on CF-LVAD support with adjustment for complications requiring UNOS listing status upgrade. Secondary end-points included freedom from delisting while on CF-LVAD support and incidence of transplantation. The study cohort comprised 2,990 patients, and propensity score matching identified 1,012 patients with similar propensity scores. There was no difference in survival during device support between patients with and without an ICD (hazard ratio [HR] = 1.20; 95% confidence interval [CI], 0.66-2.17; p = 0.55). Adjusting for device complications requiring a UNOS listing status upgrade had minimal influence (HR = 1.11; 95% CI, 0.60-2.05; p = 0.74). There was no increased risk of delisting owing to being too sick for patients with an ICD (HR = 1.08; 95% CI, 0.63-1.86; p = 0.78). Likewise, the probability of transplantation was similar (HR = 1.05; 95% CI, 0.87-1.27; p = 0.62). Among patients bridged to transplantation with a CF-LVAD, the presence of an ICD did not reduce mortality. Copyright © 2017 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

The Role of Implantable Cardioverter Defibrillators in Patients Bridged to Transplantation with a Continuous Flow Left Ventricular Assist Device: A Propensity Score Matched Analysis

PubMed Central

Clerkin, Kevin J.; Topkara, Veli K.; Mancini, Donna M.; Yuzefpolskaya, Melana; Demmer, Ryan T.; Dizon, Jose M.; Takeda, Koji; Takayama, Hiroo; Naka, Yoshifumi; Colombo, Paolo C.; Garan, A. Reshad

2016-01-01

Background Implantable cardioverter defibrillators (ICD) provide a significant mortality benefit for appropriately selected patients with advanced heart failure. ICDs are associated with a mortality benefit when used in patients with a pulsatile left ventricular assist device (LVAD). However it is unclear whether patients with a continuous flow LVAD (CF-LVAD) derive the same benefit. This study sought to determine if the presence of an ICD provided a mortality benefit during CFLVAD support as a bridge to transplantation. Methods Patients were identified in the United Network for Organ Sharing (UNOS) registry that underwent LVAD implantation as bridge to transplantation from May 2004 and April 2014, with follow-up through June 2014. The primary outcome was freedom from death while on CF-LVAD support with adjustment for complications requiring UNOS listing status upgrade. Secondary endpoints included freedom from delisting while on CF-LVAD support and incidence of transplantation. Results 2,990 patients composed the study cohort and propensity score matching identified 1,012 patients with similar propensity scores. There was no difference in survival during device support between patients with and without an ICD (Hazard Ratio [HR] 1.20, 95% Confidence Interval [CI] 0.66-2.17, p=0.55). Adjusting for device complications requiring a UNOS listing status upgrade had minimal influence (HR 1.11, 95% CI 0.60-2.05, p=0.74). There was no increased risk of delisting due to being too sick for those with an ICD (HR 1.08, 95% CI 0.63-1.86, p=0.78). Likewise, the probability of transplantation was similar (HR 1.05, 95% CI 0.87-1.27, p=0.62). Conclusions Among patients bridged to transplantation with a CF-LVAD, the presence of an ICD did not reduce mortality. PMID:28089072

Abdominal Wall Reconstruction with Concomitant Ostomy-Associated Hernia Repair: Outcomes and Propensity Score Analysis.

PubMed

Mericli, Alexander F; Garvey, Patrick B; Giordano, Salvatore; Liu, Jun; Baumann, Donald P; Butler, Charles E

2017-03-01

The optimal strategy for abdominal wall reconstruction in the presence of a stomal-site hernia is unclear. We hypothesized that the rate of ventral hernia recurrence in patients undergoing a combined ventral hernia repair and stomal-site herniorraphy would not differ clinically from the ventral hernia recurrence rate in patients undergoing an isolated ventral hernia repair. We also hypothesized that bridged ventral hernia repairs result in worse outcomes compared with reinforced repairs, regardless of stomal hernia. We retrospectively reviewed prospectively collected data from consecutive abdominal wall reconstructions performed with acellular dermal matrix (ADM) at a single center between 2000 and 2015. We compared patients who underwent a ventral hernia repair alone (AWR) and those who underwent both a ventral hernia repair and ostomy-associated herniorraphy (AWR+O). We conducted a propensity score matched analysis to compare the outcomes between the 2 groups. Multivariable Cox proportional hazards and logistic regression models were used to study associations between potential predictive or protective reconstructive strategies and surgical outcomes. We included 499 patients (median follow-up 27.2 months; interquartile range [IQR] 12.4 to 46.6 months), 118 AWR+O and 381 AWR. After propensity score matching, 91 pairs were obtained. Ventral hernia recurrence was not statistically associated with ostomy-associated herniorraphy (adjusted hazard ratio [HR] 0.7; 95% CI 0.3 to 1.5; p = 0.34). However, the AWR+O group experienced a significantly higher percentage of surgical site occurrences (34.1%) than the AWR group (18.7%; adjusted odds ratio 2.3; 95% CI 1.4 to 3.7; p < 0.001). In the AWR group, there were significantly fewer ventral hernia recurrences when the repair was reinforced compared with bridged (5.3% vs 38.5%; p < 0.001). There was no statistically significant difference in ventral hernia recurrence between the AWR and AWR+O groups. Bridging was associated with an increased rate of hernia recurrence and should be avoided if possible. Copyright © 2016 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

Propensity score matching and persistence correction to reduce bias in comparative effectiveness: the effect of cinacalcet use on all-cause mortality.

PubMed

Gillespie, Iain A; Floege, Jürgen; Gioni, Ioanna; Drüeke, Tilman B; de Francisco, Angel L; Anker, Stefan D; Kubo, Yumi; Wheeler, David C; Froissart, Marc

2015-07-01

The generalisability of randomised controlled trials (RCTs) may be limited by restrictive entry criteria or by their experimental nature. Observational research can provide complementary findings but is prone to bias. Employing propensity score matching, to reduce such bias, we compared the real-life effect of cinacalcet use on all-cause mortality (ACM) with findings from the Evaluation of Cinacalcet Therapy to Lower Cardiovascular Events (EVOLVE) RCT in chronic haemodialysis patients. Incident adult haemodialysis patients receiving cinacalcet, recruited in a prospective observational cohort from 2007-2009 (AROii; n = 10,488), were matched to non-exposed patients regardless of future exposure status. The effect of treatment crossover was investigated with inverse probability of censoring weighted and lag-censored analyses. EVOLVE ACM data were analysed largely as described for the primary composite endpoint. AROii patients receiving cinacalcet (n = 532) were matched to 1790 non-exposed patients. The treatment effect of cinacalcet on ACM in the main AROii analysis (hazard ratio 1.03 [95% confidence interval (CI) 0.78-1.35]) was closer to the null than for the Intention to Treat (ITT) analysis of EVOLVE (0.94 [95%CI 0.85-1.04]). Adjusting for non-persistence by 0- and 6-month lag-censoring and by inverse probability of censoring weight, the hazard ratios in AROii (0.76 [95%CI 0.51-1.15], 0.84 [95%CI 0.60-1.18] and 0.79 [95%CI 0.56-1.11], respectively) were comparable with those of EVOLVE (0.82 [95%CI 0.67-1.01], 0.83 [95%CI 0.73-0.96] and 0.87 [95%CI 0.71-1.06], respectively). Correcting for treatment crossover, we observed results in the 'real-life' setting of the AROii observational cohort that closely mirrored the results of the EVOLVE RCT. Persistence-corrected analyses revealed a trend towards reduced ACM in haemodialysis patients receiving cinacalcet therapy. Copyright © 2015 John Wiley & Sons, Ltd.

Effect on healthcare utilization and costs of spinal manual therapy for acute low back pain in routine care: A propensity score matched cohort study.

PubMed

Walker, Jochen; Mertens, Ulf Kai; Schmidt, Carsten Oliver; Chenot, Jean-François

2017-01-01

Spinal manual therapy (SMT) is a popular treatment option for low back pain (LBP). The aim of our analysis was to evaluate the effects of manual therapy delivered by general practitioners and ambulatory orthopedic surgeons in routine care on follow up consultations, sick leave, health service utilization and costs for acute LBP compared to matched patients not receiving manual therapy. This is a propensity score matched cohort study based on health claims data. We identified a total of 113.652 adult patients with acute LBP and no coded red flags of whom 21.021 (18%) received SMT by physicians. In the final analysis 17.965 patients in each group could be matched. Balance on patients' coded characteristics, comorbidity and prior health service utilization was achieved. The provision of SMT for acute LBP had no relevant impact on follow up visits and days of sick leave for LBP in the index billing period and the following year. SMT was associated with a higher proportion of imaging studies for LBP (30.6% vs. 23%, SMD: 0.164 [95% CI 0.143-0.185]). SMT did not lead to meaningful savings by replacing other health services for LBP. SMT for acute non-specific LBP in routine care was not clinically meaningful effective to reduce sick leave and reconsultation rates compared to no SMT and did not lead to meaningful savings by replacing other health services from the perspective of health insurance. This does not imply that SMT is ineffective but might reflect a problem with selection of suitable patients and the quality and quantity of SMT in routine care. National Manual Medicine societies should state clearly that imaging is not routinely needed prior to SMT in patients with low suspicion of presence of red flags and monitor the quality of provided services.

Multicenter observational prehospital resuscitation on helicopter study.

PubMed

Holcomb, John B; Swartz, Michael D; DeSantis, Stacia M; Greene, Thomas J; Fox, Erin E; Stein, Deborah M; Bulger, Eileen M; Kerby, Jeffrey D; Goodman, Michael; Schreiber, Martin A; Zielinski, Martin D; O'Keeffe, Terence; Inaba, Kenji; Tomasek, Jeffrey S; Podbielski, Jeanette M; Appana, Savitri N; Yi, Misung; Wade, Charles E

2017-07-01

Earlier use of in-hospital plasma, platelets, and red blood cells (RBCs) has improved survival in trauma patients with severe hemorrhage. Retrospective studies have associated improved early survival with prehospital blood product transfusion (PHT). We hypothesized that PHT of plasma and/or RBCs would result in improved survival after injury in patients transported by helicopter. Adult trauma patients transported by helicopter from the scene to nine Level 1 trauma centers were prospectively observed from January to November 2015. Five helicopter systems had plasma and/or RBCs, whereas the other four helicopter systems used only crystalloid resuscitation. All patients meeting predetermined high-risk criteria were analyzed. Patients receiving PHT were compared with patients not receiving PHT. Our primary analysis compared mortality at 3 hours, 24 hours, and 30 days, using logistic regression to adjust for confounders and site heterogeneity to model patients who were matched on propensity scores. Twenty-five thousand one hundred eighteen trauma patients were admitted, 2,341 (9%) were transported by helicopter, of which 1,058 (45%) met the highest-risk criteria. Five hundred eighty-five of 1,058 patients were flown on helicopters carrying blood products. In the systems with blood available, prehospital median systolic blood pressure (125 vs 128) and Glasgow Coma Scale (7 vs 14) was significantly lower, whereas median Injury Severity Score was significantly higher (21 vs 14). Unadjusted mortality was significantly higher in the systems with blood products available, at 3 hours (8.4% vs 3.6%), 24 hours (12.6% vs 8.9%), and 30 days (19.3% vs 13.3%). Twenty-four percent of eligible patients received a PHT. A median of 1 unit of RBCs and plasma were transfused prehospital. Of patients receiving PHT, 24% received only plasma, 7% received only RBCs, and 69% received both. In the propensity score matching analysis (n = 109), PHT was not significantly associated with mortality at any time point, although only 10% of the high-risk sample were able to be matched. Because of the unexpected imbalance in systolic blood pressure, Glasgow Coma Scale, and Injury Severity Score between systems with and without blood products on helicopters, matching was limited, and the results of this study are inconclusive. With few units transfused to each patient and small outcome differences between groups, it is likely large, multicenter, randomized studies will be required to detect survival differences in this important population. Level II.

Religiosity and the Impact of Religious Secondary Schooling

ERIC Educational Resources Information Center

Wadsworth, Allyssa A.; Walker, Jay K.

2017-01-01

Using a nationally representative longitudinal survey and incorporating propensity score matching methods, we follow secondary school students post-graduation to determine how Catholic and private religious schooling impacts religiosity. There is an established literature examining the Catholic school impact on collegiate and labor market…

Assessing the Impact of School-Based Health Centers on Academic Achievement and College Preparation Efforts: Using Propensity Score Matching to Assess School-Level Data in California.

