A Systematic Review of Validated Methods for Identifying Cerebrovascular Accident or Transient Ischemic Attack Using Administrative Data

PubMed Central

Andrade, Susan E.; Harrold, Leslie R.; Tjia, Jennifer; Cutrona, Sarah L.; Saczynski, Jane S.; Dodd, Katherine S.; Goldberg, Robert J.; Gurwitz, Jerry H.

2012-01-01

Purpose To perform a systematic review of the validity of algorithms for identifying cerebrovascular accidents (CVAs) or transient ischemic attacks (TIAs) using administrative and claims data. Methods PubMed and Iowa Drug Information Service (IDIS) searches of the English language literature were performed to identify studies published between 1990 and 2010 that evaluated the validity of algorithms for identifying CVAs (ischemic and hemorrhagic strokes, intracranial hemorrhage and subarachnoid hemorrhage) and/or TIAs in administrative data. Two study investigators independently reviewed the abstracts and articles to determine relevant studies according to pre-specified criteria. Results A total of 35 articles met the criteria for evaluation. Of these, 26 articles provided data to evaluate the validity of stroke, 7 reported the validity of TIA, 5 reported the validity of intracranial bleeds (intracerebral hemorrhage and subarachnoid hemorrhage), and 10 studies reported the validity of algorithms to identify the composite endpoints of stroke/TIA or cerebrovascular disease. Positive predictive values (PPVs) varied depending on the specific outcomes and algorithms evaluated. Specific algorithms to evaluate the presence of stroke and intracranial bleeds were found to have high PPVs (80% or greater). Algorithms to evaluate TIAs in adult populations were generally found to have PPVs of 70% or greater. Conclusions The algorithms and definitions to identify CVAs and TIAs using administrative and claims data differ greatly in the published literature. The choice of the algorithm employed should be determined by the stroke subtype of interest. PMID:22262598

Melanoma of the Skin in the Danish Cancer Registry and the Danish Melanoma Database: A Validation Study.

PubMed

Pedersen, Sidsel Arnspang; Schmidt, Sigrun Alba Johannesdottir; Klausen, Siri; Pottegård, Anton; Friis, Søren; Hölmich, Lisbet Rosenkrantz; Gaist, David

2018-05-01

The nationwide Danish Cancer Registry and the Danish Melanoma Database both record data on melanoma for purposes of monitoring, quality assurance, and research. However, the data quality of the Cancer Registry and the Melanoma Database has not been formally evaluated. We estimated the positive predictive value (PPV) of melanoma diagnosis for random samples of 200 patients from the Cancer Registry (n = 200) and the Melanoma Database (n = 200) during 2004-2014, using the Danish Pathology Registry as "gold standard" reference. We further validated tumor characteristics in the Cancer Registry and the Melanoma Database. Additionally, we estimated the PPV of in situ melanoma diagnoses in the Melanoma Database, and the sensitivity of melanoma diagnoses in 2004-2014. The PPVs of melanoma in the Cancer Registry and the Melanoma Database were 97% (95% CI = 94, 99) and 100%. The sensitivity was 90% in the Cancer Registry and 77% in the Melanoma Database. The PPV of in situ melanomas in the Melanoma Database was 97% and the sensitivity was 56%. In the Melanoma Database, we observed PPVs of ulceration of 75% and Breslow thickness of 96%. The PPV of histologic subtypes varied between 87% and 100% in the Cancer Registry and 93% and 100% in the Melanoma Database. The PPVs for anatomical localization were 83%-95% in the Cancer Registry and 93%-100% in the Melanoma Database. The data quality in both the Cancer Registry and the Melanoma Database is high, supporting their use in epidemiologic studies.

Screening for colorectal cancer in Tianhe, Guangzhou: results of combining fecal immunochemical tests and risk factors for selecting patients requiring colonoscopy.

PubMed

Liao, Yi; Li, Senmao; Chen, Chunyu; He, Xuan; Lin, Feng; Wang, Jianping; Yang, Zuli; Lan, Ping

2018-05-01

To explore the performance of a protocol combining fecal immunochemical test (FIT) and a high-risk factor questionnaire (HRFQ) for selecting patients requiring colonoscopy as part of a population-based colorectal cancer (CRC) screening program in China. From 2015 to 2016, we conducted a CRC screening program for all residents aged 45 years or older in Tianhe District, Guangzhou City, China. Participants underwent an FIT and received an HRFQ as part of primary screening. Those with positive FIT and/or HRFQ results were considered to be at high risk and were recommended to undergo colonoscopy. A total of 10 074 subjects were recruited and enrolled in the screening program. In the enrolled population, 17.5% had positive FIT results and 19.4% had positive HRFQ results. Of those recommended to undergo diagnostic colonoscopy, 773 did so. The screening method's overall positive predictive value (PPV) was 4.9% for non-adenomatous polyps, 11.4% for low-risk adenomas (LRAs), 15.9% for high-risk adenomas (HRAs) and 1.6% for CRC. The PPVs of positive FIT results for non-adenomatous polyps, LRAs, HRAs and CRC were 5.2%, 15.9%, 22.5% and 2.5%, respectively. The PPVs of positive HRFQ results for non-adenomatous polyps, LRA, HRA and CRC were 4.1%, 10.2%, 14.3% and 1.4%, respectively. The PPVs associated with combined positive FIT and HRFQ results for non-adenomatous polyps, LRAs, HRAs and CRC were 4.5%, 16.4%, 23.7% and 2.8%, respectively. Our results suggest that this two-step CRC screening strategy, involving a combination of FIT and HRFQ followed by colonoscopy, is useful to identify early-stage CRC. The high detection rates and PPVs for CRC and adenomas encourage this strategy's use in ongoing screening programs.

Sensitivity and specificity of typhoid fever rapid antibody tests for laboratory diagnosis at two sub-Saharan African sites

PubMed Central

Keddy, Karen H; Sooka, Arvinda; Letsoalo, Maupi E; Hoyland, Greta; Chaignat, Claire Lise; Morrissey, Anne B; Crump, John A

2011-01-01

Abstract Objective To evaluate three commercial typhoid rapid antibody tests for Salmonella Typhi antibodies in patients suspected of having typhoid fever in Mpumalanga, South Africa, and Moshi, United Republic of Tanzania. Methods The diagnostic accuracy of Cromotest® (semiquantitative slide agglutination and single tube Widal test), TUBEX® and Typhidot® was assessed against that of blood culture. Performance was modelled for scenarios with pretest probabilities of 5% and 50%. Findings In total 92 patients enrolled: 53 (57.6%) from South Africa and 39 (42.4%) from the United Republic of Tanzania. Salmonella Typhi was isolated from the blood of 28 (30.4%) patients. The semiquantitative slide agglutination and single-tube Widal tests had positive predictive values (PPVs) of 25.0% (95% confidence interval, CI: 0.6–80.6) and 20.0% (95% CI: 2.5–55.6), respectively. The newer typhoid rapid antibody tests had comparable PPVs: TUBEX®, 54.1% (95% CI: 36.9–70.5); Typhidot® IgM, 56.7% (95% CI: 37.4–74.5); and Typhidot® IgG, 54.3% (95% CI: 36.6–71.2). For a pretest probability of 5%, PPVs were: TUBEX®, 11.0% (95% CI: 6.6–17.9); Typhidot® IgM, 9.1% (95% CI: 5.8–14.0); and Typhidot® IgG, 11.0% (6.3–18.4). For a pretest probability of 50%, PPVs were: TUBEX®, 70.2% (95% CI: 57.3–80.5); Typhidot® IgM, 65.6% (95% CI: 54.0–75.6); and Typhidot® IgG, 70.0% (95% CI: 56.0–81.1). Conclusion Semiquantitative slide agglutination and single-tube Widal tests performed poorly. TUBEX® and Typhidot® may be suitable when pretest probability is high and blood cultures are unavailable, but their performance does not justify deployment in routine care settings in sub-Saharan Africa. PMID:21897484

Different CT perfusion algorithms in the detection of delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage.

PubMed

Cremers, Charlotte H P; Dankbaar, Jan Willem; Vergouwen, Mervyn D I; Vos, Pieter C; Bennink, Edwin; Rinkel, Gabriel J E; Velthuis, Birgitta K; van der Schaaf, Irene C

2015-05-01

Tracer delay-sensitive perfusion algorithms in CT perfusion (CTP) result in an overestimation of the extent of ischemia in thromboembolic stroke. In diagnosing delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (aSAH), delayed arrival of contrast due to vasospasm may also overestimate the extent of ischemia. We investigated the diagnostic accuracy of tracer delay-sensitive and tracer delay-insensitive algorithms for detecting DCI. From a prospectively collected series of aSAH patients admitted between 2007-2011, we included patients with any clinical deterioration other than rebleeding within 21 days after SAH who underwent NCCT/CTP/CTA imaging. Causes of clinical deterioration were categorized into DCI and no DCI. CTP maps were calculated with tracer delay-sensitive and tracer delay-insensitive algorithms and were visually assessed for the presence of perfusion deficits by two independent observers with different levels of experience. The diagnostic value of both algorithms was calculated for both observers. Seventy-one patients were included. For the experienced observer, the positive predictive values (PPVs) were 0.67 for the delay-sensitive and 0.66 for the delay-insensitive algorithm, and the negative predictive values (NPVs) were 0.73 and 0.74. For the less experienced observer, PPVs were 0.60 for both algorithms, and NPVs were 0.66 for the delay-sensitive and 0.63 for the delay-insensitive algorithm. Test characteristics are comparable for tracer delay-sensitive and tracer delay-insensitive algorithms for the visual assessment of CTP in diagnosing DCI. This indicates that both algorithms can be used for this purpose.

Examining the validity and utility of two secondary sources of food environment data against street audits in England.

PubMed

Wilkins, Emma L; Radley, Duncan; Morris, Michelle A; Griffiths, Claire

2017-12-20

Secondary data containing the locations of food outlets is increasingly used in nutrition and obesity research and policy. However, evidence evaluating these data is limited. This study validates two sources of secondary food environment data: Ordnance Survey Points of Interest data (POI) and food hygiene data from the Food Standards Agency (FSA), against street audits in England and appraises the utility of these data. Audits were conducted across 52 Lower Super Output Areas in England. All streets within each Lower Super Output Area were covered to identify the name and street address of all food outlets therein. Audit-identified outlets were matched to outlets in the POI and FSA data to identify true positives (TP: outlets in both the audits and the POI/FSA data), false positives (FP: outlets in the POI/FSA data only) and false negatives (FN: outlets in the audits only). Agreement was assessed using positive predictive values (PPV: TP/(TP + FP)) and sensitivities (TP/(TP + FN)). Variations in sensitivities and PPVs across environment and outlet types were assessed using multi-level logistic regression. Proprietary classifications within the POI data were additionally used to classify outlets, and agreement between audit-derived and POI-derived classifications was assessed. Street audits identified 1172 outlets, compared to 1100 and 1082 for POI and FSA respectively. PPVs were statistically significantly higher for FSA (0.91, CI: 0.89-0.93) than for POI (0.86, CI: 0.84-0.88). However, sensitivity values were not different between the two datasets. Sensitivity and PPVs varied across outlet types for both datasets. Without accounting for this, POI had statistically significantly better PPVs in rural and affluent areas. After accounting for variability across outlet types, FSA had statistically significantly better sensitivity in rural areas and worse sensitivity in rural middle affluence areas (relative to deprived). Audit-derived and POI-derived classifications exhibited substantial agreement (p < 0.001; Kappa = 0.66, CI: 0.63-0.70). POI and FSA data have good agreement with street audits; although both datasets had geographic biases which may need to be accounted for in analyses. Use of POI proprietary classifications is an accurate method for classifying outlets, providing time savings compared to manual classification of outlets.

Claims-Based Definition of Death in Japanese Claims Database: Validity and Implications

PubMed Central

Ooba, Nobuhiro; Setoguchi, Soko; Ando, Takashi; Sato, Tsugumichi; Yamaguchi, Takuhiro; Mochizuki, Mayumi; Kubota, Kiyoshi

2013-01-01

Background For the pending National Claims Database in Japan, researchers will not have access to death information in the enrollment files. We developed and evaluated a claims-based definition of death. Methodology/Principal Findings We used healthcare claims and enrollment data between January 2005 and August 2009 for 195,193 beneficiaries aged 20 to 74 in 3 private health insurance unions. We developed claims-based definitions of death using discharge or disease status and Charlson comorbidity index (CCI). We calculated sensitivity, specificity and positive predictive values (PPVs) using the enrollment data as a gold standard in the overall population and subgroups divided by demographic and other factors. We also assessed bias and precision in two example studies where an outcome was death. The definition based on the combination of discharge/disease status and CCI provided moderate sensitivity (around 60%) and high specificity (99.99%) and high PPVs (94.8%). In most subgroups, sensitivity of the preferred definition was also around 60% but varied from 28 to 91%. In an example study comparing death rates between two anticancer drug classes, the claims-based definition provided valid and precise hazard ratios (HRs). In another example study comparing two classes of anti-depressants, the HR with the claims-based definition was biased and had lower precision than that with the gold standard definition. Conclusions/Significance The claims-based definitions of death developed in this study had high specificity and PPVs while sensitivity was around 60%. The definitions will be useful in future studies when used with attention to the possible fluctuation of sensitivity in some subpopulations. PMID:23741526

Business list vs ground observation for measuring a food environment: saving time or waste of time (or worse)?

PubMed

Lucan, Sean C; Maroko, Andrew R; Bumol, Joel; Torrens, Luis; Varona, Monica; Berke, Ethan M

2013-10-01

In food-environment research, an alternative to resource-intensive direct observation on the ground has been the use of commercial business lists. We sought to determine how well a frequently used commercial business list measures a dense urban food environment like the Bronx, NY. On 155 Bronx street segments, investigators compared two different levels for matches between the business list and direct ground observation: lenient (by business type) and strict (by business name). For each level of matching, researchers calculated sensitivities and positive predictive values (PPVs) for the business list overall and by broad business categories: General Grocers (eg, supermarkets), Specialty Food Stores (eg, produce markets), Restaurants, and Businesses Not Primarily Selling Food (eg, newsstands). Even after cleaning the business list (eg, for cases of multiple listings at a single location), and allowing for inexactness in listed street addresses and spellings of business names, the overall performance of the business list was poor. For strict matches, the business list had an overall sensitivity of 39.3% and PPV of 45.5%. Sensitivities and PPVs by broad business categories were not meaningfully different from overall values, although sensitivity for General Grocers and PPV for Specialty Food Stores were particularly low: 26.2% and 32%, respectively. For lenient matches, sensitivities and PPVs were somewhat higher but still poor: 52.4% to 60% and 60% to 75%, respectively. The business list is inadequate to measure the actual food environment in the Bronx. If results represent performance in other settings, findings from prior studies linking food environments to diet and diet-related health outcomes using such business lists are in question, and future studies of this type should avoid relying solely on such business lists. Copyright © 2013 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

Accuracy of the hypospadias diagnoses and surgical treatment registrations in the Danish National Patient Register

PubMed Central

Lindhard, Morten Søndergaard; Jønsson, Anne Aggerholm; Henriksen, Tine Brink; Olsen, Jørn; Thorup, Jorgen; Olsen, L Henning; Ramlau-Hansen, Cecilia Høst

2017-01-01

Purpose The Danish National Health registers provide a valuable data source that offers unique opportunities for observational research, including studies on the congenital anomaly hypospadias. The accuracy of the diagnosis and surgical treatment registration of hypospadias in the Danish National Patient Register (DNPR) remains unknown. Patients and methods We randomly sampled 500 patients diagnosed with hypospadias in the DNPR from January 1, 1995 to December 31, 2012. Among these, 384 patients were also registered with surgical treatment for hypospadias. Medical records were collected and reviewed independently by two investigators. Any classification disagreements were resolved by consensus. Using the medical records as the gold standard, we estimated positive predictive values (PPVs) with 95% confidence intervals (CIs) for the hypospadias diagnoses and surgical treatment registrations overall, as well as for the clinical subtypes. Results We were able to retrieve medical records for 463 (92.6%) patients with hypospadias diagnoses and for 329 (85.7%) patients registered with surgical treatment. Presence of hypospadias was confirmed in 450 of 463 patients, yielding an overall PPV (95% CI) of 97.6% (95.8%–98.7%). For subtypes of hypospadias, the PPVs ranged between 37.5% and 72.7%. For surgical treatment of hypospadias, the overall PPV was 99.7% (97.9%–99.9%). Conclusion The validity of the registration of hypospadias diagnoses as well as surgical treatment for hypospadias in the DNPR is overall very high. For the specific subtypes of hypospadias diagnoses codes and the specific surgical treatment codes, the PPVs are lower and cautious use is warranted. However, the DNPR remains a valuable tool for future observational research on hypospadias. PMID:29042817

Adverse Drug Event Detection in Pediatric Oncology and Hematology Patients: Using Medication Triggers to Identify Patient Harm in a Specialized Pediatric Patient Population

PubMed Central

Call, Rosemary J.; Burlison, Jonathan D.; Robertson, Jennifer J.; Scott, Jeffrey R.; Baker, Donald K.; Rossi, Michael G.; Howard, Scott C.; Hoffman, James M.

2014-01-01

Objective To investigate the use of a trigger tool for adverse drug event (ADE) detection in a pediatric hospital specializing in oncology, hematology, and other catastrophic diseases. Study design A medication-based trigger tool package analyzed electronic health records from February 2009 to February 2013. Chart review determined whether an ADE precipitated the trigger. Severity was assigned to ADEs, and preventability was assessed. Preventable ADEs were compared with the hospital’s electronic voluntary event reporting system to identify whether these ADEs had been previously identified. The positive predictive values (PPVs) of the entire trigger tool and individual triggers were calculated to assess their accuracy to detect ADEs. Results Trigger occurrences (n=706) were detected in 390 patients from six medication triggers, 33 of which were ADEs (overall PPV = 16%). Hyaluronidase had the highest PPV (60%). Most ADEs were category E harm (temporary harm) per the National Coordinating Council for Medication Error Reporting and Prevention (NCC MERP) index. One event was category H harm (intervention to sustain life). Naloxone was associated with the most grade 4 ADEs per the Common Terminology Criteria for Adverse Events (CTCAE) v4.03. Twenty-one (64%) ADEs were preventable; 3 of which were submitted via the voluntary reporting system. Conclusion Most of the medication-based triggers yielded low PPVs. Refining the triggers based on patients’ characteristics and medication usage patterns could increase the PPVs and make them more useful for quality improvement. To efficiently detect ADEs, triggers must be revised to reflect specialized pediatric patient populations such as hematology and oncology patients. PMID:24768254

Adverse drug event detection in pediatric oncology and hematology patients: using medication triggers to identify patient harm in a specialized pediatric patient population.

PubMed

Call, Rosemary J; Burlison, Jonathan D; Robertson, Jennifer J; Scott, Jeffrey R; Baker, Donald K; Rossi, Michael G; Howard, Scott C; Hoffman, James M

2014-09-01

To investigate the use of a trigger tool for the detection of adverse drug events (ADE) in a pediatric hospital specializing in oncology, hematology, and other catastrophic diseases. A medication-based trigger tool package analyzed electronic health records from February 2009 to February 2013. Chart review determined whether an ADE precipitated the trigger. Severity was assigned to ADEs, and preventability was assessed. Preventable ADEs were compared with the hospital's electronic voluntary event reporting system to identify whether these ADEs had been previously identified. The positive predictive values (PPVs) of the entire trigger tool and individual triggers were calculated to assess their accuracy to detect ADEs. Trigger occurrences (n = 706) were detected in 390 patients from 6 medication triggers, 33 of which were ADEs (overall PPV = 16%). Hyaluronidase had the greatest PPV (60%). Most ADEs were category E harm (temporary harm) per the National Coordinating Council for Medication Error Reporting and Prevention index. One event was category H harm (intervention to sustain life). Naloxone was associated with the most grade 4 ADEs per the Common Terminology Criteria for Adverse Events v4.03. Twenty-one (64%) ADEs were preventable, 3 of which were submitted via the voluntary reporting system. Most of the medication-based triggers yielded low PPVs. Refining the triggers based on patients' characteristics and medication usage patterns could increase the PPVs and make them more useful for quality improvement. To efficiently detect ADEs, triggers must be revised to reflect specialized pediatric patient populations such as hematology and oncology patients. Copyright © 2014 Elsevier Inc. All rights reserved.

Positive predictive values by mammographic density and screening mode in the Norwegian Breast Cancer Screening Program.

PubMed

Moshina, Nataliia; Ursin, Giske; Roman, Marta; Sebuødegård, Sofie; Hofvind, Solveig

2016-01-01

To investigate the probability of breast cancer among women recalled due to abnormal findings on the screening mammograms (PPV-1) and among women who underwent an invasive procedure (PPV-2) by mammographic density (MD), screening mode and age. We used information about 28,826 recall examinations from 26,951 subsequently screened women in the Norwegian Breast Cancer Screening Program, 1996-2010. The radiologists who performed the recall examinations subjectively classified MD on the mammograms into three categories: fatty (<30% fibroglandular tissue); medium dense (30-70%) and dense (>70%). Screening mode was defined as screen-film mammography (SFM) and full-field digital mammography (FFDM). We examined trends of PPVs by MD, screening mode and age. We used logistic regression to estimate odds ratio (OR) of screen-detected breast cancer associated with MD among women recalled, adjusting for screening mode and age. PPV-1 and PPV-2 decreased by increasing MD, regardless of screening mode (p for trend <0.05 for both PPVs). PPV-1 and PPV-2 were statistically significantly higher for FFDM compared with SFM for women with fatty breasts. Among women recalled, the adjusted OR of breast cancer decreased with increasing MD. Compared with women with fatty breasts, the OR was 0.90 (95% CI: 0.84-0.96) for those with medium dense breasts and 0.85 (95% CI: 0.76-0.95) for those with dense breasts. PPVs decreased by increasing MD. Fewer women needed to be recalled or undergo an invasive procedure to detect one breast cancer among those with fatty versus dense breasts in the screening program in Norway, 1996-2010. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Alarm Variables for Dengue Outbreaks: A Multi-Centre Study in Asia and Latin America

PubMed Central

Bowman, Leigh R.; Tejeda, Gustavo S.; Coelho, Giovanini E.; Sulaiman, Lokman H.; Gill, Balvinder S.; McCall, Philip J.; Olliaro, Piero L.; Ranzinger, Silvia R.; Quang, Luong C.; Ramm, Ronald S.; Kroeger, Axel; Petzold, Max G.

2016-01-01

Background Worldwide, dengue is an unrelenting economic and health burden. Dengue outbreaks have become increasingly common, which place great strain on health infrastructure and services. Early warning models could allow health systems and vector control programmes to respond more cost-effectively and efficiently. Methodology/Principal Findings The Shewhart method and Endemic Channel were used to identify alarm variables that may predict dengue outbreaks. Five country datasets were compiled by epidemiological week over the years 2007–2013. These data were split between the years 2007–2011 (historic period) and 2012–2013 (evaluation period). Associations between alarm/ outbreak variables were analysed using logistic regression during the historic period while alarm and outbreak signals were captured during the evaluation period. These signals were combined to form alarm/ outbreak periods, where 2 signals were equal to 1 period. Alarm periods were quantified and used to predict subsequent outbreak periods. Across Mexico and Dominican Republic, an increase in probable cases predicted outbreaks of hospitalised cases with sensitivities and positive predictive values (PPV) of 93%/ 83% and 97%/ 86% respectively, at a lag of 1–12 weeks. An increase in mean temperature ably predicted outbreaks of hospitalised cases in Mexico and Brazil, with sensitivities and PPVs of 79%/ 73% and 81%/ 46% respectively, also at a lag of 1–12 weeks. Mean age was predictive of hospitalised cases at sensitivities and PPVs of 72%/ 74% and 96%/ 45% in Mexico and Malaysia respectively, at a lag of 4–16 weeks. Conclusions/Significance An increase in probable cases was predictive of outbreaks, while meteorological variables, particularly mean temperature, demonstrated predictive potential in some countries, but not all. While it is difficult to define uniform variables applicable in every country context, the use of probable cases and meteorological variables in tailored early warning systems could be used to highlight the occurrence of dengue outbreaks or indicate increased risk of dengue transmission. PMID:27348752

Clinical flow cytometric screening of SAP and XIAP expression accurately identifies patients with SH2D1A and XIAP/BIRC4 mutations.

PubMed

Gifford, Carrie E; Weingartner, Elizabeth; Villanueva, Joyce; Johnson, Judith; Zhang, Kejian; Filipovich, Alexandra H; Bleesing, Jack J; Marsh, Rebecca A

2014-07-01

X-linked lymphoproliferative disease is caused by mutations in two genes, SH2D1A and XIAP/BIRC4. Flow cytometric methods have been developed to detect the gene products, SAP and XIAP. However, there is no literature describing the accuracy of flow cytometric screening performed in a clinical lab setting. We reviewed the clinical flow cytometric testing results for 656 SAP and 586 XIAP samples tested during a 3-year period. Genetic testing was clinically performed as directed by the managing physician in 137 SAP (21%) and 115 XIAP (20%) samples. We included these samples for analyses of flow cytometric test accuracy. SH2D1A mutations were detected in 15/137 samples. SAP expression was low in 13/15 (sensitivity 87%, CI 61-97%). Of the 122 samples with normal sequencing, SAP was normal in 109 (specificity 89%, CI 82-94%). The positive predictive values (PPVs) and the negative predictive values (NPVs) were 50% and 98%, respectively. XIAP/BIRC4 mutations were detected in 19/115 samples. XIAP expression was low in 18/19 (sensitivity 95%, CI 73-100%). Of the 96 samples with normal sequencing, 59 had normal XIAP expression (specificity 61%, CI 51-71%). The PPVs and NPVs were 33% and 98%, respectively. Receiver-operating characteristic analysis was able to improve the specificity to 75%. Clinical flow cytometric screening tests for SAP and XIAP deficiencies offer good sensitivity and specificity for detecting genetic mutations, and are characterized by high NPVs. We recommend these tests for patients suspected of having X-linked lymphoproliferative disease type 1 (XLP1) or XLP2. © 2014 Clinical Cytometry Society.

Identifying Psoriasis and Psoriatic Arthritis Patients in Retrospective Databases When Diagnosis Codes Are Not Available: A Validation Study Comparing Medication/Prescriber Visit-Based Algorithms with Diagnosis Codes.

PubMed

Dobson-Belaire, Wendy; Goodfield, Jason; Borrelli, Richard; Liu, Fei Fei; Khan, Zeba M

2018-01-01

Using diagnosis code-based algorithms is the primary method of identifying patient cohorts for retrospective studies; nevertheless, many databases lack reliable diagnosis code information. To develop precise algorithms based on medication claims/prescriber visits (MCs/PVs) to identify psoriasis (PsO) patients and psoriatic patients with arthritic conditions (PsO-AC), a proxy for psoriatic arthritis, in Canadian databases lacking diagnosis codes. Algorithms were developed using medications with narrow indication profiles in combination with prescriber specialty to define PsO and PsO-AC. For a 3-year study period from July 1, 2009, algorithms were validated using the PharMetrics Plus database, which contains both adjudicated medication claims and diagnosis codes. Positive predictive value (PPV), negative predictive value (NPV), sensitivity, and specificity of the developed algorithms were assessed using diagnosis code as the reference standard. Chosen algorithms were then applied to Canadian drug databases to profile the algorithm-identified PsO and PsO-AC cohorts. In the selected database, 183,328 patients were identified for validation. The highest PPVs for PsO (85%) and PsO-AC (65%) occurred when a predictive algorithm of two or more MCs/PVs was compared with the reference standard of one or more diagnosis codes. NPV and specificity were high (99%-100%), whereas sensitivity was low (≤30%). Reducing the number of MCs/PVs or increasing diagnosis claims decreased the algorithms' PPVs. We have developed an MC/PV-based algorithm to identify PsO patients with a high degree of accuracy, but accuracy for PsO-AC requires further investigation. Such methods allow researchers to conduct retrospective studies in databases in which diagnosis codes are absent. Copyright © 2018 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

Explicit simulation of ice particle habits in a Numerical Weather Prediction Model

NASA Astrophysics Data System (ADS)

Hashino, Tempei

2007-05-01

This study developed a scheme for explicit simulation of ice particle habits in Numerical Weather Prediction (NWP) Models. The scheme is called Spectral Ice Habit Prediction System (SHIPS), and the goal is to retain growth history of ice particles in the Eulerian dynamics framework. It diagnoses characteristics of ice particles based on a series of particle property variables (PPVs) that reflect history of microphysieal processes and the transport between mass bins and air parcels in space. Therefore, categorization of ice particles typically used in bulk microphysical parameterization and traditional bin models is not necessary, so that errors that stem from the categorization can be avoided. SHIPS predicts polycrystals as well as hexagonal monocrystals based on empirically derived habit frequency and growth rate, and simulates the habit-dependent aggregation and riming processes by use of the stochastic collection equation with predicted PPVs. Idealized two dimensional simulations were performed with SHIPS in a NWP model. The predicted spatial distribution of ice particle habits and types, and evolution of particle size distributions showed good quantitative agreement with observation This comprehensive model of ice particle properties, distributions, and evolution in clouds can be used to better understand problems facing wide range of research disciplines, including microphysics processes, radiative transfer in a cloudy atmosphere, data assimilation, and weather modification.

Issues and Challenges in the Development of Pneumococcal Protein Vaccines: A Two Day International Symposium

PubMed Central

Ginsburg, Amy S.; Nahm, Moon H.; Khambaty, Farukh M.; Alderson, Mark R.

2013-01-01

In view of the increasing licensure and use of pneumococcal conjugate vaccines (PCVs), their relatively high cost, and growing issues with serotype emergence, there is a need to re-evaluate the role of pneumococcal protein vaccines (PPVs) and pathways to their licensure. This paper summarizes the discussion and viewpoints from an expert meeting regarding the development of PPVs. A wide spectrum of pneumococcal vaccine researchers, developers, and regulators met to review the state of PPVs, identify research and development needs, and provide consensus opinions to support the introduction of new PPVs where possible. They also discussed clinical and regulatory aspects pertinent to these vaccines and generated a series of recommendations for moving the field forward. PMID:22380821

Histological outcomes of anal high-grade cytopredictions.

PubMed

Roberts, Jennifer Margaret; Jin, Fengyi; Poynten, Isobel Mary; Law, Carmella; Templeton, David James; Thurloe, Julia Kathleen; Garland, Suzanne Marie; Grulich, Andrew Edwin; Farnsworth, Annabelle; Hillman, Richard John

2018-02-01

Longitudinal studies of histological outcomes after anal cytological screening in men who have sex with men (MSM) are rare. This study measured the positive predictive values (PPVs) of each level of baseline cytological abnormality in MSM in Sydney, Australia, over a 12-month period. The Study of the Prevention of Anal Cancer is a 3-year prospective study of the natural history of anal human papillomavirus infection in MSM at least 35 years old. For each participant with a baseline cytological abnormality, the worst histology was recorded at the baseline high-resolution anoscopy and at 6 and 12 months. PPVs for a histological high-grade squamous intraepithelial lesion (HSIL) diagnosis were calculated for each level of baseline cytological abnormality at each time point. Among 424 men who completed 3 visits, the PPV of a cytological HSIL increased from 71.6% at the baseline to 86.4% at 6 months and to 92.6% at 12 months (P < .001). For cytological atypical squamous cells, cannot rule out high-grade squamous intraepithelial lesion (ASC-H), the PPV increased from 51.5% at the baseline to 69.7% at 6 months and to 75.8% at 12 months (P = .004). At each time point, the PPV of a cytological HSIL was significantly higher than the PPV of ASC-H. The PPV of low-grade cytology reports was significantly lower than the PPV of ASC-H at each time point. In a cohort of MSM, a baseline histological HSIL diagnosis after an HSIL cytoprediction is high, and it increases with further examinations over the course of 12 months. Lower levels of cytological abnormalities have significantly lower PPVs. These data can inform patient management and the quality assessment of each aspect of the screening pathway. Cancer Cytopathol 2018;126:136-44. © 2017 American Cancer Society. © 2017 American Cancer Society.

Detection of aneurysmal subarachnoid hemorrhage 3 months after initial bleeding: evaluation of T2* and FLAIR MR sequences at 3 T in comparison with initial non-enhanced CT as a gold standard.

PubMed

Mulé, Sébastien; Soize, Sébastien; Benaissa, Azzedine; Portefaix, Christophe; Pierot, Laurent

2016-08-01

To investigate the ability of T2* and fluid-attenuated inversion recovery (FLAIR) MR sequences to detect hemosiderin deposition 3 months after aneurysmal subarachnoid hemorrhage (SAH) in comparison with early non-enhanced CT (NECT) as a gold standard. From September 2008 through May 2013, patients with aneurysmal SAH were included if a NECT less than 24 h after the onset of symptoms showed a SAH, and MRI, including T2* and FLAIR sequences, was performed 3 months later. All aneurysms were treated endovascularly. NECT and MR sequences were blindly analyzed for the presence of SAH (NECT) or hemosiderin deposition (MRI). When positive, details of the spatial distribution of SAH or hemosiderin deposits were noted. Sensitivities were calculated for each patient. Sensitivities, specificities, and positive predictive values (PPVs) were calculated for each location. Forty-nine patients (mean age 52.9 years) were included. Bleeding-related patterns were identified in 43 patients (87.8%) on T2* and 10 patients (20.4%) on FLAIR. T2* was highly predictive of the location of the initial hemorrhage, especially in the Sylvian cisterns (PPVs 95% and 100%) and the anterior interhemispheric fissure (PPV 90%). The T2* sequence can detect and localize a previous SAH a few months after aneurysmal bleeding. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Identification of Vape Shops in Two North Carolina Counties: An Approach for States without Retailer Licensing.

PubMed

Lee, Joseph G L; D'Angelo, Heather; Kuteh, Jaleel D; Martin, Ryan J

2016-10-27

Stores that sell electronic nicotine delivery systems (ENDS) as their primary product are a new phenomenon and often termed "vape shops". While vape shops are now regulated by state and federal agencies, not all states maintain lists of vape shops in operation. Standard ways of identifying tobacco retailers through off-premise alcohol permits and business listing services may not identify vape shops. We used four online business listing services (i.e., Google Maps, ReferenceUSA, YellowPages.com, Yelp) to identify vape shops in two counties in North Carolina (NC). In one county, we also assessed four vaping web sites. We drove primary and secondary roads to physically validate the identified stores and attempt to identify stores not listed online. To assess the accuracy of the online searches, we calculated sensitivity and positive predictive values (PPVs). This research was conducted in spring and summer 2016 and identified 28 vape shops online. We confirmed 16 vape shops (seven in Pitt County, NC, USA, and nine in Durham County, NC, USA). Online searches ranged in sensitivity, 62.5%-81.3%, and PPVs ranged from 73.3% to 92.3%. Because of the range of sensitivity found among the business listing services, state policymakers should consider uniform licensing requirements for vape and tobacco retailers to more easily track retailers and ensure compliance with regulations.

Identification of Vape Shops in Two North Carolina Counties: An Approach for States without Retailer Licensing

PubMed Central

Lee, Joseph G. L.; D’Angelo, Heather; Kuteh, Jaleel D.; Martin, Ryan J.