PubMed

Bersamin, Melina; Garbers, Samantha; Gaarde, Jenna; Santelli, John

2016-08-01

This study examines the association between school-based health center (SBHC) presence and school-wide measures of academic achievement and college preparation efforts. Publicly available educational and demographic data from 810 California public high schools were linked to a list of schools with an SBHC. Propensity score matching, a method to reduce bias inherent in nonrandomized control studies, was used to select comparison schools. Regression analyses, controlling for proportion of English-language learners, were conducted for each outcome including proportion of students participating in three College Board exams, graduation rates, and meeting university graduation requirements. Findings suggest that SBHC presence is positively associated with college preparation outcomes but not with academic achievement outcomes (graduation rates or meeting state graduation requirements). Future research must examine underlying mechanisms supporting this association, such as school connectedness. Additional research should explore the role that SBHC staff could have in supporting college preparation efforts. © The Author(s) 2016.

Complementary health insurance, out- of- pocket expenditures, and health services utilization: A population- based survey.

PubMed

Homaie Rad, Enayatollah; Kavosi, Zahra; Moghadamnia, Mohammad Taghi; Arefnezhad, Masoud; Arefnezhad, Masoumeh; Felezi Nasiri, Banfashe

2017-01-01

Background: Studies have shown that people using complementary health insurances have more access to health services than others. In the present study, we aimed at finding the differences between out- of- pocket payments and health service utilizations in complementary health insurances (CHIs) users and nonusers. Methods: Propensity score matching was used to compare the 2 groups. First, confounder variables were identified, and then propensity score matching was used to compare out- of- pocket expenditures with dental, general physician, hospital inpatient, emergency services, nursing, midwifery, laboratory services, specialists and rehabilitation services utilization. Results: Our results revealed no significant differences between the 2 groups in out- of- pocket health expenditures. Also, the specialist visits, inpatient services at the hospital, and dental services were higher in people who used CHIs compared to nonusers. Conclusion: People did not change their budget share for health care services after using CHIs. The payments were equal for people who were not CHIs users due to the increase in the quantity of the services.

Duodenal localization is a negative predictor of survival after small bowel adenocarcinoma resection: A population-based, propensity score-matched analysis.

PubMed

Wilhelm, Alexander; Galata, Christian; Beutner, Ulrich; Schmied, Bruno M; Warschkow, Rene; Steffen, Thomas; Brunner, Walter; Post, Stefan; Marti, Lukas

2018-03-01

This study assessed the influence of tumor localization of small bowel adenocarcinoma on survival after surgical resection. Patients with resected small bowel adenocarcinoma, ACJJ stage I-III, were identified from the Surveillance, Epidemiology, and End Results database from 2004 to 2013. The impact of tumor localization on overall and cancer-specific survival was assessed using Cox proportional hazard regression models with and without risk-adjustment and propensity score methods. Adenocarcinoma was localized to the duodenum in 549 of 1025 patients (53.6%). There was no time trend for duodenal localization (P = 0.514). The 5-year cancer-specific survival rate was 48.2% (95%CI: 43.3-53.7%) for patients with duodenal carcinoma and 66.6% (95%CI: 61.6-72.1%) for patients with cancer located in the jejunum or ileum. Duodenal localization was associated with worse overall and cancer-specific survival in univariable (HR = 1.73; HR = 1.81, respectively; both P < 0.001), multivariable (HR = 1.52; HR = 1.65; both P < 0.001), and propensity score-adjusted analyses (HR = 1.33, P = 0.012; HR = 1.50, P = 0.002). Furthermore, young age, retrieval of more than 12 regional lymph nodes, less advanced stage, and married matrimonial status were positive, independent prognostic factors. Duodenal localization is an independent risk factor for poor survival after resection of adenocarcinoma. © 2017 Wiley Periodicals, Inc.

Does delayed esophagectomy after endoscopic resection affect outcomes in patients with stage T1 esophageal cancer? A propensity score-based analysis.

PubMed

Wang, Shengfei; Huang, Yangle; Xie, Juntao; Zhuge, Lingdun; Shao, Longlong; Xiang, Jiaqing; Zhang, Yawei; Sun, Yihua; Hu, Hong; Chen, Sufeng; Lerut, Toni; Luketich, James D; Zhang, Jie; Chen, Haiquan

2018-03-01

Although endoscopic resection (ER) may be sufficient treatment for early-stage esophageal cancer, additional treatment is recommended when there is a high risk of cancer recurrence. It is unclear whether delaying esophagectomy by performing and assessing the success of ER affects outcomes as compared with immediate esophagectomy without ER. Additionally, long-term survival after sequential ER and esophagectomy required further investigation. Between 2011 and 2015, 48 patients with stage T1 esophageal cancer underwent esophagectomy after ER with curative intent at our institution. Two-to-one propensity score methods were used to identify 96 matched-control patients who were treated with esophagectomy only using baseline patient, tumor characteristics and surgical approach. Time from initial evaluation to esophagectomy, relapse-free survival, overall survival, and postoperative complications were compared between the propensity-matched groups. In the ER + esophagectomy group, the time from initial evaluation to esophagectomy was significantly longer than in the esophagectomy only group (114 vs. 8 days, p < 0.001). The incidence of dense adhesion (p = 0.347), operative time (p = 0.867), postoperative surgical complications (p = 0.966), and postoperative length of hospital stay (p = 0.125) were not significantly different between the groups. Moreover, recurrence-free survival and overall survival were also similar between the two groups (p = 0.411 and p = 0.817, respectively). Treatment of stage T1 esophageal cancer with ER prior to esophagectomy did not increase the difficulty of performing esophagectomy or the incidence of postoperative complications and did not affect survival after esophagectomy. These results suggest that ER can be recommended for patients with stage T1 cancer even if esophagectomy is warranted eventually.

Characteristics and Behavioral Outcomes for Youth in Group Care and Family-Based Care: A Propensity Score Matching Approach Using National Data

ERIC Educational Resources Information Center

James, Sigrid; Roesch, Scott; Zhang, Jin Jin

2012-01-01

This study aimed to answer two questions: (a) Given expected differences in children who are placed in group care compared to those in family-based settings, is it possible to match children on baseline characteristics? (b) Are there differences in behavioral outcomes for youth with episodes in group care versus those in family-based care? Using…

Puzzling Findings in Studying the Outcome of “Real World” Adolescent Mental Health Services: The TRAILS Study

PubMed Central

Jörg, Frederike; Ormel, Johan; Reijneveld, Sijmen A.; Jansen, Daniëlle E. M. C.; Verhulst, Frank C.; Oldehinkel, Albertine J.

2012-01-01

Background The increased use and costs of specialist child and adolescent mental health services (MHS) urge us to assess the effectiveness of these services. The aim of this paper is to compare the course of emotional and behavioural problems in adolescents with and without MHS use in a naturalistic setting. Method and Findings Participants are 2230 (pre)adolescents that enrolled in a prospective cohort study, the TRacking Adolescents' Individual Lives Survey (TRAILS). Response rate was 76%, mean age at baseline 11.09 (SD 0.56), 50.8% girls. We used data from the first three assessment waves, covering a six year period. Multiple linear regression analysis, propensity score matching, and data validation were used to compare the course of emotional and behavioural problems of adolescents with and without MHS use. The association between MHS and follow-up problem score (β 0.20, SE 0.03, p-value<0.001) was not confounded by baseline severity, markers of adolescent vulnerability or resilience nor stressful life events. The propensity score matching strategy revealed that follow-up problem scores of non-MHS-users decreased while the problem scores of MHS users remained high. When taking into account future MHS (non)use, it appeared that problem scores decreased with limited MHS use, albeit not as much as without any MHS use, and that problem scores with continuous MHS use remained high. Data validation showed that using a different outcome measure, multiple assessment waves and multiple imputation of missing values did not alter the results. A limitation of the study is that, although we know what type of MHS participants used, and during which period, we lack information on the duration of the treatment. Conclusions The benefits of MHS are questionable. Replication studies should reveal whether a critical examination of everyday care is necessary or an artefact is responsible for these results. PMID:23028584

Puzzling findings in studying the outcome of "real world" adolescent mental health services: the TRAILS study.

PubMed

Jörg, Frederike; Ormel, Johan; Reijneveld, Sijmen A; Jansen, Daniëlle E M C; Verhulst, Frank C; Oldehinkel, Albertine J

2012-01-01

The increased use and costs of specialist child and adolescent mental health services (MHS) urge us to assess the effectiveness of these services. The aim of this paper is to compare the course of emotional and behavioural problems in adolescents with and without MHS use in a naturalistic setting. Participants are 2230 (pre)adolescents that enrolled in a prospective cohort study, the TRacking Adolescents' Individual Lives Survey (TRAILS). Response rate was 76%, mean age at baseline 11.09 (SD 0.56), 50.8% girls. We used data from the first three assessment waves, covering a six year period. Multiple linear regression analysis, propensity score matching, and data validation were used to compare the course of emotional and behavioural problems of adolescents with and without MHS use. The association between MHS and follow-up problem score (β 0.20, SE 0.03, p-value<0.001) was not confounded by baseline severity, markers of adolescent vulnerability or resilience nor stressful life events. The propensity score matching strategy revealed that follow-up problem scores of non-MHS-users decreased while the problem scores of MHS users remained high. When taking into account future MHS (non)use, it appeared that problem scores decreased with limited MHS use, albeit not as much as without any MHS use, and that problem scores with continuous MHS use remained high. Data validation showed that using a different outcome measure, multiple assessment waves and multiple imputation of missing values did not alter the results. A limitation of the study is that, although we know what type of MHS participants used, and during which period, we lack information on the duration of the treatment. The benefits of MHS are questionable. Replication studies should reveal whether a critical examination of everyday care is necessary or an artefact is responsible for these results.

CT evaluation of living liver donor: Can 100-kVp plus iterative reconstruction protocol provide accurate liver volume and vascular anatomy for liver transplantation with reduced radiation and contrast dose?

PubMed

Yoshida, Morikatsu; Utsunomiya, Daisuke; Kidoh, Masafumi; Yuki, Hideaki; Oda, Seitaro; Shiraishi, Shinya; Yamamoto, Hidekazu; Inomata, Yukihiro; Yamashita, Yasuyuki

2017-06-01

We evaluated whether donor computed tomography (CT) with a combined technique of lower tube voltage and iterative reconstruction (IR) can provide sufficient preoperative information for liver transplantation.We retrospectively reviewed CT of 113 liver donor candidates. Dynamic contrast-enhanced CT of the liver was performed on the following protocol: protocol A (n = 70), 120-kVp with filtered back projection (FBP); protocol B (n = 43), 100-kVp with IR. To equalize the background covariates, one-to-one propensity-matched analysis was used. We visually compared the score of the hepatic artery (A-score), portal vein (P-score), and hepatic vein (V-score) of the 2 protocols and quantitatively correlated the graft volume obtained by CT volumetry (graft-CTv) under the 2 protocols with the actual graft weight.In total, 39 protocol-A and protocol-B candidates showed comparable preoperative clinical characteristics with propensity matching. For protocols A and B, the A-score was 3.87 ± 0.73 and 4.51 ± 0.56 (P < .01), the P-score was 4.92 ± 0.27 and 5.0 ± 0.0 (P = .07), and the V-score was 4.23 ± 0.78 and 4.82 ± 0.39 (P < .01), respectively. Correlations between the actual graft weight and graft-CTv of protocols A and B were 0.97 and 0.96, respectively.Liver-donor CT imaging under 100-kVp plus IR protocol provides better visualization for vascular structures than that under 120-kVp plus FBP protocol with comparable accuracy for graft-CTv, while lowering radiation exposure by more than 40% and reducing contrast-medium dose by 20%.

Comparison of Adjuvant Radiation Therapy Alone and Chemotherapy Alone in Surgically Resected Low-Grade Gliomas: Survival Analyses of 2253 Cases from the National Cancer Data Base.

PubMed

Wu, Jing; Neale, Natalie; Huang, Yuqian; Bai, Harrison X; Li, Xuejun; Zhang, Zishu; Karakousis, Giorgos; Huang, Raymond; Zhang, Paul J; Tang, Lei; Xiao, Bo; Yang, Li

2018-04-01

It is becoming increasingly common to incorporate chemotherapy (CT) with radiotherapy (RT) in the treatment of low-grade gliomas (LGGs) after surgical resection. However, there is a lack of literature comparing survival of patients who underwent RT or CT alone. The U.S. National Cancer Data Base was used to identify patients with histologically confirmed, World Health Organization grade 2 gliomas who received either RT alone or CT alone after surgery from 2004 to 2013. Overall survival (OS) was evaluated by Kaplan-Meier analysis, multivariable Cox proportional hazard regression, and propensity-score-matched analysis. In total, 2253 patients with World Health Organization grade 2 gliomas were included, of whom 1466 (65.1%) received RT alone and 787 (34.9%) CT alone. The median OS was 98.9 months for the RT alone group and 125.8 months for the CT alone group. On multivariable analysis, CT alone was associated with a significant OS benefit compared with RT alone (hazard ratio [HR], 0.405; 95% confidence interval, 0.277-0.592; P < 0.001). On subgroup analyses, the survival advantage of CT alone over RT alone persisted across all age groups, and for the subtotal resection and biopsy groups, but not in the gross total resection group. In propensity-score-matched analysis, CT alone still showed significantly improved OS compared with RT alone (HR, 0.612; 95% confidence interval, 0.506-0.741; P < 0.001). Our results suggest that CT alone was independently associated with longer OS compared with RT alone in patients with LGGs who underwent surgery. Copyright © 2018 Elsevier Inc. All rights reserved.

Analysis of mortality in a cohort of 650 cases of bacteremic osteoarticular infections.

PubMed

Gomez-Junyent, Joan; Murillo, Oscar; Grau, Imma; Benavent, Eva; Ribera, Alba; Cabo, Xavier; Tubau, Fe; Ariza, Javier; Pallares, Roman

2018-01-31

The mortality of patients with bacteremic osteoarticular infections (B-OAIs) is poorly understood. Whether certain types of OAIs carry higher mortality or interventions like surgical debridement can improve prognosis, are unclarified questions. Retrospective analysis of a prospective cohort of patients with B-OAIs treated at a teaching hospital in Barcelona (1985-2014), analyzing mortality (30-day case-fatality rate). B-OAIs were categorized as peripheral septic arthritis or other OAIs. Factors influencing mortality were analyzed using logistic regression models. The association of surgical debridement with mortality in patients with peripheral septic arthritis was evaluated with a multivariate logistic regression model and a propensity score matching analysis. Among 650 cases of B-OAIs, mortality was 12.2% (41.8% of deaths within 7 days). Compared with other B-OAI, cases of peripheral septic arthritis were associated with higher mortality (18.6% vs 8.3%, p < 0.001). In a multiple logistic regression model, peripheral septic arthritis was an independent predictor of mortality (adjusted odds ratio [OR] 2.12; 95% CI: 1.22-3.69; p = 0.008). Cases with peripheral septic arthritis managed with surgical debridement had lower mortality than those managed without surgery (14.7% vs 33.3%; p = 0.003). Surgical debridement was associated with reduced mortality after adjusting for covariates (adjusted OR 0.23; 95% CI: 0.09-0.57; p = 0.002) and in the propensity score matching analysis (OR 0.81; 95% CI: 0.68-0.96; p = 0.014). Among patients with B-OAIs, mortality was greater in those with peripheral septic arthritis. Surgical debridement was associated with decreased mortality in cases of peripheral septic arthritis. Copyright © 2018 Elsevier Inc. All rights reserved.

Using Propensity Score Analysis for Making Causal Claims in Research Articles

ERIC Educational Resources Information Center

Bai, Haiyan

2011-01-01

The central role of the propensity score analysis (PSA) in observational studies is for causal inference; as such, PSA is often used for making causal claims in research articles. However, there are still some issues for researchers to consider when making claims of causality using PSA results. This summary first briefly reviews PSA, followed by…

Automatic Promotion and Student Dropout: Evidence from Uganda, Using Propensity Score in Difference in Differences Model

ERIC Educational Resources Information Center

Okurut, Jeje Moses

2018-01-01

The impact of automatic promotion practice on students dropping out of Uganda's primary education was assessed using propensity score in difference in differences analysis technique. The analysis strategy was instrumental in addressing the selection bias problem, as well as biases arising from common trends over time, and permanent latent…

The Sasang Constitution as an Independent Risk Factor for Metabolic Syndrome: Propensity Matching Analysis

PubMed Central

Jang, Eunsu; Baek, Younghwa; Park, Kihyun; Lee, Siwoo

2013-01-01

The Sasang Constitutional Medicine is a traditional Korean customized medicine that classifies people into four types: Tae-eumin (TE), Soyangin (SY), Soeumin (SE), and Taeyangin. The aim of this study was to show whether the Sasang Constitution (SC) could be an independent risk factor for the metabolic syndrome (MS). Totally, 3,334 subjects from 24 Korean medicine clinics participated in this study. A one-way ANOVA for the continuous variables and a chi-square test for the prevalence of MS were conducted. A logistic regression was conducted to calculate the propensity score and the odds ratios (ORs). The prevalence for MS in TE, SY, and SE was 50.6%, 30.9%, and 17.7% (P < 0.001) before matching, and 36.7%, 28.6% and 28.2% (P = 0.042) after matching, respectively. The TE was associated with an increased OR for MS compared with the SE and SY in both crude (OR 4.773, 95% CI 3.889–5.859, and OR 2.292, 95% CI 1.942–2.704, resp.) and matched groups (OR 1.476, 95% CI 1.043–2.089, and OR 1.452, 95% CI 1.026–2.053, resp.). This study reveals that the SC, especially the TE type, could be considered as a risk element for MS even in people with otherwise similar physical characteristics. PMID:24348702

Parental Separation, Parental Alcoholism, and Timing of First Sexual Intercourse

PubMed Central

Waldron, Mary; Doran, Kelly A.; Bucholz, Kathleen K.; Duncan, Alexis E.; Lynskey, Michael T.; Madden, Pamela A. F.; Sartor, Carolyn E.; Heath, Andrew C.

2015-01-01

Purpose We examined timing of first voluntary sexual intercourse as a joint function of parental separation during childhood and parental history of alcoholism. Methods Data were drawn from a birth cohort of female like-sex twins (n=569 African Ancestry [AA], n=3415 European or other Ancestry [EA]). Cox proportional hazards regression was conducted predicting age at first sex from dummy variables coding for parental separation and parental alcoholism. Propensity score analysis was also employed comparing intact and separated families, stratified by predicted probability of separation. Results Earlier sex was reported by EA twins from separated and alcoholic families, compared to EA twins from intact nonalcoholic families, with effects most pronounced through age 14. Among AA twins, effects of parental separation and parental alcoholism were largely nonsignificant. Results of propensity score analyses confirmed unique risks from parental separation in EA families, where consistent effects of parental separation were observed across predicted probability of separation. For AA families there was poor matching on risk-factors presumed to predate separation, which limited interpretability of survival-analytic findings. Conclusions In European American families, parental separation during childhood is an important predictor of early-onset sex, beyond parental alcoholism and other correlated risk-factors. To characterize risk for African Americans associated with parental separation, additional research is needed where matching on confounders can be achieved. PMID:25907653

Effectiveness of and factors related to possession of a mother and child health handbook: an analysis using propensity score matching.

PubMed

Kawakatsu, Yoshito; Sugishita, Tomohiko; Oruenjo, Kennedy; Wakhule, Stephen; Kibosia, Kennedy; Were, Eric; Honda, Sumihisa

2015-12-01

Mother and Child Health handbooks (MCH handbooks) serve as useful health education tools for mothers and sources of information that allow health care professionals to understand patient status. Therefore, it is necessary to clarify the effectiveness of and identify the factors related to possession of an MCH handbook among parents in rural Western Kenya using propensity score matching (PSM). A community-based cross-sectional survey using a structured questionnaire was conducted in rural western Kenya from August to September, 2011. We targeted 2560 mothers with children aged 12-24 months. Both PSM and multivariate logistic analyses were used in this study. Impacts of 5.9, 9.4, and 12.6 percentage points for higher health knowledge and for proper health-seeking behavior for fever and diarrhea, respectively, were statistically significant. The significant factors affecting possession of the MCH Handbook were the child's sex, the caregiver's relationship to the child, maternal age, health knowledge, birth interval, household wealth index and CHW performance accordingly. An MCH handbook was an effective tool for improving both health knowledge and health-seeking behavior in Kenya. The further distribution and utilization of an MCH handbook is expected to be an effective way to improve both maternal and child health. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Metrics for covariate balance in cohort studies of causal effects.

PubMed

Franklin, Jessica M; Rassen, Jeremy A; Ackermann, Diana; Bartels, Dorothee B; Schneeweiss, Sebastian

2014-05-10

Inferring causation from non-randomized studies of exposure requires that exposure groups can be balanced with respect to prognostic factors for the outcome. Although there is broad agreement in the literature that balance should be checked, there is confusion regarding the appropriate metric. We present a simulation study that compares several balance metrics with respect to the strength of their association with bias in estimation of the effect of a binary exposure on a binary, count, or continuous outcome. The simulations utilize matching on the propensity score with successively decreasing calipers to produce datasets with varying covariate balance. We propose the post-matching C-statistic as a balance metric and found that it had consistently strong associations with estimation bias, even when the propensity score model was misspecified, as long as the propensity score was estimated with sufficient study size. This metric, along with the average standardized difference and the general weighted difference, outperformed all other metrics considered in association with bias, including the unstandardized absolute difference, Kolmogorov-Smirnov and Lévy distances, overlapping coefficient, Mahalanobis balance, and L1 metrics. Of the best-performing metrics, the C-statistic and general weighted difference also have the advantage that they automatically evaluate balance on all covariates simultaneously and can easily incorporate balance on interactions among covariates. Therefore, when combined with the usual practice of comparing individual covariate means and standard deviations across exposure groups, these metrics may provide useful summaries of the observed covariate imbalance. Copyright © 2013 John Wiley & Sons, Ltd.

Nutritional status and survival of maintenance hemodialysis patients receiving lanthanum carbonate.

PubMed

Komaba, Hirotaka; Kakuta, Takatoshi; Wada, Takehiko; Hida, Miho; Suga, Takao; Fukagawa, Masafumi

2018-04-16

Hyperphosphatemia and poor nutritional status are associated with increased mortality. Lanthanum carbonate is an effective, calcium-free phosphate binder, but little is known about the long-term impact on mineral metabolism, nutritional status and survival. We extended the follow-up period of a historical cohort of 2292 maintenance hemodialysis patients that was formed in late 2008. We examined 7-year all-cause mortality according to the serum phosphate levels and nutritional indicators in the entire cohort and then compared the mortality rate of the 562 patients who initiated lanthanum with that of the 562 propensity score-matched patients who were not treated with lanthanum. During a mean ± SD follow-up of 4.9 ± 2.3 years, 679 patients died in the entire cohort. Higher serum phosphorus levels and lower nutritional indicators (body mass index, albumin and creatinine) were each independently associated with an increased risk of death. In the propensity score-matched analysis, patients who initiated lanthanum had a 23% lower risk for mortality compared with the matched controls. During the follow-up period, the serum phosphorus levels tended to decrease comparably in both groups, but the lanthanum group maintained a better nutritional status than the control group. The survival benefit associated with lanthanum was unchanged after adjustment for time-varying phosphorus or other mineral metabolism parameters, but was attenuated by adjustments for time-varying indicators of nutritional status. Treatment with lanthanum is associated with improved survival in hemodialysis patients. This effect may be partially mediated by relaxation of dietary phosphate restriction and improved nutritional status.

Post-resuscitation care and outcomes of out-of-hospital cardiac arrest: a nationwide propensity score-matching analysis.

PubMed

Kim, Joo Yeong; Shin, Sang Do; Ro, Young Sun; Song, Kyoung Jun; Lee, Eui Jung; Park, Chang Bae; Hwang, Seung Sik

2013-08-01

This study aimed to determine whether active post-resuscitation care (APRC) was associated with improved out-of-hospital cardiac arrest (OHCA) outcomes on a nationwide level. We used a national OHCA cohort database consisting of hospital and ambulance data. We included all survivors of OHCA, excluding patients with non-cardiac etiology, younger than 15 years, and with unknown outcomes, from (2008 to 2010). The APRC was defined when the OHCA patients received mild therapeutic hypothermia (MTH) or active cardiac care (ACC), such as intravenous thrombolysis, percutaneous coronary intervention, coronary artery bypass surgery, and pacemaker/implantable cardioverter defibrillator insertion, as well as routine intensive care; patients receiving conservative post-resuscitation care (CPRC) served as the other group. The primary and secondary outcomes were survival to discharge and a good neurological outcome (cerebral performance category [CPC] 1-2), respectively. We extracted propensity-matched samples to control for selection bias. A multivariable logistic regression analysis was used to compare the APRC and CPRC groups adjusting for potential risks to calculate the adjusted odds ratios (ORs) and 95% confidence intervals (95% CIs). Of total 64,155 patients, 4557 survived to admission and were included in the final analysis. Out of these patients, 1599 (35.1%) cases survived to discharge, and 499 (11.0%) cases were discharged with good neurological recoveries. Overall, 695 cases (15.3%) received any APRC, including MTH (n=377, 8.3%) and ACC (370, 8.1%). The outcomes was better in the APRC group than in the CPRC group for survival to discharge (58.7% vs. 30.8%, p<0.001) and good neurological outcome (27.2% vs. 8.0%, p<0.001), respectively. In the total cohort, the adjusted ORs of the APRC group compared to those the CPRC group were 2.15 (95% CI 1.78-2.59) for survival to discharge and 2.54 (95% CI 1.98-3.27) for a good neurological outcome. In the propensity score-matched cohort, the adjusted ORs for survival to discharge and good neurological outcome of APRC were significantly favorable. Active post-resuscitation care resulted in significantly improved outcomes in adult OHCA patients with a presumed cardiac etiology in a nationwide, retrospective, observational study. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Graphical Models for Quasi-Experimental Designs

ERIC Educational Resources Information Center

Steiner, Peter M.; Kim, Yongnam; Hall, Courtney E.; Su, Dan

2017-01-01

Randomized controlled trials (RCTs) and quasi-experimental designs like regression discontinuity (RD) designs, instrumental variable (IV) designs, and matching and propensity score (PS) designs are frequently used for inferring causal effects. It is well known that the features of these designs facilitate the identification of a causal estimand…

Statins use and risk of new-onset diabetes in hypertensive patients: a population-based retrospective cohort study in Yinzhou district, Ningbo city, People's Republic of China.