2016-01-01

Stores that sell electronic nicotine delivery systems (ENDS) as their primary product are a new phenomenon and often termed “vape shops”. While vape shops are now regulated by state and federal agencies, not all states maintain lists of vape shops in operation. Standard ways of identifying tobacco retailers through off-premise alcohol permits and business listing services may not identify vape shops. We used four online business listing services (i.e., Google Maps, ReferenceUSA, YellowPages.com, Yelp) to identify vape shops in two counties in North Carolina (NC). In one county, we also assessed four vaping web sites. We drove primary and secondary roads to physically validate the identified stores and attempt to identify stores not listed online. To assess the accuracy of the online searches, we calculated sensitivity and positive predictive values (PPVs). This research was conducted in spring and summer 2016 and identified 28 vape shops online. We confirmed 16 vape shops (seven in Pitt County, NC, USA, and nine in Durham County, NC, USA). Online searches ranged in sensitivity, 62.5%–81.3%, and PPVs ranged from 73.3% to 92.3%. Because of the range of sensitivity found among the business listing services, state policymakers should consider uniform licensing requirements for vape and tobacco retailers to more easily track retailers and ensure compliance with regulations. PMID:27801793

Validation of asthma recording in electronic health records: a systematic review

PubMed Central

Nissen, Francis; Quint, Jennifer K; Wilkinson, Samantha; Mullerova, Hana; Smeeth, Liam; Douglas, Ian J

2017-01-01

Objective To describe the methods used to validate asthma diagnoses in electronic health records and summarize the results of the validation studies. Background Electronic health records are increasingly being used for research on asthma to inform health services and health policy. Validation of the recording of asthma diagnoses in electronic health records is essential to use these databases for credible epidemiological asthma research. Methods We searched EMBASE and MEDLINE databases for studies that validated asthma diagnoses detected in electronic health records up to October 2016. Two reviewers independently assessed the full text against the predetermined inclusion criteria. Key data including author, year, data source, case definitions, reference standard, and validation statistics (including sensitivity, specificity, positive predictive value [PPV], and negative predictive value [NPV]) were summarized in two tables. Results Thirteen studies met the inclusion criteria. Most studies demonstrated a high validity using at least one case definition (PPV >80%). Ten studies used a manual validation as the reference standard; each had at least one case definition with a PPV of at least 63%, up to 100%. We also found two studies using a second independent database to validate asthma diagnoses. The PPVs of the best performing case definitions ranged from 46% to 58%. We found one study which used a questionnaire as the reference standard to validate a database case definition; the PPV of the case definition algorithm in this study was 89%. Conclusion Attaining high PPVs (>80%) is possible using each of the discussed validation methods. Identifying asthma cases in electronic health records is possible with high sensitivity, specificity or PPV, by combining multiple data sources, or by focusing on specific test measures. Studies testing a range of case definitions show wide variation in the validity of each definition, suggesting this may be important for obtaining asthma definitions with optimal validity. PMID:29238227

Comparison of the Cerebrospinal Fluid (CSF) Toluidine Red Unheated Serum Test and the CSF Rapid Plasma Reagin Test with the CSF Venereal Disease Research Laboratory Test for Diagnosis of Neurosyphilis among HIV-Negative Syphilis Patients in China

PubMed Central

Zhu, Lin; Gu, Xin; Peng, Rui-Rui; Wang, Cuini; Gao, Zixiao; Gao, Ying; Shi, Mei; Guan, Zhifang; Seña, Arlene C.

2014-01-01

In this study, we aimed to investigate the performance of nontreponemal antibody tests in cerebrospinal fluid (CSF) specimens from syphilis patients. From September 2009 to September 2012, CSF specimens were collected at the Shanghai Skin Disease Hospital in Shanghai, China, from 1,132 syphilis patients without HIV infection, including 154 with symptomatic and 56 with asymptomatic neurosyphilis. All of the CSF specimens underwent testing with a rapid plasma reagin (RPR) test, an RPR-V (commercial RPR antigen diluted 1:2 in 10% saline) test, the toluidine red unheated serum test (TRUST), and the Venereal Disease Research Laboratory (VDRL) test. Specificities, sensitivities, positive predictive values (PPVs), negative predictive values (NPVs), and kappa values were calculated to determine the performances of the tests. We compared results of the CSF-VDRL, CSF-RPR, CSF-RPR-V, and CSF-TRUST among patients with symptomatic and asymptomatic neurosyphilis who had reactive CSF-Treponema pallidum particle agglutination (TPPA) test results. Overall, the CSF-VDRL test was reactive in 261 patients (23.1%). There were no cases in which the CSF-VDRL was nonreactive and CSF-RPR, CSF-RPR-V, or CSF-TRUST was reactive. Agreement between the results of CSF-TRUST and CSF-RPR was almost perfect (κ = 0.861), with substantial agreement between the results of CSF-RPR and CSF-RPR-V (κ = 0.740). The sensitivities of CSF-VDRL, CSF-RPR, CSF-RPR-V, and CSF-TRUST were 81.4%, 76.2%, 79.5%, and 76.2%, respectively. Compared to CSF-VDRL, CSF-RPR, CSF-RPR-V, and CSF-TRUST had comparable PPVs and NPVs. However, the specificity of CSF-VDRL (90.3%) was significantly lower than those of the other tests (92.7 to 93.4%). Therefore, CSF-RPR, CSF-RPR-V, and CSF-TRUST can be considered alternative tests for neurosyphilis diagnosis in HIV-negative populations, particularly when the CSF-VDRL is not available. PMID:24335955

A systematic review of validated methods for identifying hypersensitivity reactions other than anaphylaxis (fever, rash, and lymphadenopathy), using administrative and claims data.

PubMed

Schneider, Gary; Kachroo, Sumesh; Jones, Natalie; Crean, Sheila; Rotella, Philip; Avetisyan, Ruzan; Reynolds, Matthew W

2012-01-01

The Food and Drug Administration's Mini-Sentinel pilot program aims to conduct active surveillance to refine safety signals that emerge for marketed medical products. A key facet of this surveillance is to develop and understand the validity of algorithms for identifying health outcomes of interest from administrative and claims data. This article summarizes the process and findings of the algorithm review of hypersensitivity reactions. PubMed and Iowa Drug Information Service searches were conducted to identify citations applicable to the hypersensitivity reactions of health outcomes of interest. Level 1 abstract reviews and Level 2 full-text reviews were conducted to find articles using administrative and claims data to identify hypersensitivity reactions and including validation estimates of the coding algorithms. We identified five studies that provided validated hypersensitivity-reaction algorithms. Algorithm positive predictive values (PPVs) for various definitions of hypersensitivity reactions ranged from 3% to 95%. PPVs were high (i.e. 90%-95%) when both exposures and diagnoses were very specific. PPV generally decreased when the definition of hypersensitivity was expanded, except in one study that used data mining methodology for algorithm development. The ability of coding algorithms to identify hypersensitivity reactions varied, with decreasing performance occurring with expanded outcome definitions. This examination of hypersensitivity-reaction coding algorithms provides an example of surveillance bias resulting from outcome definitions that include mild cases. Data mining may provide tools for algorithm development for hypersensitivity and other health outcomes. Research needs to be conducted on designing validation studies to test hypersensitivity-reaction algorithms and estimating their predictive power, sensitivity, and specificity. Copyright © 2012 John Wiley & Sons, Ltd.

Breast cancer mammographic diagnosis performance in a public health institution: a retrospective cohort study.

PubMed

Mello, Juliana M R B; Bittelbrunn, Fernando P; Rockenbach, Marcio A B C; May, Guilherme G; Vedolin, Leonardo M; Kruger, Marilia S; Soldatelli, Matheus D; Zwetsch, Guilherme; de Miranda, Gabriel T F; Teixeira, Saone I P; Arruda, Bruna S

2017-12-01

To evaluate the quality assurance of mammography results at a reference institution for the diagnosis and treatment of breast cancer in southern Brazil, based on the BIRADS (Breast Imaging Reporting and Data System) 5th edition recommendations for auditing purposes. Retrospective cohort and cross-sectional study with 4502 patients (9668 mammographies)) who underwent at least one or both breast mammographies throughout 2013 at a regional public hospital, linked to a federal public university. The results were followed until 31 December 2014, including true positives (TPs), true negatives (TNs), false positives (FPs), false negatives (FNs), positive predictive values (PPVs), negative predictive value (NPV), sensitivity and specificity, with a confidence interval of 95%. The study showed high quality assurance, particularly regarding sensitivity (90.22%) and specificity (92.31%). The overall positive predictive value (PPV) was 65.35%, and the negative predictive value (NPV) was 98.32%. The abnormal interpretation rate (recall rate) was 12.26%. The results are appropriate when compared to the values proposed by the BIRADS 5th edition. Additionally, the study provided self-reflection considering our radiological practice, which is essential for improvements and collaboration regarding breast cancer detection. It may stimulate better radiological practice performance and continuing education, despite possible infrastructure and facility limitations. • Accurate quality performance rates are possible despite financial and governmental limitations. • Low-income institutions should develop standardised teamwork to improve radiological practice. • Regular mammography audits may help to increase the quality of public health systems.

Predictive value of autoantibody testing for validating self-reported diagnoses of rheumatoid arthritis in the Women's Health Initiative.

PubMed

Walitt, Brian; Mackey, Rachel; Kuller, Lewis; Deane, Kevin D; Robinson, William; Holers, V Michael; Chang, Yue-Fang; Moreland, Larry

2013-05-01

Rheumatoid arthritis (RA) research using large databases is limited by insufficient case validity. Of 161,808 postmenopausal women in the Women's Health Initiative, 15,691 (10.2%) reported having RA, far higher than the expected 1% population prevalence. Since chart review for confirmation of an RA diagnosis is impractical in large cohort studies, the current study (2009-2011) tested the ability of baseline serum measurements of rheumatoid factor and anti-cyclic citrullinated peptide antibodies, second-generation assay (anti-CCP2), to identify physician-validated RA among the chart-review study participants with self-reported RA (n = 286). Anti-CCP2 positivity had the highest positive predictive value (PPV) (80.0%), and rheumatoid factor positivity the lowest (44.6%). Together, use of disease-modifying antirheumatic drugs and anti-CCP2 positivity increased PPV to 100% but excluded all seronegative cases (approximately 15% of all RA cases). Case definitions inclusive of seronegative cases had PPVs between 59.6% and 63.6%. False-negative results were minimized in these test definitions, as evidenced by negative predictive values of approximately 90%. Serological measurements, particularly measurement of anti-CCP2, improved the test characteristics of RA case definitions in the Women's Health Initiative.

Importance of multi-modal approaches to effectively identify cataract cases from electronic health records.

PubMed

Peissig, Peggy L; Rasmussen, Luke V; Berg, Richard L; Linneman, James G; McCarty, Catherine A; Waudby, Carol; Chen, Lin; Denny, Joshua C; Wilke, Russell A; Pathak, Jyotishman; Carrell, David; Kho, Abel N; Starren, Justin B

2012-01-01

There is increasing interest in using electronic health records (EHRs) to identify subjects for genomic association studies, due in part to the availability of large amounts of clinical data and the expected cost efficiencies of subject identification. We describe the construction and validation of an EHR-based algorithm to identify subjects with age-related cataracts. We used a multi-modal strategy consisting of structured database querying, natural language processing on free-text documents, and optical character recognition on scanned clinical images to identify cataract subjects and related cataract attributes. Extensive validation on 3657 subjects compared the multi-modal results to manual chart review. The algorithm was also implemented at participating electronic MEdical Records and GEnomics (eMERGE) institutions. An EHR-based cataract phenotyping algorithm was successfully developed and validated, resulting in positive predictive values (PPVs) >95%. The multi-modal approach increased the identification of cataract subject attributes by a factor of three compared to single-mode approaches while maintaining high PPV. Components of the cataract algorithm were successfully deployed at three other institutions with similar accuracy. A multi-modal strategy incorporating optical character recognition and natural language processing may increase the number of cases identified while maintaining similar PPVs. Such algorithms, however, require that the needed information be embedded within clinical documents. We have demonstrated that algorithms to identify and characterize cataracts can be developed utilizing data collected via the EHR. These algorithms provide a high level of accuracy even when implemented across multiple EHRs and institutional boundaries.

Current Status of Testing for Microdeletion Syndromes and Rare Autosomal Trisomies Using Cell-Free DNA Technology.

PubMed

Yaron, Yuval; Jani, Jacques; Schmid, Maximilian; Oepkes, Dick

2015-11-01

Noninvasive prenatal testing using cell-free DNA in maternal blood for trisomy 21 was introduced in 2011. This technology has continuously evolved with the addition of screening for trisomy 18 and trisomy 13 followed by the inclusion of sex chromosome aneuploidies. Expanded noninvasive prenatal test panels have recently become available, which enable screening for microdeletion syndromes such as the 22q11.2 deletion (associated with the velocardiofacial syndrome) and others. However, the performance data for these microdeletion syndromes are derived from a small number of samples, mostly generated in vitro. Rigorous performance evaluation, as was done at least for trisomy 21 testing using cell-free DNA analysis, is difficult to perform given the rarity of each condition. In addition, detection rates may vary considerably depending on deletion size. Importantly, positive predictive values (PPVs), strongly influenced by the low prevalence, are expected to be significantly lower than 10% for most conditions. Thus, screening in an average-risk population is likely to have many more false-positives than affected cases detected. Conversely, testing in a high-risk population such as fetuses with cardiac anomalies may have higher PPVs, but a negative result needs to be considered carefully as a result of uncertain information about detection rates and a significant residual risk for other copy number variants and single gene disorders. This article integrates current knowledge on cell-free DNA testing for microdeletions with the aim to assist clinicians and policymakers in designing optimal programs for screening in pregnancy.

Apple fruit acidity is genetically diversified by natural variations in three hierarchical epistatic genes MdSAUR37, MdPP2CH and MdALMTII.

PubMed

Jia, Dongjie; Shen, Fei; Wang, Yi; Wu, Ting; Xu, Xuefeng; Zhang, Xinzhong; Han, Zhenhai

2018-05-11

Many efforts have been made to map quantitative trait loci (QTLs) to facilitate practical marker-assisted selection (MAS) in plants. In the present study, we identified four genome-wide major QTLs responsible for apple fruit acidity by MapQTL and BSA-seq analyses using two independent pedigree-based populations. Candidate genes were screened in major QTL regions, and three functional gene markers, including a non-synonymous A/G single nucleotide polymorphism (SNP) in the coding region of MdPP2CH, a 36-bp insertion in the promoter of MdSAUR37, and a previously reported SNP in MdALMTII, were validated to influence the malate content of apple fruits. In addition, MdPP2CH inactivated three vacuolar H + -ATPases (MdVHA-A3, MdVHA-B2 and MdVHA-D2) and one aluminium-activated malate transporter (MdALMTII) via dephosphorylation and negatively influenced fruit malate accumulation. The dephosphotase activity of MdPP2CH was suppressed by MdSAUR37, which implied a higher hierarchy of genetic interaction. Therefore, the MdSAUR37/MdPP2CH/MdALMTII chain cascaded hierarchical epistatic genetic effects to precisely determine apple fruit malate content. An A/G SNP (-1010) on MdMYB44 promoter region from a major QTL (qtl08.1) was closely associated with fruit malate content. The predicted phenotype values (PPVs) were estimated using the tentative genotype values of the gene markers, and the PPVs were significantly correlated with the observed phenotype values. Our findings provide an insight into plant genome-based selection in apples and will aid in conducting research to understand the physiological fundamentals of quantitative genetics. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

The discriminatory capability of existing scores to predict advanced colorectal neoplasia: a prospective colonoscopy study of 5,899 screening participants.

PubMed

Wong, Martin C S; Ching, Jessica Y L; Ng, Simpson; Lam, Thomas Y T; Luk, Arthur K C; Wong, Sunny H; Ng, Siew C; Ng, Simon S M; Wu, Justin C Y; Chan, Francis K L; Sung, Joseph J Y

2016-02-03

We evaluated the performance of seven existing risk scoring systems in predicting advanced colorectal neoplasia in an asymptomatic Chinese cohort. We prospectively recruited 5,899 Chinese subjects aged 50-70 years in a colonoscopy screening programme(2008-2014). Scoring systems under evaluation included two scoring tools from the US; one each from Spain, Germany, and Poland; the Korean Colorectal Screening(KCS) scores; and the modified Asia Pacific Colorectal Screening(APCS) scores. The c-statistics, sensitivity, specificity, positive predictive values(PPVs), and negative predictive values(NPVs) of these systems were evaluated. The resources required were estimated based on the Number Needed to Screen(NNS) and the Number Needed to Refer for colonoscopy(NNR). Advanced neoplasia was detected in 364 (6.2%) subjects. The German system referred the least proportion of subjects (11.2%) for colonoscopy, whilst the KCS scoring system referred the highest (27.4%). The c-statistics of all systems ranged from 0.56-0.65, with sensitivities ranging from 0.04-0.44 and specificities from 0.74-0.99. The modified APCS scoring system had the highest c-statistics (0.65, 95% C.I. 0.58-0.72). The NNS (12-19) and NNR (5-10) were similar among the scoring systems. The existing scoring systems have variable capability to predict advanced neoplasia among asymptomatic Chinese subjects, and further external validation should be performed.

Two year psychosocial and mental health outcomes for refugees subjected to restrictive or supportive immigration policies.

PubMed

Steel, Zachary; Momartin, Shakeh; Silove, Derrick; Coello, Marianio; Aroche, Jorge; Tay, Kuo Wei

2011-04-01

Australia has been at the forefront of implementing immigration policies that aim to limit the flow of asylum seekers over recent decades. Two controversial polices have been the use of immigration detention for unauthorized arrivals and the issuing of temporary protection visas (TPVs) for refugees who arrived without valid visas. We conducted a longitudinal survey over 2 years commencing in 2003 of 104 consecutive refugees from Iran and Afghanistan attending a state-wide early intervention program in New South Wales. The sample included those released from immigration detention on TPVs (n = 47) and others granted permanent protection visas prior to entering Australia (PPVs, n = 57). Psychological symptoms were assessed at baseline and follow-up by the Harvard Trauma Questionnaire (HTQ), the Hopkins symptom checklist-25 (HSCL), the GHQ-30 and the Penn State Worry Questionnaires (PSWQ). English language competency, daily living difficulties and coping-related activities were also assessed. The results indicated that TPVs had higher baseline scores than PPVs on the HTQ PTSD scale, the HSCL scales, and the GHQ. ANCOVA models adjusting for baseline symptom scores indicated an increase in anxiety, depression and overall distress for TPVs whereas PPVs showed improvement over time. PTSD remained high at follow-up for TPVs and low amongst PPVs with no significant change over time. The TPVs showed a significant increase in worry at follow-up. TPVs showed no improvement in their English language skills and became increasingly socially withdrawn whereas PPVs exhibited substantial language improvements and became more socially engaged. TPV holders also reported persistently higher levels of distress in relation to a wide range of post-migration living difficulties whereas PPVs reported few problems in meeting these resettlement challenges. The data suggest a pattern of growing mental distress, ongoing resettlement difficulties, social isolation, and difficulty in the acculturation process amongst refugees subject to restrictive immigration policies. Copyright © 2011 Elsevier Ltd. All rights reserved.

Importance of multi-modal approaches to effectively identify cataract cases from electronic health records

PubMed Central

Rasmussen, Luke V; Berg, Richard L; Linneman, James G; McCarty, Catherine A; Waudby, Carol; Chen, Lin; Denny, Joshua C; Wilke, Russell A; Pathak, Jyotishman; Carrell, David; Kho, Abel N; Starren, Justin B

2012-01-01

Objective There is increasing interest in using electronic health records (EHRs) to identify subjects for genomic association studies, due in part to the availability of large amounts of clinical data and the expected cost efficiencies of subject identification. We describe the construction and validation of an EHR-based algorithm to identify subjects with age-related cataracts. Materials and methods We used a multi-modal strategy consisting of structured database querying, natural language processing on free-text documents, and optical character recognition on scanned clinical images to identify cataract subjects and related cataract attributes. Extensive validation on 3657 subjects compared the multi-modal results to manual chart review. The algorithm was also implemented at participating electronic MEdical Records and GEnomics (eMERGE) institutions. Results An EHR-based cataract phenotyping algorithm was successfully developed and validated, resulting in positive predictive values (PPVs) >95%. The multi-modal approach increased the identification of cataract subject attributes by a factor of three compared to single-mode approaches while maintaining high PPV. Components of the cataract algorithm were successfully deployed at three other institutions with similar accuracy. Discussion A multi-modal strategy incorporating optical character recognition and natural language processing may increase the number of cases identified while maintaining similar PPVs. Such algorithms, however, require that the needed information be embedded within clinical documents. Conclusion We have demonstrated that algorithms to identify and characterize cataracts can be developed utilizing data collected via the EHR. These algorithms provide a high level of accuracy even when implemented across multiple EHRs and institutional boundaries. PMID:22319176

External Validation of Risk Prediction Scores for Invasive Candidiasis in a Medical/Surgical Intensive Care Unit: An Observational Study

PubMed Central

Ahmed, Armin; Baronia, Arvind Kumar; Azim, Afzal; Marak, Rungmei S. K.; Yadav, Reema; Sharma, Preeti; Gurjar, Mohan; Poddar, Banani; Singh, Ratender Kumar

2017-01-01

Background: The aim of this study was to conduct external validation of risk prediction scores for invasive candidiasis. Methods: We conducted a prospective observational study in a 12-bedded adult medical/surgical Intensive Care Unit (ICU) to evaluate Candida score >3, colonization index (CI) >0.5, corrected CI >0.4 (CCI), and Ostrosky's clinical prediction rule (CPR). Patients' characteristics and risk factors for invasive candidiasis were noted. Patients were divided into two groups; invasive candidiasis and no-invasive candidiasis. Results: Of 198 patients, 17 developed invasive candidiasis. Discriminatory power (area under receiver operator curve [AUROC]) for Candida score, CI, CCI, and CPR were 0.66, 0.67, 0.63, and 0.62, respectively. A large number of patients in the no-invasive candidiasis group (114 out of 181) were exposed to antifungal agents during their stay in ICU. Subgroup analysis was carried out after excluding such patients from no-invasive candidiasis group. AUROC of Candida score, CI, CCI, and CPR were 0.7, 0.7, 0.65, and 0.72, respectively, and positive predictive values (PPVs) were in the range of 25%–47%, along with negative predictive values (NPVs) in the range of 84%–96% in the subgroup analysis. Conclusion: Currently available risk prediction scores have good NPV but poor PPV. They are useful for selecting patients who are not likely to benefit from antifungal therapy. PMID:28904481

Photoinduced Gilch Polymerization: A Basically New Access to Poly(p-phenylene vinylenes) (PPVs) of Exciting Constitutional Homogeneity.

PubMed

Kuch, Serena; Vilbrandt, Nicole; Rehahn, Matthias

2016-05-01

A novel procedure has been developed for the Gilch reaction leading to poly(p-phenylene vinylenes) (PPVs). In the first step, selective activation of the starting material is achieved at low temperature. Subsequently, controlled chain growth is induced by lighting the α-halo-p-quinodimethane monomer. In contrast to the thermal Gilch polymerization, the photoinduced process allows adjusting crucial parameters such as intensity and energy of light. The progress of PPV formation can be followed visually or by in situ UV-vis spectroscopy. If the polymers are formed under appropriate conditions, they show very high molar masses, polydispersities in the common range, and higher constitutional homogeneity than thermally grown PPVs. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Radiolabeled choline PET/CT before salvage lymphadenectomy dissection: a systematic review and meta-analysis.

PubMed

Evangelista, Laura; Zattoni, Fabio; Karnes, Robert J; Novara, Giacomo; Lowe, Val

2016-12-01

To provide a systematic review of recently published reports and carry out a meta-analysis on the use of radiolabeled choline PET/computed tomography (CT) as a guide for salvage lymph node dissection (sLND) in prostate cancer patients with biochemical recurrence after primary treatments. Bibliographic database searches, from 2005 to May 2015, including Pubmed, Web of Science, and TripDatabase, were performed to find studies that included only patients who underwent sLND after radiolabeled choline PET/CT alone or in combination with other imaging modalities. For the qualitative assessment, all studies including the selected population were considered. Conversely, for the quantitative assessment, articles were included only if absolute numbers of true positive, true negative, false positive, and false negative test results were available or derivable from the text for lymph node metastases. Reviews, clinical reports, and editorial articles were excluded from analyses. Eighteen studies fulfilled the inclusion criteria and were assessed qualitatively. A total of 750 patients underwent radiolabeled choline (such as C-choline or F-choline) PET/CT before sLND. A quantitative evaluation was performed in nine studies. A patient-based, a lesion-based, and a site-based analysis was carried out in nine, four, and five studies, respectively. The pooled sensitivities were 85.3% [95% confidence interval (CI): 78.5-90.3%], 56.2% (95% CI: 41.6-69.7%), 75.3% (95% CI: 56.6-87.7%), and 63.7% (95% CI: 41-81.6%), respectively, for patient-based, lesion-based, pelvic site-based, and retroperitoneal site-based analysis. The pooled positive predictive values (PPVs) were 75% (95% CI: 68-80.9%), 85.8% (95% CI: 66.8-94.8%), 81.2% (95% CI: 70.1-88.9%), and 75.2% (95% CI: 58.7-86.7%), respectively, in the same analyses. High heterogeneities among the studies were found for sensitivities and PPVs ranging between 61.7-93.3% and 60.6-94.5%, respectively. Radiolabeled choline PET/CT has only a moderate sensitivity for the detection of metastatic lymph nodes in patients who are candidates for sLND, although the pooled PPVs ranged between 75 and 85.8% for all type of subanalyses. The presence of high heterogeneity among the studies should be considered carefully.

Lumboperitoneal Shunts for the Treatment of Idiopathic Normal Pressure Hydrocephalus: A Comparison of Small-Lumen Abdominal Catheters to Gravitational Add-On Valves in a Single Center.

PubMed

Nakajima, Madoka; Miyajima, Masakazu; Akiba, Chihiro; Ogino, Ikuko; Kawamura, Kaito; Sugano, Hidenori; Hara, Takeshi; Tange, Yuichi; Fusegi, Keiko; Karagiozov, Kostadin; Arai, Hajime

2018-04-23

Treating idiopathic normal pressure hydrocephalus (iNPH) with lumboperitoneal shunts (LPSs) may cause cerebrospinal fluid (CSF) overdrainage. To investigate whether LPSs, including gravitational "add-on" and programmable pressure valves (PPVs/+GVs), reduce complications and improve outcomes. We compared PPVs/+small lumen abdominal catheters (SLs) to PPVs/+GVs using different opening pressures for supine and standing positions. We analyzed 115 patients with iNPH in 2 consequent cohorts: 48 patients receiving LPSs with PPVs/+SLs and 67 patients receiving LPSs with PPVs/+GVs. The modified Rankin Scale (mRS), Japan iNPH grading scale, Mini Mental State Examination, Frontal Assessment Battery, and CSF biomarkers were evaluated. Comparisons of postoperative clinical factors in 64 patients in the PPV/+SL and PPV/+GV groups using 1:1 propensity score matching revealed differences in the mean (±standard deviation) postoperative mRS (2.65 ± 1.07 vs 2.16 ± 1.02, P = .049) and gait disturbance scores (1.97 ± 1.03 vs 1.39 ± 0.92, P = .011). Thus, outcomes improved in the LPS group with the GV. Serious and nonserious adverse event rates for the PPV/+SL and PPV/+GV groups were 22.9% and 19.4% (P = .647) and 38% and 17.9% (P = .018), respectively, indicating higher rates of subdural collections for the PPV/+SL group. This is the first study to examine LPS treatment for iNPH using a GV in tandem with a PPV. Our results suggest that the CSF shunt flow volume is restricted in the standing position and maintained in the supine position, thus improving iNPH symptoms. This may reduce intracranial CSF hypotension-related complications.

Choosing a design to fit the situation: how to improve specificity and positive predictive values using Bayesian lot quality assurance sampling.

PubMed

Olives, Casey; Pagano, Marcello

2013-02-01

Lot Quality Assurance Sampling (LQAS) is a provably useful tool for monitoring health programmes. Although LQAS ensures acceptable Producer and Consumer risks, the literature alleges that the method suffers from poor specificity and positive predictive values (PPVs). We suggest that poor LQAS performance is due, in part, to variation in the true underlying distribution. However, until now the role of the underlying distribution in expected performance has not been adequately examined. We present Bayesian-LQAS (B-LQAS), an approach to incorporating prior information into the choice of the LQAS sample size and decision rule, and explore its properties through a numerical study. Additionally, we analyse vaccination coverage data from UNICEF's State of the World's Children in 1968-1989 and 2008 to exemplify the performance of LQAS and B-LQAS. Results of our numerical study show that the choice of LQAS sample size and decision rule is sensitive to the distribution of prior information, as well as to individual beliefs about the importance of correct classification. Application of the B-LQAS approach to the UNICEF data improves specificity and PPV in both time periods (1968-1989 and 2008) with minimal reductions in sensitivity and negative predictive value. LQAS is shown to be a robust tool that is not necessarily prone to poor specificity and PPV as previously alleged. In situations where prior or historical data are available, B-LQAS can lead to improvements in expected performance.

Non-Culture Diagnostics for Invasive Candidiasis: Promise and Unintended Consequences

PubMed Central

Clancy, Cornelius J.; Nguyen, M. Hong

2018-01-01

Blood cultures are positive for Candida species in < 50% and < 20% of hematogenously disseminated and intra-abdominal candidiasis, respectively. Non-culture tests such as mannan, anti-mannan antibody, Candida albicans germ tube antibody (CAGTA), 1,3-β-d-glucan (BDG), the T2Candida nanodiagnostic panel, and polymerase chain reaction (PCR) are available for clinical use, but their roles in patient care are uncertain. Sensitivity/specificity of combined mannan/anti-mannan, BDG, T2Candida and PCR for candidemia are ~80%/80%, ~80%/80%, ~90%/98%, and ~90%/90%, respectively. Limited data for intra-abdominal candidiasis suggest CAGTA, BDG sensitivity/specificity of ~65%/75% and PCR sensitivity of ~85–90%. PCR specificity has varied widely for intra-abdominal candidiasis (33–97%), and T2Candida data are lacking. Tests will be useful if restricted to cases in which positive and negative predictive values (PPVs, NPVs) differ in a clinically meaningful way from the pre-test likelihood of invasive candidiasis. In some patients, PPVs are sufficient to justify antifungal treatment, even if blood cultures are negative. In most patients, NPVs of each test are excellent, which may support decisions to withhold antifungal therapy. If test results are not interpreted judiciously, non-culture diagnostics may have unintended consequences for stewardship and infection prevention programs. In particular, discrepant non-culture test-positive/culture-negative results may promote inappropriate antifungal treatment of patients who are unlikely to have candidiasis, and lead to spurious reporting of hospital-acquired infections. In conclusion, non-culture Candida diagnostics have potential to advance patient care, but this promise will be realized only if users understand tests’ strengths and limitations, and plan proactively for how best to employ them at their hospitals. PMID:29463043

Automated segmentation of lesions including subretinal hyperreflective material in neovascular age-related macular degeneration.

PubMed

Lee, Hyungwoo; Kang, Kyung Eun; Chung, Hyewon; Kim, Hyung Chan

2018-04-12

To evaluate an automated segmentation algorithm with a convolutional neural network (CNN) to quantify and detect intraretinal fluid (IRF), subretinal fluid (SRF), pigment epithelial detachment (PED), and subretinal hyperreflective material (SHRM) through analyses of spectral domain optical coherence tomography (SD-OCT) images from patients with neovascular age-related macular degeneration (nAMD). Reliability and validity analysis of a diagnostic tool. We constructed a dataset including 930 B-scans from 93 eyes of 93 patients with nAMD. A CNN-based deep neural network was trained using 11550 augmented images derived from 550 B-scans. The performance of the trained network was evaluated using a validation set including 140 B-scans and a test set of 240 B-scans. The Dice coefficient, positive predictive value (PPV), sensitivity, relative area difference (RAD), and intraclass correlation coefficient (ICC) were used to evaluate segmentation and detection performance. Good agreement was observed for both segmentation and detection of lesions between the trained network and clinicians. The Dice coefficients for segmentation of IRF, SRF, SHRM, and PED were 0.78, 0.82, 0.75, and 0.80, respectively; the PPVs were 0.79, 0.80, 0.75, and 0.80, respectively; and the sensitivities were 0.77, 0.84, 0.73, and 0.81, respectively. The RADs were -4.32%, -10.29%, 4.13%, and 0.34%, respectively, and the ICCs were 0.98, 0.98, 0.97, and 0.98, respectively. All lesions were detected with high PPVs (range 0.94-0.99) and sensitivities (range 0.97-0.99). A CNN-based network provides clinicians with quantitative data regarding nAMD through automatic segmentation and detection of pathological lesions, including IRF, SRF, PED, and SHRM. Copyright © 2018 Elsevier Inc. All rights reserved.

Self-reported hepatitis A vaccination as a predictor of hepatitis A virus antibody protection in U.S. adults: National Health and Nutrition Examination Survey 2007-2012.

PubMed

Denniston, Maxine M; Monina Klevens, R; Jiles, Ruth B; Murphy, Trudy V

2015-07-31

To estimate the predictive value of self-reported hepatitis A vaccine (HepA) receipt for the presence of hepatitis A virus (HAV) antibody (anti-HAV) from either past infection or vaccination, as an indicator of HAV protection. Using 2007-2012 National Health and Nutrition Examination Survey data, we assigned participants to 4 groups based on self-reported HepA receipt and anti-HAV results. We compared characteristics across groups and calculated three measures of agreement between self-report and serologic status (anti-HAV): percentage concordance, and positive (PPV) and negative (NPV) predictive values. Using logistic regression we investigated factors associated with agreement between self-reported vaccination status and serological results. Demographic and other characteristics varied significantly across the 4 groups. Overall agreement between self-reported HepA receipt and serological results was 63.6% (95% confidence interval [CI] 61.9-65.2); PPV and NPV of self-reported vaccination status for serological result were 47.0% (95% CI 44.2-49.8) and 69.4% (95% CI 67.0-71.8), respectively. Mexican American and foreign-born adults had the highest PPVs (71.5% [95% CI 65.9-76.5], and 75.8% [95% CI 71.4-79.7]) and the lowest NPVs (21.8% [95% CI 18.5-25.4], and 20.0% [95% CI 17.2-23.1]), respectively. Young (ages 20-29 years), US-born, and non-Hispanic White adults had the lowest PPVs (37.9% [95% CI 34.5-41.5], 39.1% [95% CI, 36.0-42.3], and 39.8% [36.1-43.7]), and the highest NPVs (76.9% [95% CI 72.2-81.0, 78.5% [95% CI 76.5-80.4)], and 80.6% [95% CI 78.2-82.8), respectively. Multivariate logistic analyses found age, race/ethnicity, education, place of birth and income to be significantly associated with agreement between self-reported vaccination status and serological results. When assessing hepatitis A protection, self-report of not having received HepA was most likely to identify persons at risk for hepatitis A infection (no anti-HAV) among young, US-born and non-Hispanic White adults, and self-report of HepA receipt was least likely to be reliable among adults with the same characteristics. Copyright © 2015. Published by Elsevier Ltd.

Evaluation of an influenza-like illness case definition in the diagnosis of influenza among patients with acute febrile illness in Cambodia.

PubMed

Kasper, Matthew R; Wierzba, Thomas F; Sovann, Ly; Blair, Patrick J; Putnam, Shannon D

2010-11-07

Influenza-like illness (ILI) is often defined as fever (>38.0°C) with cough or sore throat. In this study, we tested the sensitivity, specificity, and positive and negative predictive values of this case definition in a Cambodia patient population. Passive clinic-based surveillance was established at nine healthcare centers to identify the causes of acute undifferentiated fever in patients aged two years and older seeking treatment. Fever was defined as tympanic membrane temperature >38°C lasting more than 24 hours and less than 10 days. Influenza virus infections were identified by polymerase chain reaction. From July 2008 to December 2008, 2,639 patients were enrolled. From 884 (33%) patients positive for influenza, 652 presented with ILI and 232 acute fever patients presented without ILI. Analysis by age group identified no significant differences between influenza positive patients from the two groups. Positive predictive values (PPVs) varied during the course of the influenza season and among age groups. The ILI case definition can be used to identify a significant percentage of patients with influenza infection during the influenza season in Cambodia, assisting healthcare providers in its diagnosis and treatment. However, testing samples based on the criteria of fever alone increased our case detection by 34%.