PubMed

Li, Hailong; Lin, Hongbo; Zhao, Houyu; Xu, Yang; Cheng, Yinchu; Shen, Peng; Zhan, Siyan

2018-01-01

Reports have suggested that statin use is associated with an increased incidence of type 2 diabetes mellitus (T2DM). Guidelines suggested that statins should be prescribed in hypertensive patients for primary prevention. However, there were very few studies on the risk of T2DM associated with statin use among patients with hypertension in mainland People's Republic of China. To determine the association between statin use and new-onset diabetes mellitus among patients with hypertension in mainland People's Republic of China. We performed a retrospective cohort study of hypertensive patients using the Yinzhou regional health care database from January 1, 2010, to August 31, 2016. Patients aged 30-90 years old without T2DM were eligible for inclusion. We identified new statin initiators and nonusers by using prescription records of inpatients and outpatients. Multivariate Cox model and propensity score methods were used to adjust potential confounders, including age, sex, body mass index, comorbidities, lifestyle characteristics, and baseline antihypertensive drug use. The risk of incident T2DM among statin initiators compared to nonusers was estimated by the Cox proportional hazards model. Propensity scores for statin use were then developed using logistic regression, statin initiators were matched 1:1 with nonusers according to propensity scores with the nearest neighbor matching method within 0.2 caliper width, and Cox regression was again conducted. Among 67,993 patients (21,551 statin initiators; 46,442 nonusers), the unadjusted incidence rate of incident T2DM was higher in statin initiators than nonusers (25.68 versus 14.19 events/1,000 person-years; adjusted hazard ratio: 1.55; 95% confidence interval: 1.44-1.66). After propensity score 1:1 matching (19,818 statin initiators; 19,818 nonusers), baseline characteristics between 2 groups were balanced except that the nonusers group was 0.53 years older on average ( P <0.001). Then statin use was still associated with a significant increased risk for T2DM in the matched cohort (adjusted hazard ratio: 1.54; 95% confidence interval: 1.41-1.67). Subgroup analyses also demonstrated similar findings. Our study indicated an association between statin use and an increased risk of new-onset diabetes mellitus. It provides better understanding of statin and new-onset diabetes mellitus association among hypertensive patients in real-word setting. As an observational study, our findings were prone to unmeasured confounding and bias.

Comparative efficacy of switching to natalizumab in active multiple sclerosis

PubMed Central

Spelman, Timothy; Kalincik, Tomas; Zhang, Annie; Pellegrini, Fabio; Wiendl, Heinz; Kappos, Ludwig; Tsvetkova, Larisa; Belachew, Shibeshih; Hyde, Robert; Verheul, Freek; Grand-Maison, Francois; Izquierdo, Guillermo; Grammond, Pierre; Duquette, Pierre; Lugaresi, Alessandra; Lechner-Scott, Jeannette; Oreja-Guevara, Celia; Hupperts, Raymond; Petersen, Thor; Barnett, Michael; Trojano, Maria; Butzkueven, Helmut

2015-01-01

Objective To compare treatment efficacy and persistence in patients who switched to natalizumab versus those who switched between glatiramer acetate (GA) and interferon-beta (IFNβ) after an on-treatment relapse on IFNβ or GA using propensity score matched real-world datasets. Methods Patients included were registered in MSBase or the TYSABRI Observational Program (TOP), had relapsed on IFNβ or GA within 12 months prior to switching to another therapy, and had initiated natalizumab or IFNβ/GA treatment ≤6 months after discontinuing prior therapy. Covariates were balanced across post switch treatment groups by propensity score matching at treatment initiation. Relapse, persistence, and disability measures were compared between matched treatment arms in the total population (n = 869/group) and in subgroups defined by prior treatment history (IFNβ only [n = 578/group], GA only [n = 165/group], or both IFNβ and GA [n = 176/group]). Results Compared to switching between IFNβ and GA, switching to natalizumab reduced annualized relapse rate in year one by 65–75%, the risk of first relapse by 53–82% (mean follow-up 1.7–2.2 years) and treatment discontinuation events by 48–65% (all P ≤ 0.001). In the total population, switching to natalizumab reduced the risk of confirmed disability progression by 26% (P = 0.036) and decreased the total disability burden by 1.54 EDSS-years (P < 0.0001) over the first 24 months post switch. Interpretation Using large, real-world, propensity-matched datasets we demonstrate that after a relapse on IFNβ or GA, switching to natalizumab (rather than between IFNβ and GA) led to superior outcomes for patients in all measures assessed. Results were consistent regardless of the prior treatment identity. PMID:25909083

Maintenance steroid use at 30 days post-transplant and outcomes of pediatric heart transplantation: A propensity matched analysis of the Pediatric Heart Transplant Study database.

PubMed

Auerbach, Scott R; Kukreja, Manisha; Gilbert, Deborah; Bastardi, Heather; Feingold, Brian; Knecht, Kenneth; Kaufman, Beth D; Brown, Robert N; Miyamoto, Shelley D

2015-08-01

Maintenance steroid (MS) use in pediatric heart transplantation is variable. The purpose of this study was to evaluate the impact of MS use on graft outcomes. All patients <18 years old in the Pediatric Heart Transplant Study database at the time of first heart transplant between 1993 and 2011 who survived ≥30 days post-transplant and were from centers with a protocolized approach to MS use were included (N = 2,178). Patients were grouped by MS use at 30 days post-transplant as MS+ or MS- (no MS use). Propensity score analysis was used to generate matched groups of MS+ and MS- patients based on pre-transplant and peri-transplant factors. Kaplan-Meier survival analysis was used to compare freedom from graft loss, graft loss secondary to rejection, rejection, rejection with severe hemodynamic compromise (RSHC), malignancy, and infection between groups. Of patients, 1,393 (64%) were MS+ and 785 (36%) were MS-. There were 315 MS- patients who had propensity matched MS+ controls. Kaplan-Meier estimates showed no difference in graft loss (p = 0.9) or graft loss secondary to rejection (p = 0.09). At 1 year post-transplant, there was no difference in freedom from rejection (p = 0.15) or malignancy (p = 0.07), but there was lower freedom from RSHC and infection in the MS- group (p = 0.05 and p = 0.02, respectively). MS use at 30 days post-transplant was not associated with enhanced graft survival after pediatric heart transplant. MS- patients had a higher incidence of RSHC and infection. These risks should be taken into consideration when determining MS use for pediatric recipients of heart transplants. Copyright © 2015 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

Are older adults living in more equal counties healthier than older adults living in more unequal counties? A propensity score matching approach.

PubMed

Choi, HwaJung; Burgard, Sarah; Elo, Irma T; Heisler, Michele

2015-09-01

We assessed the potential contextual effect of income inequality on health by: 1) comparing individuals with similar socioeconomic status (SES) but who reside in counties with different levels of income inequality; and 2) examining whether the potential effect of county-level income inequality on health varies across SES groups. We used the Health and Retirement Study, a nationally representative study of Americans over the age of 50. Using propensity score matching, we selected SES-comparable individuals living in high-income inequality counties and in low-income inequality counties. We examined differences in self-rated overall health outcomes and in other specific physical/mental health outcomes between the two groups using logistic regression (n = 34,994) and imposing different sample restrictions based on residential duration in the area. We then used logistic regression with interactions to assess whether, and if so how, health outcomes differed among participants of different SES groups defined by wealth, income, and education. In bivariate analyses of the unmatched full sample, adults living in high-income inequality counties have worse health outcomes for most health measures. After propensity score matching, adults in high-income inequality counties had worse self-rated health status (AOR = 1.12; 95% CI 1.04-1.19) and were more likely to report diagnosed psychiatric problems (AOR = 1.08; 95% CI 0.99-1.19) than their matched counterparts in low-income inequality counties. These associations were stronger with longer-term residents in the area. Adverse health outcomes associated with living in high-income inequality counties were significant particularly for individuals in the 30(th) or greater percentiles of income/wealth distribution and those without a college education. In summary, after using more precise matching methods to compare individuals with similar characteristics and addressing measurement error by excluding more recently arrived county residents, adults living in high-income inequality counties had worse reported overall physical and mental health than adults living in low-income inequality counties. Copyright © 2015 Elsevier Ltd. All rights reserved.

Are older adults living in more equal counties healthier than older adults living in more unequal counties? A propensity score matching approach

PubMed Central

Choi, HwaJung; Burgard, Sarah; Elo, Irma T.; Heisler, Michele

2015-01-01

We assessed the potential contextual effect of income inequality on health by: 1) comparing individuals with similar socioeconomic status (SES) but who reside in counties with different levels of income inequality; and 2) examining whether the potential effect of county-level income inequality on health varies across SES groups. We used the Health and Retirement Study, a nationally representative study of Americans over the age of 50. Using propensity score matching, we selected SES-comparable individuals living in high-income inequality counties and in low-income inequality counties. We examined differences in self-rated overall health outcomes and in other specific physical/mental health outcomes between the two groups using logistic regression (n=34,994) and imposing different sample restrictions based on residential duration in the area. We then used logistic regression with interactions to assess whether, and if so how, health outcomes differed among participants of different SES groups defined by wealth, income, and education. In bivariate analyses of the unmatched full sample, adults living in high-income inequality counties have worse health outcomes for most health measures. After propensity score matching, adults in high-income inequality counties had worse self-rated health status (AOR=1.12; 95% CI 1.04–1.19) and were more likely to report diagnosed psychiatric problems (AOR=1.08; 95% CI 0.99–1.19) than their matched counterparts in low-income inequality counties. These associations were stronger with longer-term residents in the area. Adverse health outcomes associated with living in high-income inequality counties were significant particularly for individuals in the 30th or greater percentiles of income/wealth distribution and those without a college education. In summary, after using more precise matching methods to compare individuals with similar characteristics and addressing measurement error by excluding more recently arrived county residents, adults living in high-income inequality counties had worse reported overall physical and mental health than adults living in low-income inequality counties. PMID:26256736

Estimating the effect of gang membership on nonviolent and violent delinquency: a counterfactual analysis.

PubMed

Barnes, J C; Beaver, Kevin M; Miller, J Mitchell

2010-01-01

This study reconsiders the well-known link between gang membership and criminal involvement. Recently developed analytical techniques enabled the approximation of an experimental design to determine whether gang members, after being matched with similarly situated nongang members, exhibited greater involvement in nonviolent and violent delinquency. Findings indicated that while gang membership is a function of self-selection, selection effects alone do not account for the greater involvement in delinquency exhibited by gang members. After propensity score matching was employed, gang members maintained a greater involvement in both nonviolent and violent delinquency when measured cross-sectionally, but only violent delinquency when measured longitudinally. Additional analyses using inverse probability of treatment weights reaffirmed these conclusions. © 2010 Wiley-Liss, Inc.

Effects of health intervention program on cardiometabolic risk profiles from health evaluation center in Asian population: a longitudinal study and propensity analysis.

PubMed

Liu, Chuan-Chuan; Hung, Chung-Lieh; Shih, Shou-Chuan; Ko, Hung-Ju; Chang, Ray-E

2015-08-20

Health intervention program (HIP) based on diet and lifestyle modifications had been shown to improve cardiovascular risks. The effects of such program on a variety of cardiometabolic outcome measures conducted in a strict analysis remained relatively unexplored. A total of 2,660 participants (mean age: 43.3 ± 10 years, 63.6% male) underwent annual health survey from our health evaluation department. We implemented health intervention program (HIP) in which diet and lifestyle modifications including smoking cessation and advised physical activities were introduced. We further studied the effects of HIP on several cardiometabolic outcome measures including Framingham, metabolic scores and renal function in terms of Egfr with a mean follow-up period of 38.5 months. Propensity score (PS) matching (HIP vs non-HIP group) was used to avoid effects of case selection bias. Totally 1,004 (502 subjects for each group) left after PS matching protocol (both HIP and non-HIP group). The HIP group showed significant decline of waist circumference (-1.46 ± 0.61, p = 0.016), post-prandial glucose (-6.77 ± 2.06, p = 0.001), and total cholesterol level (-4.42 ± 2.15, p = 0.04), with borderline increase in eGFR (1.72 ± 0.94, p = 0.068) after an average of 1.91 ± 1.14 year follow up period. Exercise behavior significantly increased for those who received HIP when compared to the non-HIP group (44.6 vs 52.4 %, p = 0.014). PS matching and difference-in-difference (DID) analysis further confirmed the beneficial effects of ATP III reduction by HIP (-0.36 ± 0.06, p < 0.05). We demonstrated in our study that several cardiometabolic profiles can be substantially improved after health intervention introduction at the health evaluation center, supporting the beneficial evidence of such health intervention programs implementation based on primary prevention view points.

Oncologic Safety of Local Excision Compared With Total Mesorectal Excision for ypT0-T1 Rectal Cancer: A Propensity Score Analysis.

PubMed

Jung, Sung Min; Yu, Chang Sik; Park, In Ja; Kim, Tae Won; Kim, Jong Hoon; Yoon, Yong Sik; Lim, Seok-Byung; Kim, Jin Cheon

2016-05-01

Good oncologic outcomes, demonstrated by a complete pathologic response after preoperative chemoradiotherapy (PCRT), have led to local excision (LE) in selected patients with rectal cancer. We evaluated the oncologic safety of LE compared with total mesorectal excision (TME) in patients with ypT0-T1 rectal cancer.A retrospective review of 304 patients who underwent PCRT, followed by LE or TME, for ypT0-T1 rectal cancer was performed. Propensity scores were computed and used to match groups (LE:TME = 1:1), and analysis of disease-free survival (DFS) and overall survival (OS) was made by comparing patients who underwent LE or TME. Prognostic factors of relapse were analyzed for all patients.Tumor categories were ypT0 in 25 (61.9%) cases, ypTis in 6 (14.3%) cases, and ypT1 in 11 (26.2%) cases for the LE group, and ypT0 in 28 (66.7%) cases, ypTis in 4 (9.5%) cases, and ypT1 in 10 (23.8%) cases for the matched TME patients. There was no significant difference between the matched LE and TME groups in relapse (4.8% and 7.14%, respectively; P = 0.646), 5-year DFS (95.2% vs 91.6%; P = 0.33) and 5-year OS (96.6% vs 88.0%; P = 0.238). In the multivariate Cox regression analysis, tumor distance from the anal verge (hazard ratio [HR] = 0.78; 95% confidence interval (CI) = 0.616-0.992) and the tumor grade (HR = 4.29; 95% CI = 1.430-12.886) were significantly associated with the recurrence risk.LE results in oncologic outcomes that are comparable to those achieved by TME in selected patients with ypT0-T1 rectal cancer after PCRT.

Using School Scholarships to Estimate the Effect of Private Education on the Academic Achievement of Low-Income Students in Chile

ERIC Educational Resources Information Center

Anand, Priyanka; Mizala, Alejandra; Repetto, Andrea

2009-01-01

This paper estimates the impact of private education on the academic achievement of low-income students in Chile. To deal with selection bias, we use propensity score matching to compare the test scores of reduced-fee paying, low-income students in fee-charging private voucher schools to those of similar students in public schools and free private…

Can We Train Machine Learning Methods to Outperform the High-dimensional Propensity Score Algorithm?

PubMed

Karim, Mohammad Ehsanul; Pang, Menglan; Platt, Robert W

2018-03-01

The use of retrospective health care claims datasets is frequently criticized for the lack of complete information on potential confounders. Utilizing patient's health status-related information from claims datasets as surrogates or proxies for mismeasured and unobserved confounders, the high-dimensional propensity score algorithm enables us to reduce bias. Using a previously published cohort study of postmyocardial infarction statin use (1998-2012), we compare the performance of the algorithm with a number of popular machine learning approaches for confounder selection in high-dimensional covariate spaces: random forest, least absolute shrinkage and selection operator, and elastic net. Our results suggest that, when the data analysis is done with epidemiologic principles in mind, machine learning methods perform as well as the high-dimensional propensity score algorithm. Using a plasmode framework that mimicked the empirical data, we also showed that a hybrid of machine learning and high-dimensional propensity score algorithms generally perform slightly better than both in terms of mean squared error, when a bias-based analysis is used.

Two-Year versus One-Year Head Start Program Impact: Addressing Selection Bias by Comparing Regression Modeling with Propensity Score Analysis

ERIC Educational Resources Information Center

Leow, Christine; Wen, Xiaoli; Korfmacher, Jon

2015-01-01

This article compares regression modeling and propensity score analysis as different types of statistical techniques used in addressing selection bias when estimating the impact of two-year versus one-year Head Start on children's school readiness. The analyses were based on the national Head Start secondary dataset. After controlling for…

Effectiveness and safety of dabigatran versus acenocoumarol in ‘real-world’ patients with atrial fibrillation

PubMed Central

Korenstra, Jennie; Wijtvliet, E. Petra J.; Veeger, Nic J.G.M.; Geluk, Christiane A.; Bartels, G. Louis; Posma, Jan L.; Piersma-Wichers, Margriet; Van Gelder, Isabelle C.; Rienstra, Michiel; Tieleman, Robert G.

2016-01-01

Aims Randomized trials showed non-inferior or superior results of the non-vitamin-K-antagonist oral anticoagulants (NOACs) compared with warfarin. The aim of this study was to assess the effectiveness and safety of dabigatran (direct thrombin inhibitor) vs. acenocoumarol (vitamin K antagonist) in patients with atrial fibrillation (AF) in daily clinical practice. Methods and results In this observational study, we evaluated all consecutive patients who started anticoagulation because of AF in our outpatient clinic from 2010 to 2013. Data were collected from electronic patient charts. Primary outcomes were stroke or systemic embolism and major bleeding. Propensity score matching was applied to address the non-randomized design. In total, 920 consecutive AF patients were enrolled (442 dabigatran, 478 acenocoumarol), of which 2 × 383 were available for analysis after propensity score matching. Mean follow-up duration was 1.5 ± 0.56 year. The mean calculated stroke risk according to the CHA2DS2-VASc score was 3.5%/year in dabigatran vs. 3.7%/year acenocoumarol-treated patients. The actual incidence rate of stroke or systemic embolism was 0.8%/year [95% confidence interval (CI): 0.2–2.1] vs. 1.0%/year (95% CI: 0.4–2.1), respectively. Multivariable analysis confirmed this lower but non-significant risk in dabigatran vs. acenocoumarol after adjustment for the CHA2DS2-VASc score [hazard ratio (HR)dabigatran = 0.72, 95% CI: 0.20–2.63, P = 0.61]. According to the HAS-BLED score, the mean calculated bleeding risk was 1.7%/year in both groups. Actual incidence rate of major bleeding was 2.1%/year (95% CI: 1.0–3.8) in the dabigatran vs. 4.3%/year (95% CI: 2.9–6.2) in acenocoumarol. This over 50% reduction remained significant after adjustment for the HAS-BLED score (HRdabigatran = 0.45, 95% CI: 0.22–0.93, P = 0.031). Conclusion In ‘real-world’ patients with AF, dabigatran appears to be as effective, but significantly safer than acenocoumarol. PMID:26843571

Body composition and personality traits in so-Yang type males.

PubMed

Yoon, Jiwon; Nam, Jiho; Leem, Chae Hun; Kim, Jong Yeol

2017-08-22

The purpose of the present study was to examine the body composition of So-Yang type males according to Sasang constitutional medicine, which is popular in Korea. Different Sasang constitutional types are associated with different muscle distributions, body shapes, and disease susceptibilities. We used the Sasang Personality Questionnaire (SPQ) as a measure of the temperament of each Sasang type. In total, 953 subjects aged over 20 years were recruited in Korea. We collected anthropometric parameters and bioimpedence information from the subjects and administered the SPQ. A logistic regression was conducted to calculate propensity scores. The percentage of skeletal muscle mass in So-Yang (SY) and non-So-Yang (non-SY) males was 45.8 ± 2.7 and 44.2 ± 3.3, respectively, before matching and 45.8 ± 2.6 and 44.9 ± 3.0, respectively, after propensity score matching. The extracellular water (ECW)/intracellular water (ICW) and extracellular water (ECW)/total body water (TBW) ratios and SPQ scores were significantly different between the SY and non-SY types. This study suggested that the SY type may be significantly and independently associated with body composition and could be associated with personality.

Influence of alcohol use on mortality and expenditure during hospital admission: a cross-sectional study

PubMed Central

Peng, Shu-Hui; Hsu, Shiun-Yuan; Kuo, Pao-Jen; Rau, Cheng-Shyuan; Cheng, Ya-Ai; Hsieh, Ching-Hua

2016-01-01

Objectives This study was designed to investigate the effect of alcohol intoxication on clinical presentation of hospitalised adult trauma patients at a Level I trauma centre using propensity score matching. Design Cross-sectional study. Setting Taiwan. Participants Detailed data of 929 hospitalised adult trauma patients with alcohol intoxication, aged 20–65 years, and 10 104 corresponding patients without alcohol intoxication were retrieved from the Trauma Registry System between 1 January 2009 and 31 December 2014. Alcohol intoxication was defined as a blood alcohol concentration (BAC) ≥50 mg/dL. Main outcome measures In-hospital mortality and expenditure. Results Patients with alcohol intoxication presented with significantly higher short-term mortality (OR: 3.0, 95% CI 2.0 to 4.4; p<0.001) than patients without alcohol intoxication. However, on comparison with propensity score-matched patients with respect to sex, age, comorbidity, Glasgow Coma Scale (GCS), injury region based on Abbreviated Injury Scale (AIS) and Injury Severity Score (ISS), alcohol intoxication did not significantly influence mortality (OR: 0.8, 95% CI 0.5 to 1.4; p=0.563). This implied that the higher mortality of alcohol-intoxicated patients was attributable to patient characteristics such as a higher injury severity rather than alcohol intoxication. Even on comparison with sex-matched, age-matched and comorbidity-matched patients without alcohol intoxication, patients with alcohol intoxication still had significantly higher total expenditure (17.4% higher), cost of operation (40.3% higher), cost of examination (52.8% higher) and cost of pharmaceuticals (38.3% higher). Conclusions The associated higher mortality of adult trauma patients with alcohol intoxication was completely attributable to other patient characteristics and associated injury severity rather than the effects of alcohol. However, patients with alcohol intoxication incurred significantly higher expenditure than patients without alcohol intoxication, even on comparison with sex-matched, age-matched and comorbidity-matched patients without alcohol intoxication. PMID:27803110

Meta-analysis of pemetrexed plus carboplatin doublet safety profile in first-line non-squamous non-small cell lung cancer studies.

PubMed

Okamoto, Isamu; Schuette, Wolfgang H W; Stinchcombe, Thomas E; Rodrigues-Pereira, José; San Antonio, Belén; Chen, Jian; Liu, Jingyi; John, William J; Zinner, Ralph G

2017-05-01

This meta-analysis compared safety profiles (selected drug-related treatment-emergent adverse events [TEAEs]) of first-line pemetrexed plus carboplatin (PCb) area under the concentration-time curve 5 mg/min•mL (PCb5) or 6 mg/min•mL (PCb6), two widely used regimens in clinical practice for advanced non-squamous non-small cell lung cancer. All patients received pemetrexed 500 mg/m 2 every 21 days with either of two carboplatin doses for up to 4-6 cycles. Safety profiles of PCb doses were compared using three statistical analysis methods: frequency table analysis (FTA), generalized linear mixed effect model (GLMM), and the propensity score method. Efficacy outcomes of PCb5 and PCb6 regimens were summarized. A total of 486 patients mainly from the US, Europe, and East Asia were included in the analysis; 22% (n = 105) received PCb5 in one trial and 78% (n = 381) received PCb6 in four trials. The FTA comparison demonstrated that PCb5 vs PCb6 was associated with a statistically significantly lower incidence of TEAEs, including all-grade thrombocytopenia, anemia, fatigue, and vomiting, and grade 3/4 thrombocytopenia. In the GLMM analysis, PCb5 patients were numerically less likely to experience all-grade and grade 3/4 neutropenia, anemia, and thrombocytopenia. The propensity score regression analysis showed PCb5 group patients were significantly less likely than PCb6 group patients to experience all-grade hematologic TEAEs and grade 3/4 thrombocytopenia and anemia. After applying propensity score 1:1 matching, FTA analysis showed that the PCb5 group had significantly less all-grade and grade 3/4 hematologic toxicities. Overall efficacy outcomes, including overall survival, progression-free survival, and response rate, were similar between the two carboplatin doses. Acknowledging the limitations of this meta-analysis of five trials, heterogeneous in patient's characteristics and trial designs, the results show that the PCb5 regimen was generally associated with a better safety profile than PCb6 across three statistical approaches, with no apparent impact on survival outcomes.