Predictors of Poor Seizure Control in Children Managed at a Tertiary Care Hospital of Eastern Nepal

PubMed Central

POUDEL, Prakash; CHITLANGIA, Mohit; POKHAREL, Rita

2016-01-01

Objective Various factors have been claimed to predict outcome of afebrile seizures in children. This study was aimed to find out the predictors of poor seizure control in children at a resource limited setting. Materials & Methods This prospective study was done from July 1st, 2009 to January 31st, 2012 at B.P. Koirala Institute of Health Sciences, Nepal. Children (1 month-20 yr of age) with afebrile seizures presenting to pediatric neurology clinic were studied. Significant predictors on bivariate analysis were further analyzed with binary logistic model to find out the true predictors. Positive predictive values (PPVs) and negative predictive values (NPVs) for the true predictors were calculated. Results Out of 256 patients (male: female ratio 3:2) with afebrile seizures followed up for median duration of 27 (IQR 12-50) months, seizure was poorly controlled in 20% patients. Three factors predicted poor seizure control. They were frequent (≥1 per month) seizures at onset (OR 12.76, 95% CI 1.44-112.73, PPV 25%, NPV 98%); remote symptomatic etiology (OR 3.56, 95% CI 1.04-12.17, PPV 36%, NPV 92%); and need of more than one anticonvulsant drug (polytherapy) (OR 12.83, 95% CI 5.50-29.9, PPV 56%, NPV 96%). The strongest predictor was need of polytherapy. When all three factors were present, PPV and NPV for prediction of poor seizure control were 70% and 90% respectively. Conclusion Frequent seizures at onset, remote symptomatic etiology of seizure and need of polytherapy were associated with poor seizure control in children with afebrile seizures. PMID:27375756

Choosing a design to fit the situation: how to improve specificity and positive predictive values using Bayesian lot quality assurance sampling

PubMed Central

Olives, Casey; Pagano, Marcello

2013-01-01

Background Lot Quality Assurance Sampling (LQAS) is a provably useful tool for monitoring health programmes. Although LQAS ensures acceptable Producer and Consumer risks, the literature alleges that the method suffers from poor specificity and positive predictive values (PPVs). We suggest that poor LQAS performance is due, in part, to variation in the true underlying distribution. However, until now the role of the underlying distribution in expected performance has not been adequately examined. Methods We present Bayesian-LQAS (B-LQAS), an approach to incorporating prior information into the choice of the LQAS sample size and decision rule, and explore its properties through a numerical study. Additionally, we analyse vaccination coverage data from UNICEF’s State of the World’s Children in 1968–1989 and 2008 to exemplify the performance of LQAS and B-LQAS. Results Results of our numerical study show that the choice of LQAS sample size and decision rule is sensitive to the distribution of prior information, as well as to individual beliefs about the importance of correct classification. Application of the B-LQAS approach to the UNICEF data improves specificity and PPV in both time periods (1968–1989 and 2008) with minimal reductions in sensitivity and negative predictive value. Conclusions LQAS is shown to be a robust tool that is not necessarily prone to poor specificity and PPV as previously alleged. In situations where prior or historical data are available, B-LQAS can lead to improvements in expected performance. PMID:23378151

CT colonography without cathartic preparation: positive predictive value and patient experience in clinical practice.

PubMed

Zueco Zueco, Carmen; Sobrido Sampedro, Carolina; Corroto, Juan D; Rodriguez Fernández, Paula; Fontanillo Fontanillo, Manuela

2012-06-01

To determine the positive predictive value (PPV) for polyps ≥ 6 mm detected at CT colonography (CTC) performed without cathartic preparation, with low-dose iodine faecal tagging regimen and to evaluate patient experience. 1920 average-risk patients underwent CTC without cathartic preparation. Faecal tagging was performed by diatrizoate meglumine and diatrizoate sodium at a total dose of 60 ml (22.2 g of iodine).The standard interpretation method was primary 3D with 2D problem solving. We calculated per-patient and per-polyp PPV in relation to size and morphology. All colonic segments were evaluated for image quality (faecal tagging, amount of liquid and solid residual faeces and luminal distension). Patients completed a questionnaire before and after CTC to assess preparation and examination experience. Per-polyp PPV for detected lesions of ≥ 6 mm, 6-9 mm, ≥ 10 mm and ≥ 30 mm were 94.3%, 93.1%, 94.7% and 98%, respectively. Per-polyp PPV, according to lesion morphology, was 94.6%, 97.3% and 85.1% for sessile, pedunculated and flat polyps, respectively. Per-patient PPV was 92.8%. Preparation without frank cathartics was reported to cause minimal discomfort by 78.9% of patients. CTC without cathartic preparation and low-dose iodine faecal tagging may yield high PPVs for lesions ≥ 6 mm and is well accepted by patients. • Computed tomographic colonography (CTC) without cathartic preparation is well accepted by patients • Cathartic-free faecal tagging CTC yields high positive predictive values • CTC without cathartic preparation could improve uptake of colorectal cancer screening.

What's the agreement between self-reported and biochemical verification of drug use? A look at permanent supportive housing residents.

PubMed

Rendon, Alexis; Livingston, Melvin; Suzuki, Sumihiro; Hill, Whitney; Walters, Scott

2017-07-01

Self-reported substance use is commonly used as an outcome measure in treatment research. We evaluated the validity of self-reported drug use in a sample of 334 adults with mental health problems who were residing in supportive housing programs. The primary analysis was the calculation of the positive predictive values (PPVs) of self-report compared to an oral fluid test taken at the same time. A sensitivity analysis compared the positive predictive values of two self-reported drug use histories: biological testing window (ranging between the past 96h to 30days depending on drug type) or the full past 90-day comparison window (maximum length recorded during interview). A multivariable logistic regression was used to predict discordance between self-report and the drug test for users. Self-reported drug use and oral fluid drug tests were compared to determine the positive predictive value for amphetamines/methamphetamines/PCP (47.1% agreement), cocaine (43.8% agreement), and marijuana (69.7% agreement) drug tests. Participants who misreported their drug use were more likely to be older, non-White, have no medical insurance, and not report any alcohol use. In general, amphetamine/methamphetamine/PCP and cocaine use was adequately captured by the biological test, while marijuana use was best captured by a combination of self-report and biological data. Using the full past 90day comparison window resulted in higher concordance with the oral fluid drug test, indicating that self-reported drug use in the past 90days may be a proxy for drug use within the biological testing window. Self-report has some disadvantages when used as the sole measure of drug use in this population. Copyright © 2017 Elsevier Ltd. All rights reserved.

Accuracy of HIV-related risk behaviors reported by female sex workers, Iran: a method to quantify measurement bias in marginalized populations.

PubMed

Mirzazadeh, Ali; Haghdoost, Ali Akbar; Nedjat, Saharnaz; Navadeh, Soodabeh; McFarland, Willi; Mohammad, Kazem

2013-02-01

We quantified discrepancies in reported behaviors of female sex workers (FSW) by comparing 63 face-to-face interviews (FTFI) to in-depth interviews (IDI), with corroboration of the directions and magnitudes of reporting by a panel of psychologists who work with FSW. Sensitivities, specificities, positive and negative predictive values (PPV and NPV) were assessed for FTFI responses using IDI as a "gold standard". Sensitivities were lowest in reporting symptoms of sexually transmitted infections (63.9 %), finding sex partners in venues (52.4 %) and not receiving HIV test results (66.7 %). Specificities (all >83 %) and PPVs (all >74.0 %) were higher than NPV. FSW significantly under-reported number of clients, sexual contacts and non-condom use sex acts with clients and number of days engaging in sex work in the preceding week. This study provides a quantified gauge of reporting biases in FSW behaviors. Such estimates and methods help better understand true HIV risk in marginalized populations and calibrate survey estimates accordingly.

Blood pressure-to-height ratio for screening prehypertension and hypertension in Chinese children.

PubMed

Dong, B; Wang, Z; Wang, H-J; Ma, J

2015-10-01

The diagnosis of hypertension in children is complicated because of the multiple age-, sex- and height-specific thresholds. To simplify the process of diagnosis, blood pressure-to-height ratio (BPHR) was employed in this study. Data were obtained from a Chinese national survey conducted in 2010, and 197 191 children aged 7-17 years were included. High normal and elevated blood pressure (BP) were defined according to the National High Blood Pressure Education Program (NHBPEP) Working Group definition. The optimal thresholds were selected by Youden's index. Sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV) and area under the curve (AUC) were assessed for the performance of these thresholds. The systolic and diastolic BPHR thresholds for identifying high normal BP were 0.84/0.55, 0.78/0.50 and 0.75/0.46 for children aged 7-8 years, 9-11 years and 12-17 years, respectively. The corresponding thresholds for identifying elevated BP were 0.87/0.57, 0.81/0.53 and 0.76/0.49, respectively. These proposed thresholds revealed high sensitivity and NPVs, all above 0.96, moderate to high specificity and AUCs, and low PPVs. Our finding suggested the proposed BPHR thresholds were accurate for identifying children without high normal or elevated BP, and could be employed to simplify the procedure of screening prehypertension and hypertension in children.

Clinical performances of two real-time PCR assays and bDNA/TMA to early monitor treatment outcome in patients with chronic hepatitis C.

PubMed

Martinot-Peignoux, Michelle; Khiri, Hacène; Leclere, Laurence; Maylin, Sarah; Marcellin, Patrick; Halfon, Philippe

2009-11-01

Early viral monitoring is essential for the management of treatment outcome in patients with chronic hepatitis C. A variety of commercially available assays are now available to quantify HCV-RNA in routine clinical practice. Compare the clinical results of 3 commercially available assays to evaluate the positive predictive value (PPV) and the negative predictive value (NPV) of rapid virological response (RVR) at week 4 and early virological response (EVR) at week 12. 287 patients treated with standard care regimen combination therapy were studied. HCV-RNA values measured at baseline, week 4, week 12 with VERSANT HCV 3.0 Assay (bDNA), and VERSANT HCV-RNA Qualitative Assay (TMA) (bDNA/TMA); COBAS Ampliprep/COBAS/TaqMan (CAP/CTM) and Abbott m2000sp extraction/m2000rt amplification system (ART). RVR was defined as undetectable serum HCV-RNA and EVR as a > OR =2 log decline in baseline viral load (BLV). Median (range) BVLs were: 5.585(2.585-6.816), 5.189(2.792-7.747) and 4.804(2.380-6.580) log(10)IU/ml, with bDNA/TMA, CAP/CTM and ART, respectively (p<0.01); RVR was observed in 22%, 30% and 27% of the patients and PPVs were 97%, 91% and 94% with bDNA/TMA, CAP/CTM and ART, respectively (p=0.317). EVR was observed in 76%, 73% and 67% of the patients and NPVs were 93%, 83% and 79% with bDNA/TMA, CAP/CTM and ART, respectively (p=0.09). Treatment monitoring should include both detection of serum HCV-RNA at week 4 to predict SVR and at week 12 to predict non-SVR. The value of all 3 assays was similar for evaluating RVR or EVR. Because of viral load discrepancies the same assay should be used throughout patient treatment follow-up.

Self-reported hepatitis A vaccination as a predictor of hepatitis A virus antibody protection in U.S. adults: National Health and Nutrition Examination Survey 2007–2012

PubMed Central

Denniston, Maxine M.; Klevens, R. Monina; Jiles, Ruth B.; Murphy, Trudy V.

2015-01-01

Objectives To estimate the predictive value of self-reported hepatitis A vaccine (HepA) receipt for the presence of hepatitis A virus (HAV) antibody (anti-HAV) from either past infection or vaccination, as an indicator of HAV protection. Methods Using 2007–2012 National Health and Nutrition Examination Survey data, we assigned participants to 4 groups based on self-reported HepA receipt and anti-HAV results. We compared characteristics across groups and calculated three measures of agreement between self-report and serologic status (anti- HAV): percentage concordance, and positive (PPV) and negative (NPV) predictive values. Using logistic regression we investigated factors associated with agreement between self-reported vaccination status and serological results. Results Demographic and other characteristics varied significantly across the 4 groups. Overall agreement between self-reported HepA receipt and serological results was 63.6% (95% confidence interval [CI] 61.9–65.2); PPV and NPV of self-reported vaccination status for serological result were 47.0% (95% CI 44.2–49.8) and 69.4% (95% CI 67.0–71.8), respectively. Mexican American and foreign-born adults had the highest PPVs (71.5% [95% CI 65.9–76.5], and 75.8% [95% CI 71.4–79.7]) and the lowest NPVs (21.8% [95% CI 18.5–25.4], and 20.0% [95% CI 17.2–23.1]), respectively. Young (ages 20–29 years), US-born, and non-Hispanic White adults had the lowest PPVs (37.9% [95% CI 34.5–41.5], 39.1% [95% CI, 36.0–42.3], and 39.8% [36.1–43.7]), and the highest NPVs (76.9% [95% CI 72.2–81.0, 78.5% [95% CI 76.5–80.4)], and 80.6% [95% CI 78.2–82.8), respectively. Multivariate logistic analyses found age, race/ethnicity, education, place of birth and income to be significantly associated with agreement between self-reported vaccination status and serological results. Conclusions When assessing hepatitis A protection, self-report of not having received HepA was most likely to identify persons at risk for hepatitis A infection (no anti-HAV) among young, US-born and non-Hispanic White adults, and self-report of HepA receipt was least likely to be reliable among adults with the same characteristics. PMID:26116252

Subcategorization of Suspicious Breast Lesions (BI-RADS Category 4) According to MRI Criteria: Role of Dynamic Contrast-Enhanced and Diffusion-Weighted Imaging.

PubMed

Maltez de Almeida, João Ricardo; Gomes, André Boechat; Barros, Thomas Pitangueira; Fahel, Paulo Eduardo; de Seixas Rocha, Mário

2015-07-01

The purposes of this study were to investigate whether dynamic contrast-enhanced MRI is adequate for subcategorization of suspicious lesions (BI-RADS category 4) and to evaluate whether use of DWI improves diagnostic performance. The study group was composed of 103 suspicious lesions found in 83 subjects. Patient ages and lesion sizes were compiled, and two radiologists reanalyzed the images; subcategorized the findings as BI-RADS 4A, 4B, or 4C; and calculated apparent diffusion coefficient (ADC) values. The stratified variables were tested by univariate analysis and inserted in two multivariate predictive models, which were used to generate ROC curves and compare AUCs. Positive predictive values (PPVs) for each subcategory and ADC level were calculated, and interobserver agreement was tested. Forty-four (42.7%) suspicious findings proved malignant. Except for age (p = 0.08), all stratified predictor variables were significant in univariate analyses (p < 0.01). Logistic regression models did not differ substantially after comparison of the ROC curves (p = 0.09), but the one including ADC values was slightly better: AUC of 0.89 (95% CI, 0.82-0.95) against AUC of 0.85 (95% CI, 0.78-0.93). PPV increased progressively in each BI-RADS 4 subcategory (4A, 0.15; 4B, 0.37; 4C, 0.84). ADC values of 1.10 × 10(-3) mm(2)/s or less had the second highest PPV (0.77). Interobserver agreement was substantial at a kappa value of 0.80 (95% CI, 0.70-0.90; p < 0.01). Risk stratification of suspicious lesions (BI-RADS category 4) can be satisfactorily performed with DCE-MRI and slightly improved when DWI is introduced.

Does Low PAPP-A Predict Adverse Placenta-Mediated Outcomes in a Low-Risk Nulliparous Population? the Great Obstetrical Syndromes (GOS) Study.

PubMed

Boutin, Amélie; Gasse, Cédric; Demers, Suzanne; Blanchet, Geneviève; Giguère, Yves; Bujold, Emmanuel

2018-06-01

First-trimester low concentration of pregnancy-associated plasma protein A (PAPP-A) has been associated with adverse perinatal outcomes in high-risk populations. This study aimed to estimate the ability of PAPP-A to identify adverse outcomes in a low-risk population. The study investigators recruited nulliparous women with singleton pregnancy at their 11-13-week ultrasound scan. Serum samples were collected, and maternal PAPP-A concentration was measured using the B⋅R⋅A⋅H⋅M⋅S PAPP-A KRYPTOR (ThermoFisher Scientific, Hennigsdorf, Germany) automated assay. PAPP-A was reported in multiple of median (MoM) adjusted for GA. Participants were followed until delivery for pregnancy outcomes including preeclampsia (PE), SGA <3rd percentile, and fetal death. Receiver operating characteristic curves with the area under the curve (AUC) were used to evaluate the predictive value of PAPP-A. The investigators calculated the detection rates (DRs) and positive predictive values (PPVs) of a PAPP-A < 0.4 MoM. The study investigators recruited 4739 eligible participants at a mean GA of 13 ± 6 weeks. The investigators observed 232 (4.9%) cases of PE, 84 (1.8%) cases of SGA, and 14 (0.3%) fetal deaths. PAPP-A was moderately associated with PE (AUC 0.57; 95% CI 0.53-0.61) and SGA (AUC 0.62; 95% CI 0.56-0.69), but not with fetal death (AUC 0.43; 95% CI 0.23-0.63). PAPP-A < 0.4 MoM was observed in 364 (7.7%) participants and had poor predictive values for PE (DR 9.8%; PPV 6.3%), SGA (DR 18.1%; PPV 4.4%), and fetal death (DR 21.4%; PPV 0.9%). Isolated first trimester PAPP-A has a limited predictive value for adverse pregnancy outcomes (other than trisomies). Low PAPP-A (<0.4 MoM) should be used in combination with other markers for the prediction of PE, SGA, or fetal death, and it does not constitute an indication for low-dose aspirin. Copyright © 2018 Society of Obstetricians and Gynaecologists of Canada. Published by Elsevier Inc. All rights reserved.

Platelet indices and netrophil to lymphocyte ratio in adults with acute appendicitis.

PubMed

Kostakis, I D; Machairas, N; Damaskos, C; Doula, C; Tsaparas, P; Charalampoudis, P; Spartalis, E; Sotiropoulos, G C; Kouraklis, G

2016-03-01

A study was performed in adults with acute appendicitis and matched controls to assess the utility of the platelet indices and neutrophil to lymphocyte ratio, as a diagnostic adjunct. Data were retrospectively collected from a complete blood count test of 155 adult patients (72 men and 83 women) with histologically proven acute appendicitis upon admission, and of 50 healthy adults (20 men and 30 women). The parameters for white blood cells and platelets were compared between the two groups, and for each gender separately. A higher white blood cell count, neutrophil count, neutrophil percentage, neutrophil to lymphocyte ratio and lower lymphocyte percentage was reported in patients with acute appendicitis than that in the healthy controls, with high areas under the curve (AUC), sensitivities, specifi cities, positive predictive values (PPVs) and moderate negative predictive values (NPVs). The lymphocyte count was lower in patients than it was in the healthy controls. The platletcrit was lower in the female patients than that in the female controls, whereas a difference was not detected in the male participants. Differences were not detected with regard to platelet count, mean platelet volume and platelet distribution width for both genders. The neutrophil to lymphocyte ratio increases and lymphocyte percentage decreases in acute appendicitis, and can be used as an additional diagnostic marker. Plateletcrit, and therefore total platelet mass, is reduced in women with acute appendicitis, indicating the involvement of platelets in its pathophysiology. However, it is neither a reliable predictor or excluder of the disease.

Predictive values of diagnostic codes for identifying serious hypocalcemia and dermatologic adverse events among women with postmenopausal osteoporosis in a commercial health plan database.

PubMed

Wang, Florence T; Xue, Fei; Ding, Yan; Ng, Eva; Critchlow, Cathy W; Dore, David D

2018-04-10

Post-marketing safety studies of medicines often rely on administrative claims databases to identify adverse outcomes following drug exposure. Valid ascertainment of outcomes is essential for accurate results. We aim to quantify the validity of diagnostic codes for serious hypocalcemia and dermatologic adverse events from insurance claims data among women with postmenopausal osteoporosis (PMO). We identified potential cases of serious hypocalcemia and dermatologic events through ICD-9 diagnosis codes among women with PMO within claims from a large US healthcare insurer (June 2005-May 2010). A physician adjudicated potential hypocalcemic and dermatologic events identified from the primary position on emergency department (ED) or inpatient claims through medical record review. Positive predictive values (PPVs) and 95% confidence intervals (CIs) quantified the fraction of potential cases that were confirmed. Among 165,729 patients with PMO, medical charts were obtained for 40 of 55 (73%) potential hypocalcemia cases; 16 were confirmed (PPV 40%, 95% CI 25-57%). The PPV was higher for ED than inpatient claims (82 vs. 24%). Among 265 potential dermatologic events (primarily urticaria or rash), we obtained 184 (69%) charts and confirmed 128 (PPV 70%, 95% CI 62-76%). The PPV was higher for ED than inpatient claims (77 vs. 39%). Diagnostic codes for hypocalcemia and dermatologic events may be sufficient to identify events giving rise to emergency care, but are less accurate for identifying events within hospitalizations.

Predictive value of Borrelia burgdorferi IgG antibody levels in patients referred to a tertiary Lyme centre.

PubMed

Zwerink, M; Zomer, T P; van Kooten, B; Blaauw, G; van Bemmel, T; van Hees, B C; Vermeeren, Y M; Landman, G W

2018-03-01

A two-step testing strategy is recommended in serological testing for Lyme borreliosis; positive and indeterminate enzyme-linked immunosorbent assay (ELISA) results are confirmed with immunoblots. Several ELISAs quantify the concentration of antibodies tested, however, no recommendation exists for an upper cut-off value at which an IgG ELISA is sufficient and the immunoblot can be omitted. The study objective was to determine at which IgG antibody level an immunoblot does not have any additional predictive value compared to ELISA results. Data of adult patients who visited a tertiary Lyme centre between 2008 and 2014 were analysed. Both an ELISA (Enzygnost Lyme link VlsE IgG) and immunoblot (recomLine blot Borrelia) were performed. Clinical data were extracted from the patient's digital medical record. Positive predictive values (PPVs) for either previous or active infection with Borrelia burgdorferi s.l. were calculated for different cut-off ELISA IgG antibody levels where the immunoblot was regarded as reference test. In total, 1454 patients were included. According to the two-step test strategy, 486 (33%), 69 (5%) and 899 (62%) patients had positive, indeterminate and negative Borrelia IgG serology, respectively. At IgG levels of 500 IU/ml and higher, all immunoblots were positive, resulting in a 100% PPV (95% CI: 97.0-100). At IgG levels of 200 IU/ml and higher, the PPV was 99.3% (95% CI: 97.4-99.8). In conclusion, at IgG levels of 200 IU/ml and higher, an ELISA was sufficient to detect antibodies to Borrelia burgdorferi s.l. At those IgG levels, a confirmatory immunoblot may be omitted in patients referred to a tertiary Lyme centre. Before these results can be implemented in routine diagnosis of Lyme borreliosis, confirmation of the results is necessary in other patient populations and using other quantitative ELISAs and immunoblots. Copyright © 2017 Elsevier GmbH. All rights reserved.

'Peripheric' pancreatic cysts: performance of CT scan, MRI and endoscopy according to final pathological examination.

PubMed

Duconseil, P; Turrini, O; Ewald, J; Soussan, J; Sarran, A; Gasmi, M; Moutardier, V; Delpero, J R

2015-06-01

To assess the accuracy of pre-operative staging in patients with peripheral pancreatic cystic neoplasms (pPCNs). From 2005 to 2011, 148 patients underwent a pancreatectomy for pPCNs. The pre-operative examination methods of computed tomography (CT), magnetic resonance imaging (MRI), endoscopic ultrasonography (EUS) were compared for their ability to predict the suggested diagnosis accurately, and the definitive diagnosis was affirmed by pathological examination. A mural nodule was detected in 34 patients (23%): only 1 patient (3%) had an invasive pPCN at the final histological examination. A biopsy was performed in 79 patients (53%) during EUS: in 55 patients (70%), the biopsy could not conclude a diagnosis; the biopsy provided the correct and wrong diagnosis in 19 patients (24%) and 5 patients (6%), respectively. A correct diagnosis was affirmed by CT, EUS and pancreatic MRI in 60 (41%), 103 (74%) and 80 (86%) patients (when comparing EUS and MRI; P = 0.03), respectively. The positive predictive values (PPVs) of CT, EUS and MRI were 70%, 75% and 87%, respectively. Pancreatic MRI appears to be the most appropriate examination to diagnose pPCNs accurately. EUS alone had a poor PPV. Mural nodules in a PCN should not be considered an indisputable sign of pPCN invasiveness. © 2015 International Hepato-Pancreato-Biliary Association.

Validity of administrative data claim-based methods for identifying individuals with diabetes at a population level.

PubMed

Southern, Danielle A; Roberts, Barbara; Edwards, Alun; Dean, Stafford; Norton, Peter; Svenson, Lawrence W; Larsen, Erik; Sargious, Peter; Lau, David C W; Ghali, William A

2010-01-01

This study assessed the validity of a widely-accepted administrative data surveillance methodology for identifying individuals with diabetes relative to three laboratory data reference standard definitions for diabetes. We used a combination of linked regional data (hospital discharge abstracts and physician data) and laboratory data to test the validity of administrative data surveillance definitions for diabetes relative to a laboratory data reference standard. The administrative discharge data methodology includes two definitions for diabetes: a strict administrative data definition of one hospitalization code or two physician claims indicating diabetes; and a more liberal definition of one hospitalization code or a single physician claim. The laboratory data, meanwhile, produced three reference standard definitions based on glucose levels +/- HbA1c levels. Sensitivities ranged from 68.4% to 86.9% for the administrative data definitions tested relative to the three laboratory data reference standards. Sensitivities were higher for the more liberal administrative data definition. Positive predictive values (PPV), meanwhile, ranged from 53.0% to 88.3%, with the liberal administrative data definition producing lower PPVs. These findings demonstrate the trade-offs of sensitivity and PPV for selecting diabetes surveillance definitions. Centralized laboratory data may be of value to future surveillance initiatives that use combined data sources to optimize case detection.

Validation of an Improved Computer-Assisted Technique for Mining Free-Text Electronic Medical Records.

PubMed

Duz, Marco; Marshall, John F; Parkin, Tim

2017-06-29

The use of electronic medical records (EMRs) offers opportunity for clinical epidemiological research. With large EMR databases, automated analysis processes are necessary but require thorough validation before they can be routinely used. The aim of this study was to validate a computer-assisted technique using commercially available content analysis software (SimStat-WordStat v.6 (SS/WS), Provalis Research) for mining free-text EMRs. The dataset used for the validation process included life-long EMRs from 335 patients (17,563 rows of data), selected at random from a larger dataset (141,543 patients, ~2.6 million rows of data) and obtained from 10 equine veterinary practices in the United Kingdom. The ability of the computer-assisted technique to detect rows of data (cases) of colic, renal failure, right dorsal colitis, and non-steroidal anti-inflammatory drug (NSAID) use in the population was compared with manual classification. The first step of the computer-assisted analysis process was the definition of inclusion dictionaries to identify cases, including terms identifying a condition of interest. Words in inclusion dictionaries were selected from the list of all words in the dataset obtained in SS/WS. The second step consisted of defining an exclusion dictionary, including combinations of words to remove cases erroneously classified by the inclusion dictionary alone. The third step was the definition of a reinclusion dictionary to reinclude cases that had been erroneously classified by the exclusion dictionary. Finally, cases obtained by the exclusion dictionary were removed from cases obtained by the inclusion dictionary, and cases from the reinclusion dictionary were subsequently reincluded using Rv3.0.2 (R Foundation for Statistical Computing, Vienna, Austria). Manual analysis was performed as a separate process by a single experienced clinician reading through the dataset once and classifying each row of data based on the interpretation of the free-text notes. Validation was performed by comparison of the computer-assisted method with manual analysis, which was used as the gold standard. Sensitivity, specificity, negative predictive values (NPVs), positive predictive values (PPVs), and F values of the computer-assisted process were calculated by comparing them with the manual classification. Lowest sensitivity, specificity, PPVs, NPVs, and F values were 99.82% (1128/1130), 99.88% (16410/16429), 94.6% (223/239), 100.00% (16410/16412), and 99.0% (100×2×0.983×0.998/[0.983+0.998]), respectively. The computer-assisted process required few seconds to run, although an estimated 30 h were required for dictionary creation. Manual classification required approximately 80 man-hours. The critical step in this work is the creation of accurate and inclusive dictionaries to ensure that no potential cases are missed. It is significantly easier to remove false positive terms from a SS/WS selected subset of a large database than search that original database for potential false negatives. The benefits of using this method are proportional to the size of the dataset to be analyzed. ©Marco Duz, John F Marshall, Tim Parkin. Originally published in JMIR Medical Informatics (http://medinform.jmir.org), 29.06.2017.

Validation of an Improved Computer-Assisted Technique for Mining Free-Text Electronic Medical Records

PubMed Central

Marshall, John F; Parkin, Tim

2017-01-01

Background The use of electronic medical records (EMRs) offers opportunity for clinical epidemiological research. With large EMR databases, automated analysis processes are necessary but require thorough validation before they can be routinely used. Objective The aim of this study was to validate a computer-assisted technique using commercially available content analysis software (SimStat-WordStat v.6 (SS/WS), Provalis Research) for mining free-text EMRs. Methods The dataset used for the validation process included life-long EMRs from 335 patients (17,563 rows of data), selected at random from a larger dataset (141,543 patients, ~2.6 million rows of data) and obtained from 10 equine veterinary practices in the United Kingdom. The ability of the computer-assisted technique to detect rows of data (cases) of colic, renal failure, right dorsal colitis, and non-steroidal anti-inflammatory drug (NSAID) use in the population was compared with manual classification. The first step of the computer-assisted analysis process was the definition of inclusion dictionaries to identify cases, including terms identifying a condition of interest. Words in inclusion dictionaries were selected from the list of all words in the dataset obtained in SS/WS. The second step consisted of defining an exclusion dictionary, including combinations of words to remove cases erroneously classified by the inclusion dictionary alone. The third step was the definition of a reinclusion dictionary to reinclude cases that had been erroneously classified by the exclusion dictionary. Finally, cases obtained by the exclusion dictionary were removed from cases obtained by the inclusion dictionary, and cases from the reinclusion dictionary were subsequently reincluded using Rv3.0.2 (R Foundation for Statistical Computing, Vienna, Austria). Manual analysis was performed as a separate process by a single experienced clinician reading through the dataset once and classifying each row of data based on the interpretation of the free-text notes. Validation was performed by comparison of the computer-assisted method with manual analysis, which was used as the gold standard. Sensitivity, specificity, negative predictive values (NPVs), positive predictive values (PPVs), and F values of the computer-assisted process were calculated by comparing them with the manual classification. Results Lowest sensitivity, specificity, PPVs, NPVs, and F values were 99.82% (1128/1130), 99.88% (16410/16429), 94.6% (223/239), 100.00% (16410/16412), and 99.0% (100×2×0.983×0.998/[0.983+0.998]), respectively. The computer-assisted process required few seconds to run, although an estimated 30 h were required for dictionary creation. Manual classification required approximately 80 man-hours. Conclusions The critical step in this work is the creation of accurate and inclusive dictionaries to ensure that no potential cases are missed. It is significantly easier to remove false positive terms from a SS/WS selected subset of a large database than search that original database for potential false negatives. The benefits of using this method are proportional to the size of the dataset to be analyzed. PMID:28663163

Candida colonization as a risk marker for invasive candidiasis in mixed medical-surgical intensive care units: development and evaluation of a simple, standard protocol.

PubMed

Lau, Anna F; Kabir, Masrura; Chen, Sharon C-A; Playford, E Geoffrey; Marriott, Deborah J; Jones, Michael; Lipman, Jeffrey; McBryde, Emma; Gottlieb, Thomas; Cheung, Winston; Seppelt, Ian; Iredell, Jonathan; Sorrell, Tania C

2015-04-01

Colonization with Candida species is an independent risk factor for invasive candidiasis (IC), but the minimum and most practicable parameters for prediction of IC have not been optimized. We evaluated Candida colonization in a prospective cohort of 6,015 nonneutropenic, critically ill patients. Throat, perineum, and urine were sampled 72 h post-intensive care unit (ICU) admission and twice weekly until discharge or death. Specimens were cultured onto chromogenic agar, and a subset underwent molecular characterization. Sixty-three (86%) patients who developed IC were colonized prior to infection; 61 (97%) tested positive within the first two time points. The median time from colonization to IC was 7 days (range, 0 to 35). Colonization at any site was predictive of IC, with the risk of infection highest for urine colonization (relative risk [RR]=2.25) but with the sensitivity highest (98%) for throat and/or perineum colonization. Colonization of ≥2 sites and heavy colonization of ≥1 site were significant independent risk factors for IC (RR=2.25 and RR=3.7, respectively), increasing specificity to 71% to 74% but decreasing sensitivity to 48% to 58%. Molecular testing would have prompted a resistance-driven decision to switch from fluconazole treatment in only 11% of patients infected with C. glabrata, based upon species-level identification alone. Positive predictive values (PPVs) were low (2% to 4%) and negative predictive values (NPVs) high (99% to 100%) regardless of which parameters were applied. In the Australian ICU setting, culture of throat and perineum within the first two time points after ICU admission captures 84% (61/73 patients) of subsequent IC cases. These optimized parameters, in combination with clinical risk factors, should strengthen development of a setting-specific risk-predictive model for IC. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

What Should Be the Cut Point for Classification Criteria of Studies in Gout? A Conjoint Analysis.

PubMed

Fransen, Jaap; Kievit, Wietske; Neogi, Tuhina; Schumacher, Ralph; Jansen, Tim; Dalbeth, Nicola; Taylor, William J

2016-11-01

To determine the acceptable level of positive predictive value (PPV) and negative predictive value (NPV) for classification criteria for gout, given the type of study. We conducted an international web-based survey with 91 general practitioners and rheumatologists experienced in gout. Conjoint analysis was used as the framework for designing and analyzing pairs of 2 profiles, each describing a study type, a PPV, and an NPV. There were 5 study types presented: a phase III randomized controlled trial (RCT) of a nonsteroidal antiinflammatory drug versus prednisone for acute gout flares, a phase III RCT of a biologic agent for acute gout flares, a phase II RCT of a novel uricosuric drug of unknown efficacy and limited toxicity data, a case-control, genome-wide association study of gout, and a cohort study examining long-term outcomes of gout. PPV and NPV both had 5 levels ranging from 60-99%. The panelists in majority were male (65%) rheumatologists (93%) with an average of 19 years of practice, seeing 5 to 60 gout patients monthly. PPV was most highly weighted in decision making: the relative importance was 59% for PPV, 29% for NPV, and 13% for study type. The preferred PPV was 90% or 80%, with an accompanying NPV of 70% or 80%, dependent on study type. Preferred PPVs and NPVs range between 70% and 90% and differ by study type. A single cut point can be a reasonable approach for all study types if a PPV of 90% and NPV of 80% is approximated. © 2016, American College of Rheumatology.

The emergency department prediction of disposition (EPOD) study.

PubMed

Vaghasiya, Milan R; Murphy, Margaret; O'Flynn, Daniel; Shetty, Amith

2014-11-01

Emergency departments (ED) continue to evolve models of care and streaming as interventions to tackle the effects of access block and overcrowding. Tertiary ED may be able to design patient-flow based on predicted dispositions in the department. Segregating discharge-stream patients may help develop patient-flows within the department, which is less affected by availability of beds in a hospital. We aim to determine if triage nurses and ED doctors can predict disposition outcomes early in the patient journey and thus lead to successful streaming of patients in the ED. During this study, triage nurses and ED doctors anonymously predicted disposition outcomes for patients presenting to triage after their brief assessments. Patient disposition at the 24-h post ED presentation was considered as the actual outcome and compared against predicted outcomes. Triage nurses were able to predict actual discharges of 445 patients out of 490 patients with a positive predictive value (PPV) of 90.8% (95% CI 87.8-93.2%). ED registrars were able to predict actual discharges of 85 patients out of 93 patients with PPV of 91.4% (95% CI 83.3-95.9%). ED consultants were able to predict actual discharges of 111 patients out of 118 patients with PPV 94.1% (95% CI 87.7-97.4%). PPVs for admission among ED consultants, ED registrars and Triage nurses were 59.7%, 54.4% and 48.5% respectively. Triage nurses, ED consultants and ED registrars are able to predict a patient's discharge disposition at triage with high levels of confidence. Triage nurses, ED consultants, and ED registrars can predict patients who are likely to be admitted with equal ability. This data may be used to develop specific admission and discharge streams based on early decision-making in EDs by triage nurses, ED registrars or ED consultants. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

Characteristics of PI-RADS 4 lesions within the prostatic peripheral zone: a retrospective diagnostic accuracy study evaluating 170 lesions.

PubMed

Shankar, Prasad R; Curci, Nicole E; Davenport, Matthew S

2017-12-02

To determine whether peripheral zone PI-RADS 4 observations can be further risk-stratified. This was an IRB-approved HIPAA-compliant retrospective diagnostic accuracy study. Peripheral zone PI-RADS 4 observations prospectively identified at the study institution from 8/1/2015 to 12/31/2016 (n = 170 in 149 mpMRIs) were reviewed independently by two blinded genitourinary radiologists on the basis of (a) PI-RADS v2 shape, (b) pattern of peripheral zone sparing, and (c) rationale for PI-RADS 4 designation. Reference standard was targeted MR-ultrasound fusion biopsy and detection of Gleason 7+ prostate cancer. Positive predictive values (PPVs) were calculated. Predictors were assessed with binary logistic regression. PI-RADS 4 lesions with a DWI score of 4 were more likely to represent Gleason 7+ prostate cancer (p = 0.008-0.01; Reader 1 PPV: 53%; Reader 2 PPV: 48%). Pattern of peripheral zone sparing and most lesion shapes were not predictive (p > 0.05); however, oval lesions were predictive for Reader 1 (PPV = 59%, p = 0.03) and lentiform lesions were predictive for Reader 2 (PPV = 74%, p = 0.01). Lesions scored as "not meeting PI-RADS 4 criteria" had significantly lower PPV (p = 0.016-0.003; Reader 1 PPV: 14%, Reader 2 PPV: 16%). Peripheral zone PI-RADS 4 lesions with a DWI score of 4 are more likely Gleason 7+ cancer than those with a DWI score of 3. Lesions overcalled as PI-RADS 4 have PPV similar to published PI-RADS 3 data. Lesion shape and peripheral zone sparing in general do not predict Gleason 7+ cancer within PI-RADS 4 observations.

[Cost recovery for the treatment of retinal and vitreal diseases by pars plana vitrectomy under the German DRG system].

PubMed

Framme, C; Franz, D; Mrosek, S; Helbig, H

2007-10-01

Since 2004 inpatient health care in Germany is paid according to calculated DRGs. Only a few university hospitals participated in distinct cost calculations of clinical treatment. It was the aim of this study to check the cost recovery at a University Eye Hospital for the surgical treatment of retinal and vitreal diseases by pars plana vitrectomy (ppV), which are included in DRGs C03Z and C17Z. The performance data for both DRGs were collected for the years 2005 and 2006 using the E1 sheets according to section 21 KHEntG. The mean duration of all procedures was collected by data from the internal controlling. Costs for single operations were calculated from fixed and variable costs for the operation theatre and the ward including costs for personnel and material. In the 2-year period of 4,721 inpatient procedures 1,307 ppVs were performed. Each ppV had fixed surgical costs of 130.60 EUR; personnel costs varied between 575 EUR (C03Z; including cataract surgery; mean OP duration: 85 min) and 510 EUR (C17Z; no cataract surgery; mean OP duration: 73 min) at a proportion between general anaesthesia and local anaesthesia of 80/20. For a pure ppV material costs were 255 EUR. Additional adjuncts such as an encircling band, perfluorcarbon, ICG, tPA, gas and silicon oil or cataract surgery led to extra costs between 51 EUR and 250 EUR per adjunct und were used in 56% (C03Z) and 74.5% (C17Z) of all procedures. Costs for hospitalisation were about 1765 EUR at a mean residence time of 6.5 days. Thus, the overall costs of a pure basic ppV amounted to 2975 EUR (C03Z) and 2661 EUR (C17Z). In consideration of the current relative DRG weights of 1.08 and 0.957 and a current base rate of 2787.19 EUR in Bavaria, cost recovery is only given for basic ppV but not for complex ppVs having higher material and personnel costs. Additionally, the costs for multiple surgeries as occur in 5.9% of cases are not compensated by the DRG system. The reimbursement for inpatient ppVs in a University environment is not covered for complex procedures requiring more cost-effective material and personnel time. To consider an adequate cost recovery for these procedures a DRG split for both DRGs (C03Z and C17Z) in basic ppVs and complex ppVs is required. We recommend this proposal for the InEK.

Workgroup Report by the Joint Task Force Involving American Academy of Allergy, Asthma & Immunology (AAAAI); Food Allergy, Anaphylaxis, Dermatology and Drug Allergy (FADDA) (Adverse Reactions to Foods Committee and Adverse Reactions to Drugs, Biologicals, and Latex Committee); and the Centers for Disease Control and Prevention Botulism Clinical Treatment Guidelines Workgroup-Allergic Reactions to Botulinum Antitoxin: A Systematic Review.

PubMed

Schussler, Edith; Sobel, Jeremy; Hsu, Joy; Yu, Patricia; Meaney-Delman, Dana; Grammer, Leslie C; Nowak-Wegrzyn, Anna

2017-12-27

Naturally occurring botulism is rare, but a large number of cases could result from unintentional or intentional contamination of a commercial food. Despeciated, equine-derived, heptavalent botulinum antitoxin (HBAT) is licensed in the United States. Timely treatment reduces morbidity and mortality, but concerns that botulinum antitoxin can induce anaphylaxis exist. We sought to quantify the allergy risk of botulinum antitoxin treatment and the usefulness of skin testing to assess this risk. We conducted a systematic review of (1) allergic reactions to botulinum antitoxin and (2) the predictive value of skin testing (ST) before botulinum antitoxin administration. We searched 5 scientific literature databases, reviewed articles' references, and obtained data from the HBAT manufacturer and from the Centers for Disease Control and Prevention. Anaphylaxis incidence was determined for HBAT and previously employed botulinum antitoxins. We calculated the positive predictive value (PPV) and negative predictive value (NPV) of ST for anaphylaxis related to HBAT and other botulinum antitoxins. Seven articles were included. Anaphylaxis incidence was 1.64% (5/305 patients) for HBAT and 1.16% (8/687 patients) for all other botulinum antitoxins (relative risk, 1.41 [95% confidence interval, .47-4.27]; P = .5). Observed values for both PPV and NPV for HBAT-ST (33 patients) were 100%. Observed PPVs and NPVs of ST for other botulinum antitoxins (302 patients) were 0-56% and 50%-100%, respectively. There were no reports of fatal anaphylaxis. Considering the <2 % rate of anaphylaxis, fatal outcomes, modest predictive value of ST, resource requirements for ST, and the benefits of early treatment, data do not support delaying HBAT administration to perform ST in a mass botulinum toxin exposure. Anaphylactic reactions may occur among 1%-2% of botulinum antitoxin recipients and will require epinephrine and antihistamine treatment and, possibly, intensive care. Published by Oxford University Press for the Infectious Diseases Society of America 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Placental Alpha Microglobulin-1 Compared With Fetal Fibronectin to Predict Preterm Delivery in Symptomatic Women.

PubMed

Wing, Deborah A; Haeri, Sina; Silber, Angela C; Roth, Cheryl K; Weiner, Carl P; Echebiri, Nelson C; Franco, Albert; Pappas, Lanissa M; Yeast, John D; Brebnor, Angelle A; Quirk, J Gerald; Murphy, Aisling M; Laurent, Louise C; Field, Nancy T; Norton, Mary E

2017-12-01

To compare the rapid bedside test for placental α microglobulin-1 with the instrumented fetal fibronectin test for prediction of imminent spontaneous preterm delivery among women with symptoms of preterm labor. We conducted a prospective observational study on pregnant women with signs or symptoms suggestive of preterm labor between 24 and 35 weeks of gestation with intact membranes and cervical dilatation less than 3 cm. Participants were prospectively enrolled at 15 U.S. academic and community centers. Placental α microglobulin-1 samples did not require a speculum examination. Health care providers were blinded to placental α microglobulin-1 results. Fetal fibronectin samples were collected through speculum examination per manufacturer requirements and sent to a certified laboratory for testing using a cutoff of 50 ng/mL. The coprimary endpoints were positive predictive value (PPV) superiority and negative predictive value (NPV) noninferiority of placental α microglobulin-1 compared with fetal fibronectin for the prediction of spontaneous preterm birth within 7 days and within 14 days. Of 796 women included in the study cohort, 711 (89.3%) had both placental α microglobulin-1 and fetal fibronectin results and valid delivery outcomes available for analysis. The overall rate of preterm birth was 2.4% (17/711) within 7 days of testing and 4.2% (30/711) within 14 days of testing with respective rates of spontaneous preterm birth of 1.3% (9/703) and 2.9% (20/701). Fetal fibronectin was detected in 15.5% (110/711), and placental α microglobulin-1 was detected in 2.4% (17/711). The PPVs for spontaneous preterm delivery within 7 days or less among singleton gestations (n=13) for placental α microglobulin-1 and fetal fibronectin were 23.1% (3/13) and 4.3% (4/94), respectively (P<.025 for superiority). The NPVs were 99.5% (619/622) and 99.6% (539/541) for placental α microglobulin-1 and fetal fibronectin, respectively (P<.001 for noninferiority). Although placental α microglobulin-1 performed the same as fetal fibronectin in ruling out spontaneous preterm delivery among symptomatic women, it demonstrated statistical superiority in predicting it.

Rapid diagnostic tests for malaria at sites of varying transmission intensity in Uganda.

PubMed

Hopkins, Heidi; Bebell, Lisa; Kambale, Wilson; Dokomajilar, Christian; Rosenthal, Philip J; Dorsey, Grant

2008-02-15

In Africa, fever is often treated presumptively as malaria, resulting in misdiagnosis and the overuse of antimalarial drugs. Rapid diagnostic tests (RDTs) for malaria may allow improved fever management. We compared RDTs based on histidine-rich protein 2 (HRP2) and RDTs based on Plasmodium lactate dehydrogenase (pLDH) with expert microscopy and PCR-corrected microscopy for 7000 patients at sites of varying malaria transmission intensity across Uganda. When all sites were considered, the sensitivity of the HRP2-based test was 97% when compared with microscopy and 98% when corrected by PCR; the sensitivity of the pLDH-based test was 88% when compared with microscopy and 77% when corrected by PCR. The specificity of the HRP2-based test was 71% when compared with microscopy and 88% when corrected by PCR; the specificity of the pLDH-based test was 92% when compared with microscopy and >98% when corrected by PCR. Based on Plasmodium falciparum PCR-corrected microscopy, the positive predictive value (PPV) of the HRP2-based test was high (93%) at all but the site with the lowest transmission rate; the pLDH-based test and expert microscopy offered excellent PPVs (98%) for all sites. The negative predictive value (NPV) of the HRP2-based test was consistently high (>97%); in contrast, the NPV for the pLDH-based test dropped significantly (from 98% to 66%) as transmission intensity increased, and the NPV for expert microscopy decreased significantly (99% to 54%) because of increasing failure to detect subpatent parasitemia. Based on the high PPV and NPV, HRP2-based RDTs are likely to be the best diagnostic choice for areas with medium-to-high malaria transmission rates in Africa.

Identification of Gambling Problems in Primary Care: Properties of the NODS-CLiP Screening Tool.

PubMed

Cowlishaw, Sean; McCambridge, Jim; Kessler, David

2018-06-25

There are several brief screening tools for gambling that possess promising psychometric properties, but have uncertain utility in generalist healthcare environments which prioritize prevention and brief interventions. This study describes an examination of the National Opinion Research Centre Diagnostic and Statistical Manual of Mental Disorders Screen for Gambling Problems (NODS-CLiP), in comparison with the Problem Gambling Severity Index (PGSI), when used to operationalize gambling problems across a spectrum of severity. Data were obtained from 1058 primary care attendees recruited from 11 practices in England who completed various measures including the NODS-CLiP and PGSI. The performance of the former was defined by estimates of sensitivity, specificity, positive predictive values (PPVs), and negative predictive values (NPVs), when PGSI indicators of problem gambling (5+) and any gambling problems (1+), respectively, were reference standards. The NODS-CLiP demonstrated perfect sensitivity for problem gambling, along with high specificity and a NPV, but a low PPV. There was much lower sensitivity when the indicator of any gambling problems was the reference standard, with capture rates indicating only 20% of patients exhibiting low to moderate severity gambling problems (PGSI 1-4) were identified by the NODS-CLiP. The NODS-CLiP performs well when identifying severe cases of problem gambling, but lacks sensitivity for less severe problems and may be unsuitable for settings which prioritize prevention and brief interventions. There is a need for screening measures which are sensitive across the full spectrum of risk and severity, and can support initiatives for improving identification and responses to gambling problems in healthcare settings such as primary care.

High-performance polymeric photovoltaic cells with a gold chloride-treated polyacrylonitrile hole extraction interlayer

NASA Astrophysics Data System (ADS)

Jeong, Ji-Ho; Noh, Yong-Jin; Kim, Seok-Soon; Kwon, Sung-Nam; Na, Seok-In

2018-03-01

We introduce a high efficiency polymeric photovoltaic cell (PPV) to be obtained by polyacrylonitrile (PAN) hole extraction layer (HEL) modification with gold chloride (AuCl3). The role of PAN HELs with AuCl3 and their effects on solar cell performances were studied with ultraviolet photoemission spectroscopy, atomic force microscopy, internal resistances in PPVs, and current-voltage power curves. The resultant PPVs with AuCl3-treated PAN HELs showed improved cell efficiency compared to PSCs with no interlayer and PAN without AuCl3. Furthermore, with AuCl3-treated PAN, we finally achieved a high efficiency of 6.91%, and a desirable PPV-stability in poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b‧]dithiophe-ne-2,6-diyl][3-fluoro-2-[(2-thylhexyl)carbonyl]-thieno[3,4-b]thiophenediyl

Rapid and Accurate Diagnosis Based on Real-Time PCR Cycle Threshold Value for the Identification of Campylobacter jejuni, astA Gene-Positive Escherichia coli, and eae Gene-Positive E. coli.

PubMed

Kawase, Jun; Asakura, Hiroshi; Kurosaki, Morito; Oshiro, Hitoshi; Etoh, Yoshiki; Ikeda, Tetsuya; Watahiki, Masanori; Kameyama, Mitsuhiro; Hayashi, Fumi; Kawakami, Yuta; Murakami, Yoshiko; Tsunomori, Yoshie

2018-01-23

We previously developed a multiplex real-time PCR assay (Rapid Foodborne Bacterial Screening 24 ver.5, [RFBS24 ver.5]) for simultaneous detection of 24 foodborne bacterial targets. Here, to overcome the discrepancy of the results from RFBS24 ver.5 and bacterial culture methods (BC), we analyzed 246 human clinical samples from 49 gastroenteritis outbreaks using RFBS24 ver.5 and evaluated the correlation between the cycle threshold (CT) value of RFBS24 ver.5 and the BC results. The results showed that the RFBS24 ver.5 was more sensitive than BC for Campylobacter jejuni and Escherichia coli harboring astA or eae, with positive predictive values (PPV) of 45.5-87.0% and a kappa coefficient (KC) of 0.60-0.92, respectively. The CTs were significantly different between BC-positive and -negative samples (p ＜ 0.01). All RFBS24 ver.5-positive samples were BC-positive under the lower confidence interval (CI) limit of 95% or 99% for the CT of the BC-negative samples. We set the 95% or 99% CI lower limit to the determination CT (d-CT) to discriminate for assured BC-positive results (d-CTs: 27.42-30.86), and subsequently the PPVs (94.7%-100.0%) and KCs (0.89-0.95) of the 3 targets were increased. Together, we concluded that the implication of a d-CT-based approach would be a valuable tool for rapid and accurate diagnoses using the RFBS24 ver.5 system.

Performance assessment of urine flow cytometry (UFC) to screen urines to reflex to culture in immunocompetent and immunosuppressed hosts.

PubMed

Stefanovic, Aleksandra; Roscoe, Diane; Ranasinghe, Romali; Wong, Titus; Bryce, Elizabeth; Porter, Charlene; Lim, Adelina; Grant, Jennifer; Ng, Karen; Pudek, Morris

2017-09-01

Urine flow cytometry (UFC) is an automated method to quantify bacterial and white blood cell (WBC) counts. We aimed to determine whether a threshold for these parameters can be set to use UFC as a sensitive screen to predict which urine samples will subsequently grow in culture. Urines submitted to our microbiology laboratory at a tertiary care centre from 22 July 2015-17 February 2016 underwent UFC (Sysmex UF-1000i) analysis, regular urinalysis and urine culture. Positive urine cultures were defined as growth ≥104 c.f.u. ml-1 of organisms associated with urinary tract infections. The correlation of UFC bacterial and WBC counts with urine culture was assessed using receiver operating characteristics curves. The sensitivity (SN), specificity (SP), negative predictive values (NPVs), positive predictive values (PPVs) and false negative rate (FNR) were calculated at various thresholds in immunocompetent and immunosuppressed patients. A total of 15 046 urine specimens were submitted, of which 14 908 were analysable in the study. The average time to UFC result from receipt in the laboratory was 0.76 h (+/-1.04). The test performance at a set threshold of UFC bacteria ≥20 or WBC >5 was: SN=96.0 %, SP=39.2 %, PPV=47.0 %, NPV=94.5 % and FNR=4.0 %. This threshold eliminates 26 % of urine cultures. Immunosuppressed hosts had a lower sensitivity of 90.6 % and a higher FNR of 9.4 %. UFC is a rapid and sensitive method to screen out urine samples that will subsequently be negative and to reflex urines to culture that will subsequently grow. UFC results are available within 1 h from receipt and enable the elimination of culture when the set threshold is not met.

Rapid Prediction of Hematologic Acute Radiation Syndrome in Radiation Injury Patients Using Peripheral Blood Cell Counts.

PubMed

Port, M; Pieper, B; Knie, T; Dörr, H; Ganser, A; Graessle, D; Meineke, V; Abend, M

2017-08-01

Rapid clinical triage of radiation injury patients is essential for determining appropriate diagnostic and therapeutic interventions. We examined the utility of blood cell counts (BCCs) in the first three days postirradiation to predict clinical outcome, specifically for hematologic acute radiation syndrome (HARS). We analyzed BCC test samples from radiation accident victims (n = 135) along with their clinical outcome HARS severity scores (H1-4) using the System for Evaluation and Archiving of Radiation Accidents based on Case Histories (SEARCH) database. Data from nonirradiated individuals (H0, n = 132) were collected from an outpatient facility. We created binary categories for severity scores, i.e., 1 (H0 vs. H1-4), 2 (H0-1 vs. H2-4) and 3 (H0-2 vs. H3-4), to assess the discrimination ability of BCCs using unconditional logistic regression analysis. The test sample contained 454 BCCs from 267 individuals. We validated the discrimination ability on a second independent group comprised of 275 BCCs from 252 individuals originating from SEARCH (HARS 1-4), an outpatient facility (H0) and hospitals (e.g., leukemia patients, H4). Individuals with a score of H0 were easily separated from exposed individuals based on developing lymphopenia and granulocytosis. The separation of H0 and H1-4 became more prominent with increasing hematologic severity scores and time. On day 1, lymphocyte counts were most predictive for discriminating binary categories, followed by granulocytes and thrombocytes. For days 2 and 3, an almost complete separation was achieved when BCCs from different days were combined, supporting the measurement of sequential BCC. We found an almost complete discrimination of H0 vs. irradiated individuals during model validation (negative predictive value, NPV > 94%) for all three days, while the correct prediction of exposed individuals increased from day 1 (positive predictive value, PPV 78-89%) to day 3 (PPV > 90%). The models were unable to provide predictions for 10.9% of the test samples, because the PPVs or NPVs did not reach a 95% likelihood defined as the lower limit for a prediction. We developed a prediction model spreadsheet to provide early and prompt diagnostic predictions and therapeutic recommendations including identification of the worried well, requirement of hospitalization or development of severe hematopoietic syndrome. These results improve the provisional classification of HARS. For the final diagnosis, further procedures (sequential diagnosis, retrospective dosimetry, clinical follow-up, etc.) must be taken into account. Clinical outcome of radiation injury patients can be rapidly predicted within the first three days postirradiation using peripheral BCC.

A family of membrane-shaping proteins at ER subdomains regulates pre-peroxisomal vesicle biogenesis.

PubMed

Joshi, Amit S; Huang, Xiaofang; Choudhary, Vineet; Levine, Tim P; Hu, Junjie; Prinz, William A

2016-11-21

Saccharomyces cerevisiae contains three conserved reticulon and reticulon-like proteins that help maintain ER structure by stabilizing high membrane curvature in ER tubules and the edges of ER sheets. A mutant lacking all three proteins has dramatically altered ER morphology. We found that ER shape is restored in this mutant when Pex30p or its homologue Pex31p is overexpressed. Pex30p can tubulate membranes both in cells and when reconstituted into proteoliposomes, indicating that Pex30p is a novel ER-shaping protein. In contrast to the reticulons, Pex30p is low abundance, and we found that it localizes to subdomains in the ER. We show that these ER subdomains are the sites where most preperoxisomal vesicles (PPVs) are generated. In addition, overproduction or deletion of Pex30p or Pex31p alters the size, shape, and number of PPVs. Our findings suggest that Pex30p and Pex31p help shape and generate regions of the ER where PPV biogenesis occurs.

Are all quantitative postmarketing signal detection methods equal? Performance characteristics of logistic regression and Multi-item Gamma Poisson Shrinker.

PubMed

Berlin, Conny; Blanch, Carles; Lewis, David J; Maladorno, Dionigi D; Michel, Christiane; Petrin, Michael; Sarp, Severine; Close, Philippe

2012-06-01

The detection of safety signals with medicines is an essential activity to protect public health. Despite widespread acceptance, it is unclear whether recently applied statistical algorithms provide enhanced performance characteristics when compared with traditional systems. Novartis has adopted a novel system for automated signal detection on the basis of disproportionality methods within a safety data mining application (Empirica™ Signal System [ESS]). ESS uses two algorithms for routine analyses: empirical Bayes Multi-item Gamma Poisson Shrinker and logistic regression (LR). A model was developed comprising 14 medicines, categorized as "new" or "established." A standard was prepared on the basis of safety findings selected from traditional sources. ESS results were compared with the standard to calculate the positive predictive value (PPV), specificity, and sensitivity. PPVs of the lower one-sided 5% and 0.05% confidence limits of the Bayes geometric mean (EB05) and of the LR odds ratio (LR0005) almost coincided for all the drug-event combinations studied. There was no obvious difference comparing the PPV of the leading Medical Dictionary for Regulatory Activities (MedDRA) terms to the PPV for all terms. The PPV of narrow MedDRA query searches was higher than that for broad searches. The widely used threshold value of EB05 = 2.0 or LR0005 = 2.0 together with more than three spontaneous reports of the drug-event combination produced balanced results for PPV, sensitivity, and specificity. Consequently, performance characteristics were best for leading terms with narrow MedDRA query searches irrespective of applying Multi-item Gamma Poisson Shrinker or LR at a threshold value of 2.0. This research formed the basis for the configuration of ESS for signal detection at Novartis. Copyright © 2011 John Wiley & Sons, Ltd.

Developing Electronic Health Record Algorithms That Accurately Identify Patients With Systemic Lupus Erythematosus.

PubMed

Barnado, April; Casey, Carolyn; Carroll, Robert J; Wheless, Lee; Denny, Joshua C; Crofford, Leslie J

2017-05-01

To study systemic lupus erythematosus (SLE) in the electronic health record (EHR), we must accurately identify patients with SLE. Our objective was to develop and validate novel EHR algorithms that use International Classification of Diseases, Ninth Revision (ICD-9), Clinical Modification codes, laboratory testing, and medications to identify SLE patients. We used Vanderbilt's Synthetic Derivative, a de-identified version of the EHR, with 2.5 million subjects. We selected all individuals with at least 1 SLE ICD-9 code (710.0), yielding 5,959 individuals. To create a training set, 200 subjects were randomly selected for chart review. A subject was defined as a case if diagnosed with SLE by a rheumatologist, nephrologist, or dermatologist. Positive predictive values (PPVs) and sensitivity were calculated for combinations of code counts of the SLE ICD-9 code, a positive antinuclear antibody (ANA), ever use of medications, and a keyword of "lupus" in the problem list. The algorithms with the highest PPV were each internally validated using a random set of 100 individuals from the remaining 5,759 subjects. The algorithm with the highest PPV at 95% in the training set and 91% in the validation set was 3 or more counts of the SLE ICD-9 code, ANA positive (≥1:40), and ever use of both disease-modifying antirheumatic drugs and steroids, while excluding individuals with systemic sclerosis and dermatomyositis ICD-9 codes. We developed and validated the first EHR algorithm that incorporates laboratory values and medications with the SLE ICD-9 code to identify patients with SLE accurately. © 2016, American College of Rheumatology.

Comparison between two commercially available serological tests and polymerase chain reaction in the diagnosis of Cryptosporidium in animals and diarrhoeic children.

PubMed

Helmy, Yosra A; Krücken, Jürgen; Nöckler, Karsten; von Samson-Himmelstjerna, Georg; Zessin, Karl-H

2014-01-01

For the detection of Cryptosporidium species in 804 animals and 165 diarrhoeic children (<10 years) in Egypt, two copro-antigen tests, the RIDASCREEN® Cryptosporidium test [enzyme immunoassay (EIA)] and the RIDA®QUICK Cryptosporidium/Giardia Combi [immuno-chromatographic test (ICT)] as well as polymerase chain reaction (PCR) were used. Prevalence of Cryptosporidium was 15.0, 19.5 and 32.3% in animals and 2.4, 6.7 and 49.1% in children using EIA, ICT and PCR, respectively.Using PCR as reference method, animal samples sensitivity (Se) of the EIA was 46.5% when questionable samples were considered positive, whereas specificity (Sp) was 100%. Se of the ICT was 60.4% while Sp was 100%. Positive predictive values (PPVs) for both EIA and ICT test were 100%, and negative predictive values (NPVs) for EIA were 79.7 and 84.1% for ICT. For the children samples, the Se of EIA was 5%, Sp was 100%, PPV was 100% and NPV was 52.2%, while the Se of ICT was 13.6%, Sp was 100%, PPV was 100% and NPV was 54.6%.The Kappa score of agreement between PCR and ICT was 67.4%, 54.1% between PCR and EIA and 84.4% between ICT and EIA. Until the second serial dilution of the EIA and ICT test, 9 × 10(3) oocysts/μl of Cryptosporidia was detected, whereas in PCR, they were detected until the sixth serial dilution. Copro-antigen tests were easy to perform and less time-consuming but less sensitive compared to PCR. They obviously are best applicable for screening and epidemiological studies of large numbers of subjects, for batch specimen processing and in isolated or rural areas where reliable tests like PCR are unfeasible. When in children, a single stool sample is used for the diagnosis of clinical cases; better results can be obtained when non-standardized PCR due low specificity is coupled with copro-antigen tests.

Identifying Patients with Severe Sepsis Using Administrative Claims: Patient-Level Validation of the Angus Implementation of the International Consensus Conference Definition of Severe Sepsis

PubMed Central

Iwashyna, Theodore J.; Odden, Andrew; Rohde, Jeffrey; Bonham, Catherine; Kuhn, Latoya; Malani, Preeti; Chen, Lena; Flanders, Scott

2012-01-01

Background Severe sepsis is a common and costly problem. Although consistently defined clinically by consensus conference since 1991, there have been several different implementations of the severe sepsis definition using ICD-9-CM codes for research. We conducted a single center, patient-level validation of one common implementation of the severe sepsis definition, the so-called “Angus” implementation. Methods Administrative claims for all hospitalizations for patients initially admitted to general medical services from an academic medical center in 2009–2010 were reviewed. On the basis of ICD-9-CM codes, hospitalizations were sampled for review by three internal medicine-trained hospitalists. Chart reviews were conducted with a structured instrument, and the gold standard was the hospitalists’ summary clinical judgment on whether the patient had severe sepsis. Results 3,146 (13.5%) hospitalizations met ICD-9-CM criteria for severe sepsis by the Angus implementation (“Angus-positive”) and 20,142 (86.5%) were Angus-negative. Chart reviews were performed for 92 randomly-selected Angus-positive and 19 randomly-selected Angus-negative hospitalizations. Reviewers had a kappa of 0.70. The Angus implementation’s positive predictive value (PPV) was 70.7% (95%CI: 51.2%, 90.5%). The negative predictive value was 91.5% (95%CI: 79.0%, 100%). The sensitivity was 50.4% (95%CI: 14.8%, 85.7%). Specificity was 96.3% (95%CI: 92.4%, 100%). Two alternative ICD-9-CM implementations had high PPVs but sensitivities of less than 20%. Conclusions The Angus implementation of the international consensus conference definition of severe sepsis offers a reasonable but imperfect approach to identifying patients with severe sepsis when compared with a gold standard of structured review of the medical chart by trained hospitalists. PMID:23001437

The association between premorbid cognitive ability and social functioning and suicide among young men: A historical-prospective cohort study.

PubMed

Weiser, Mark; Fenchel, Daphna; Werbeloff, Nomi; Goldberg, Shira; Fruchter, Eyal; Reichenberg, Abraham; Burshtein, Shimon; Large, Matthew; Davidson, Michael; Lubin, Gad

2017-01-01

Previous studies have found associations between low cognitive ability and later completed suicide. The aim of this study was to examine the association between cognitive ability and social functioning in adolescence, and later completed suicide in a large population-based longitudinal study. Data from the Israeli Draft Board Register for 634,655 Israeli male adolescents aged 16 and 17 was linked to a causes-of-death data registry, with a mean follow-up of 10.6 years for completed suicide. Our results show that in males without a psychiatric diagnosis, both low (adjusted HR=1.51, 95% CI: 1.19-1.92) and high (adjusted HR=1.36, 95% CI: 1.04-1.77) cognitive ability, and very poor (adjusted HR=2.30, 95% CI: 1.34-3.95) and poor (adjusted HR=1.64, 95% CI: 1.34-2.07) social functioning were associated with increased risk for later completed suicide; however positive predictive values were low (PPVs=0.09% and 0.10%, for low cognitive ability and very poor or poor social functioning, respectively). No association between cognitive ability or social functioning and risk for suicide was found in males with a psychiatric diagnosis. These data do not support the clinical utility of screening for such potential predictors. Copyright © 2017 Elsevier B.V. and ECNP. All rights reserved.

Public-Private Venture’s Contribution to Improved Quality of Life

DTIC Science & Technology

2005-02-08

management priority and is recognized as a key item on the administration’s agenda to improve the quality of life for our service members. These public...private ventures (PPVs) will significantly improve the quality of life for Marine families residing in base housing because they offer an increased

Proposed biopsy performance benchmarks for MRI based on an audit of a large academic center.

PubMed

Sedora Román, Neda I; Mehta, Tejas S; Sharpe, Richard E; Slanetz, Priscilla J; Venkataraman, Shambhavi; Fein-Zachary, Valerie; Dialani, Vandana

2018-05-01

Performance benchmarks exist for mammography (MG); however, performance benchmarks for magnetic resonance imaging (MRI) are not yet fully developed. The purpose of our study was to perform an MRI audit based on established MG and screening MRI benchmarks and to review whether these benchmarks can be applied to an MRI practice. An IRB approved retrospective review of breast MRIs was performed at our center from 1/1/2011 through 12/31/13. For patients with biopsy recommendation, core biopsy and surgical pathology results were reviewed. The data were used to derive mean performance parameter values, including abnormal interpretation rate (AIR), positive predictive value (PPV), cancer detection rate (CDR), percentage of minimal cancers and axillary node negative cancers and compared with MG and screening MRI benchmarks. MRIs were also divided by screening and diagnostic indications to assess for differences in performance benchmarks amongst these two groups. Of the 2455 MRIs performed over 3-years, 1563 were performed for screening indications and 892 for diagnostic indications. With the exception of PPV2 for screening breast MRIs from 2011 to 2013, PPVs were met for our screening and diagnostic populations when compared to the MRI screening benchmarks established by the Breast Imaging Reporting and Data System (BI-RADS) 5 Atlas ® . AIR and CDR were lower for screening indications as compared to diagnostic indications. New MRI screening benchmarks can be used for screening MRI audits while the American College of Radiology (ACR) desirable goals for diagnostic MG can be used for diagnostic MRI audits. Our study corroborates established findings regarding differences in AIR and CDR amongst screening versus diagnostic indications. © 2017 Wiley Periodicals, Inc.

Characterization of plasma cytokines in an infant population cohort of challenge-proven food allergy.

PubMed

Dang, T D; Tang, M L K; Koplin, J J; Licciardi, P V; Eckert, J K; Tan, T; Gurrin, L C; Ponsonby, A-L; Dharmage, S C; Allen, K J

2013-10-01

Sensitization to food allergens indicates the production of food-specific IgE; however, sensitization is not a definite indicator of allergic reaction upon ingestion (N Engl J Med, 344, 2001, 30: J Allergy Clin Immunol, 120, 2007, 491). Currently, food challenge is the best approach to identify the presence or absence of allergy. While 95% positive predictive values (PPVs) thresholds for sIgE can assist with identifying increased likelihood of allergy among those who are sensitized, there are no specific biological markers that differentiate between allergic and sensitized individuals. To determine whether plasma serum cytokine profiles predict (i) sensitization to peanut and egg and (ii) food allergy among sensitized infants. Peanut-sensitized (PT) and egg-sensitized 14-month-old infants and nonsensitized controls enrolled in HealthNuts, a population-based study of food allergy, underwent an oral food challenge (OFC). Blood was collected within 1 h after OFC. Serum levels of Th1, Th2 and regulatory cytokines were determined in allergic (n = 79), sensitized (n = 40) and nonsensitized, nonallergic (n = 37) infants by multiplex assay. Food-sensitized infants had significantly higher plasma IL-4, IL-13, IL-12p70 and lower IL-10 levels compared to nonsensitized infants. IL-10 and IL-6 levels were significantly higher in sensitized compared with allergic infants. Egg-allergic infants had significantly higher IL-13 and IL-12p70 levels compared to peanut-allergic (PA) infants. Levels of Th2-related cytokines in plasma are higher in food-sensitized infants, irrespective of clinical food allergy status. In contrast, IL-10 levels appear to predict food allergy among sensitized infants. Differences in IL-13 and IL-12p70 between egg- and peanut-allergic infants could help explain the different resolution rates of the allergies. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Synthesis of Conjugated Polymers Containing cis-Phenylenevinylenes by Titanium Mediated Reductions

PubMed Central

Moslin, Ryan M.; Espino, Christine G.; Swager, Timothy M.