Intraoperative use of dextran is associated with cardiac complications after carotid endarterectomy

PubMed Central

Farber, Alik; Tan, Tze-Woei; Rybin, Denis; Kalish, Jeffrey A.; Hamburg, Naomi M.; Doros, Gheorghe; Goodney, Philip P.; Cronenwett, Jack L.

2013-01-01

Objective Although dextran has been theorized to diminish the risk of stroke associated with carotid endarterectomy (CEA), variation exists in its use. We evaluated outcomes of dextran use in patients undergoing CEA to clarify its utility. Methods We studied all primary CEAs performed by 89 surgeons within the Vascular Study Group of New England database (2003–2010). Patients were stratified by intraoperative dextran use. Outcomes included perioperative death, stroke, myocardial infarction (MI), and congestive heart failure (CHF). Group and propensity score matching was performed for risk-adjusted comparisons, and multivariable logistic and gamma regressions were used to examine associations between dextran use and outcomes. Results There were 6641 CEAs performed, with dextran used in 334 procedures (5%). Dextran-treated and untreated patients were similar in age (70 years) and symptomatic status (25%). Clinical differences between the cohorts were eliminated by statistical adjustment. In crude, group-matched, and propensity-matched analyses, the stroke/death rate was similar for the two cohorts (1.2%). Dextran-treated patients were more likely to suffer postoperative MI (crude: 2.4% vs 1.0%; P = .03; group-matched: 2.4% vs 0.6%; P = .01; propensity-matched: 2.4% vs 0.5%; P = .003) and CHF (2.1% vs 0.6%; P = .01; 2.1% vs 0.5%; P = .01; 2.1% vs 0.2%; P < .001). In multivariable analysis of the crude sample, dextran was associated with a higher risk of postoperative MI (odds ratio, 3.52; 95% confidence interval, 1.62–7.64) and CHF (odds ratio, 5.71; 95% confidence interval, 2.35–13.89). Conclusions Dextran use was not associated with lower perioperative stroke but was associated with higher rates of MI and CHF. Taken together, our findings suggest limited clinical utility for routine use of intraoperative dextran during CEA. PMID:23337295

Social-Emotional Effects of Early Childhood Education Programs in Tulsa

ERIC Educational Resources Information Center

Gormley, William T., Jr.; Phillips, Deborah A.; Newmark, Katie; Welti, Kate; Adelstein, Shirley

2011-01-01

This article assesses the effects of Tulsa, Oklahoma's early childhood education programs on social-emotional outcomes, examining teacher ratings of children's behavior from the Adjustment Scales for Preschool Intervention and a measure of attentiveness using fixed effects regressions with propensity score matching. The sample includes 2,832…

Academic Remediation-Focused Alternative Schools: Impact on Student Outcomes

ERIC Educational Resources Information Center

Wilkerson, Kimber L.; Afacan, Kemal; Yan, Min-Chi; Justin, Whitney; Datar, Sujata D.

2016-01-01

School districts offer specialized programming for secondary students who experience high rates of course failure or low credit accumulation. While these alternative programs are meant to increase student success, little research evaluates outcomes for students attending them. In this study, we used propensity score matching (PSM) to investigate…

Use of Propensity Score Matching for Training Research with Observational Data

ERIC Educational Resources Information Center

Gemici, Sinan; Rojewski, Jay W.; Lee, In Heok

2012-01-01

Evaluations of vocational education and training (VET) programs play a key role in informing training policy in Australia and elsewhere. Increasingly, such evaluations use observational data from surveys or administrative collections to assess the effectiveness of VET programs and interventions. The difficulty associated with using observational…

Assessing Readiness for Online Education--Research Models for Identifying Students at Risk

ERIC Educational Resources Information Center

Wladis, Claire; Conway, Katherine M.; Hachey, Alyse C.

2016-01-01

This study explored the interaction between student characteristics and the online environment in predicting course performance and subsequent college persistence among students in a large urban U.S. university system. Multilevel modeling, propensity score matching, and the KHB decomposition method were used. The most consistent pattern observed…

A propensity score matching analysis of dasatinib and nilotinib as a frontline therapy for patients with chronic myeloid leukemia in chronic phase.

PubMed

Takahashi, Koichi; Kantarjian, Hagop M; Yang, Yulong; Sasaki, Koji; Jain, Preetesh; DellaSala, Sara; Ravandi, Farhad; Kadia, Tapan; Pemmaraju, Naveen; Daver, Naval; Borthakur, Gautam; Garcia-Manero, Guillermo; Jabbour, Elias; Cortes, Jorge E

2016-11-15

Both dasatinib and nilotinib are approved frontline therapy for chronic myeloid leukemia in chronic phase (CML-CP) based on randomized trials compared with imatinib. However, no head-to-head comparison of dasatinib and nilotinib has been conducted in patients with newly diagnosed CML-CP. The authors conducted a propensity score (PS) matched comparison of patients with CML-CP who received frontline therapy with either dasatinib (N = 102) or nilotinib (N = 104) under the respective phase 2 trials conducted in parallel. PS matching resulted in 87 patients from each trial being matched for pretreatment characteristics. The 3-month BCR-ABL1/ABL1 ratio <10% rate was 93% with dasatinib and 94% with nilotinib (P = .25); the rates of major molecular response at 12 months were 77% and 85%, respectively (P = .13); and the rates of molecular response with 4.5-log reduction in the ratio at 36 months were 66% and 64%, respectively (P = .96). All other clinically relevant responses were similar between the 2 treatment cohorts. The 3-year probability of event-free survival was 89% among the patients who received dasatinib and 87% among those who received nilotinib (P = .99), and the corresponding 3-year overall survival probabilities were 99% and 93%, respectively (P = .95). No statistical difference was observed between the dasatinib and nilotinib groups in any of the other survival endpoints. The treatment discontinuation rate also was similar between the 2 cohorts (dasatinib group, 18%; nilotinib group, 19%; P = .82). In a PS-matched cohort of patients with newly diagnosed CML-CP, dasatinib and nilotinib offer similar response and survival outcomes. Both drugs can be considered reasonable standard-of-care options as first-line therapy for patients with CML-CP. Cancer 2016;122:3336-3343. © 2016 American Cancer Society. © 2016 American Cancer Society.

Traumatic injuries among adult obese patients in southern Taiwan: a cross-sectional study based on a trauma registry system.

PubMed

Chuang, Jung-Fang; Rau, Cheng-Shyuan; Kuo, Pao-Jen; Chen, Yi-Chun; Hsu, Shiun-Yuan; Hsieh, Hsiao-Yun; Hsieh, Ching-Hua

2016-03-18

The adverse impact of obesity has been extensively studied in the general population; however, the added risk of obesity on trauma-related mortality remains controversial. This study investigated and compared mortality as well injury patterns and length of stay (LOS) in obese and normal-weight patients hospitalized for trauma in the hospital and intensive care unit (ICU) of a Level I trauma center in southern Taiwan. Detailed data of 880 obese adult patients with body mass index (BMI) ≥ 30 kg/m(2) and 5391 normal-weight adult patients (25 > BMI ≥ 18.5 kg/m(2)) who had sustained a trauma injury between January 1, 2009 and December 31, 2013 were retrieved from the Trauma Registry System. Pearson's chi-squared, Fisher's exact, and independent Student's t-tests were used to compare differences between groups. Propensity score matching with logistic regression was used to evaluate the effect of obesity on mortality. In this study, obese patients were more often men, motorcycle riders and pedestrians, and had a lower proportion of alcohol intoxication compared to normal-weight patients. Analysis of Abbreviated Injury Scale scores revealed that obese trauma patients presented with a higher rate of injury to the thorax, but a lower rate of facial injuries than normal-weight patients. No significant differences were found between obese and normal-weight patients regarding Injury Severity Score (ISS), Trauma-Injury Severity Score (TRISS), mortality, the proportion of patients admitted to the ICU, or LOS in ICU. After propensity score matching, logistic regression of 66 well-matched pairs did not show a significant influence of obesity on mortality (odds ratio: 1.51, 95% confidence interval: 0.54-4.23 p = 0.438). However, significantly longer hospital LOS (10.6 vs. 9.5 days, respectively, p = 0.044) was observed in obese patients than in normal-weight patients, particularly obese patients with pelvic, tibial, or fibular fractures. Compared to normal-weight patients, obese patients presented with different injury characteristics and bodily injury patterns but no difference in mortality.

Is early limited surgery associated with a more benign disease course in Crohn’s disease?

PubMed Central

Golovics, Petra Anna; Lakatos, Laszlo; Nagy, Attila; Pandur, Tunde; Szita, Istvan; Balogh, Mihaly; Molnar, Csaba; Komaromi, Erzsebet; Lovasz, Barbara Dorottya; Mandel, Michael; Veres, Gabor; Kiss, Lajos S; Vegh, Zsuzsanna; Lakatos, Peter Laszlo

2013-01-01

AIM: To analyze the difference in disease course and need for surgery in patients with Crohn’s disease (CD). METHODS: Data of 506 patients with incident CD were analyzed (age at diagnosis: 31.5 ± 13.8 years). Both hospital and outpatient records were collected prospectively with a complete clinical follow-up and comprehensively reviewed in the population-based Veszprem province database, which includes incident CD patients diagnosed between January 1, 1977 and December 31, 2008. Follow-up data were collected until December 31, 2009. All patients included had at least 1 year of follow-up available. Patients with indeterminate colitis at diagnosis were excluded from the analysis. RESULTS: Overall, 73 patients (14.4%) required resective surgery within 1 year of diagnosis. Steroid exposure and need for biological therapy were lower in patients with early limited surgery (P < 0.001 and P = 0.09). In addition, surgery rates during follow-up in patients with and without early surgery differed significantly after matching on propensity scores (P < 0.001, HR = 0.23). The need for reoperation was also lower in patients with early limited resective surgery (P = 0.038, HR = 0.42) in a Kaplan-Meier and multivariate Cox regression (P = 0.04) analysis. However, this advantage was not observed after matching on propensity scores (PLogrank = 0.656, PBreslow = 0.498). CONCLUSION: Long-term surgery rates and overall exposure to steroids and biological agents were lower in patients with early limited resective surgery, but reoperation rates did not differ. PMID:24282358

A single-arm trial indirect comparison investigation: a proof-of-concept method to predict venous leg ulcer healing time for a new acellular synthetic matrix matched to standard care control.