2009-01-01

The utility of Sato's titanium-mediated reduction of alkynes towards the synthesis of all cis-poly(phenylenevinylene)s (PPVs) is demonstrated by the syn-selective reduction of a variety of model diynes as well as a tetrayne. This technique was then applied to the reduction of a poly(phenyleneethynylene) (PPE) to provide the corresponding all-cis PPV polymer. PMID:20827441

Outcome of breast lesions diagnosed as lesion of uncertain malignant potential (B3) or suspicious of malignancy (B4) on needle core biopsy, including detailed review of epithelial atypia.

PubMed

Rakha, Emad A; Ho, Bernard C; Naik, Veena; Sen, Soumadri; Hamilton, Lisa J; Hodi, Zsolt; Ellis, Ian O; Lee, Andrew H S

2011-03-01

To provide updated evidence of the outcome of breast lesions of uncertain malignant potential (B3) and suspicious of malignancy (B4) diagnosed on needle core biopsy (NCB) and analyse the outcome of the different types of intraductal epithelial atypia. One-hundred and forty-nine B3 and 26 B4 NCBs diagnosed over a 2-year period (2007-2008) were compared with those diagnosed over a previous 2-year period (1998-2000). The proportion of B3 diagnoses increased from 3.1% to 4.5%, and the positive predictive value (PPV) of malignancy of a B3 core decreased from 25% to 10%. Increased diagnosis of radial scar and reductions in the PPV of lobular neoplasia and of atypical intraductal proliferation may explain the reduction in the PPV of the B3 group as a whole. There were no significant changes in the proportion of B4 diagnosis (1.1% and 0.8%) or the PPV of B4 (83% and 88%). Review of cores with intraductal atypia showed a wide range of PPVs, from 100% for suspicious of ductal carcinoma in situ, to 40% for atypical ductal hyperplasia categorized as B3, and 14% for isolated flat epithelial atypia. The study has found a decrease in the PPV for a B3 diagnosis and suggests possible explanations. © 2011 Blackwell Publishing Limited.

SU-C-207B-03: A Geometrical Constrained Chan-Vese Based Tumor Segmentation Scheme for PET

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

Chen, L; Zhou, Z; Wang, J

Purpose: Accurate segmentation of tumor in PET is challenging when part of tumor is connected with normal organs/tissues with no difference in intensity. Conventional segmentation methods, such as thresholding or region growing, cannot generate satisfactory results in this case. We proposed a geometrical constrained Chan-Vese based scheme to segment tumor in PET for this special case by considering the similarity between two adjacent slices. Methods: The proposed scheme performs segmentation in a slice-by-slice fashion where an accurate segmentation of one slice is used as the guidance for segmentation of rest slices. For a slice that the tumor is not directlymore » connected to organs/tissues with similar intensity values, a conventional clustering-based segmentation method under user’s guidance is used to obtain an exact tumor contour. This is set as the initial contour and the Chan-Vese algorithm is applied for segmenting the tumor in the next adjacent slice by adding constraints of tumor size, position and shape information. This procedure is repeated until the last slice of PET containing tumor. The proposed geometrical constrained Chan-Vese based algorithm was implemented in Matlab and its performance was tested on several cervical cancer patients where cervix and bladder are connected with similar activity values. The positive predictive values (PPV) are calculated to characterize the segmentation accuracy of the proposed scheme. Results: Tumors were accurately segmented by the proposed method even when they are connected with bladder in the image with no difference in intensity. The average PPVs were 0.9571±0.0355 and 0.9894±0.0271 for 17 slices and 11 slices of PET from two patients, respectively. Conclusion: We have developed a new scheme to segment tumor in PET images for the special case that the tumor is quite similar to or connected to normal organs/tissues in the image. The proposed scheme can provide a reliable way for segmenting tumors.« less

Better Housing Now: Public-Private Venture Housing at Big Bend National Park, Texas

DTIC Science & Technology

1990-03-01

PPVs will be most effective in parks with a potential for off-park commercial activity and a large number of housing units. Our feasibility analysis ...1-10 Alternative Forms of Construction ...................... 1-11 Analysis of the Alternatives ............................ 1-12...Continued) Appendix D. Data Used in House Model for Big Bend Case Study .......................... D-1 -D- 6 Appendix E. Sensitivity Analysis

Validity of Diagnostic Codes for Acute Stroke in Administrative Databases: A Systematic Review

PubMed Central

McCormick, Natalie; Bhole, Vidula; Lacaille, Diane; Avina-Zubieta, J. Antonio

2015-01-01

Objective To conduct a systematic review of studies reporting on the validity of International Classification of Diseases (ICD) codes for identifying stroke in administrative data. Methods MEDLINE and EMBASE were searched (inception to February 2015) for studies: (a) Using administrative data to identify stroke; or (b) Evaluating the validity of stroke codes in administrative data; and (c) Reporting validation statistics (sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), or Kappa scores) for stroke, or data sufficient for their calculation. Additional articles were located by hand search (up to February 2015) of original papers. Studies solely evaluating codes for transient ischaemic attack were excluded. Data were extracted by two independent reviewers; article quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies tool. Results Seventy-seven studies published from 1976–2015 were included. The sensitivity of ICD-9 430-438/ICD-10 I60-I69 for any cerebrovascular disease was ≥ 82% in most [≥ 50%] studies, and specificity and NPV were both ≥ 95%. The PPV of these codes for any cerebrovascular disease was ≥ 81% in most studies, while the PPV specifically for acute stroke was ≤ 68%. In at least 50% of studies, PPVs were ≥ 93% for subarachnoid haemorrhage (ICD-9 430/ICD-10 I60), 89% for intracerebral haemorrhage (ICD-9 431/ICD-10 I61), and 82% for ischaemic stroke (ICD-9 434/ICD-10 I63 or ICD-9 434&436). For in-hospital deaths, sensitivity was 55%. For cerebrovascular disease or acute stroke as a cause-of-death on death certificates, sensitivity was ≤ 71% in most studies while PPV was ≥ 87%. Conclusions While most cases of prevalent cerebrovascular disease can be detected using 430-438/I60-I69 collectively, acute stroke must be defined using more specific codes. Most in-hospital deaths and death certificates with stroke as a cause-of-death correspond to true stroke deaths. Linking vital statistics and hospitalization data may improve the ascertainment of fatal stroke. PMID:26292280

Which imaging modality is most effective for identifying pseudotumours in metal-on-metal hip resurfacings requiring revision: ultrasound or MARS-MRI or both?

PubMed

Matharu, G S; Mansour, R; Dada, O; Ostlere, S; Pandit, H G; Murray, D W

2016-01-01

The aims of this study were to compare the diagnostic test characteristics of ultrasound alone, metal artefact reduction sequence MRI (MARS-MRI) alone, and ultrasound combined with MARS-MRI for identifying intra-operative pseudotumours in metal-on-metal hip resurfacing (MoMHR) patients undergoing revision surgery. This retrospective diagnostic accuracy study involved 39 patients (40 MoMHRs). The time between imaging modalities was a mean of 14.6 days (0 to 90), with imaging performed at a mean of 5.3 months (0.06 to 12) before revision. The prevalence of intra-operative pseudotumours was 82.5% (n = 33). Agreement with the intra-operative findings was 82.5% (n = 33) for ultrasound alone, 87.5% (n = 35) for MARS-MRI alone, and 92.5% (n = 37) for ultrasound and MARS-MRI combined. The diagnostic characteristics for ultrasound alone and MARS-MRI alone reached similar sensitivities (90.9% vs 93.9%) and positive predictive values (PPVs; 88.2% vs 91.2%), but higher specificities (57.1% vs 42.9%) and negative predictive values (NPVs; 66.7% vs 50.0%) were achieved with MARS-MRI. Ultrasound and MARS-MRI combined produced 100% sensitivity and 100% NPV, whilst maintaining both specificity (57.1%) and PPV (91.7%). For the identification of a pseudotumour, which was confirmed at revision surgery, agreement was substantial for ultrasound and MARS-MRI combined (κ = 0.69), moderate for MARS-MRI alone (κ = 0.54), and fair for ultrasound alone (κ = 0.36). These findings suggest that ultrasound and/or MARS-MRI have a role when assessing patients with a MoMHR, with the choice dependent on local financial constraints and the availability of ultrasound expertise. However in patients with a MoMHR who require revision, combined imaging was most effective. Combined imaging with ultrasound and MARS-MRI always identified intra-operative pseudotumours if present. Furthermore, if neither imaging modality showed a pseudotumour, one was not found intra-operatively. ©2016 The British Editorial Society of Bone & Joint Surgery.

Screening for anxiety disorders in patients with coronary artery disease.

PubMed

Bunevicius, Adomas; Staniute, Margarita; Brozaitiene, Julija; Pop, Victor J M; Neverauskas, Julius; Bunevicius, Robertas

2013-03-11

Anxiety disorders are prevalent and associated with poor prognosis in patients with coronary artery disease (CAD). However, studies examining screening of anxiety disorders in CAD patients are lacking. In the present study we evaluated the prevalence of anxiety disorders in patients with CAD and diagnostic utility of self-rating scales for screening of anxiety disorders. Five-hundred and twenty-three CAD patients not receiving psychotropic treatments at initiation of rehabilitation program completed self-rating scales (Hospital Anxiety and Depression Scale or HADS; Spielberger State-Anxiety Inventory or SSAI; and Spielberger Trait-Anxiety Inventory or STAI) and were interviewed for generalized anxiety disorder (GAD), social phobia, panic disorder and agoraphobia (Mini-International Neuropsychiatric Interview or MINI). Thirty-eight (7%) patients were diagnosed with anxiety disorder(s), including GAD (5%), social phobia (2%), agoraphobia (1%) and panic disorder (1%). Areas under the ROC curve of the HADS Anxiety subscale (HADS-A), STAI and SSAI for screening of any anxiety disorder were .81, .80 and .72, respectively. Optimal cut-off values for screening of any anxiety disorders were ≥ 8 for the HADS-A (sensitivity = 82%; specificity = 76%; and positive predictive value (PPV) = 21%); ≥ 45 for the STAI (sensitivity = 89%; specificity = 56%; and PPV = 14%); and ≥ 40 for the SSAI (sensitivity = 84%; specificity = 55%; PPV = 13%). In a subgroup of patients (n = 340) scoring below the optimal major depressive disorder screening cut-off value of HADS-Depression subscale (score <5), the HADS-A, STAI and SSAI had moderate-high sensitivity (range from 69% to 89%) and low PPVs (≤ 22%) for GAD and any anxiety disorders. Anxiety disorders are prevalent in CAD patients but can be reliably identified using self-rating scales. Anxiety self-rating scales had comparable sensitivities but the HADS-A had greater specificity and PPV when compared to the STAI and SSAI for screening of anxiety disorders. However, false positive rates were high, suggesting that patients with positive screening results should undergo psychiatric interview prior to initiating treatment for anxiety disorders and that routine use of anxiety self-rating scales for screening purposes can increase healthcare costs. Anxiety screening has incremental value to depression screening for identifying anxiety disorders.

A systematic review of validated methods for identifying patients with rheumatoid arthritis using administrative or claims data.

PubMed

Chung, Cecilia P; Rohan, Patricia; Krishnaswami, Shanthi; McPheeters, Melissa L

2013-12-30

To review the evidence supporting the validity of billing, procedural, or diagnosis code, or pharmacy claim-based algorithms used to identify patients with rheumatoid arthritis (RA) in administrative and claim databases. We searched the MEDLINE database from 1991 to September 2012 using controlled vocabulary and key terms related to RA and reference lists of included studies were searched. Two investigators independently assessed the full text of studies against pre-determined inclusion criteria and extracted the data. Data collected included participant and algorithm characteristics. Nine studies reported validation of computer algorithms based on International Classification of Diseases (ICD) codes with or without free-text, medication use, laboratory data and the need for a diagnosis by a rheumatologist. These studies yielded positive predictive values (PPV) ranging from 34 to 97% to identify patients with RA. Higher PPVs were obtained with the use of at least two ICD and/or procedure codes (ICD-9 code 714 and others), the requirement of a prescription of a medication used to treat RA, or requirement of participation of a rheumatologist in patient care. For example, the PPV increased from 66 to 97% when the use of disease-modifying antirheumatic drugs and the presence of a positive rheumatoid factor were required. There have been substantial efforts to propose and validate algorithms to identify patients with RA in automated databases. Algorithms that include more than one code and incorporate medications or laboratory data and/or required a diagnosis by a rheumatologist may increase the PPV. Copyright © 2013 Elsevier Ltd. All rights reserved.

Symptoms of adult chronic and acute leukaemia before diagnosis: large primary care case-control studies using electronic records.

PubMed

Shephard, Elizabeth A; Neal, Richard D; Rose, Peter W; Walter, Fiona M; Hamilton, Willie

2016-03-01

Leukaemia is the eleventh commonest UK cancer. The four main subtypes have different clinical profiles, particularly between chronic and acute types. To identify the symptom profiles of chronic and acute leukaemia in adults in primary care. Matched case-control studies using Clinical Practice Research Datalink records. Putative symptoms of leukaemia were identified in the year before diagnosis. Conditional logistic regression was used for analysis, and positive predictive values (PPVs) were calculated to estimate risk. Of cases diagnosed between 2000 and 2009, 4655 were aged ≥40 years (2877 chronic leukaemia (CL), 937 acute leukaemia (AL), 841 unreported subtype). Ten symptoms were independently associated with CL, the three strongest being: lymphadenopathy (odds ratio [OR] 22, 95% confidence interval [CI] = 13 to 36), weight loss (OR 3.0, 95% CI = 2.1 to 4.2), and bruising (OR 2.3, 95% CI = 1.6 to 3.2). Thirteen symptoms were independently associated with AL, the three strongest being: nosebleeds and/or bleeding gums (OR 5.7, 95% CI = 3.1 to 10), fever (OR 5.3, 95% CI = 2.7 to 10), and fatigue (OR 4.4, 95% CI = 3.3 to 6.0). No individual symptom or combination of symptoms had a PPV >1%. The symptom profiles of CL and AL have both overlapping and distinct features. This presents a dichotomy for GPs: diagnosis, by performing a full blood count, is easy; however, the symptoms of leukaemia are non-specific and of relatively low risk. This explains why many leukaemia diagnoses are unexpected findings. © British Journal of General Practice 2016.

Validation of current procedural terminology codes for rotavirus vaccination among infants in two commercially insured US populations.

PubMed

Hoffman, Veena; Everage, Nicholas J; Quinlan, Scott C; Skerry, Kathleen; Esposito, Daina; Praet, Nicolas; Rosillon, Dominique; Holick, Crystal N; Dore, David D

2016-12-01

We validated procedure codes used in health insurance claims for reimbursement of rotavirus vaccination by comparing claims for monovalent live-attenuated human rotavirus vaccine (RV1) and live, oral pentavalent rotavirus vaccine (RV5) to medical records. Using administrative data from two commercially insured United States populations, we randomly sampled vaccination claims for RV1 and RV5 from a cohort of infants aged less than 1 year from an ongoing post-licensure safety study of rotavirus vaccines. The codes for RV1 and RV5 found in claims were confirmed through medical record review. The positive predictive value (PPV) of the Current Procedural Terminology codes for RV1 and RV5 was calculated as the number of medical record-confirmed vaccinations divided by the number of medical records obtained. Medical record review confirmed 92 of 104 RV1 vaccination claims (PPV: 88.5%; 95% CI: 80.7-93.9%) and 98 of 113 RV5 vaccination claims (PPV: 86.7%; 95% CI: 79.1-92.4%). Among the 217 medical records abstracted, only three (1.4%) of vaccinations were misclassified in claims-all were RV5 misclassified as RV1. The medical records corresponding to 9 RV1 and 15 RV5 claims contained insufficient information to classify the type of rotavirus vaccine. Misclassification of rotavirus vaccines is infrequent within claims. The PPVs reported here are conservative estimates as those with insufficient information in the medical records were assumed to be incorrectly coded in the claims. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Detection of incidental colorectal pathology on positron emission tomography/computed tomography.

PubMed

Mui, Milton; Akhurst, Timothy; Warrier, Satish K; Lynch, A Craig; Heriot, Alexander G

2018-03-01

Positron emission tomography/computed tomography (PET/CT) is an important modality in cancer imaging. With its increasing availability and use, it is not uncommon to detect incidental focal colorectal 18 F-FDG uptake which poses a diagnostic challenge, as they may be associated with malignant or pre-malignant colorectal lesions. The aim of our study is to determine the proportion of these findings which represents true pathology. Patients with incidental focal colorectal 18 F-FDG uptake on PET/CT who subsequently underwent colonoscopy between January 2002 to September 2013 were identified from a prospective database in a tertiary referral centre. PET/CT results were correlated with colonoscopy and pathology results in these patients. Positive predictive values (PPVs) and 95% confidence intervals (CIs) of PET/CT in the detection of incidental colorectal pathology were calculated. A total of 148 patients (92 men and 56 women), with a mean age 73 years (range of 36 to 93 years) were included in the study. A total of 170 foci of colorectal 18 F-FDG uptake were detected on PET/CT. Of these, 101 foci corresponded to a malignant or pre-malignant lesion (PPV 59%; 95% CI: 52-67%). On a per-patient analysis, 93 patients had at least one focus of colorectal 18 F-FDG uptake which corresponded to a pre-malignant or malignant lesion (PPV 63%; 95% CI: 54-71%). Focal colorectal 18 F-FDG uptake on PET/CT is associated with a significant proportion of malignant or pre-malignant lesions. Further evaluation with colonoscopy is recommended. © 2016 Royal Australasian College of Surgeons.

Which are the most useful scales for predicting repeat self-harm? A systematic review evaluating risk scales using measures of diagnostic accuracy

PubMed Central

Quinlivan, L; Cooper, J; Davies, L; Hawton, K; Gunnell, D; Kapur, N

2016-01-01

Objectives The aims of this review were to calculate the diagnostic accuracy statistics of risk scales following self-harm and consider which might be the most useful scales in clinical practice. Design Systematic review. Methods We based our search terms on those used in the systematic reviews carried out for the National Institute for Health and Care Excellence self-harm guidelines (2012) and evidence update (2013), and updated the searches through to February 2015 (CINAHL, EMBASE, MEDLINE, and PsychINFO). Methodological quality was assessed and three reviewers extracted data independently. We limited our analysis to cohort studies in adults using the outcome of repeat self-harm or attempted suicide. We calculated diagnostic accuracy statistics including measures of global accuracy. Statistical pooling was not possible due to heterogeneity. Results The eight papers included in the final analysis varied widely according to methodological quality and the content of scales employed. Overall, sensitivity of scales ranged from 6% (95% CI 5% to 6%) to 97% (CI 95% 94% to 98%). The positive predictive value (PPV) ranged from 5% (95% CI 3% to 9%) to 84% (95% CI 80% to 87%). The diagnostic OR ranged from 1.01 (95% CI 0.434 to 2.5) to 16.3 (95%CI 12.5 to 21.4). Scales with high sensitivity tended to have low PPVs. Conclusions It is difficult to be certain which, if any, are the most useful scales for self-harm risk assessment. No scales perform sufficiently well so as to be recommended for routine clinical use. Further robust prospective studies are warranted to evaluate risk scales following an episode of self-harm. Diagnostic accuracy statistics should be considered in relation to the specific service needs, and scales should only be used as an adjunct to assessment. PMID:26873046

Real-Time Monitoring of Results During First Year of Dutch Colorectal Cancer Screening Program and Optimization by Altering Fecal Immunochemical Test Cut-Off Levels.

PubMed

Toes-Zoutendijk, Esther; van Leerdam, Monique E; Dekker, Evelien; van Hees, Frank; Penning, Corine; Nagtegaal, Iris; van der Meulen, Miriam P; van Vuuren, Anneke J; Kuipers, Ernst J; Bonfrer, Johannes M G; Biermann, Katharina; Thomeer, Maarten G J; van Veldhuizen, Harriët; Kroep, Sonja; van Ballegooijen, Marjolein; Meijer, Gerrit A; de Koning, Harry J; Spaander, Manon C W; Lansdorp-Vogelaar, Iris

2017-03-01

After careful pilot studies and planning, the national screening program for colorectal cancer (CRC), with biennial fecal immunochemical tests (FITs), was initiated in The Netherlands in 2014. A national information system for real-time monitoring was developed to allow for timely evaluation. Data were collected from the first year of this screening program to determine the importance of planning and monitoring for optimal screening program performance. The national information system of the CRC screening program kept track of the number of invitations sent in 2014, FIT kits returned, and colonoscopies performed. Age-adjusted rates of participation, the number of positive test results, and positive predictive values (PPVs) for advanced neoplasia were determined weekly, quarterly, and yearly. In 2014, there were 741,914 persons invited for FIT; of these, 529,056 (71.3%; 95% CI, 71.2%-71.4%) participated. A few months into the program, real-time monitoring showed that rates of participation and positive test results (10.6%; 95% CI, 10.5%-10.8%) were higher than predicted and the PPV was lower (42.1%; 95% CI, 41.3%-42.9%) than predicted based on pilot studies. To reduce the burden of unnecessary colonoscopies and alleviate colonoscopy capacity, the cut-off level for a positive FIT result was increased from 15 to 47 μg Hb/g feces halfway through 2014. This adjustment decreased the percentage of positive test results to 6.7% (95% CI, 6.6%-6.8%) and increased the PPV to 49.1% (95% CI, 48.3%-49.9%). In total, the first year of the Dutch screening program resulted in the detection of 2483 cancers and 12,030 advanced adenomas. Close monitoring of the implementation of the Dutch national CRC screening program allowed for instant adjustment of the FIT cut-off levels to optimize program performance. Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.

Public-Private Ventures for Morale, Welfare, and Recreation Activities. A Solution to the Loss of Appropriated Funds. Volume 1. Findings, Conclusions, and Recommendations

DTIC Science & Technology

1990-07-01

following section, we discuss the type of food and beverage industry that might participate with the Navy in club P/PVs. Test Sites The club systems we...Characteristics The retail food and beverage industry has three distinctively different components: cafeterias, restaurants, and clubs. Companies operating in...but all are market-driven. For example, the various sectors of the retail food and beverage industry are highly competitive and have evolved into

Magnetic Resonance and Ultrasound Image Fusion Supported Transperineal Prostate Biopsy Using the Ginsburg Protocol: Technique, Learning Points, and Biopsy Results.

PubMed

Hansen, Nienke; Patruno, Giulio; Wadhwa, Karan; Gaziev, Gabriele; Miano, Roberto; Barrett, Tristan; Gnanapragasam, Vincent; Doble, Andrew; Warren, Anne; Bratt, Ola; Kastner, Christof

2016-08-01

Prostate biopsy supported by transperineal image fusion has recently been developed as a new method to the improve accuracy of prostate cancer detection. To describe the Ginsburg protocol for transperineal prostate biopsy supported by multiparametric magnetic resonance imaging (mpMRI) and transrectal ultrasound (TRUS) image fusion, provide learning points for its application, and report biopsy results. The article is supplemented by a Surgery in Motion video. This single-centre retrospective outcome study included 534 patients from March 2012 to October 2015. A total of 107 had no previous prostate biopsy, 295 had benign TRUS-guided biopsies, and 159 were on active surveillance for low-risk cancer. A Likert scale reported mpMRI for suspicion of cancer from 1 (no suspicion) to 5 (cancer highly likely). Transperineal biopsies were obtained under general anaesthesia using BiopSee fusion software (Medcom, Darmstadt, Germany). All patients had systematic biopsies, two cores from each of 12 anatomic sectors. Likert 3-5 lesions were targeted with a further two cores per lesion. Any cancer and Gleason score 7-10 cancer on biopsy were noted. Descriptive statistics and positive predictive values (PPVs) and negative predictive values (NPVs) were calculated. The detection rate of Gleason score 7-10 cancer was similar across clinical groups. Likert scale 3-5 MRI lesions were reported in 378 (71%) of the patients. Cancer was detected in 249 (66%) and Gleason score 7-10 cancer was noted in 157 (42%) of these patients. PPV for detecting 7-10 cancer was 0.15 for Likert score 3, 0.43 for score 4, and 0.63 for score 5. NPV of Likert 1-2 findings was 0.87 for Gleason score 7-10 and 0.97 for Gleason score ≥4+3=7 cancer. Limitations include lack of data on complications. Transperineal prostate biopsy supported by MRI/TRUS image fusion using the Ginsburg protocol yielded high detection rates of Gleason score 7-10 cancer. Because the NPV for excluding Gleason score 7-10 cancer was very high, prostate biopsies may not be needed for all men with elevated prostate-specific antigen values and nonsuspicious mpMRI. We present our technique to sample (biopsy) the prostate by the transperineal route (the area between the scrotum and the anus) to detect prostate cancer using a fusion of magnetic resonance and ultrasound images to guide the sampling. Copyright © 2016 European Association of Urology. All rights reserved.

Clinical Value of a One-Stop-Shop Low-Dose Lung Screening Combined with (18)F-FDG PET/CT for the Detection of Metastatic Lung Nodules from Colorectal Cancer.

PubMed

Han, Yeon-Hee; Lim, Seok Tae; Jeong, Hwan-Jeong; Sohn, Myung-Hee

2016-06-01

The aim of this study was to evaluate the clinical usefulness of additional low-dose high-resolution lung computed tomography (LD-HRCT) combined with (18)F-fluoro-2-deoxyglucose positron emission tomography with CT ((18)F-FDG PET/CT) compared with conventional lung setting image of (18)F-FDG PET/CT for the detection of metastatic lung nodules from colorectal cancer. From January 2011 to September 2011, 649 patients with colorectal cancer underwent additional LD-HRCT at maximum inspiration combined with (18)F-FDG PET/CT. Forty-five patients were finally diagnosed to have lung metastasis based on histopathologic study or clinical follow-up. Twenty-five of the 45 patients had ≤5 metastatic lung nodules and the other 20 patients had >5 metastatic nodules. One hundred and twenty nodules in the 25 patients with ≤5 nodules were evaluated by conventional lung setting image of (18)F-FDG PET/CT and by additional LD-HRCT respectively. Sensitivities, specificities, diagnostic accuracies, positive predictive values (PPVs), and negative predictive values (NPVs) of conventional lung setting image of (18)F-FDG PET/CT and additional LD-HRCT were calculated using standard formulae. The McNemar test and receiver-operating characteristic (ROC) analysis were performed. Of the 120 nodules in the 25 patients with ≤5 metastatic lung nodules, 66 nodules were diagnosed as metastatic. Eleven of the 66 nodules were confirmed histopathologically and the others were diagnosed by clinical follow-up. Conventional lung setting image of (18)F-FDG PET/CT detected 40 of the 66 nodules and additional LD-HRCT detected 55 nodules. All 15 nodules missed by conventional lung setting imaging but detected by additional LD-HRCT were <1 cm in size. The sensitivity, specificity, and diagnostic accuracy of the modalities were 60.6 %, 85.2 %, and 71.1 % for conventional lung setting image and 83.3 %, 88.9 %, and 85.8 % for additional LD-HRCT. By ROC analysis, the area under the ROC curve (AUC) of conventional lung setting image and additional LD-HRCT were 0.712 and 0.827 respectively. Additional LD-HRCT with maximum inspiration was superior to conventional lung setting image of (18)F-FDG PET/CT for the detection of metastatic lung nodules from colorectal cancer (P < 0.05).

Validation of a Plasma-Based Comprehensive Cancer Genotyping Assay Utilizing Orthogonal Tissue- and Plasma-Based Methodologies.

PubMed

Odegaard, Justin I; Vincent, John J; Mortimer, Stefanie; Vowles, James V; Ulrich, Bryan C; Banks, Kimberly C; Fairclough, Stephen R; Zill, Oliver A; Sikora, Marcin; Mokhtari, Reza; Abdueva, Diana; Nagy, Rebecca J; Lee, Christine E; Kiedrowski, Lesli A; Paweletz, Cloud P; Eltoukhy, Helmy; Lanman, Richard B; Chudova, Darya I; Talasaz, AmirAli

2018-04-24

Purpose: To analytically and clinically validate a circulating cell-free tumor DNA sequencing test for comprehensive tumor genotyping and demonstrate its clinical feasibility. Experimental Design: Analytic validation was conducted according to established principles and guidelines. Blood-to-blood clinical validation comprised blinded external comparison with clinical droplet digital PCR across 222 consecutive biomarker-positive clinical samples. Blood-to-tissue clinical validation comprised comparison of digital sequencing calls to those documented in the medical record of 543 consecutive lung cancer patients. Clinical experience was reported from 10,593 consecutive clinical samples. Results: Digital sequencing technology enabled variant detection down to 0.02% to 0.04% allelic fraction/2.12 copies with ≤0.3%/2.24-2.76 copies 95% limits of detection while maintaining high specificity [prevalence-adjusted positive predictive values (PPV) >98%]. Clinical validation using orthogonal plasma- and tissue-based clinical genotyping across >750 patients demonstrated high accuracy and specificity [positive percent agreement (PPAs) and negative percent agreement (NPAs) >99% and PPVs 92%-100%]. Clinical use in 10,593 advanced adult solid tumor patients demonstrated high feasibility (>99.6% technical success rate) and clinical sensitivity (85.9%), with high potential actionability (16.7% with FDA-approved on-label treatment options; 72.0% with treatment or trial recommendations), particularly in non-small cell lung cancer, where 34.5% of patient samples comprised a directly targetable standard-of-care biomarker. Conclusions: High concordance with orthogonal clinical plasma- and tissue-based genotyping methods supports the clinical accuracy of digital sequencing across all four types of targetable genomic alterations. Digital sequencing's clinical applicability is further supported by high rates of technical success and biomarker target discovery. Clin Cancer Res; 1-11. ©2018 AACR. ©2018 American Association for Cancer Research.

Validation of chronic obstructive pulmonary disease recording in the Clinical Practice Research Datalink (CPRD-GOLD)

PubMed Central

Quint, Jennifer K; Müllerova, Hana; DiSantostefano, Rachael L; Forbes, Harriet; Eaton, Susan; Hurst, John R; Davis, Kourtney; Smeeth, Liam

2014-01-01

Objectives The optimal method of identifying people with chronic obstructive pulmonary disease (COPD) from electronic primary care records is not known. We assessed the accuracy of different approaches using the Clinical Practice Research Datalink, a UK electronic health record database. Setting 951 participants registered with a CPRD practice in the UK between 1 January 2004 and 31 December 2012. Individuals were selected for ≥1 of 8 algorithms to identify people with COPD. General practitioners were sent a brief questionnaire and additional evidence to support a COPD diagnosis was requested. All information received was reviewed independently by two respiratory physicians whose opinion was taken as the gold standard. Primary outcome measure The primary measure of accuracy was the positive predictive value (PPV), the proportion of people identified by each algorithm for whom COPD was confirmed. Results 951 questionnaires were sent and 738 (78%) returned. After quality control, 696 (73.2%) patients were included in the final analysis. All four algorithms including a specific COPD diagnostic code performed well. Using a diagnostic code alone, the PPV was 86.5% (77.5–92.3%) while requiring a diagnosis plus spirometry plus specific medication; the PPV was slightly higher at 89.4% (80.7–94.5%) but reduced case numbers by 10%. Algorithms without specific diagnostic codes had low PPVs (range 12.2–44.4%). Conclusions Patients with COPD can be accurately identified from UK primary care records using specific diagnostic codes. Requiring spirometry or COPD medications only marginally improved accuracy. The high accuracy applies since the introduction of an incentivised disease register for COPD as part of Quality and Outcomes Framework in 2004. PMID:25056980

Symptoms of adult chronic and acute leukaemia before diagnosis: large primary care case-control studies using electronic records

PubMed Central

Shephard, Elizabeth A; Neal, Richard D; Rose, Peter W; Walter, Fiona M; Hamilton, Willie

2016-01-01

Background Leukaemia is the eleventh commonest UK cancer. The four main subtypes have different clinical profiles, particularly between chronic and acute types. Aim To identify the symptom profiles of chronic and acute leukaemia in adults in primary care. Design and setting Matched case-control studies using Clinical Practice Research Datalink records. Method Putative symptoms of leukaemia were identified in the year before diagnosis. Conditional logistic regression was used for analysis, and positive predictive values (PPVs) were calculated to estimate risk. Results Of cases diagnosed between 2000 and 2009, 4655 were aged ≥40 years (2877 chronic leukaemia (CL), 937 acute leukaemia (AL), 841 unreported subtype). Ten symptoms were independently associated with CL, the three strongest being: lymphadenopathy (odds ratio [OR] 22, 95% confidence interval [CI] = 13 to 36), weight loss (OR 3.0, 95% CI = 2.1 to 4.2), and bruising (OR 2.3, 95% CI = 1.6 to 3.2). Thirteen symptoms were independently associated with AL, the three strongest being: nosebleeds and/or bleeding gums (OR 5.7, 95% CI = 3.1 to 10), fever (OR 5.3, 95% CI = 2.7 to 10), and fatigue (OR 4.4, 95% CI = 3.3 to 6.0). No individual symptom or combination of symptoms had a PPV >1%. Conclusion The symptom profiles of CL and AL have both overlapping and distinct features. This presents a dichotomy for GPs: diagnosis, by performing a full blood count, is easy; however, the symptoms of leukaemia are non-specific and of relatively low risk. This explains why many leukaemia diagnoses are unexpected findings. PMID:26917658

The Study of Cardiovascular Health Outcomes in the Era of Claims Data: The Cardiovascular Health Study

PubMed Central

Psaty, Bruce M; Delaney, Joseph A; Arnold, Alice M; Curtis, Lesley H; Fitzpatrick, Annette L; Heckbert, Susan R; McKnight, Barbara; Ives, Diane; Gottdiener, John S; Kuller, Lewis H; Longstreth, W T

2015-01-01

Background Increasingly, the diagnostic codes from administrative claims data are being used as clinical outcomes. Methods and Results Data from the Cardiovascular Health Study (CHS) were used to compare event rates and risk-factor associations between adjudicated hospitalized cardiovascular events and claims-based methods of defining events. The outcomes of myocardial infarction (MI), stroke, and heart failure (HF) were defined in three ways: 1) the CHS adjudicated event (CHS[adj]); 2) selected ICD9 diagnostic codes only in the primary position for Medicare claims data from the Center for Medicare and Medicaid Services (CMS[1st]); and 3) the same selected diagnostic codes in any position (CMS[any]). Conventional claims-based methods of defining events had high positive predictive values (PPVs) but low sensitivities. For instance, the PPV of an ICD9 code of 410.×1 for a new acute MI in the first position was 90.6%, but this code identified only 53.8% of incident MIs. The observed event rates were low. For MI, the incidence was 14.9 events per 1000 person years for CHS[adj] MI, 8.6 for CMS[1st] and 12.2 for CMS[any]. In general, CVD risk factor associations were similar across the three methods of defining events. Indeed, traditional CVD risk factors were also associated with all first hospitalizations not due to an MI. Conclusions The use of diagnostic codes from claims data as clinical events, especially when restricted to primary diagnoses, leads to an underestimation of event rates. Additionally, claims-based events data represent a composite endpoint that includes the outcome of interest and selected (misclassified) non-event hospitalizations. PMID:26538580

PheKB: a catalog and workflow for creating electronic phenotype algorithms for transportability.