PubMed

Shannon, Ronald; Nelson, Andrea

2017-08-01

To compare data on time to healing from two separate cohorts: one treated with a new acellular synthetic matrix plus standard care (SC) and one matched from four large UK pragmatic, randomised controlled trials [venous leg ulcer (VLU) evidence network]. We introduce a new proof-of-concept strategy to a VLU clinical evidence network, propensity score matching and sensitivity analysis to predict the feasibility of the new acellular synthetic matrix plus SC for success in future randomised, controlled clinical trials. Prospective data on chronic VLUs from a safety and effectiveness study on an acellular synthetic matrix conducted in one wound centre in the UK (17 patients) and three wound centres in Australia (36 patients) were compared retrospectively to propensity score-matched data from patients with comparable leg ulcer disease aetiology, age, baseline ulcer area, ulcer duration, multi-layer compression bandaging and majority of care completed in specialist wound centres (average of 1 visit per week), with the outcome measures at comparable follow-up periods from patients enrolled in four prospective, multicentre, pragmatic, randomised studies of venous ulcers in the UK (the comparison group; VLU evidence network). Analysis using Kaplan-Meier survival curves showed a mean healing time of 73·1 days for ASM plus SC (ASM) treated ulcers in comparison with 83·5 days for comparison group ulcers treated with SC alone (Log rank test, χ 2 5·779, P = 0·016) within 12 weeks. Sensitivity analysis indicates that an unobserved covariate would have to change the odds of healing for SC by a factor of 1·1 to impact the baseline results. Results from this study predict a significant effect on healing time when using a new ASM as an adjunct to SC in the treatment of non-healing venous ulcers in the UK, but results are sensitive to unobserved covariates that may be important in healing time comparison. © 2016 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

Adverse Outcomes After Palliative Radiation Therapy for Uncomplicated Spine Metastases: Role of Spinal Instability and Single-Fraction Radiation Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lam, Tai-Chung, E-mail: lamtaichung@gmail.com; Uno, Hajime; Krishnan, Monica

2015-10-01

Purpose: Level I evidence demonstrates equivalent pain response after single-fraction (SF) or multifraction (MF) radiation therapy (RT) for bone metastases. The purpose of this study is to provide additional data to inform the incidence and predictors of adverse outcomes after RT for spine metastases. Methods and Materials: At a single institution, 299 uncomplicated spine metastases (without cord compression, prior RT, or surgery) treated with RT from 2008 to 2013 were retrospectively reviewed. The spinal instability neoplastic score (SINS) was used to assess spinal instability. The primary outcome was time to first spinal adverse event (SAE) at the site, including symptomaticmore » vertebral fracture, hospitalization for site-related pain, salvage surgery, interventional procedure, new neurologic symptoms, or cord compression. Fine and Gray's multivariable model assessed associations of the primary outcome with SINS, SF RT, and other significant baseline factors. Propensity score matched analysis further assessed the relationship of SF RT to first SAEs. Results: The cumulative incidence of first SAE after SF RT (n=66) was 6.8% at 30 days, 16.9% at 90 days, and 23.6% at 180 days. For MF RT (n=233), the incidence was 3.5%, 6.4%, and 9.2%, respectively. In multivariable analysis, SF RT (hazard ratio [HR] = 2.8, 95% confidence interval [CI] 1.5-5.2, P=.001) and SINS ≥11 (HR=2.5 , 95% CI 1.3-4.9, P=.007) were predictors of the incidence of first SAE. In propensity score matched analysis, first SAEs had developed in 22% of patients with SF RT versus 6% of those with MF RT cases (HR=3.9, 95% CI 1.6-9.6, P=.003) at 90 days after RT. Conclusion: In uncomplicated spinal metastases treated with RT alone, spinal instability with SINS ≥11 and SF RT were associated with a higher rate of SAEs.« less

Three-Year Outcomes of Surgical Versus Endovascular Revascularization for Critical Limb Ischemia

PubMed Central

Takahara, Mitsuyoshi; Soga, Yoshimitsu; Kodama, Akio; Terashi, Hiroto; Azuma, Nobuyoshi

2017-01-01

Background— The aim of this study was to compare clinical outcomes between surgical reconstruction and endovascular therapy (EVT) for critical limb ischemia (CLI) in today’s real-world settings. Methods and Results— This multicenter, prospective, observational study registered and followed 548 Japanese CLI patients. The registration was in advance of revascularization; 197 patients were scheduled to receive surgical reconstruction, and the remaining 351 were scheduled to receive EVT. The primary end point was 3-year amputation-free survival, compared between the 2 treatments in an intention-to-treat manner, using propensity score matching. Interaction analysis was additionally performed to explore which subgroups had better outcomes with surgical reconstruction or EVT. After propensity score matching, the 3-year amputation-free survival was not significantly different between the 2 groups (52% [95% confidence interval, 43%–60%] and 52% [95% confidence interval, 44–60%]; P=0.26). Subsequent interaction analysis identified (1) Wound, Ischemia, and foot Infection (WIfI) classification W-3, (2) fI-2/3, (3) history of ipsilateral minor amputation, (4) history of revascularization after CLI onset, and (5) bilateral CLI as the factors more favorable for surgical reconstruction, whereas (1) diabetes mellitus, (2) renal failure, (3) anemia, (4) history of nonadherence to cardiovascular risk management, and (5) contralateral major amputation were as those less favorable for surgical reconstruction. Conclusions— The 3-year amputation-free survival was not different between surgical reconstruction and EVT in the overall CLI population. The subsequent interaction analysis suggested that there would be a subgroup more suited for surgical reconstruction and another benefiting more from EVT. Clinical Trial Registration— URL: http://www.umin.ac.jp/ctr/. Unique identifier: UMIN000007050. PMID:29246911

Postmastectomy radiation therapy for lymph node-negative, locally advanced breast cancer after modified radical mastectomy: analysis of the NCI Surveillance, Epidemiology, and End Results database.

PubMed

Yu, James B; Wilson, Lynn D; Dasgupta, Tina; Castrucci, William A; Weidhaas, Joanne B

2008-07-01

The role of postmastectomy radiotherapy (PMRT) for lymph node-negative locally advanced breast carcinoma (T3N0M0) after modified radical mastectomy (MRM) with regard to improvement in survival remains an area of controversy. The 1973-2004 National Cancer Institute (NCI) Surveillance, Epidemiology, and End Results (SEER) database was examined for patients with T3N0M0 ductal, lobular, or mixed ductal and lobular carcinoma of the breast who underwent MRM, treated from 1988-2003. Patients who were men, who had positive lymph nodes, who survived < or =6 months, for whom breast cancer was not the first malignancy, who had nonbeam radiation, intraoperative or preoperative radiation were excluded. The average treatment effect of PMRT on mortality was estimated with a propensity score case-matched analysis. In all, 1777 patients were identified; 568 (32%) patients received PMRT. Median tumor size was 6.3 cm. The median number of lymph nodes examined was 14 (range, 1-49). Propensity score matched case-control analysis showed no improvement in overall survival with the delivery of PMRT in this group. Older patients, patients with ER- disease (compared with ER+), and patients with high-grade tumors (compared with well differentiated) had increased mortality. The use of PMRT for T3N0M0 breast carcinoma after MRM is not associated with an increase in overall survival. It was not possible to analyze local control in this study given the limitations of the SEER database. The impact of potential improvement in local control as it relates to overall survival should be the subject of further investigation. (Copyright) 2008 American Cancer Society.

The Effect of Smoking on Thirty-Day Postoperative Complications After Total Joint Arthroplasty: A Propensity Score-Matched Analysis.

PubMed

Sahota, Shawn; Lovecchio, Francis; Harold, Ryan E; Beal, Matthew D; Manning, David W

2018-01-01

Total joint arthroplasty (TJA) is a highly successful treatment, but is burdensome to the national healthcare budget. National quality initiatives seek to reduce costly complications. Smoking's role in perioperative complication after TJA is less well known. This study aims to identify smoking's independent contribution to the risk of short-term complication after TJA. All patients undergoing primary TJA between 2011 and 2012 were selected from the American College of Surgeon's National Surgical Quality Improvement Program's database. Outcomes of interest included rates of readmission, reoperation, mortality, surgical complications, and medical complications. To eliminate confounders between smokers and nonsmokers, a propensity score was used to generate a 1:1 match between groups. A total of 1251 smokers undergoing TJA met inclusion criteria. Smokers in the combined total hip and knee arthroplasty cohort had higher 30-day readmission (4.8% vs 3.2%, P = .041), were more likely to have a surgical complication (odds ratio 1.84, 95% confidence interval 1.21-2.80), and had a higher rate of deep surgical site infection (SSI) (1.1% vs 0.2%, P = .007). Analysis of total hip arthroplasty only revealed that smokers had higher rates of deep SSI (1.3% vs 0.2%, P = .038) and higher readmission rate (4.3% vs 2.2%, P = .034). Analysis of total knee arthroplasty only revealed greater surgical complications (2.8% vs 1.2%, P = .048) and superficial SSI (1.8% vs 0.2%, P = .002) in smokers. Smoking in TJA is associated with higher rates of SSI, surgical complications, and readmission. Copyright © 2017 Elsevier Inc. All rights reserved.

Risk of anastomotic leak after laparoscopic versus open colectomy.

PubMed

Murray, Alice C A; Chiuzan, Cody; Kiran, Ravi P

2016-12-01

Anastomotic leak following colorectal surgery is associated with significant morbidity and mortality. With the widespread adoption of laparoscopy, data from initial clinical trials evaluating the efficacy of laparoscopic when compared to open surgery may not currently be generalizable. We assess the risk of anastomotic leak after laparoscopic versus open colorectal resection using a nationwide database with standardized definitions. The 2012-2013 ACS-NSQIP targeted colectomy data were queried for all elective colorectal resections. Characteristics were compared for those patients undergoing laparoscopic versus open operations. Univariable and multivariable analyses, followed by a propensity score-matched analysis, were performed to assess the impact of laparoscopy on the development of an anastomotic leak. Of 23,568 patients, 3.4 % developed an anastomotic leak. Laparoscopic surgery was associated with a leak rate of 2.8 % (n = 425) and open surgery, 4.5 % (n = 378, p < 0.0001). Patients who developed a leak were more likely to die within 30 days of surgery (5.7 vs. 0.6 %, p < 0.0001). Patients who underwent laparoscopic surgery compared to open were younger (61 vs. 63 years, p = 0, p = 0.045) and with fewer comorbidities. On univariable analysis laparoscopic surgery was associated with reduced odds of developing an anastomotic leak (OR 0.60, p < 0.0001), and this remained after adjusting for all significant preoperative and disease-related confounders (OR 0.69, 95 % CI 0.58-0.82). A propensity score-matched analysis confirmed benefit of laparoscopic surgery over open surgery for anastomotic leak. Laparoscopic colectomy is safe and associated with reduced odds of developing an anastomotic leak following colectomy when controlling for patient-, disease- and procedure-related factors.

Association of statins with aortic, peripheral, and visceral artery aneurysm development.

PubMed

Mansi, Ishak A; Frei, Christopher R; Halm, Ethan A; Mortensen, Eric M

2017-08-01

Objectives Prior studies examining the effects of statins on arterial aneurysm development and progression yielded conflicting results due to their smaller size and presence of residual confounders. The objective of this study is to examine the association of statins with risk of being diagnosed with aortic, peripheral, and visceral artery aneurysm. Methods This was a retrospective cohort study of Tricare enrollees (from 1 October 2003 to 31 March 2012). Main outcomes were diagnosis of aortic, peripheral, or visceral artery aneurysm and undergoing aortic aneurysm repair procedure during follow-up period. Using 115 baseline characteristics, we generated a propensity score to match statin users and nonusers and examine the odds of outcomes (primary analysis). Secondary analysis examined outcomes at various subcohorts. Results Out of 10,910 statin users and 49,545 nonusers, we propensity score-matched 6728 pairs of statin users and nonusers. Statin users and nonusers had similar odds of being diagnosed with aortic, peripheral, and visceral artery aneurysms (odds ratio [OR]: 1.06, 95% confidence interval [95% CI]: 0.85-1.33) and of undergoing aortic aneurysm repair procedures (OR: 0.54, 95% CI: 0.22-1.35). Secondary analysis showed a tendency toward fewer aortic aneurysm procedures among statin users that did not reach statistical significance. However, high-intensity statin users in comparison to non-intensive statin users had higher adjusted odds of aortic, peripheral, and visceral artery aneurysms (OR: 1.76, 95% CI: 1.37-2.25, p < .0001). Conclusions This study does not support a clinically significant benefit or harm from statins regarding development of arterial aneurysm. However, secondary analyses may support the hypothesis proposed by previous research proposing a bidirectional role for statins.

Association between thoracic aortic disease and inguinal hernia.

PubMed

Olsson, Christian; Eriksson, Per; Franco-Cereceda, Anders

2014-08-21

The study hypothesis was that thoracic aortic disease (TAD) is associated with a higher-than-expected prevalence of inguinal hernia. Such an association has been reported for abdominal aortic aneurysm (AAA) and hernia. Unlike AAA, TAD is not necessarily detectable with clinical examination or ultrasound, and there are no population-based screening programs for TAD. Therefore, conditions associated with TAD, such as inguinal hernia, are of particular clinical relevance. The prevalence of inguinal hernia in subjects with TAD was determined from nation-wide register data and compared to a non-TAD group (patients with isolated aortic stenosis). Groups were balanced using propensity score matching. Multivariable statistical analysis (logistic regression) was performed to identify variables independently associated with hernia. Hernia prevalence was 110 of 750 (15%) in subjects with TAD versus 29 of 301 (9.6%) in non-TAD, P=0.03. This statistically significant difference remained after propensity score matching: 21 of 159 (13%) in TAD versus 14 of 159 (8.9%) in non-TAD, P<0.001. Variables independently associated with hernia in multivariable analysis were male sex (odds ratio [OR] with 95% confidence interval [95% CI]) 3.4 (2.1 to 5.4), P<0.001; increased age, OR 1.02/year (1.004 to 1.04), P=0.014; and TAD, OR 1.8 (1.1 to 2.8), P=0.015. The prevalence of inguinal hernia (15%) in TAD is higher than expected in a general population and higher in TAD, compared to non-TAD. TAD is independently associated with hernia in multivariable analysis. Presence or history of hernia may be of importance in detecting TAD, and the association warrants further study. © 2014 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Small Versus Large-Sized Drug-Eluting Beads (DEBIRI) for the Treatment of Hepatic Colorectal Metastases: A Propensity Score Matching Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Akinwande, Olaguoke K., E-mail: gokeakin@gmail.com; Philips, Prejesh, E-mail: prejesh.philips@louisville.edu; Duras, Petr, E-mail: durasp@seznam.cz

2015-04-15

PurposeTo compare the feasibility, safety, and efficacy with small and large irinotecan drug-eluting beads (DEBIRI) for treating hepatic colorectal metastases.MethodsUsing our prospectively maintained, multi-center, intra-arterial therapy registry, we identified 196 patients treated with a combination of large beads (100–300 to 500–700 μm) and patients treated with a combination of small beads (70–150 to 100–300 μm). To minimize selection bias, a propensity score analysis was performed to compare both groups.ResultsUnadjusted analysis consisted of 196 and 30 patients treated with large and small beads, respectively. The adjusted analysis consisted of 19 patients each. Unadjusted analysis showed decreased all-grade (p = <0.001) and high-grade adverse effects (p = 0.02)more » in the small bead group, with a persisting trend toward decreased overall side effects in the adjusted analysis favoring small beads (p = 0.09) The adjusted analysis showed the percentage dose delivered (delivered dose/intended dose) was significantly greater in the small bead group compared to the large bead group (96 vs 79 %; p = 0.005). There were also a lower percentage of treatments terminating in complete stasis in the adjusted analysis (0.0035). Adjusted analysis also showed increased objective response rate (ORR) at 12 months (p = 0.04), with a corresponding trend also seen in the unadjusted analysis (0.09).ConclusionSmaller beads result in increased dose delivery probably due to less propensity to reach complete stasis. It may also lead to more durable long-term efficacy. Smaller beads also demonstrate similarly low toxicity compared to large-sized beads with a trend toward less toxicity.« less

Outcomes Following Three-Factor Inactive Prothrombin Complex Concentrate Versus Recombinant Activated Factor VII Administration During Cardiac Surgery.