PubMed

Kirby, Jacqueline C; Speltz, Peter; Rasmussen, Luke V; Basford, Melissa; Gottesman, Omri; Peissig, Peggy L; Pacheco, Jennifer A; Tromp, Gerard; Pathak, Jyotishman; Carrell, David S; Ellis, Stephen B; Lingren, Todd; Thompson, Will K; Savova, Guergana; Haines, Jonathan; Roden, Dan M; Harris, Paul A; Denny, Joshua C

2016-11-01

Health care generated data have become an important source for clinical and genomic research. Often, investigators create and iteratively refine phenotype algorithms to achieve high positive predictive values (PPVs) or sensitivity, thereby identifying valid cases and controls. These algorithms achieve the greatest utility when validated and shared by multiple health care systems.Materials and Methods We report the current status and impact of the Phenotype KnowledgeBase (PheKB, http://phekb.org), an online environment supporting the workflow of building, sharing, and validating electronic phenotype algorithms. We analyze the most frequent components used in algorithms and their performance at authoring institutions and secondary implementation sites. As of June 2015, PheKB contained 30 finalized phenotype algorithms and 62 algorithms in development spanning a range of traits and diseases. Phenotypes have had over 3500 unique views in a 6-month period and have been reused by other institutions. International Classification of Disease codes were the most frequently used component, followed by medications and natural language processing. Among algorithms with published performance data, the median PPV was nearly identical when evaluated at the authoring institutions (n = 44; case 96.0%, control 100%) compared to implementation sites (n = 40; case 97.5%, control 100%). These results demonstrate that a broad range of algorithms to mine electronic health record data from different health systems can be developed with high PPV, and algorithms developed at one site are generally transportable to others. By providing a central repository, PheKB enables improved development, transportability, and validity of algorithms for research-grade phenotypes using health care generated data. © The Author 2016. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

PheKB: a catalog and workflow for creating electronic phenotype algorithms for transportability

PubMed Central

Kirby, Jacqueline C; Speltz, Peter; Rasmussen, Luke V; Basford, Melissa; Gottesman, Omri; Peissig, Peggy L; Pacheco, Jennifer A; Tromp, Gerard; Pathak, Jyotishman; Carrell, David S; Ellis, Stephen B; Lingren, Todd; Thompson, Will K; Savova, Guergana; Haines, Jonathan; Roden, Dan M; Harris, Paul A

2016-01-01

Objective Health care generated data have become an important source for clinical and genomic research. Often, investigators create and iteratively refine phenotype algorithms to achieve high positive predictive values (PPVs) or sensitivity, thereby identifying valid cases and controls. These algorithms achieve the greatest utility when validated and shared by multiple health care systems. Materials and Methods We report the current status and impact of the Phenotype KnowledgeBase (PheKB, http://phekb.org), an online environment supporting the workflow of building, sharing, and validating electronic phenotype algorithms. We analyze the most frequent components used in algorithms and their performance at authoring institutions and secondary implementation sites. Results As of June 2015, PheKB contained 30 finalized phenotype algorithms and 62 algorithms in development spanning a range of traits and diseases. Phenotypes have had over 3500 unique views in a 6-month period and have been reused by other institutions. International Classification of Disease codes were the most frequently used component, followed by medications and natural language processing. Among algorithms with published performance data, the median PPV was nearly identical when evaluated at the authoring institutions (n = 44; case 96.0%, control 100%) compared to implementation sites (n = 40; case 97.5%, control 100%). Discussion These results demonstrate that a broad range of algorithms to mine electronic health record data from different health systems can be developed with high PPV, and algorithms developed at one site are generally transportable to others. Conclusion By providing a central repository, PheKB enables improved development, transportability, and validity of algorithms for research-grade phenotypes using health care generated data. PMID:27026615

Validation study in four health-care databases: upper gastrointestinal bleeding misclassification affects precision but not magnitude of drug-related upper gastrointestinal bleeding risk.

PubMed

Valkhoff, Vera E; Coloma, Preciosa M; Masclee, Gwen M C; Gini, Rosa; Innocenti, Francesco; Lapi, Francesco; Molokhia, Mariam; Mosseveld, Mees; Nielsson, Malene Schou; Schuemie, Martijn; Thiessard, Frantz; van der Lei, Johan; Sturkenboom, Miriam C J M; Trifirò, Gianluca

2014-08-01

To evaluate the accuracy of disease codes and free text in identifying upper gastrointestinal bleeding (UGIB) from electronic health-care records (EHRs). We conducted a validation study in four European electronic health-care record (EHR) databases such as Integrated Primary Care Information (IPCI), Health Search/CSD Patient Database (HSD), ARS, and Aarhus, in which we identified UGIB cases using free text or disease codes: (1) International Classification of Disease (ICD)-9 (HSD, ARS); (2) ICD-10 (Aarhus); and (3) International Classification of Primary Care (ICPC) (IPCI). From each database, we randomly selected and manually reviewed 200 cases to calculate positive predictive values (PPVs). We employed different case definitions to assess the effect of outcome misclassification on estimation of risk of drug-related UGIB. PPV was 22% [95% confidence interval (CI): 16, 28] and 21% (95% CI: 16, 28) in IPCI for free text and ICPC codes, respectively. PPV was 91% (95% CI: 86, 95) for ICD-9 codes and 47% (95% CI: 35, 59) for free text in HSD. PPV for ICD-9 codes in ARS was 72% (95% CI: 65, 78) and 77% (95% CI: 69, 83) for ICD-10 codes (Aarhus). More specific definitions did not have significant impact on risk estimation of drug-related UGIB, except for wider CIs. ICD-9-CM and ICD-10 disease codes have good PPV in identifying UGIB from EHR; less granular terminology (ICPC) may require additional strategies. Use of more specific UGIB definitions affects precision, but not magnitude, of risk estimates. Copyright © 2014 Elsevier Inc. All rights reserved.

Validation of a coding algorithm for intra-abdominal surgeries and adhesion-related complications in an electronic medical records database

PubMed Central

Scott, Frank I; Mamtani, Ronac; Haynes, Kevin; Goldberg, David S; Mahmoud, Najjia N.; Lewis, James D

2016-01-01

PURPOSE Epidemiological data on adhesion-related complications following intra-abdominal surgery are limited. We tested the accuracy of recording of these surgeries and complications within The Health Improvement Network (THIN), a primary care database within the United Kingdom. METHODS Individuals within THIN from 1995–2011 with an incident intra-abdominal surgery and subsequent bowel obstruction (SBO) or adhesiolysis were identified using diagnostic codes. To compute positive predictive values (PPVs), requests were sent to treating physicians of patients with these diagnostic codes to confirm the surgery, SBO, or adhesiolysis code. Completeness of recording was estimated by comparing observed surgical rates within THIN to expected rates derived from the Hospital Episode Statistics (HES) dataset within England. Cumulative incidence rates of adhesion-related complications at 5 years were compared to a previously published cohort within Scotland. RESULTS 217 of 245 (89%) questionnaires were returned (180 SBO and 37 adhesiolysis). The PPV of codes for surgery was 94.5% (95%CI: 91–97%). 88.8% of procedure types were correctly coded. The PPV for SBO and adhesiolysis was 86.1% (95% CI: 80–91%) and 89.2% (95% CI: 75–97%), respectively. Colectomy, appendectomy, and cholecystectomy rates within THIN were 99%, 95%, and 84% of rates observed in national HES data, respectively. Cumulative incidence rates of adhesion related complications following colectomy, appendectomy, and small bowel surgery were similar to those published previously. CONCLUSIONS Surgical procedures, SBO, and adhesiolysis can be accurately identified within THIN using diagnostic codes. THIN represents a new tool for assessing patient-specific risk factors for adhesion-related complications and long term outcomes. PMID:26860870

Validity and diagnostic accuracy of the Luganda version of the 9-item and 2-item Patient Health Questionnaire for detecting major depressive disorder in rural Uganda.

PubMed

Nakku, J E M; Rathod, S D; Kizza, D; Breuer, E; Mutyaba, K; Baron, E C; Ssebunnya, J; Kigozi, F

2016-01-01

The prevalence of depression in rural Ugandan communities is high and yet detection and treatment of depression in the primary care setting is suboptimal. Short valid depression screening measures may improve detection of depression. We describe the validation of the Luganda translated nine- and two-item Patient Health Questionnaires (PHQ-9 and PHQ-2) as screening tools for depression in two rural primary care facilities in Eastern Uganda. A total of 1407 adult respondents were screened consecutively using the nine-item Luganda PHQ. Of these 212 were randomly selected to respond to the Mini International Neuropsychiatric Interview diagnostic questionnaire. Descriptive statistics for respondents' demographic characteristics and PHQ scores were generated. The sensitivity, specificity and positive predictive values (PPVs), and area under the ROC curve were determined for both the PHQ-9 and PHQ-2. The optimum trade-off between sensitivity and PPV was at a cut-off of ≧5. The weighted area under the receiver Operating Characteristic curve was 0.74 (95% CI 0.60-0.89) and 0.68 (95% CI 0.54-0.82) for PHQ-9 and PHQ-2, respectively. The Luganda translation of the PHQ-9 was found to be modestly useful in detecting depression. The PHQ-9 performed only slightly better than the PHQ-2 in this rural Ugandan Primary care setting. Future research could improve on diagnostic accuracy by considering the idioms of distress among Luganda speakers, and revising the PHQ-9 accordingly. The usefulness of the PHQ-2 in this rural population should be viewed with caution.

Infant and dyadic assessment in early community-based screening for autism spectrum disorder with the PREAUT grid

PubMed Central

Crespin, Graciela; Laznik, Marie-Christine; Cherif Idrissi El Ganouni, Oussama; Sarradet, Jean-Louis; Bauby, Colette; Dandres, Anne-Marie; Ruiz, Emeline; Bursztejn, Claude; Xavier, Jean; Falissard, Bruno; Bodeau, Nicolas; Cohen, David; Saint-Georges, Catherine

2017-01-01

Background The need for early treatment of autism spectrum disorders (ASD) necessitates early screening. Very few tools have been prospectively tested with infants of less than 12 months of age. The PREAUT grid is based on dyadic assessment through interaction and shared emotion and showed good metrics for predicting ASD in very-high-risk infants with West syndrome. Methods We assessed the ability of the PREAUT grid to predict ASD in low-risk individuals by prospectively following and screening 12,179 infants with the PREAUT grid at four (PREAUT-4) and nine (PREAUT-9) months of age. A sample of 4,835 toddlers completed the Checklist for Autism in Toddlers (CHAT) at 24 months (CHAT-24) of age. Children who were positive at one screening (N = 100) were proposed a clinical assessment (including the Children Autism Rating Scale, a Developmental Quotient, and an ICD-10-based clinical diagnosis if appropriate) in the third year of life. A randomly selected sample of 1,100 individuals who were negative at all screenings was followed by the PMI team from three to five years of age to identify prospective false negative cases. The clinical outcome was available for 45% (N = 45) of positive children and 52.6% (N = 579) of negative children. Results Of the 100 children who screened positive, 45 received a diagnosis at follow-up. Among those receiving a diagnosis, 22 were healthy, 10 were diagnosed with ASD, seven with intellectual disability (ID), and six had another developmental disorder. Thus, 50% of infants positive at one screening subsequently received a neurodevelopmental diagnosis. The PREAUT grid scores were significantly associated with medium and high ASD risk status on the CHAT at 24 months (odds ratio of 12.1 (95%CI: 3.0–36.8), p < 0.001, at four months and 38.1 (95%CI: 3.65–220.3), p < 0.001, at nine months). Sensitivity (Se), specificity, negative predictive values, and positive predictive values (PPVs) for PREAUT at four or nine months, and CHAT at 24 months, were similar [PREAUT-4: Se = 16.0 to 20.6%, PPV = 25.4 to 26.3%; PREAUT-9: Se = 30.5 to 41.2%, PPV = 20.2 to 36.4%; and CHAT-24: Se = 33.9 to 41.5%, PPV = 27.3 to 25.9%]. The repeated use of the screening instruments increased the Se but not PPV estimates [PREAUT and CHAT combined: Se = 67.9 to 77.7%, PPV = 19.0 to 28.0%]. Conclusions The PREAUT grid can contribute to very early detection of ASD and its combination with the CHAT may improve the early diagnosis of ASD and other neurodevelopmental disorders. PMID:29216234

Infant and dyadic assessment in early community-based screening for autism spectrum disorder with the PREAUT grid.

PubMed

Olliac, Bertrand; Crespin, Graciela; Laznik, Marie-Christine; Cherif Idrissi El Ganouni, Oussama; Sarradet, Jean-Louis; Bauby, Colette; Dandres, Anne-Marie; Ruiz, Emeline; Bursztejn, Claude; Xavier, Jean; Falissard, Bruno; Bodeau, Nicolas; Cohen, David; Saint-Georges, Catherine

2017-01-01

The need for early treatment of autism spectrum disorders (ASD) necessitates early screening. Very few tools have been prospectively tested with infants of less than 12 months of age. The PREAUT grid is based on dyadic assessment through interaction and shared emotion and showed good metrics for predicting ASD in very-high-risk infants with West syndrome. We assessed the ability of the PREAUT grid to predict ASD in low-risk individuals by prospectively following and screening 12,179 infants with the PREAUT grid at four (PREAUT-4) and nine (PREAUT-9) months of age. A sample of 4,835 toddlers completed the Checklist for Autism in Toddlers (CHAT) at 24 months (CHAT-24) of age. Children who were positive at one screening (N = 100) were proposed a clinical assessment (including the Children Autism Rating Scale, a Developmental Quotient, and an ICD-10-based clinical diagnosis if appropriate) in the third year of life. A randomly selected sample of 1,100 individuals who were negative at all screenings was followed by the PMI team from three to five years of age to identify prospective false negative cases. The clinical outcome was available for 45% (N = 45) of positive children and 52.6% (N = 579) of negative children. Of the 100 children who screened positive, 45 received a diagnosis at follow-up. Among those receiving a diagnosis, 22 were healthy, 10 were diagnosed with ASD, seven with intellectual disability (ID), and six had another developmental disorder. Thus, 50% of infants positive at one screening subsequently received a neurodevelopmental diagnosis. The PREAUT grid scores were significantly associated with medium and high ASD risk status on the CHAT at 24 months (odds ratio of 12.1 (95%CI: 3.0-36.8), p < 0.001, at four months and 38.1 (95%CI: 3.65-220.3), p < 0.001, at nine months). Sensitivity (Se), specificity, negative predictive values, and positive predictive values (PPVs) for PREAUT at four or nine months, and CHAT at 24 months, were similar [PREAUT-4: Se = 16.0 to 20.6%, PPV = 25.4 to 26.3%; PREAUT-9: Se = 30.5 to 41.2%, PPV = 20.2 to 36.4%; and CHAT-24: Se = 33.9 to 41.5%, PPV = 27.3 to 25.9%]. The repeated use of the screening instruments increased the Se but not PPV estimates [PREAUT and CHAT combined: Se = 67.9 to 77.7%, PPV = 19.0 to 28.0%]. The PREAUT grid can contribute to very early detection of ASD and its combination with the CHAT may improve the early diagnosis of ASD and other neurodevelopmental disorders.

[Development of Peptide Vaccines for Triple-Negative Breast Cancer Treatment].

PubMed

Toh, Uhi; Saku, Shuko; Okabe, Mina; Iwakuma, Nobutaka; Kimitsuki, Yuko; Akashi, Momoko; Ogo, Etsuyo; Yamada, Akira; Shichijo, Shigeki; Itoh, Kyogo; Akagi, Yoshito

2016-10-01

Our previous phase II clinical trial showed that therapeutically selected personalized peptide vaccines(PPVs)were effective at boosting anticancer immunity; the immune response after PPV was associated with a clinical outcome as a prognostic factor for metastatic breast cancer(mBC). We conducted an early phase II study to evaluate the safety and efficacy of a new regimen using multiple peptide vaccines(KRM-19)for patients with metastatictriple -negative breast cancer. KRM-19 consisted of 19 mixed peptides chosen from the previously reported 31 PPVs according to their anti-tumor immunologiceffec ts and safety profiles for patients with mBC. All patients had histologically confirmed measurable ER-PgR-HER2- mBC and their human leukocyte antigen(HLA) / -A molecules were A2, A3, A11, A24, A26, A31, or A33. KRM-19(19mg/mL)was administrated subcutaneously every week for a total of 6 doses. Concurrent conventional chemo- and/or endocrine therapy were not permitted during treatment. This was an open-label, early phase II study. The primary endpoint was safety and anti-tumor immunologic effect, while the secondary endpoints were clinical responses and progression-free survival(PFS). The estimated enrollment was 10-15 and 8 patients were enrolled(Clinical trial registry number: UMIN000014616). Measurement of peptide-specific cytotoxic T lymphocyte and IgG responses were conducted before and after vaccination. The correlation between PFS and the increased IgG response and/or CTL levels were investigated.

Effectiveness of computer-aided diagnosis (CADx) of breast pathology using immunohistochemistry results of core needle biopsy samples for synaptophysin, oestrogen receptor and CK14/p63 for classification of epithelial proliferative lesions of the breast.

PubMed

Maeda, Ichiro; Kubota, Manabu; Ohta, Jiro; Shinno, Kimika; Tajima, Shinya; Ariizumi, Yasushi; Doi, Masatomo; Oana, Yoshiyasu; Kanemaki, Yoshihide; Tsugawa, Koichiro; Ueno, Takahiko; Takagi, Masayuki

2017-12-01

The aim of this study was to develop a computer-aided diagnosis (CADx) system for identifying breast pathology. Two sets of 100 consecutive core needle biopsy (CNB) specimens were collected for test and validation studies. All 200 CNB specimens were stained with antibodies targeting oestrogen receptor (ER), synaptophysin and CK14/p63. All stained slides were scanned in a whole-slide imaging system and photographed. The photographs were analysed using software to identify the proportions of tumour cells that were positive and negative for each marker. In the test study, the cut-off values for synaptophysin (negative and positive) and CK14/p63 (negative and positive) were decided using receiver operating characteristic (ROC) analysis. For ER analysis, samples were divided into groups with <10% positive or >10% positive cells and decided using receiver operating characteristic (ROC) analysis. Finally, these two groups categorised as ER-low, ER-intermediate (non-low and non-high) and ER-high groups. In the validation study, the second set of immunohistochemical slides were analysed using these cut-off values. The cut-off values for synaptophysin, <10% ER positive, >10% ER positive and CK14/p63 were 0.14%, 2.17%, 77.93% and 18.66%, respectively. The positive predictive value for malignancy (PPV) was 100% for synaptophysin-positive/ER-high/(CK14/p63)-any or synaptophysin-positive/ER-low/(CK14/p63)-any. The PPV was 25% for synaptophysin-positive/ER-intermediate/(CK14/p63)-positive. For synaptophysin-negative/(CK14/p63)-negative, the PPVs for ER-low, ER-intermediate and ER-high were 100%, 80.0% and 95.8%, respectively. The PPV was 4.5% for synaptophysin-negative/ER-intermediate/(CK14/p63)-positive. The CADx system was able to analyse sufficient data for all types of epithelial proliferative lesions of the breast including invasive breast cancer. This system may be useful for pathological diagnosis of breast CNB in routine investigations. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Glucose-6-phosphate dehydrogenase deficiency among Yemeni children residing in malaria-endemic areas of Hodeidah governorate and evaluation of a rapid diagnostic test for its detection.

PubMed

Abdul-Ghani, Rashad; Mahdy, Mohammed A K; Saif-Ali, Reyadh; Alkubati, Sameer A; Alqubaty, Abdulhabib R; Al-Mikhlafy, Abdullah A; Al-Eryani, Samira M; Al-Mekhlafi, Abdusalam M; Alhaj, Ali

2016-06-21

Glucose-6-phosphate dehydrogenase (G6PD) deficiency, the most common genetic enzymopathy worldwide, is associated with an acute haemolytic anaemia in individuals exposed to primaquine. The present study aimed to determine G6PD deficiency among Yemeni children in malaria-endemic areas as well as to assess the performance of the CareStart™ G6PD rapid diagnostic test (RDT) for its detection. A cross-sectional study recruiting 400 children from two rural districts in Hodeidah governorate was conducted. Socio-demographic data and blood samples were collected and G6PD deficiency was qualitatively detected in fresh blood in the field using the CareStart™ G6PD RDT, while the enzymatic assay was used to quantitatively measure enzyme activity. Performance of the CareStart™ G6PD RDT was assessed by calculating its sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) against the reference enzymatic assay. The ranges of enzyme activity were 0.14-18.45 and 0.21-15.94 units/g haemoglobin (U/gHb) for males and females, respectively. However, adjusted male median G6PD activity was 5.0 U/gHb. Considering the adjusted male median as representing 100 % normal enzyme activity, the prevalence rates of G6PD deficiency were 12.0 and 2.3 % at the cut-off activities of ≤60 and ≤10 %, respectively. Multivariable analysis showed that gender, district of residence and consanguinity between parents were independent risk factors for G6PD deficiency at the cut-off activity of ≤30 % of normal. The CareStart™ G6PD RDT showed 100 % sensitivity and NPV for detecting G6PD deficiency at the cut-off activities of ≤10 and ≤20 % of normal activity compared to the reference enzymatic method. However, it showed specificity levels of 90.0 and 95.4 % as well as positive/deficient predictive values (PPVs) of 18.0 and 66.0 % at the cut-off activities of ≤10 and ≤20 %, respectively, compared to the reference method. G6PD deficiency with enzyme activity of ≤60 % of normal is prevalent among 12.0 % of children residing in malaria-endemic areas of Hodeidah governorate, with 2.3 % having severe G6PD deficiency. Gender, district of residence and consanguinity between parents are significant independent predictors of G6PD deficiency at the cut-off activity of ≤30 % of normal among children in malaria-endemic areas of Hodeidah. The CareStart™ G6PD RDT proved reliable as a point-of-care test to screen for severely G6PD-deficient patients, with 100 % sensitivity and NPV, and it can be used for making clinical decisions prior to the administration of primaquine in malaria elimination strategies.

TU-C-12A-12: Differentiating Bone Lesions and Degenerative Joint Disease in NaF PET/CT Scans Using Machine Learning

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

Perk, T; Bradshaw, T; Muzahir, S

2014-06-15

Purpose: [F-18]NaF PET can be used to image bone metastases; however, tracer uptake in degenerative joint disease (DJD) often appears similar to metastases. This study aims to develop and compare different machine learning algorithms to automatically identify regions of [F-18]NaF scans that correspond to DJD. Methods: 10 metastatic prostate cancer patients received whole body [F-18]NaF PET/CT scans prior to treatment. Image segmentation resulted in 852 ROIs, 69 of which were identified by a nuclear medicine physician as DJD. For all ROIs, various PET and CT textural features were computed. ROIs were divided into training and testing sets used to trainmore » eight different machine learning classifiers. Classifiers were evaluated based on receiver operating characteristics area under the curve (AUC), sensitivity, specificity, and positive predictive value (PPV). We also assessed the added value of including CT features in addition to PET features for training classifiers. Results: The training set consisted of 37 DJD ROIs with 475 non-DJD ROIs, and the testing set consisted of 32 DJD ROIs with 308 non-DJD ROIs. Of all classifiers, generalized linear models (GLM), decision forests (DF), and support vector machines (SVM) had the best performance. AUCs of GLM (0.929), DF (0.921), and SVM (0.889) were significantly higher than the other models (p<0.001). GLM and DF, overall, had the best sensitivity, specificity, and PPV, and gave a significantly better performance (p<0.01) than all other models. PET/CT GLM classifiers had higher AUC than just PET or just CT. GLMs built using PET/CT information had superior or comparable sensitivities, specificities and PPVs to just PET or just CT. Conclusion: Machine learning algorithms trained with PET/CT features were able to identify some cases of DJD. GLM outperformed the other classification algorithms. Using PET and CT information together was shown to be superior to using PET or CT features alone. Research supported by the Prostate Cancer Foundation.« less

Clinical Model for NASH and Advanced Fibrosis in Adult Patients With Diabetes and NAFLD: Guidelines for Referral in NAFLD

PubMed Central

Bazick, Jessica; Donithan, Michele; Neuschwander-Tetri, Brent A.; Kleiner, David; Brunt, Elizabeth M.; Wilson, Laura; Doo, Ed; Lavine, Joel; Tonascia, James

2015-01-01

OBJECTIVE Approximately 18 million people in the U.S. have coexisting type 2 diabetes and nonalcoholic fatty liver disease (NAFLD). It is not known who among these patients has nonalcoholic steatohepatitis (NASH) with advanced fibrosis. Therefore, we aimed to determine factors that are associated with both NASH and advanced fibrosis in patients with diabetes and NAFLD in order to identify who should be prioritized for referral to a hepatologist for further diagnostic evaluation and treatment. RESEARCH DESIGN AND METHODS This study was derived from the NASH Clinical Research Network studies and included 1,249 patients with biopsy-proven NAFLD (including a model development cohort of 346 patients and an independent validation cohort of 100 patients with type 2 diabetes as defined by the American Diabetes Association criteria). Outcome measures were presence of NASH or advanced fibrosis (stage 3 or 4) using cross-validated, by jackknife method, multivariable-adjusted area under the receiver operating characteristic curve (AUROC) and 95% CI. RESULTS The mean ± SD age and BMI of patients with diabetes and NAFLD was 52.5 ± 10.3 years and 35.8 ± 6.8 kg/m2, respectively. The prevalence of NASH and advanced fibrosis was 69.2% and 41.0%, respectively. The model for NASH included white race, BMI, waist, alanine aminotransferase (ALT), Aspartate aminotransferase (AST), albumin, HbA1c, HOMA of insulin resistance, and ferritin with an AUROC of 0.80 (95% CI 0.75–0.84, P = 0.007). The specificity, sensitivity, negative predictive values (NPVs), and positive predictive values (PPVs) were 90.0%, 56.8%, 47.7%, and 93.2%, respectively, and the model correctly classified 67% of patients as having NASH. The model for predicting advanced fibrosis included age, Hispanic ethnicity, BMI, waist-to-hip ratio, hypertension, ALT-to-AST ratio, alkaline phosphatase, isolated abnormal alkaline phosphatase, bilirubin (total and direct), globulin, albumin, serum insulin, hematocrit, international normalized ratio, and platelet count with an AUROC of 0.80 (95% CI 0.76–0.85, P < 0.001). The specificity, sensitivity, NPV, and PPV were 90.0%, 57%, 75.1%, and 80.2%, respectively, and the model correctly classified 76.6% of patients as having advanced fibrosis. Results remained consistent for both models in the validation cohort. The proposed model performed better than the NAFLD fibrosis score in detecting advanced fibrosis. CONCLUSIONS Routinely available clinical variables can be used to quantify the likelihood of NASH or advanced fibrosis in adult diabetic patients with NAFLD. The clinical models presented can be used to guide clinical decision making about referrals of patients with diabetes and NAFLD to hepatologists. PMID:25887357

The influence of prostate-specific antigen density on positive and negative predictive values of multiparametric magnetic resonance imaging to detect Gleason score 7-10 prostate cancer in a repeat biopsy setting.

PubMed

Hansen, Nienke L; Barrett, Tristan; Koo, Brendan; Doble, Andrew; Gnanapragasam, Vincent; Warren, Anne; Kastner, Christof; Bratt, Ola

2017-05-01

To evaluate the influence of prostate-specific antigen density (PSAD) on positive (PPV) and negative (NPV) predictive values of multiparametric magnetic resonance imaging (mpMRI) to detect Gleason score ≥7 cancer in a repeat biopsy setting. Retrospective study of 514 men with previous prostate biopsy showing no or Gleason score 6 cancer. All had mpMRI, graded 1-5 on a Likert scale for cancer suspicion, and subsequent targeted and 24-core systematic image-fusion guided transperineal biopsy in 2013-2015. The NPVs and PPVs of mpMRIs for detecting Gleason score ≥7 cancer were calculated (±95% confidence intervals) for PSAD ≤0.1, 0.1-0.2, ≤0.2 and >0.2 ng/mL/mL, and compared by chi-square test for linear trend. Gleason score ≥7 cancer was detected in 31% of the men. The NPV of Likert 1-2 mpMRI was 0.91 (±0.04) with a PSAD of ≤0.2 ng/mL/mL and 0.71 (±0.16) with a PSAD of >0.2 ng/mL/mL (P = 0.003). For Likert 3 mpMRI, PPV was 0.09 (±0.06) with a PSAD of ≤0.2 ng/mL/mL and 0.44 (±0.19) with a PSAD of >0.2 ng/mL/mL (P = 0.002). PSAD also significantly affected the PPV of Likert 4-5 mpMRI lesions: the PPV was 0.47 (±0.08) with a PSAD of ≤0.2 ng/mL/mL and 0.66 (±0.10) with a PSAD of >0.2 ng/mL/mL (P < 0.001). In a repeat biopsy setting, a PSAD of ≤0.2 ng/mL/mL is associated with low detection of Gleason score ≥7 prostate cancer, not only in men with negative mpMRI, but also in men with equivocal imaging. Surveillance, rather than repeat biopsy, may be appropriate for these men. Conversely, biopsies are indicated in men with a high PSAD, even if an mpMRI shows no suspicious lesion, and in men with an mpMRI suspicious for cancer, even if the PSAD is low. © 2016 The Authors BJU International © 2016 BJU International Published by John Wiley & Sons Ltd.

Can We Rely on Pharmacy Claims Databases to Ascertain Maternal Use of Medications during Pregnancy?

PubMed

Zhao, Jin-Ping; Sheehy, Odile; Gorgui, Jessica; Bérard, Anick

2017-04-03

Administrative databases are increasingly used to measure drug exposure in perinatal pharmacoepidemiology. We aimed to estimate the concordance between records of prescriptions filled in pharmacies and self-reported drug use during pregnancy. Data on self-reported medication use were collected at each trimester of pregnancy among a sub-sample from the Organization of Teratology Information Specialists Antidepressants in Pregnancy Cohort. Women were eligible if they were Quebec resident and provided their pharmacist's contact information. Maternal self-reports were compared with prescriptions filled in pharmacies, which are transferred to pharmaceutical services files of Quebec provincial health plan database (Régie de l'asssurance maladie du Québec). Positive and negative predictive values (PPV and NPV) for medications taken chronically (antidepressants, thyroid hormones), acutely (antibiotics), and as needed (antiemetics, asthma medications) were calculated. Among the 93 participants (mean age = 30.2 ± 3.8 years), 41.9% (n = 39) took at least one antidepressant during pregnancy according to self-reports, and 39.8% (n = 37) according to pharmacy records. Other commonly used drugs were antiemetics (self-reported 22.6%, pharmacy record 24.7%), antibiotics (20.4%, 16.1%), asthma medications (15.1%, 15.1%), and thyroid hormones (10.8%, 8.6%). PPVs and NPVs were: (1) chronic medication: antidepressants PPV = 100% (95% confidence interval [CI], 100-100%), NPV = 96% (95% CI, 92-100%); thyroid hormones PPV = 100% (95% CI, 100-100%), NPV = 98% (95% CI, 95-100%); (2) Acute medication: antibiotics PPV = 87% (95% CI, 70-100%), NPV = 92% (95% CI, 86-98%); (3) as needed medications: antiemetics: PPV = 78% (95% CI, 62-95%), NPV = 96% (95% CI, 91-100%); asthma: PPV = 33% (95% CI, 3-64%), NPV = 99% (95% CI, 97-100%). The high PPV and NPV validate the use of filled prescription data in large databases as a measure of medication exposure. Birth Defects Research 109:423-431, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Absence of epithelial atypia in B3-lesions of the breast is associated with decreased risk for malignancy.

PubMed

Mayer, Sebastian; Kayser, Gian; Rücker, Gerta; Bögner, Diana; Hirschfeld, Marc; Hug, Christiane; Stickeler, Elmar; Gitsch, Gerald; Erbes, Thalia

2017-02-01

Lesions of uncertain malignant potential (B3) represent a heterogeneous group with an overall risk for malignancy of 9.85-35.1% after total resection. Positive predictive values (PPV) for malignancy vary depending on B3 subtype. The aim of this study was to evaluate the PPV for malignancy in B3 lesions and to determine the clinical significance of atypia-dependent sub-classification (a = without epithelial atypia; b = with epithelial atypia) of B3 into B3a and B3b and papillary lesions (PL) in PLa and PLb. 219 patients with histopathologically proven B3 lesions on core needle/vacuum-assisted biopsy who subsequently underwent diagnostic excision biopsy were included in this study. PPVs for malignancy were reported for B3 in general and all B3 sub-categories. Logistic regression analysis identified associations between B3-subgroups and outcome after excision biopsy as well as the impact of clinical and diagnostic findings on excision diagnosis. The overall PPV rate was 10.0% (22/219). Excision histology exhibited a higher malignancy rate in PLb (2/7; PPV: 28.6%) than in PLa (6/127; PPV: 4.7%) (p = 0.057) and in B3b (12/50; PPV: 24.0%) compared to B3a category (8/165; PPV: 4.8%) (p < 0.001). These findings support the necessity of B3 lesion sub-classification into B3a and B3b and of PL into PLa and PLb when considering epithelial atypia. The determination of atypia status represents a relevant factor in risk-stratification for clinical management of B3 lesions. Should future studies using the sub-classification of PL confirm these results, observation may be a safe option for the clinical management of patients with asymptomatic PLa lesions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Impact of Immediate Interpretation of Screening Tomosynthesis Mammography on Performance Metrics.

PubMed

Winkler, Nicole S; Freer, Phoebe; Anzai, Yoshimi; Hu, Nan; Stein, Matthew

2018-05-07

This study aimed to compare performance metrics for immediate and delayed batch interpretation of screening tomosynthesis mammograms. This HIPAA compliant study was approved by institutional review board with a waiver of consent. A retrospective analysis of screening performance metrics for tomosynthesis mammograms interpreted in 2015 when mammograms were read immediately was compared to historical controls from 2013 to 2014 when mammograms were batch interpreted after the patient had departed. A total of 5518 screening tomosynthesis mammograms (n = 1212 for batch interpretation and n = 4306 for immediate interpretation) were evaluated. The larger sample size for the latter group reflects a group practice shift to performing tomosynthesis for the majority of patients. Age, breast density, comparison examinations, and high-risk status were compared. An asymptotic proportion test and multivariable analysis were used to compare performance metrics. There was no statistically significant difference in recall or cancer detection rates for the batch interpretation group compared to immediate interpretation group with respective recall rate of 6.5% vs 5.3% = +1.2% (95% confidence interval -0.3 to 2.7%; P = .101) and cancer detection rate of 6.6 vs 7.2 per thousand = -0.6 (95% confidence interval -5.9 to 4.6; P = .825). There was no statistically significant difference in positive predictive values (PPVs) including PPV1 (screening recall), PPV2 (biopsy recommendation), or PPV 3 (biopsy performed) with batch interpretation (10.1%, 42.1%, and 40.0%, respectively) and immediate interpretation (13.6%, 39.2%, and 39.7%, respectively). After adjusting for age, breast density, high-risk status, and comparison mammogram, there was no difference in the odds of being recalled or cancer detection between the two groups. There is no statistically significant difference in interpretation performance metrics for screening tomosynthesis mammograms interpreted immediately compared to those interpreted in a delayed fashion. Copyright © 2018. Published by Elsevier Inc.

Accuracy of angina pectoris and acute coronary syndrome in the Danish National Patient Register.