PubMed

Harper, Patrick C; Smith, Mark M; Brinkman, Nathan J; Passe, Melissa A; Schroeder, Darrell R; Said, Sameh M; Nuttall, Gregory A; Oliver, William C; Barbara, David W

2018-02-01

To compare outcomes following inactive prothrombin complex concentrate (PCC) or recombinant activated factor VII (rFVIIa) administration during cardiac surgery. Retrospective propensity-matched analysis. Academic tertiary-care center. Patients undergoing cardiac surgery requiring cardiopulmonary bypass who received either rFVIIa or the inactive 3-factor PCC. Outcomes following intraoperative administration of rFVIIa (263) or factor IX complex (72) as rescue therapy to treat bleeding. In the 24 hours after surgery, propensity-matched patients receiving PCC versus rFVIIa had significantly less chest tube outputs (median difference -464 mL, 95% confidence interval [CI] -819 mL to -110 mL), fresh frozen plasma transfusion rates (17% v 38%, p = 0.028), and platelet transfusion rates (26% v 49%, p = 0.027). There were no significant differences between propensity-matched groups in postoperative stroke, deep venous thrombosis, pulmonary embolism, myocardial infarction, or intracardiac thrombus. Postoperative dialysis was significantly less likely in patients administered PCC versus rFVIIa following propensity matching (odds ratio = 0.3, 95% CI 0.1-0.7). No significant difference in 30-day mortality in patients receiving PCC versus rFVIIa was present following propensity matching. Use of rFVIIa versus inactive PCCs was significantly associated with renal failure requiring dialysis and increased postoperative bleeding and transfusions. Copyright © 2018 Elsevier Inc. All rights reserved.

Observational studies using propensity score analysis underestimated the effect sizes in critical care medicine.

PubMed

Zhang, Zhongheng; Ni, Hongying; Xu, Xiao

2014-08-01

Propensity score (PS) analysis has been increasingly used in critical care medicine; however, its validation has not been systematically investigated. The present study aimed to compare effect sizes in PS-based observational studies vs. randomized controlled trials (RCTs) (or meta-analysis of RCTs). Critical care observational studies using PS were systematically searched in PubMed from inception to April 2013. Identified PS-based studies were matched to one or more RCTs in terms of population, intervention, comparison, and outcome. The effect sizes of experimental treatments were compared for PS-based studies vs. RCTs (or meta-analysis of RCTs) with sign test. Furthermore, ratio of odds ratio (ROR) was calculated from the interaction term of treatment × study type in a logistic regression model. A ROR < 1 indicates greater benefit for experimental treatment in RCTs compared with PS-based studies. RORs of each comparison were pooled by using meta-analytic approach with random-effects model. A total of 20 PS-based studies were identified and matched to RCTs. Twelve of the 20 comparisons showed greater beneficial effect for experimental treatment in RCTs than that in PS-based studies (sign test P = 0.503). The difference was statistically significant in four comparisons. ROR can be calculated from 13 comparisons, of which four showed significantly greater beneficial effect for experimental treatment in RCTs. The pooled ROR was 0.71 (95% CI: 0.63, 0.79; P = 0.002), suggesting that RCTs (or meta-analysis of RCTs) were more likely to report beneficial effect for the experimental treatment than PS-based studies. The result remained unchanged in sensitivity analysis and meta-regression. In critical care literature, PS-based observational study is likely to report less beneficial effect of experimental treatment compared with RCTs (or meta-analysis of RCTs). Copyright © 2014 Elsevier Inc. All rights reserved.

Supplemental Analytic Sample Equivalence Tables for Student Characteristics and Achievement in 22 KIPP Middle Schools: A Report from the National Evaluation of KIPP Middle Schools

ERIC Educational Resources Information Center

Tuttle, Christina Clark; Teh, Bing-ru; Nichols-Barrer, Ira; Gill, Brian P.; Gleason, Philip

2010-01-01

In this set of four supplemental tables, the authors compare the baseline test scores of the treatment and matched control group samples observed in each year after KIPP entry (outcome years 1 to 4). As discussed in Chapter III, the authors used an iterative propensity score estimation procedure to calculate each student's probability of entering…

Retail clinic utilization associated with lower total cost of care.

PubMed

Sussman, Andrew; Dunham, Lisette; Snower, Kristen; Hu, Min; Matlin, Olga S; Shrank, William H; Choudhry, Niteesh K; Brennan, Troyen

2013-04-01

To better understand the impact of retail clinic use on a patient's annual total cost of care. A propensity score matched-pair, cohort design was used to analyze healthcare spending patterns among CVS Caremark employees in the year following a visit to a MinuteClinic, the retail clinics inside CVS pharmacies. De-identified medical and pharmacy claims for CVS Caremark employees and their dependents who received care at a retail clinic between June 1, 2009, and May 31, 2010, were matched to those of subjects who received care elsewhere. High-dimensional propensity score and greedy matching techniques were used to create a 1-to-1 matched cohort that was analyzed using generalized linear regression models. Individuals using a retail clinic had a lower total cost of care (-$262; 95% confidence interval, -$510 to -$31; P = .025) in the year following their clinic visit than individuals who received care in other settings. This savings was primarily due to lower medical expenses at physicians' offices ($77 savings, P = .008) and hospital inpatient care ($121 savings, P = .049). The 6022 retail clinic users also had 142 (12%) fewer emergency department visits (P = .01), though this was not related to significant cost savings. This study found that retail clinic use was associated with lower overall total cost of care compared with that at alternative sites. Savings may extend beyond the retail clinic visit itself to other types of medical utilization.

Cisplatin and Etoposide Versus Carboplatin and Paclitaxel With Concurrent Radiotherapy for Stage III Non–Small-Cell Lung Cancer: An Analysis of Veterans Health Administration Data

PubMed Central

Santana-Davila, Rafael; Devisetty, Kiran; Szabo, Aniko; Sparapani, Rodney; Arce-Lara, Carlos; Gore, Elizabeth M.; Moran, Amy; Williams, Christina D.; Kelley, Michael J.; Whittle, Jeffrey

2015-01-01

Purpose The optimal chemotherapy regimen to use with radiotherapy in stage III non–small-cell lung cancer is unknown. Here, we compare the outcome of patents treated within the Veterans Health Administration with either etoposide-cisplatin (EP) or carboplatin-paclitaxel (CP). Methods We identified patients treated with EP and CP with concurrent radiotherapy from 2001 to 2010. Survival rates were compared using Cox proportional hazards regression models with adjustments for confounding provided by propensity score methods and an instrumental variables analysis. Comorbidities and treatment complications were identified through administrative data. Results A total of 1,842 patients were included; EP was used in 27% (n = 499). Treatment with EP was not associated with a survival advantage in a Cox proportional hazards model (hazard ratio [HR], 0.97; 95% CI, 0.85 to 1.10), a propensity score matched cohort (HR, 1.07; 95% CI, 0.91 to 1.24), or a propensity score adjusted model (HR, 0.97; 95% CI, 0.85 to 1.10). In an instrumental variables analysis, there was no survival advantage for patients treated in centers where EP was used more than 50% of the time as compared with centers where EP was used in less than 10% of the patients (HR, 1.07; 95% CI, 0.90 to 1.26). Patients treated with EP, compared with patients treated with CP, had more hospitalizations (2.4 v 1.7 hospitalizations, respectively; P < .001), outpatient visits (17.6 v 12.6 visits, respectively; P < .001), infectious complications (47.3% v 39.4%, respectively; P = .0022), acute kidney disease/dehydration (30.5% v 21.2%, respectively; P < .001), and mucositis/esophagitis (18.6% v 14.4%, respectively; P = .0246). Conclusion After accounting for prognostic variables, patients treated with EP versus CP had similar overall survival, but EP was associated with increased morbidity. PMID:25422491

Impacts of age of onset of substance use disorders on risk of adult incarceration among disadvantaged urban youth: a propensity score matching approach.

PubMed

Slade, Eric P; Stuart, Elizabeth A; Salkever, David S; Karakus, Mustafa; Green, Kerry M; Ialongo, Nicholas

2008-05-01

Age of onset of substance use disorders in adolescence and early adulthood could be associated with higher rates of adult criminal incarceration in the U.S., but evidence of these associations is scarce. Propensity score matching was used to estimate the association between adolescent-onset substance use disorders and the rate of incarceration, as well as incarceration costs and self-reported criminal arrests and convictions, of young men predominantly from African American, lower income, urban households. Age of onset was differentiated by whether onset of the first disorder occurred by age 16. Onset of a substance use disorder by age 16, but not later onset, was associated with a fourfold greater risk of adult incarceration for substance related offenses as compared to no disorder (0.35 vs. 0.09, P=0.044). Onset by age 16 and later onset were both positively associated with incarceration costs and risk of arrest and conviction, though associations with crime outcomes were more consistent with respect to onset by age 16. Results were robust to propensity score adjustment for observable predictors of substance use in adolescence and involvement in crime as an adult. Among young men in this high risk minority sample, having a substance use disorder by age 16 was associated with higher risk of incarceration for substance related offenses in early adulthood and with more extensive criminal justice system involvement as compared to having no disorder or having a disorder beginning at a later age.

Maternal Employment and Child Development: A Fresh Look Using Newer Methods

ERIC Educational Resources Information Center

Hill, Jennifer L.; Waldfogel, Jane; Brooks-Gunn, Jeanne; Han, Wen-Jui

2005-01-01

The employment rate for mothers with young children has increased dramatically over the past 25 years. Estimating the effects of maternal employment on children's development is challenged by selection bias and the missing data endemic to most policy research. To address these issues, this study uses propensity score matching and multiple…

An Illustrative Example of Propensity Score Matching with Education Research

ERIC Educational Resources Information Center

Lane, Forrest C.; To, Yen M.; Shelley, Kyna; Henson, Robin K.

2012-01-01

Researchers may be interested in examining the impact of programs that prepare youth and adults for successful careers but unable to implement experimental designs with true randomization of participants. As a result, these studies can be compromised by underlying factors that impact group selection and thus lead to potentially biased results.…

Risky Sexual Behavior: A Race-Specific Social Consequence of Obesity

ERIC Educational Resources Information Center

Leech, Tamara G. J.; Dias, Janice Johnson

2012-01-01

Scant attention has been given to the consequence of actual weight status for adolescents' sexual wellbeing. In this article, we investigate the race-specific connection between obesity and risky sexual behavior among adolescent girls. Propensity scores and radius matching are used to analyze a sample of 340 adolescents aged 16-17 who participated…

Time Spent on the Internet by Multicultural Adolescents in Korea

ERIC Educational Resources Information Center

Lim, Yangmi; Nam, Su-Jung

2017-01-01

This study analysed "The 8th Online Survey of Adolescent Health and Behaviour in 2012", which is a government-approved statistical survey of Internet use and patterns in Korea. We conducted a propensity score matching (PSM) to control for economic status differences between monocultural and multicultural families and an ANOVA to estimate…