PubMed

Bork, Christian Sørensen; Al-Zuhairi, Karam Sadoon; Hansen, Steen Møller; Delekta, Joanna; Joensen, Albert Marni

2017-05-01

The Danish National Patient Register (DNPR)is widely used for research and administrative purposes. However, its usability is highly dependent of the validity of the registered data. We therefore aimed to determine the positive predictive value (PPV) of angina pectoris and acute coronary syndrome (ACS) in the DNPR. We selected a random sample of 500 patients registered with angina pectoris and a random sample of 500 patients registered with ACS among all hospitalisations at any department in Northern Denmark between 1 January 2007 and 31 December 2007. We reviewed the medical records of the sample patients and recorded whether the angina pectoris and the ACS diagnoses were valid, based on the European Society of Cardiology criteria. The PPV of definite and probable angina pectoris was 45.9% (95% confidence interval (CI): 41.3-50.6%), whereas the PPV of verified ACS was 86.6% (95% CI: 83.3-89.5%). Stratification by hospital department revealed significantly higher PPVs for diagnoses received in a cardiology unit for both angina pectoris (61.7%; 95% CI: 53.4-69.6%) and ACS (95.5%; 95% CI: 91.3-98.0%). Stratification by gender showed a significantly higher PPV among men registered with angina pectoris (51.2%; 95% CI: 45.3-57.1%). The angina pectoris and ACS data contained in the DNPR should be used with caution in register studies if validation is not possible. Restricting analyses of ACS data to patients discharged from cardiology wards may be a useful option in register-based studies. none. not relevant. Articles published in the DMJ are “open access”. This means that the articles are distributed under the terms of the Creative Commons Attribution Non-commercial License, which permits any non-commercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited.

Efficiency of International Classification of Diseases, Ninth Revision, Billing Code Searches to Identify Emergency Department Visits for Blood or Body Fluid Exposures through a Statewide Multicenter Database

PubMed Central

Rosen, Lisa M.; Liu, Tao; Merchant, Roland C.

2016-01-01

BACKGROUND Blood and body fluid exposures are frequently evaluated in emergency departments (EDs). However, efficient and effective methods for estimating their incidence are not yet established. OBJECTIVE Evaluate the efficiency and accuracy of estimating statewide ED visits for blood or body fluid exposures using International Classification of Diseases, Ninth Revision (ICD-9), code searches. DESIGN Secondary analysis of a database of ED visits for blood or body fluid exposure. SETTING EDs of 11 civilian hospitals throughout Rhode Island from January 1, 1995, through June 30, 2001. PATIENTS Patients presenting to the ED for possible blood or body fluid exposure were included, as determined by prespecified ICD-9 codes. METHODS Positive predictive values (PPVs) were estimated to determine the ability of 10 ICD-9 codes to distinguish ED visits for blood or body fluid exposure from ED visits that were not for blood or body fluid exposure. Recursive partitioning was used to identify an optimal subset of ICD-9 codes for this purpose. Random-effects logistic regression modeling was used to examine variations in ICD-9 coding practices and styles across hospitals. Cluster analysis was used to assess whether the choice of ICD-9 codes was similar across hospitals. RESULTS The PPV for the original 10 ICD-9 codes was 74.4% (95% confidence interval [CI], 73.2%–75.7%), whereas the recursive partitioning analysis identified a subset of 5 ICD-9 codes with a PPV of 89.9% (95% CI, 88.9%–90.8%) and a misclassification rate of 10.1%. The ability, efficiency, and use of the ICD-9 codes to distinguish types of ED visits varied across hospitals. CONCLUSIONS Although an accurate subset of ICD-9 codes could be identified, variations across hospitals related to hospital coding style, efficiency, and accuracy greatly affected estimates of the number of ED visits for blood or body fluid exposure. PMID:22561713

Accuracy of lung cancer ICD-9-CM codes in Umbria, Napoli 3 Sud and Friuli Venezia Giulia administrative healthcare databases: a diagnostic accuracy study

PubMed Central

Montedori, Alessandro; Bidoli, Ettore; Serraino, Diego; Fusco, Mario; Giovannini, Gianni; Casucci, Paola; Franchini, David; Granata, Annalisa; Ciullo, Valerio; Vitale, Maria Francesca; Gobbato, Michele; Chiari, Rita; Cozzolino, Francesco; Orso, Massimiliano; Orlandi, Walter

2018-01-01

Objectives To assess the accuracy of International Classification of Diseases 9th Revision–Clinical Modification (ICD-9-CM) codes in identifying subjects with lung cancer. Design A cross-sectional diagnostic accuracy study comparing ICD-9-CM 162.x code (index test) in primary position with medical chart (reference standard). Case ascertainment was based on the presence of a primary nodular lesion in the lung and cytological or histological documentation of cancer from a primary or metastatic site. Setting Three operative units: administrative databases from Umbria Region (890 000 residents), ASL Napoli 3 Sud (NA) (1 170 000 residents) and Friuli Venezia Giulia (FVG) Region (1 227 000 residents). Participants Incident subjects with lung cancer (n=386) diagnosed in primary position between 2012 and 2014 and a population of non-cases (n=280). Outcome measures Sensitivity, specificity and positive predictive value (PPV) for 162.x code. Results 130 cases and 94 non-cases were randomly selected from each database and the corresponding medical charts were reviewed. Most of the diagnoses for lung cancer were performed in medical departments. True positive rates were high for all the three units. Sensitivity was 99% (95% CI 95% to 100%) for Umbria, 97% (95% CI 91% to 100%) for NA, and 99% (95% CI 95% to 100%) for FVG. The false positive rates were 24%, 37% and 23% for Umbria, NA and FVG, respectively. PPVs were 79% (73% to 83%)%) for Umbria, 58% (53% to 63%)%) for NA and 79% (73% to 84%)%) for FVG. Conclusions Case ascertainment for lung cancer based on imaging or endoscopy associated with histological examination yielded an excellent sensitivity in all the three administrative databases. PPV was moderate for Umbria and FVG but lower for NA. PMID:29773701

Validity of the coding for herpes simplex encephalitis in the Danish National Patient Registry.

PubMed

Jørgensen, Laura Krogh; Dalgaard, Lars Skov; Østergaard, Lars Jørgen; Andersen, Nanna Skaarup; Nørgaard, Mette; Mogensen, Trine Hyrup

2016-01-01

Large health care databases are a valuable source of infectious disease epidemiology if diagnoses are valid. The aim of this study was to investigate the accuracy of the recorded diagnosis coding of herpes simplex encephalitis (HSE) in the Danish National Patient Registry (DNPR). The DNPR was used to identify all hospitalized patients, aged ≥15 years, with a first-time diagnosis of HSE according to the International Classification of Diseases, tenth revision (ICD-10), from 2004 to 2014. To validate the coding of HSE, we collected data from the Danish Microbiology Database, from departments of clinical microbiology, and from patient medical records. Cases were classified as confirmed, probable, or no evidence of HSE. We estimated the positive predictive value (PPV) of the HSE diagnosis coding stratified by diagnosis type, study period, and department type. Furthermore, we estimated the proportion of HSE cases coded with nonspecific ICD-10 codes of viral encephalitis and also the sensitivity of the HSE diagnosis coding. We were able to validate 398 (94.3%) of the 422 HSE diagnoses identified via the DNPR. Hereof, 202 (50.8%) were classified as confirmed cases and 29 (7.3%) as probable cases providing an overall PPV of 58.0% (95% confidence interval [CI]: 53.0-62.9). For "Encephalitis due to herpes simplex virus" (ICD-10 code B00.4), the PPV was 56.6% (95% CI: 51.1-62.0). Similarly, the PPV for "Meningoencephalitis due to herpes simplex virus" (ICD-10 code B00.4A) was 56.8% (95% CI: 39.5-72.9). "Herpes viral encephalitis" (ICD-10 code G05.1E) had a PPV of 75.9% (95% CI: 56.5-89.7), thereby representing the highest PPV. The estimated sensitivity was 95.5%. The PPVs of the ICD-10 diagnosis coding for adult HSE in the DNPR were relatively low. Hence, the DNPR should be used with caution when studying patients with encephalitis caused by herpes simplex virus.

Clinical Model for NASH and Advanced Fibrosis in Adult Patients With Diabetes and NAFLD: Guidelines for Referral in NAFLD.

PubMed

Bazick, Jessica; Donithan, Michele; Neuschwander-Tetri, Brent A; Kleiner, David; Brunt, Elizabeth M; Wilson, Laura; Doo, Ed; Lavine, Joel; Tonascia, James; Loomba, Rohit

2015-07-01

Approximately 18 million people in the U.S. have coexisting type 2 diabetes and nonalcoholic fatty liver disease (NAFLD). It is not known who among these patients has nonalcoholic steatohepatitis (NASH) with advanced fibrosis. Therefore, we aimed to determine factors that are associated with both NASH and advanced fibrosis in patients with diabetes and NAFLD in order to identify who should be prioritized for referral to a hepatologist for further diagnostic evaluation and treatment. This study was derived from the NASH Clinical Research Network studies and included 1,249 patients with biopsy-proven NAFLD (including a model development cohort of 346 patients and an independent validation cohort of 100 patients with type 2 diabetes as defined by the American Diabetes Association criteria). Outcome measures were presence of NASH or advanced fibrosis (stage 3 or 4) using cross-validated, by jackknife method, multivariable-adjusted area under the receiver operating characteristic curve (AUROC) and 95% CI. The mean ± SD age and BMI of patients with diabetes and NAFLD was 52.5 ± 10.3 years and 35.8 ± 6.8 kg/m(2), respectively. The prevalence of NASH and advanced fibrosis was 69.2% and 41.0%, respectively. The model for NASH included white race, BMI, waist, alanine aminotransferase (ALT), Aspartate aminotransferase (AST), albumin, HbA1c, HOMA of insulin resistance, and ferritin with an AUROC of 0.80 (95% CI 0.75-0.84, P = 0.007). The specificity, sensitivity, negative predictive values (NPVs), and positive predictive values (PPVs) were 90.0%, 56.8%, 47.7%, and 93.2%, respectively, and the model correctly classified 67% of patients as having NASH. The model for predicting advanced fibrosis included age, Hispanic ethnicity, BMI, waist-to-hip ratio, hypertension, ALT-to-AST ratio, alkaline phosphatase, isolated abnormal alkaline phosphatase, bilirubin (total and direct), globulin, albumin, serum insulin, hematocrit, international normalized ratio, and platelet count with an AUROC of 0.80 (95% CI 0.76-0.85, P < 0.001). The specificity, sensitivity, NPV, and PPV were 90.0%, 57%, 75.1%, and 80.2%, respectively, and the model correctly classified 76.6% of patients as having advanced fibrosis. Results remained consistent for both models in the validation cohort. The proposed model performed better than the NAFLD fibrosis score in detecting advanced fibrosis. Routinely available clinical variables can be used to quantify the likelihood of NASH or advanced fibrosis in adult diabetic patients with NAFLD. The clinical models presented can be used to guide clinical decision making about referrals of patients with diabetes and NAFLD to hepatologists. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

The foodscape: classification and field validation of secondary data sources across urban/rural and socio-economic classifications in England

PubMed Central

2012-01-01

Background In recent years, alongside the exponential increase in the prevalence of overweight and obesity, there has been a change in the food environment (foodscape). This research focuses on methods used to measure and classify the foodscape. This paper describes the foodscape across urban/rural and socio-economic divides. It examines the validity of a database of food outlets obtained from Local Authority sources (secondary level & desk based), across urban/rural and socio-economic divides by conducting fieldwork (ground-truthing). Additionally this paper tests the efficacy of using a desk based classification system to describe food outlets, compared with ground-truthing. Methods Six geographically defined study areas were purposively selected within North East England consisting of two Lower Super Output Areas (LSOAs; a small administrative geography) each. Lists of food outlets were obtained from relevant Local Authorities (secondary level & desk based) and fieldwork (ground-truthing) was conducted. Food outlets were classified using an existing tool. Positive predictive values (PPVs) and sensitivity analysis was conducted to explore validation of secondary data sources. Agreement between 'desk' and 'field' based classifications of food outlets were assessed. Results There were 438 food outlets within all study areas; the urban low socio-economic status (SES) area had the highest number of total outlets (n = 210) and the rural high SES area had the least (n = 19). Differences in the types of outlets across areas were observed. Comparing the Local Authority list to fieldwork across the geographical areas resulted in a range of PPV values obtained; with the highest in urban low SES areas (87%) and the lowest in Rural mixed SES (79%). While sensitivity ranged from 95% in the rural mixed SES area to 60% in the rural low SES area. There were no significant associations between field/desk percentage agreements across any of the divides. Conclusion Despite the relatively small number of areas, this work furthers our understanding of the validity of using secondary data sources to identify and classify the foodscape in a variety of geographical settings. While classification of the foodscape using secondary Local Authority food outlet data with information obtained from the internet, is not without its difficulties, desk based classification would be an acceptable alternative to fieldwork, although it should be used with caution. PMID:22472206

Periodic Screening Pelvic Examination: Evidence Report and Systematic Review for the US Preventive Services Task Force.

PubMed

Guirguis-Blake, Janelle M; Henderson, Jillian T; Perdue, Leslie A

2017-03-07

Recent changes in the periodicity of cervical cancer screening have led to questions about the role of screening pelvic examinations among asymptomatic women. To systematically review literature on health benefits, accuracy, and harms of the screening pelvic examination for gynecologic conditions for the US Preventive Services Task Force (USPSTF). MEDLINE, PubMed, and Cochrane Central Register of Controlled Trials for relevant English-language studies published through January 13, 2016, with surveillance through August 3, 2016. Two reviewers independently screened abstracts and studies. The search yielded 8678 unique citations; 316 full-text articles were reviewed, and 9 studies including 27 630 patients met inclusion criteria. Two reviewers rated study quality using USPSTF criteria. Morbidity; mortality; diagnostic accuracy for any gynecologic cancer or condition except cervical cancer, gonorrhea, and chlamydia, which are covered by other USPSTF screening recommendations; harms (false-positive rates, false-negative rates, surgery rates). No trials examined the effectiveness of the pelvic examination in reducing all-cause mortality, reducing cancer- and disease-specific morbidity and mortality, or improving quality of life. Eight studies reported accuracy for the screening pelvic examination: ovarian cancer (4 studies; n = 26 432), bacterial vaginosis (2 studies; n = 930), trichomoniasis (1 study; n = 779), and genital herpes (1 study; n = 779). In the 4 ovarian cancer screening studies, low prevalence of ovarian cancer consistently resulted in low positive predictive values (PPVs) and false-positive rates, with a lack of precision in accuracy estimates (sensitivity range, 0%-100%; specificity range, 91%-99%; PPV range, 0%-3.6%; negative predictive value [NPV] range, ≥99%). Each diagnostic accuracy study for bacterial vaginosis, trichomoniasis, and genital herpes was performed in a high-prevalence population with substantial proportions of symptomatic patients and reported accuracy characteristics for individual physical examination findings (bacterial vaginosis, homogeneous discharge: sensitivity range, 69%-79%; specificity range, 54%-97%; PPV range, 52%-95%; NPV range, 79%-80%; herpes simplex virus, vulvar ulcerations: sensitivity, 20%; specificity, 98%; PPV, 88%; NPV, 57%; trichomoniasis, colpitis macularis: sensitivity, 2%; specificity, 100%; PPV, 100%; NPV, 85%). Surgery rates resulting from an abnormal screening pelvic examination for ovarian cancer ranged from 5% to 36% at 1 year, with the largest study reporting an 11% surgery rate and 1% complication rate within 1 year of a screening pelvic examination with abnormal findings. No direct evidence was identified for overall benefits and harms of the pelvic examination as a 1-time or periodic screening test. Limited evidence was identified regarding the diagnostic accuracy and harms of routine screening pelvic examinations in asymptomatic primary care populations.

Receipt of Glucose Testing and Performance of Two US Diabetes Screening Guidelines, 2007–2012

PubMed Central

Bullard, Kai McKeever; Ali, Mohammed K.; Imperatore, Giuseppina; Geiss, Linda S.; Saydah, Sharon H.; Albu, Jeanine B.; Cowie, Catherine C.; Sohler, Nancy; Albright, Ann; Gregg, Edward W.

2015-01-01

Background Screening guidelines are used to help identify prediabetes and diabetes before implementing evidence-based prevention and treatment interventions. We examined screening practices benchmarking against two US guidelines, and the capacity of each guideline to identify dysglycemia. Methods Using 2007–2012 National Health and Nutrition Examination Surveys, we analyzed nationally-representative, cross-sectional data from 5,813 fasting non-pregnant adults aged ≥20 years without self-reported diabetes. We examined proportions of adults eligible for diagnostic glucose testing and those who self-reported receiving testing in the past three years, as recommended by the American Diabetes Association (ADA) and the US Preventive Services Task Force (USPSTF-2008) guidelines. For each screening guideline, we also assessed sensitivity, specificity, and positive (PPV) and negative predictive values in identifying dysglycemia (defined as fasting plasma glucose ≥100 mg/dl or hemoglobin A1c ≥5.7%). Results In 2007–2012, 73.0% and 23.7% of US adults without diagnosed diabetes met ADA and USPSTF-2008 criteria for screening, respectively; and 91.5% had at least one major risk factor for diabetes. Of those ADA- or USPSTF-eligible adults, about 51% reported being tested within the past three years. Eligible individuals not tested were more likely to be lower educated, poorer, uninsured, or have no usual place of care compared to tested eligible adults. Among adults with ≥1 major risk factor, 45.7% reported being tested, and dysglycemia yields (i.e., PPV) ranged from 45.8% (high-risk ethnicity) to 72.6% (self-reported prediabetes). ADA criteria and having any risk factor were more sensitive than the USPSTF-2008 guideline (88.8–97.7% vs. 31.0%) but less specific (13.5–39.7% vs. 82.1%) in recommending glucose testing, resulting in lower PPVs (47.7–54.4% vs. 58.4%). Conclusion Diverging recommendations and variable performance of different guidelines may be impeding national diabetes prevention and treatment efforts. Efforts to align screening recommendations may result in earlier identification of adults at high risk for prediabetes and diabetes. PMID:25928306

Differential patterns of lifetime multiple anxiety disorder comorbidity between Latino adults with bipolar I and major depressive disorders.

PubMed

Dilsaver, Steven C; Benazzi, Franco; Akiskal, Kareen K; Akiskal, Hagop S

2008-01-01

To determine the lifetime rates of panic disorder, obsessive-compulsive disorder (OCD), social phobia, and posttraumatic stress disorder (PTSD) among adult Latino patients with major depressive disorder (MDD) and bipolar disorder (BPD), and whether there are dose-response relationships between loading for comorbid anxiety disorders, the probability of having BPD, and attributes of severity of illness. In a public sector clinic for the indigent located in a semiclosed rural community, 187 consecutively presenting affectively ill Latino patients were evaluated by use of the Structured Clinical Interview for DSM-IV. Polarity and the lifetime prevalence of panic disorder, OCD, social phobia, and PTSD were determined. Logistic regression was used to test associations. Trends in positive predictive values (PPVs) and likelihood ratios were assessed to determine whether dose-response relationships existed between loading for comorbid anxiety disorders and the likelihood of having BPD as opposed to MDD, psychosis, suicidal ideation, and suicide attempts. Of 187 subjects, 118 (63.1%) had MDD and 69 (36.9%) had BPD. The odds ratio of a patient with BPD, relative to MDD, of having panic disorder was 4.6 (p< .0001), OCD 7.6 (p< .0001), social phobia 6.0 (p< .0001) and PTSD 5.3 (p< .0001). The PPV of having BPD was 91.3% and of having psychotic features 83.0% if one had all four anxiety disorders. There was a dose-response relationship between loading for comorbid anxiety disorders and the likelihood of having had a suicide attempt (but not suicidal ideation). As previously reported by us for juvenile patients, Latino adults with BPD had a remarkably high risk of having each anxiety disorder relative to patients with MDD. The results indicate that the risk of having BPD, having a psychosis, and making a suicide attempt becomes increasingly great as the number of comorbid anxiety disorders increases. These data, which are consistent with the notion of anxious bipolarity, provide further support for a possible anxious diathesis in bipolar disorder.

Validity of the coding for herpes simplex encephalitis in the Danish National Patient Registry

PubMed Central

Jørgensen, Laura Krogh; Dalgaard, Lars Skov; Østergaard, Lars Jørgen; Andersen, Nanna Skaarup; Nørgaard, Mette; Mogensen, Trine Hyrup

2016-01-01

Background Large health care databases are a valuable source of infectious disease epidemiology if diagnoses are valid. The aim of this study was to investigate the accuracy of the recorded diagnosis coding of herpes simplex encephalitis (HSE) in the Danish National Patient Registry (DNPR). Methods The DNPR was used to identify all hospitalized patients, aged ≥15 years, with a first-time diagnosis of HSE according to the International Classification of Diseases, tenth revision (ICD-10), from 2004 to 2014. To validate the coding of HSE, we collected data from the Danish Microbiology Database, from departments of clinical microbiology, and from patient medical records. Cases were classified as confirmed, probable, or no evidence of HSE. We estimated the positive predictive value (PPV) of the HSE diagnosis coding stratified by diagnosis type, study period, and department type. Furthermore, we estimated the proportion of HSE cases coded with nonspecific ICD-10 codes of viral encephalitis and also the sensitivity of the HSE diagnosis coding. Results We were able to validate 398 (94.3%) of the 422 HSE diagnoses identified via the DNPR. Hereof, 202 (50.8%) were classified as confirmed cases and 29 (7.3%) as probable cases providing an overall PPV of 58.0% (95% confidence interval [CI]: 53.0–62.9). For “Encephalitis due to herpes simplex virus” (ICD-10 code B00.4), the PPV was 56.6% (95% CI: 51.1–62.0). Similarly, the PPV for “Meningoencephalitis due to herpes simplex virus” (ICD-10 code B00.4A) was 56.8% (95% CI: 39.5–72.9). “Herpes viral encephalitis” (ICD-10 code G05.1E) had a PPV of 75.9% (95% CI: 56.5–89.7), thereby representing the highest PPV. The estimated sensitivity was 95.5%. Conclusion The PPVs of the ICD-10 diagnosis coding for adult HSE in the DNPR were relatively low. Hence, the DNPR should be used with caution when studying patients with encephalitis caused by herpes simplex virus. PMID:27330328

National Performance Benchmarks for Modern Diagnostic Digital Mammography: Update from the Breast Cancer Surveillance Consortium.

PubMed

Sprague, Brian L; Arao, Robert F; Miglioretti, Diana L; Henderson, Louise M; Buist, Diana S M; Onega, Tracy; Rauscher, Garth H; Lee, Janie M; Tosteson, Anna N A; Kerlikowske, Karla; Lehman, Constance D

2017-04-01

Purpose To establish contemporary performance benchmarks for diagnostic digital mammography with use of recent data from the Breast Cancer Surveillance Consortium (BCSC). Materials and Methods Institutional review board approval was obtained for active or passive consenting processes or to obtain a waiver of consent to enroll participants, link data, and perform analyses. Data were obtained from six BCSC registries (418 radiologists, 92 radiology facilities). Mammogram indication and assessments were prospectively collected for women undergoing diagnostic digital mammography and linked with cancer diagnoses from state cancer registries. The study included 401 548 examinations conducted from 2007 to 2013 in 265 360 women. Results Overall diagnostic performance measures were as follows: cancer detection rate, 34.7 per 1000 (95% confidence interval [CI]: 34.1, 35.2); abnormal interpretation rate, 12.6% (95% CI: 12.5%, 12.7%); positive predictive value (PPV) of a biopsy recommendation (PPV 2 ), 27.5% (95% CI: 27.1%, 27.9%); PPV of biopsies performed (PPV 3 ), 30.4% (95% CI: 29.9%, 30.9%); false-negative rate, 4.8 per 1000 (95% CI: 4.6, 5.0); sensitivity, 87.8% (95% CI: 87.3%, 88.4%); and specificity, 90.5% (95% CI: 90.4%, 90.6%). Among cancers detected, 63.4% were stage 0 or 1 cancers, 45.6% were minimal cancers, the mean size of invasive cancers was 21.2 mm, and 69.6% of invasive cancers were node negative. Performance metrics varied widely across diagnostic indications, with cancer detection rate (64.5 per 1000) and abnormal interpretation rate (18.7%) highest for diagnostic mammograms obtained to evaluate a breast problem with a lump. Compared with performance during the screen-film mammography era, diagnostic digital performance showed increased abnormal interpretation and cancer detection rates and decreasing PPVs, with less than 70% of radiologists within acceptable ranges for PPV 2 and PPV 3 . Conclusion These performance measures can serve as national benchmarks that may help transform the marked variation in radiologists' diagnostic performance into targeted quality improvement efforts. © RSNA, 2017 Online supplemental material is available for this article.

Thienopyrazine-based low-bandgap polymers for flexible polymer solar cells

NASA Astrophysics Data System (ADS)

Sensfuss, S.; Blankenburg, L.; Schache, H.; Shokhovets, S.; Erb, T.; Konkin, A.; Herasimovich, A.; Scheinert, S.; Shahid, M.; Sell, S.; Klemm, E.

2010-09-01

The optical gaps of the low-bandgap PPVs (PM-20, PM-19, PM-18) are decreased down to 1.6-1.7 eV compared with that of MDMO-PPV (2.2 eV). The best lateral hole mobility was determined to be 2.1 × 10-3 cm2/V s (PM-18) in field effect transistors and exceeds that of MDMO-PPV (poly-[ 2-methoxy-5-(3'^'.7'^'-dimethyloctyloxy)-1.4-phenylenevinylene], 8.5 × 10-4 cm2/V s). This allows to reduce the PCBM ([6.6]-phenyl-C61(71)-butanoic acid methyl ester) content in solar cell devices down to 1:2 w/w giving a better η_AM1.5 than for MDMO-PPV:[60]-PCBM cells (PM-19:[60]-PCBM 2.32% on ITO-PET, 2.86% on ITO glass). The charge transfer to PCBM as acceptor occurs quite normally and shows an effective charge separation using light-induced spin resonance spectroscopy (LESR). The [70]-PCBM-bullet signals are shifted to lower field related to those of [60]-PCBM-bullet and overlap more with the polaron signal of PM-19. The LESR g-factor components of [70]-PCBM-bullet are reported for the first time. The external quantum efficiency peak values achieve up to 42% at 350-400 nm and 26% at 640 nm (PM-19:[60]-PCBM).

Evaluation of Eligibility Criteria Used to Identify Patients for Medication Therapy Management Services: A Retrospective Cohort Study in a Medicare Advantage Part D Population.

PubMed

Lee, Janet S; Yang, Jianing; Stockl, Karen M; Lew, Heidi; Solow, Brian K

2016-01-01

General eligibility criteria used by the Centers for Medicare & Medicaid Services (CMS) to identify patients for medication therapy management (MTM) services include having multiple chronic conditions, taking multiple Part D drugs, and being likely to incur annual drug costs that exceed a predetermined threshold. The performance of these criteria in identifying patients in greatest need of MTM services is unknown. Although there are numerous possible versions of MTM identification algorithms that satisfy these criteria, there are limited data that evaluate the performance of MTM services using eligibility thresholds representative of those used by the majority of Part D sponsors. To (a) evaluate the performance of the 2013 CMS MTM eligibility criteria thresholds in identifying Medicare Advantage Prescription Drug (MAPD) plan patients with at least 2 drug therapy problems (DTPs) relative to alternative criteria threshold levels and (b) identify additional patient risk factors significantly associated with the number of DTPs for consideration as potential future MTM eligibility criteria. All patients in the Medicare Advantage Part D population who had pharmacy eligibility as of December 31, 2013, were included in this retrospective cohort study. Study outcomes included 7 different types of DTPs: use of high-risk medications in the elderly, gaps in medication therapy, medication nonadherence, drug-drug interactions, duplicate therapy, drug-disease interactions, and brand-to-generic conversion opportunities. DTPs were identified for each member based on 6 months of most recent pharmacy claims data and 14 months of most recent medical claims data. Risk factors examined in this study included patient demographics and prior health care utilization in the most recent 6 months. Descriptive statistics were used to summarize patient characteristics and to evaluate unadjusted relationships between the average number of DTPs identified per patient and each risk factor. Quartile values identified in the study population for number of diseases, number of drugs, and annual spend were used as potential new criteria thresholds, resulting in 27 new MTM criteria combinations. The performance of each eligibility criterion was evaluated using sensitivity, specificity, positive predictive values (PPVs), and negative predictive values (NPVs). Patients identified with at least 2 DTPs were defined as those who would benefit from MTM services and were used as the gold standard. As part of a sensitivity analysis, patients identified with at least 1 DTP were used as the gold standard. Lastly, a multivariable negative binomial regression model was used to evaluate the relationship between each risk factor and the number of identified DTPs per patient while controlling for the patients' number of drugs, number of chronic diseases, and annual drug spend. A total of 2,578,336 patients were included in the study. The sensitivity, specificity, PPV, and NPV of CMS MTM criteria for the 2013 plan year were 15.3%, 95.6%, 51.3%, and 78.8%, respectively. Sensitivity and PPV improved when the drug count threshold increased from 8 to 10, and when the annual drug cost decreased from $3,144 to $2,239 or less. Results were consistent when at least 1 DTP was used as the gold standard. The adjusted rate of DTPs was significantly greater among patients identified with higher drug and disease counts, annual drug spend, and prior ER or outpatient or hospital visits. Patients with higher median household incomes who were male, younger, or white had significantly lower rates of DTPs. The performance of MTM eligibility criteria can be improved by increasing the threshold values for drug count while decreasing the threshold value for annual drug spend. Furthermore, additional risk factors, such as a recent ER or hospital visit, may be considered as potential MTM eligibility criteria.

Measuring Post-Partum Haemorrhage in Low-Resource Settings: The Diagnostic Validity of Weighed Blood Loss versus Quantitative Changes in Hemoglobin

PubMed Central

Atukunda, Esther Cathyln; Mugyenyi, Godfrey Rwambuka; Obua, Celestino; Atuhumuza, Elly Bronney; Musinguzi, Nicholas; Tornes, Yarine Fajardo; Agaba, Amon Ganaafa; Siedner, Mark Jacob

2016-01-01

Background Accurate estimation of blood loss is central to prompt diagnosis and management of post-partum hemorrhage (PPH), which remains a leading cause of maternal mortality in low-resource countries. In such settings, blood loss is often estimated visually and subjectively by attending health workers, due to inconsistent availability of laboratory infrastructure. We evaluated the diagnostic accuracy of weighed blood loss (WBL) versus changes in peri-partum hemoglobin to detect PPH. Methods Data from this analysis were collected as part of a randomized controlled trial comparing oxytocin with misoprostol for PPH (NCT01866241). Blood samples for complete blood count were drawn on admission and again prior to hospital discharge or before blood transfusion. During delivery, women were placed on drapes and had pre-weighed sanitary towels placed around their perineum. Blood was then drained into a calibrated container and the sanitary towels were added to estimate WBL, where each gram of blood was estimated as a milliliter. Sensitivity, specificity, negative and positive predictive values (PPVs) were calculated at various blood volume loss and time combinations, and we fit receiver-operator curves using blood loss at 1, 2, and 24 hours compared to a reference standard of haemoglobin decrease of >10%. Results A total of 1,140 women were enrolled in the study, of whom 258 (22.6%) developed PPH, defined as a haemoglobin drop >10%, and 262 (23.0%) had WBL ≥500mL. WBL generally had a poor sensitivity for detection of PPH (<75% for most volume-time combinations). In contrast, the specificity of WBL was high with blood loss ≥ 500mL at 1h and ≥750mL at any time points excluding PPH in over 97% of women. As such, WBL has a high PPV (>85%) in high prevalence settings when WBL exceeds 750mL. Conclusion WBL has poor sensitivity but high specificity compared to laboratory-based methods of PPH diagnosis. These characteristics correspond to a high PPV in areas with high PPH prevalence. Although WBL is not useful for excluding PPH, this low-cost, simple and reproducible method is promising as a reasonable method to identify significant PPH in such settings where quantifiable red cell indices are unavailable. PMID:27050823

(18)F-FACBC (anti1-amino-3-(18)F-fluorocyclobutane-1-carboxylic acid) versus (11)C-choline PET/CT in prostate cancer relapse: results of a prospective trial.

PubMed

Nanni, Cristina; Zanoni, Lucia; Pultrone, Cristian; Schiavina, Riccardo; Brunocilla, Eugenio; Lodi, Filippo; Malizia, Claudio; Ferrari, Matteo; Rigatti, Patrizio; Fonti, Cristina; Martorana, Giuseppe; Fanti, Stefano

2016-08-01

To compare the accuracy of (18)F-FACBC and (11)C-choline PET/CT in patients radically treated for prostate cancer presenting with biochemical relapse. This prospective study enrolled 100 consecutive patients radically treated for prostate cancer and presenting with rising PSA. Of these 100 patients, 89 were included in the analysis. All had biochemical relapse after radical prostatectomy (at least 3 months previously), had (11)C-choline and (18)F-FACBC PET/CT performed within 1 week and were off hormonal therapy at the time of the scans. The two tracers were compared directly in terms of overall positivity/negativity on both a per-patient basis and a per-site basis. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy were calculated for both the tracers; follow-up at 1 year (including correlative imaging, PSA trend and pathology when available) was considered as the standard of reference. In 51 patients the results were negative and in 25 patients positive with both the tracers, in eight patients the results were positive with (18)F-FACBC but negative with (11)C-choline, and in five patients the results were positive with (11)C-choline but negative with (18)F-FACBC. Overall in 49 patients the results were false-negative (FN), in two true-negative, in 24 true-positive (TP) and in none false-positive (FP) with both tracers. In terms of discordances between the tracers: (1) in one patient, the result was FN with (11)C-choline but FP with (18)F-FACBC (lymph node), (2) in seven, FN with (11)C-choline but TP with (18)F-FACBC (lymph node in five, bone in one, local relapse in one), (3) in one, FP with (11)C-choline (lymph node) but TP with (18)F-FACBC (local relapse), (4) in two, FP with (11)C-choline (lymph nodes in one, local relapse in one) but FN with (18)F-FACBC, and (5) in three, TP with (11)C-choline (lymph nodes in two, bone in one) but FN with (18)F-FACBC. With (11)C-choline and (18)F-FACBC, sensitivities were 32 % and 37 %, specificities 40 % and 67 %, accuracies 32 % and 38 %, PPVs 90 % and 97 %, and NPVs 3 % and 4 %, respectively. Categorizing patients by PSA level (<1 ng/ml 28 patients, 1 - <2 ng/ml 28 patients, 2 - <3 ng/ml 11 patients, ≥3 ng/ml 22 patients), the number (percent) of patients with TP findings were generally higher with (18)F-FACBC than with (11)C-choline: six patients (21 %) and four patients (14 %), eight patients (29 %) and eight patients (29 %), five patients (45 %) and four patients (36 %), and 13 patients (59 %) and 11 patients (50 %), respectively. (18)F-FACBC can be considered an alternative tracer superior to (11)C-choline in the setting of patients with biochemical relapse after radical prostatectomy.

Diagnostic performance of 18F-FDG PET/CT and whole-body diffusion-weighted imaging with background body suppression (DWIBS) in detection of lymph node and bone metastases from pediatric neuroblastoma.

PubMed

Ishiguchi, Hiroaki; Ito, Shinji; Kato, Katsuhiko; Sakurai, Yusuke; Kawai, Hisashi; Fujita, Naotoshi; Abe, Shinji; Narita, Atsushi; Nishio, Nobuhiro; Muramatsu, Hideki; Takahashi, Yoshiyuki; Naganawa, Shinji

2018-06-01

Recent many studies have shown that whole body "diffusion-weighted imaging with background body signal suppression" (DWIBS) seems a beneficial tool having higher tumor detection sensitivity without ionizing radiation exposure for pediatric tumors. In this study, we evaluated the diagnostic performance of whole body DWIBS and 18 F-FDG PET/CT for detecting lymph node and bone metastases in pediatric patients with neuroblastoma. Subjects in this retrospective study comprised 13 consecutive pediatric patients with neuroblastoma (7 males, 6 females; mean age, 2.9 ± 2.0 years old) who underwent both 18 F-FDG PET/CT and whole-body DWIBS. All patients were diagnosed as neuroblastoma on the basis of pathological findings. Eight regions of lymph nodes and 17 segments of skeletons in all patients were evaluated. The images of 123 I-MIBG scintigraphy/SPECT-CT, bone scintigraphy/SPECT, and CT were used to confirm the presence of lymph node and bone metastases. Two radiologists trained in nuclear medicine evaluated independently the uptake of lesions in 18 F-FDG PET/CT and the signal-intensity of lesions in whole-body DWIBS visually. Interobserver difference was overcome through discussion to reach a consensus. The sensitivities, specificities, and overall accuracies of 18 F-FDG PET/CT and whole-body DWIBS were compared using McNemer's test. Positive predictive values (PPVs) and negative predictive values (NPVs) of both modalities were compared using Fisher's exact test. The total numbers of lymph node regions and bone segments which were confirmed to have metastasis in the total 13 patients were 19 and 75, respectively. The sensitivity, specificity, overall accuracy, PPV, and NPV of 18 F-FDG PET/CT for detecting lymph node metastasis from pediatric neuroblastoma were 100, 98.7, 98.9, 95.0, and 100%, respectively, and those for detecting bone metastasis were 90.7, 73.1, 80.3, 70.1, and 91.9%, respectively. In contrast, the sensitivity, specificity, overall accuracy, PPV, and NPV of whole-body DWIBS for detecting bone metastasis from pediatric neuroblastoma were 94.7, 24.0, 53.0, 46.4 and 86.7%, respectively, whereas those for detecting lymph node metastasis were 94.7, 85.3, 87.2, 62.1, and 98.5%, respectively. The low specificity, overall accuracy, and PPV of whole-body DWIBS for detecting bone metastasis were due to a high incidence of false-positive findings (82/108, 75.9%). The specificity, overall accuracy, and PPV of whole-body DWIBS for detecting lymph node metastasis were also significantly lower than those of 18 F-FDG PET/CT for detecting lymph node metastasis, although the difference between these 2 modalities was less than that for detecting bone metastasis. The specificity, overall accuracy, and PPV of whole-body DWIBS are significantly lower than those of 18 F-FDG PET/CT because of a high incidence of false-positive findings particularly for detecting bone metastasis, whereas whole-body DWIBS shows a similar level of sensitivities for detecting lymph node and bone metastases to those of 18 F-FDG PET/CT. DWIBS should be carefully used for cancer staging in children because of its high incidence of false-positive findings in skeletons.

Validation of asthma recording in the Clinical Practice Research Datalink (CPRD)

PubMed Central

Morales, Daniel R; Mullerova, Hana; Smeeth, Liam; Douglas, Ian J; Quint, Jennifer K

2017-01-01

Objectives The optimal method of identifying people with asthma from electronic health records in primary care is not known. The aim of this study is to determine the positive predictive value (PPV) of different algorithms using clinical codes and prescription data to identify people with asthma in the United Kingdom Clinical Practice Research Datalink (CPRD). Methods 684 participants registered with a general practitioner (GP) practice contributing to CPRD between 1 December 2013 and 30 November 2015 were selected according to one of eight predefined potential asthma identification algorithms. A questionnaire was sent to the GPs to confirm asthma status and provide additional information to support an asthma diagnosis. Two study physicians independently reviewed and adjudicated the questionnaires and additional information to form a gold standard for asthma diagnosis. The PPV was calculated for each algorithm. Results 684 questionnaires were sent, of which 494 (72%) were returned and 475 (69%) were complete and analysed. All five algorithms including a specific Read code indicating asthma or non-specific Read code accompanied by additional conditions performed well. The PPV for asthma diagnosis using only a specific asthma code was 86.4% (95% CI 77.4% to 95.4%). Extra information on asthma medication prescription (PPV 83.3%), evidence of reversibility testing (PPV 86.0%) or a combination of all three selection criteria (PPV 86.4%) did not result in a higher PPV. The algorithm using non-specific asthma codes, information on reversibility testing and respiratory medication use scored highest (PPV 90.7%, 95% CI (82.8% to 98.7%), but had a much lower identifiable population. Algorithms based on asthma symptom codes had low PPVs (43.1% to 57.8%)%). Conclusions People with asthma can be accurately identified from UK primary care records using specific Read codes. The inclusion of spirometry or asthma medications in the algorithm did not clearly improve accuracy. Ethics and dissemination The protocol for this research was approved by the Independent Scientific Advisory Committee (ISAC) for MHRA Database Research (protocol number15_257) and the approved protocol was made available to the journal and reviewers during peer review. Generic ethical approval for observational research using the CPRD with approval from ISAC has been granted by a Health Research Authority Research Ethics Committee (East Midlands—Derby, REC reference number 05/MRE04/87). The results will be submitted for publication and will be disseminated through research conferences and peer-reviewed journals. PMID:28801439

Predictive value of stroke discharge diagnoses in the Danish National Patient Register.

PubMed

Lühdorf, Pernille; Overvad, Kim; Schmidt, Erik B; Johnsen, Søren P; Bach, Flemming W

2017-08-01

To determine the positive predictive values for stroke discharge diagnoses, including subarachnoidal haemorrhage, intracerebral haemorrhage and cerebral infarction in the Danish National Patient Register. Participants in the Danish cohort study Diet, Cancer and Health with a stroke discharge diagnosis in the National Patient Register between 1993 and 2009 were identified and their medical records were retrieved for validation of the diagnoses. A total of 3326 records of possible cases of stroke were reviewed. The overall positive predictive value for stroke was 69.3% (95% confidence interval (CI) 67.8-70.9%). The predictive values differed according to hospital characteristics, with the highest predictive value of 87.8% (95% CI 85.5-90.1%) found in departments of neurology and the lowest predictive value of 43.0% (95% CI 37.6-48.5%) found in outpatient clinics. The overall stroke diagnosis in the Danish National Patient Register had a limited predictive value. We therefore recommend the critical use of non-validated register data for research on stroke. The possibility of optimising the predictive values based on more advanced algorithms should be considered.

Translation, adaptation, and validation of the Sunderland Scale and the Cubbin & Jackson Revised Scale in Portuguese

PubMed Central

Sousa, Bruno

2013-01-01

Objective To translate into Portuguese and evaluate the measuring properties of the Sunderland Scale and the Cubbin & Jackson Revised Scale, which are instruments for evaluating the risk of developing pressure ulcers during intensive care. Methods This study included the process of translation and adaptation of the scales to the Portuguese language, as well as the validation of these tools. To assess the reliability, Cronbach alpha values of 0.702 to 0.708 were identified for the Sunderland Scale and the Cubbin & Jackson Revised Scale, respectively. The validation criteria (predictive) were performed comparatively with the Braden Scale (gold standard), and the main measurements evaluated were sensitivity, specificity, positive predictive value, negative predictive value, and area under the curve, which were calculated based on cutoff points. Results The Sunderland Scale exhibited 60% sensitivity, 86.7% specificity, 47.4% positive predictive value, 91.5% negative predictive value, and 0.86 for the area under the curve. The Cubbin & Jackson Revised Scale exhibited 73.3% sensitivity, 86.7% specificity, 52.4% positive predictive value, 94.2% negative predictive value, and 0.91 for the area under the curve. The Braden scale exhibited 100% sensitivity, 5.3% specificity, 17.4% positive predictive value, 100% negative predictive value, and 0.72 for the area under the curve. Conclusions Both tools demonstrated reliability and validity for this sample. The Cubbin & Jackson Revised Scale yielded better predictive values for the development of pressure ulcers during intensive care. PMID:23917975

Incorporating geographical factors with artificial neural networks to predict reference values of erythrocyte sedimentation rate

PubMed Central

2013-01-01

Background The measurement of the Erythrocyte Sedimentation Rate (ESR) value is a standard procedure performed during a typical blood test. In order to formulate a unified standard of establishing reference ESR values, this paper presents a novel prediction model in which local normal ESR values and corresponding geographical factors are used to predict reference ESR values using multi-layer feed-forward artificial neural networks (ANN). Methods and findings Local normal ESR values were obtained from hospital data, while geographical factors that include altitude, sunshine hours, relative humidity, temperature and precipitation were obtained from the National Geographical Data Information Centre in China. The results show that predicted values are statistically in agreement with measured values. Model results exhibit significant agreement between training data and test data. Consequently, the model is used to predict the unseen local reference ESR values. Conclusions Reference ESR values can be established with geographical factors by using artificial intelligence techniques. ANN is an effective method for simulating and predicting reference ESR values because of its ability to model nonlinear and complex relationships. PMID:23497145

Incorporating geographical factors with artificial neural networks to predict reference values of erythrocyte sedimentation rate.

PubMed

Yang, Qingsheng; Mwenda, Kevin M; Ge, Miao

2013-03-12

The measurement of the Erythrocyte Sedimentation Rate (ESR) value is a standard procedure performed during a typical blood test. In order to formulate a unified standard of establishing reference ESR values, this paper presents a novel prediction model in which local normal ESR values and corresponding geographical factors are used to predict reference ESR values using multi-layer feed-forward artificial neural networks (ANN). Local normal ESR values were obtained from hospital data, while geographical factors that include altitude, sunshine hours, relative humidity, temperature and precipitation were obtained from the National Geographical Data Information Centre in China.The results show that predicted values are statistically in agreement with measured values. Model results exhibit significant agreement between training data and test data. Consequently, the model is used to predict the unseen local reference ESR values. Reference ESR values can be established with geographical factors by using artificial intelligence techniques. ANN is an effective method for simulating and predicting reference ESR values because of its ability to model nonlinear and complex relationships.

Predictive value and construct validity of the work functioning screener-healthcare (WFS-H).

PubMed

Boezeman, Edwin J; Nieuwenhuijsen, Karen; Sluiter, Judith K

2016-05-25

To test the predictive value and convergent construct validity of a 6-item work functioning screener (WFS-H). Healthcare workers (249 nurses) completed a questionnaire containing the work functioning screener (WFS-H) and a work functioning instrument (NWFQ) measuring the following: cognitive aspects of task execution and general incidents, avoidance behavior, conflicts and irritation with colleagues, impaired contact with patients and their family, and level of energy and motivation. Productivity and mental health were also measured. Negative and positive predictive values, AUC values, and sensitivity and specificity were calculated to examine the predictive value of the screener. Correlation analysis was used to examine the construct validity. The screener had good predictive value, since the results showed that a negative screener score is a strong indicator of work functioning not hindered by mental health problems (negative predictive values: 94%-98%; positive predictive values: 21%-36%; AUC:.64-.82; sensitivity: 42%-76%; and specificity 85%-87%). The screener has good construct validity due to moderate, but significant (p<.001), associations with productivity (r=.51), mental health (r=.48), and distress (r=.47). The screener (WFS-H) had good predictive value and good construct validity. Its score offers occupational health professionals a helpful preliminary insight into the work functioning of healthcare workers.

Relationships among values, achievement orientations, and attitudes in youth sport.

PubMed

Lee, Martin J; Whitehead, Jean; Ntoumanis, Nikos; Hatzigeorgiadis, Antonis

2008-10-01

This research examines the value-expressive function of attitudes and achievement goal theory in predicting moral attitudes. In Study 1, the Youth Sport Values Questionnaire (YSVQ; Lee, Whitehead, & Balchin, 2000) was modified to measure moral, competence, and status values. In Study 2, structural equation modeling on data from 549 competitors (317 males, 232 females) aged 12-15 years showed that moral and competence values predicted prosocial attitudes, whereas moral (negatively) and status values (positively) predicted antisocial attitudes. Competence and status values predicted task and ego orientation, respectively, and task and ego orientation partially mediated the effect of competence values on prosocial attitudes and of status values on antisocial attitudes, respectively. The role of sport values is discussed, and new research directions are proposed.

Cardiothoracic ratio for prediction of left ventricular dilation: a systematic review and pooled analysis.

PubMed

Loomba, Rohit S; Shah, Parinda H; Nijhawan, Karan; Aggarwal, Saurabh; Arora, Rohit

2015-03-01

Increased cardiothoracic ratio noted on chest radiographs often prompts concern and further evaluation with additional imaging. This study pools available data assessing the utility of cardiothoracic ratio in predicting left ventricular dilation. A systematic review of the literature was conducted to identify studies comparing cardiothoracic ratio by chest x-ray to left ventricular dilation by echocardiography. Electronic databases were used to identify studies which were then assessed for quality and bias, with those with adequate quality and minimal bias ultimately being included in the pooled analysis. The pooled data were used to determine the sensitivity, specificity, positive predictive value and negative predictive value of cardiomegaly in predicting left ventricular dilation. A total of six studies consisting of 466 patients were included in this analysis. Cardiothoracic ratio had 83.3% sensitivity, 45.4% specificity, 43.5% positive predictive value and 82.7% negative predictive value. When a secondary analysis was conducted with a pediatric study excluded, a total of five studies consisting of 371 patients were included. Cardiothoracic ratio had 86.2% sensitivity, 25.2% specificity, 42.5% positive predictive value and 74.0% negative predictive value. Cardiothoracic ratio as determined by chest radiograph is sensitive but not specific for identifying left ventricular dilation. Cardiothoracic ratio also has a strong negative predictive value for identifying left ventricular dilation.

Customized versus population-based birth weight charts for the detection of neonatal growth and perinatal morbidity in a cross-sectional study of term neonates.

PubMed

Carberry, Angela E; Raynes-Greenow, Camille H; Turner, Robin M; Jeffery, Heather E

2013-10-15

Customized birth weight charts that incorporate maternal characteristics are now being adopted into clinical practice. However, there is controversy surrounding the value of these charts in the prediction of growth and perinatal outcomes. The objective of this study was to assess the use of customized charts in predicting growth, defined by body fat percentage, and perinatal morbidity. A total of 581 term (≥37 weeks' gestation) neonates born in Sydney, Australia, in 2010 were included. Body fat percentage measurements were taken by using air displacement plethysmography. Objective composite measurements of perinatal morbidity were used to identify neonates who had poor outcomes; these data were extracted from medical records. The value of customized charts was assessed by calculating positive predictive values, negative predictive values, and odds ratios with 95% confidence intervals. Customized versus population-based charts did not improve the prediction of either low body fat percentage (59% vs. 66% positive predictive value and 87% vs. 89% negative predictive value, respectively) or high body fat percentage (48% vs. 53% positive predictive value and 90% vs. 89% negative predictive value, respectively). Customized charts were not better than population-based charts at predicting perinatal morbidity (for customized charts, odds ratio = 1.02, 95% confidence interval: 1.01, 1.04; for population-based charts, odds ratio = 1.03, 95% confidence interval: 1.01, 1.05) per percentile decrease in birth weight. Customized birth weight charts do not provide significant improvements over population-based charts in predicting neonatal growth and morbidity.

21 CFR 868.1890 - Predictive pulmonary-function value calculator.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Predictive pulmonary-function value calculator. 868.1890 Section 868.1890 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... pulmonary-function value calculator. (a) Identification. A predictive pulmonary-function value calculator is...

21 CFR 868.1890 - Predictive pulmonary-function value calculator.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Predictive pulmonary-function value calculator. 868.1890 Section 868.1890 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... pulmonary-function value calculator. (a) Identification. A predictive pulmonary-function value calculator is...

[Phenotypic trends and breeding values for canine congenital sensorineural deafness in Dalmatian dogs].

PubMed

Blum, Meike; Distl, Ottmar

2014-01-01

In the present study, breeding values for canine congenital sensorineural deafness, the presence of blue eyes and patches have been predicted using multivariate animal models to test the reliability of the breeding values for planned matings. The dataset consisted of 6669 German Dalmatian dogs born between 1988 and 2009. Data were provided by the Dalmatian kennel clubs which are members of the German Association for Dog Breeding and Husbandry (VDH). The hearing status for all dogs was evaluated using brainstem auditory evoked potentials. The reliability using the prediction error variance of breeding values and the realized reliability of the prediction of the phenotype of future progeny born in each one year between 2006 and 2009 were used as parameters to evaluate the goodness of prediction through breeding values. All animals from the previous birth years were used for prediction of the breeding values of the progeny in each of the up-coming birth years. The breeding values based on pedigree records achieved an average reliability of 0.19 for the future 1951 progeny. The predictive accuracy (R2) for the hearing status of single future progeny was at 1.3%. Combining breeding values for littermates increased the predictive accuracy to 3.5%. Corresponding values for maternal and paternal half-sib groups were at 3.2 and 7.3%. The use of breeding values for planned matings increases the phenotypic selection response over mass selection. The breeding values of sires may be used for planned matings because reliabilities and predictive accuracies for future paternal progeny groups were highest.

Adjustment of regional regression equations for urban storm-runoff quality using at-site data

USGS Publications Warehouse

Barks, C.S.

1996-01-01

Regional regression equations have been developed to estimate urban storm-runoff loads and mean concentrations using a national data base. Four statistical methods using at-site data to adjust the regional equation predictions were developed to provide better local estimates. The four adjustment procedures are a single-factor adjustment, a regression of the observed data against the predicted values, a regression of the observed values against the predicted values and additional local independent variables, and a weighted combination of a local regression with the regional prediction. Data collected at five representative storm-runoff sites during 22 storms in Little Rock, Arkansas, were used to verify, and, when appropriate, adjust the regional regression equation predictions. Comparison of observed values of stormrunoff loads and mean concentrations to the predicted values from the regional regression equations for nine constituents (chemical oxygen demand, suspended solids, total nitrogen as N, total ammonia plus organic nitrogen as N, total phosphorus as P, dissolved phosphorus as P, total recoverable copper, total recoverable lead, and total recoverable zinc) showed large prediction errors ranging from 63 percent to more than several thousand percent. Prediction errors for 6 of the 18 regional regression equations were less than 100 percent and could be considered reasonable for water-quality prediction equations. The regression adjustment procedure was used to adjust five of the regional equation predictions to improve the predictive accuracy. For seven of the regional equations the observed and the predicted values are not significantly correlated. Thus neither the unadjusted regional equations nor any of the adjustments were appropriate. The mean of the observed values was used as a simple estimator when the regional equation predictions and adjusted predictions were not appropriate.

Virtual World Currency Value Fluctuation Prediction System Based on User Sentiment Analysis.

PubMed

Kim, Young Bin; Lee, Sang Hyeok; Kang, Shin Jin; Choi, Myung Jin; Lee, Jung; Kim, Chang Hun

2015-01-01

In this paper, we present a method for predicting the value of virtual currencies used in virtual gaming environments that support multiple users, such as massively multiplayer online role-playing games (MMORPGs). Predicting virtual currency values in a virtual gaming environment has rarely been explored; it is difficult to apply real-world methods for predicting fluctuating currency values or shares to the virtual gaming world on account of differences in domains between the two worlds. To address this issue, we herein predict virtual currency value fluctuations by collecting user opinion data from a virtual community and analyzing user sentiments or emotions from the opinion data. The proposed method is straightforward and applicable to predicting virtual currencies as well as to gaming environments, including MMORPGs. We test the proposed method using large-scale MMORPGs and demonstrate that virtual currencies can be effectively and efficiently predicted with it.

Virtual World Currency Value Fluctuation Prediction System Based on User Sentiment Analysis

PubMed Central

Kim, Young Bin; Lee, Sang Hyeok; Kang, Shin Jin; Choi, Myung Jin; Lee, Jung; Kim, Chang Hun

2015-01-01

In this paper, we present a method for predicting the value of virtual currencies used in virtual gaming environments that support multiple users, such as massively multiplayer online role-playing games (MMORPGs). Predicting virtual currency values in a virtual gaming environment has rarely been explored; it is difficult to apply real-world methods for predicting fluctuating currency values or shares to the virtual gaming world on account of differences in domains between the two worlds. To address this issue, we herein predict virtual currency value fluctuations by collecting user opinion data from a virtual community and analyzing user sentiments or emotions from the opinion data. The proposed method is straightforward and applicable to predicting virtual currencies as well as to gaming environments, including MMORPGs. We test the proposed method using large-scale MMORPGs and demonstrate that virtual currencies can be effectively and efficiently predicted with it. PMID:26241496

Positive predictive value of infective endocarditis in the Danish National Patient Registry: a validation study.

PubMed

Østergaard, Lauge; Adelborg, Kasper; Sundbøll, Jens; Pedersen, Lars; Loldrup Fosbøl, Emil; Schmidt, Morten

2018-05-30

The positive predictive value of an infective endocarditis diagnosis is approximately 80% in the Danish National Patient Registry. However, since infective endocarditis is a heterogeneous disease implying long-term intravenous treatment, we hypothesiszed that the positive predictive value varies by length of hospital stay. A total of 100 patients with first-time infective endocarditis in the Danish National Patient Registry were identified from January 2010 - December 2012 at the University hospital of Aarhus and regional hospitals of Herning and Randers. Medical records were reviewed. We calculated the positive predictive value according to admission length, and separately for patients with a cardiac implantable electronic device and a prosthetic heart valve using the Wilson score method. Among the 92 medical records available for review, the majority of the patients had admission length ⩾2 weeks. The positive predictive value increased with length of admission. In patients with admission length <2 weeks the positive predictive value was 65% while it was 90% for admission length ⩾2 weeks. The positive predictive value was 81% for patients with a cardiac implantable electronic device and 87% for patients with a prosthetic valve. The positive predictive value of the infective endocarditis diagnosis in the Danish National Patient Registry is high for patients with admission length ⩾2 weeks. Using this algorithm, the Danish National Patient Registry provides a valid source for identifying infective endocarditis for research.

Development of a Gestational Age-Specific Case Definition for Neonatal Necrotizing Enterocolitis.

PubMed

Battersby, Cheryl; Longford, Nick; Costeloe, Kate; Modi, Neena

2017-03-01

Necrotizing enterocolitis (NEC) is a major cause of neonatal morbidity and mortality. Preventive and therapeutic research, surveillance, and quality improvement initiatives are hindered by variations in case definitions. To develop a gestational age (GA)-specific case definition for NEC. We conducted a prospective 34-month population study using clinician-recorded findings from the UK National Neonatal Research Database between December 2011 and September 2014 across all 163 neonatal units in England. We split study data into model development and validation data sets and categorized GA into groups (group 1, less than 26 weeks' GA; group 2, 26 to less than 30 weeks' GA; group 3, 30 to less than 37 weeks' GA; group 4, 37 or more weeks' GA). We entered GA, birth weight z score, and clinical and abdominal radiography findings as candidate variables in a logistic regression model, performed model fitting 1000 times, averaged the predictions, and used estimates from the fitted model to develop an ordinal NEC score and cut points to develop a dichotomous case definition based on the highest area under the receiver operating characteristic curves [AUCs] and positive predictive values [PPVs]. Abdominal radiography performed to investigate clinical concerns. Ordinal NEC likelihood score, dichotomous case definition, and GA-specific probability plots. Of the 3866 infants, the mean (SD) birth weight was 2049.1 (1941.7) g and mean (SD) GA was 32 (5) weeks; 2032 of 3663 (55.5%) were male. The total included 2978 infants (77.0%) without NEC and 888 (23.0%) with NEC. Infants with NEC in group 1 were less likely to present with pneumatosis (31.1% vs 47.2%; P = .01), blood in stool (11.8% vs 29.6%; P < .001), or mucus in stool (2.1% vs 5.6%; P = .048) but more likely to present with gasless abdominal radiography findings (6.3% vs 0.9%; P = .009) compared with infants with NEC in group 3. In the ordinal NEC score analysis, we allocated 3 points to pneumatosis, 2 points to blood in stool, and 1 point each to abdominal tenderness and abdominal discoloration; 1 point was assigned if 1 or more of pneumoperitoneum, fixed loop, and portal venous gas were present, and 1 point was assigned if both increased and/or bilious aspirates and abdominal distension were present. The cutoff scores for the dichotomous GA-specific case definition were 2 or greater for infants in groups 1 and 2, 3 or greater for infants in group 3, and 4 or greater for infants in group 4. The ordinal NEC score and dichotomous case definition discriminated well between infants with (AUC, 87%) and without (AUC, 80%) NEC. The case definition has a sensitivity of 66.2% (95% CI, 63.0-69.4), a specificity of 94.4% (95% CI, 93.2-95.4), an AUC of 80.0% (95% CI, 79-82), and a PPV of 85.5% (95% CI, 82.6-88.1). Applying the cut points to the 431 infants who underwent a laparotomy yielded a sensitivity of 76.5% (95% CI, 70.0-82.1), a specificity of 74.4% (95% CI, 68.3-80.0), an AUC of 75.0% (95% CI, 71.0- 80.0), and a PPV of 72.9% (95% CI, 66.4-78.7). The risk of NEC and clinical presentation are associated with GA. Adoption of a consistent GA-specific case definition would strengthen global efforts to reduce the population burden of this devastating neonatal disease.

Familism Values, Family Time, and Mexican-Origin Young Adults’ Depressive Symptoms

PubMed Central

Zeiders, Katharine H.; Updegraff, Kimberly A.; Umaña-Taylor, Adriana J.; McHale, Susan M.; Padilla, Jenny

2015-01-01

Using longitudinal data across eight years, this study examined how parents’ familism values in early adolescence predicted youths’ depressive symptoms in young adulthood via youths’ familism values and family time. We examined these processes among 246 Mexican-origin families using interview and phone-diary data. Findings revealed that fathers’ familism values predicted male and female youths’ familism values in middle adolescence. For female youth only, fathers’ familism values also predicted youths’ family time in late adolescence. The link between family time and young adults’ depressive symptoms depended on parental acceptance and adolescent gender: Among female and male youth, family time predicted fewer depressive symptoms, but only when paternal acceptance was high. For female adolescents only, family time predicted fewer depressive symptoms when maternal acceptance was high but more depressive symptoms when maternal acceptance was low. Findings highlight family dynamics as the mechanisms through which familism values have implications for youths’ adjustment. PMID:26778855

Sensitivity and specificity of subacute computerized neurocognitive testing and symptom evaluation in predicting outcomes after sports-related concussion.

PubMed

Lau, Brian C; Collins, Michael W; Lovell, Mark R

2011-06-01

Concussions affect an estimated 136 000 high school athletes yearly. Computerized neurocognitive testing has been shown to be appropriately sensitive and specific in diagnosing concussions, but no studies have assessed its utility to predict length of recovery. Determining prognosis during subacute recovery after sports concussion will help clinicians more confidently address return-to-play and academic decisions. To quantify the prognostic ability of computerized neurocognitive testing in combination with symptoms during the subacute recovery phase from sports-related concussion. Cohort study (prognosis); Level of evidence, 2. In sum, 108 male high school football athletes completed a computer-based neurocognitive test battery within 2.23 days of injury and were followed until returned to play as set by international guidelines. Athletes were grouped into protracted recovery (>14 days; n = 50) or short-recovery (≤14 days; n = 58). Separate discriminant function analyses were performed using total symptom score on Post-Concussion Symptom Scale, symptom clusters (migraine, cognitive, sleep, neuropsychiatric), and Immediate Postconcussion Assessment and Cognitive Testing neurocognitive scores (verbal memory, visual memory, reaction time, processing speed). Multiple discriminant function analyses revealed that the combination of 4 symptom clusters and 4 neurocognitive composite scores had the highest sensitivity (65.22%), specificity (80.36%), positive predictive value (73.17%), and negative predictive value (73.80%) in predicting protracted recovery. Discriminant function analyses of total symptoms on the Post-Concussion Symptom Scale alone had a sensitivity of 40.81%; specificity, 79.31%; positive predictive value, 62.50%; and negative predictive value, 61.33%. The 4 symptom clusters alone discriminant function analyses had a sensitivity of 46.94%; specificity, 77.20%; positive predictive value, 63.90%; and negative predictive value, 62.86%. Discriminant function analyses of the 4 computerized neurocognitive scores alone had a sensitivity of 53.20%; specificity, 75.44%; positive predictive value, 64.10%; and negative predictive value, 66.15%. The use of computerized neurocognitive testing in conjunction with symptom clusters results improves sensitivity, specificity, positive predictive value, and negative predictive value of predicting protracted recovery compared with each used alone. There is also a net increase in sensitivity of 24.41% when using neurocognitive testing and symptom clusters together compared with using total symptoms on Post-Concussion Symptom Scale alone.

Can blood and semen presepsin levels in males predict pregnancy in couples undergoing intra-cytoplasmic sperm injection?

PubMed

Ovayolu, Ali; Arslanbuğa, Cansev Yilmaz; Gun, Ismet; Devranoglu, Belgin; Ozdemir, Arman; Cakar, Sule Eren

2016-01-01

To determine whether semen and plasma presepsin values measured in men with normozoospermia and oligoasthenospermia undergoing invitro-fertilization would be helpful in predicting ongoing pregnancy and live birth. Group-I was defined as patients who had pregnancy after treatment and Group-II comprised those with no pregnancy. Semen and blood presepsin values were subsequently compared between the groups. Parametric comparisons were performed using Student's t-test, and non-parametric comparisons were conducted using the Mann-Whitney U test. There were 42 patients in Group-I and 72 in Group-II. In the context of successful pregnancy and live birth, semen presepsin values were statistically significantly higher in Group-I than in Group-II (p= 0.004 and p= 0.037, respectively). The most appropriate semen presepsin cut-off value for predicting both ongoing pregnancy and live birth was calculated as 199 pg/mL. Accordingly, their sensitivity was 64.5% to 59.3%, their specificity was 57.0% to 54.2%, and their positive predictive value was 37.0% to 29.6%, respectively; their negative predictive value was 80.4% in both instances. Semen presepsin values could be a new marker that may enable the prediction of successful pregnancy and/or live birth. Its negative predictive values are especially high.

Methods of developing core collections based on the predicted genotypic value of rice ( Oryza sativa L.).

PubMed

Li, C T; Shi, C H; Wu, J G; Xu, H M; Zhang, H Z; Ren, Y L

2004-04-01

The selection of an appropriate sampling strategy and a clustering method is important in the construction of core collections based on predicted genotypic values in order to retain the greatest degree of genetic diversity of the initial collection. In this study, methods of developing rice core collections were evaluated based on the predicted genotypic values for 992 rice varieties with 13 quantitative traits. The genotypic values of the traits were predicted by the adjusted unbiased prediction (AUP) method. Based on the predicted genotypic values, Mahalanobis distances were calculated and employed to measure the genetic similarities among the rice varieties. Six hierarchical clustering methods, including the single linkage, median linkage, centroid, unweighted pair-group average, weighted pair-group average and flexible-beta methods, were combined with random, preferred and deviation sampling to develop 18 core collections of rice germplasm. The results show that the deviation sampling strategy in combination with the unweighted pair-group average method of hierarchical clustering retains the greatest degree of genetic diversities of the initial collection. The core collections sampled using predicted genotypic values had more genetic diversity than those based on phenotypic values.

Assessing the predictive value of the American Board of Family Practice In-training Examination.

PubMed

Replogle, William H; Johnson, William D

2004-03-01

The American Board of Family Practice In-training Examination (ABFP ITE) is a cognitive examination similar in content to the ABFP Certification Examination (CE). The ABFP ITE is widely used in family medicine residency programs. It was originally developed and intended to be used for assessment of groups of residents. Despite lack of empirical support, however, some residency programs are using ABFP ITE scores as individual resident performance indicators. This study's objective was to estimate the positive predictive value of the ABFP ITE for identifying residents at risk for poor performance on the ABFP CE or a subsequent ABFP ITE. We used a normal distribution model for correlated test scores and Monte Carlo simulation to investigate the effect of test reliability (measurement errors) on the positive predictive value of the ABFP ITE. The positive predictive value of the composite score was .72. The positive predictive value of the eight specialty subscales ranged from .26 to .57. Only the composite score of the ABFP ITE has acceptable positive predictive value to be used as part of a comprehension resident evaluation system. The ABFP ITE specialty subscales do not have sufficient positive predictive value or reliability to warrant use as performance indicators.

Low-Complexity Lossless and Near-Lossless Data Compression Technique for Multispectral Imagery

NASA Technical Reports Server (NTRS)

Xie, Hua; Klimesh, Matthew A.

2009-01-01

This work extends the lossless data compression technique described in Fast Lossless Compression of Multispectral- Image Data, (NPO-42517) NASA Tech Briefs, Vol. 30, No. 8 (August 2006), page 26. The original technique was extended to include a near-lossless compression option, allowing substantially smaller compressed file sizes when a small amount of distortion can be tolerated. Near-lossless compression is obtained by including a quantization step prior to encoding of prediction residuals. The original technique uses lossless predictive compression and is designed for use on multispectral imagery. A lossless predictive data compression algorithm compresses a digitized signal one sample at a time as follows: First, a sample value is predicted from previously encoded samples. The difference between the actual sample value and the prediction is called the prediction residual. The prediction residual is encoded into the compressed file. The decompressor can form the same predicted sample and can decode the prediction residual from the compressed file, and so can reconstruct the original sample. A lossless predictive compression algorithm can generally be converted to a near-lossless compression algorithm by quantizing the prediction residuals prior to encoding them. In this case, since the reconstructed sample values will not be identical to the original sample values, the encoder must determine the values that will be reconstructed and use these values for predicting later sample values. The technique described here uses this method, starting with the original technique, to allow near-lossless compression. The extension to allow near-lossless compression adds the ability to achieve much more compression when small amounts of distortion are tolerable, while retaining the low complexity and good overall compression effectiveness of the original algorithm.

Predictive Value of Matrix Metalloproteinases and Their Inhibitors for Mortality in Septic Patients: A Cohort Study.

PubMed

Serrano-Gomez, Sergio; Burgos-Angulo, Gabriel; Niño-Vargas, Daniela Camila; Niño, María Eugenia; Cárdenas, María Eugenia; Chacón-Valenzuela, Estephania; McCosham, Diana Margarita; Peinado-Acevedo, Juan Sebastián; Lopez, M Marcos; Cunha, Fernando; Pazin-Filho, Antonio; Ilarraza, Ramses; Schulz, Richard; Torres-Dueñas, Diego

2017-01-01

Over 170 biomarkers are being investigated regarding their prognostic and diagnostic accuracy in sepsis in order to find new tools to reduce morbidity and mortality. Matrix metalloproteinases (MMPs) and their inhibitors have been recently studied as promising new prognostic biomarkers in patients with sepsis. This study is aimed at determining the utility of several cutoff points of these biomarkers to predict mortality in patients with sepsis. A multicenter, prospective, analytic cohort study was performed in the metropolitan area of Bucaramanga, Colombia. A total of 289 patients with sepsis and septic shock were included. MMP-9, MMP-2, tissue inhibitor of metalloproteinase 1 (TIMP-1), TIMP-2, TIMP-1/MMP-9 ratio, and TIMP-2/MMP-2 ratio were determined in blood samples. Value ranges were correlated with mortality to estimate sensitivity, specificity, positive predictive value, negative predictive value, and area under the receiving operating characteristic curve. Sensitivity ranged from 33.3% (MMP-9/TIMP-1 ratio) to 60.6% (TIMP-1) and specificity varied from 38.8% (MMP-2/TIMP-2 ratio) to 58.5% (TIMP-1). As for predictive values, positive predictive value range was from 17.5% (MMP-9/TIMP-1 ratio) to 70.4% (MMP-2/TIMP-2 ratio), whereas negative predictive values were between 23.2% (MMP-2/TIMP-2 ratio) and 80.9% (TIMP-1). Finally, area under the curve scores ranged from 0.31 (MMP-9/TIMP-1 ratio) to 0.623 (TIMP-1). Although TIMP-1 showed higher sensitivity, specificity, and negative predictive value, with a representative population sample, we conclude that none of the evaluated biomarkers had significant predictive value for mortality.

Anticipating Their Future: Adolescent Values for the Future Predict Adult Behaviors

PubMed Central

Finlay, Andrea; Wray-Lake, Laura; Warren, Michael; Maggs, Jennifer L.

2014-01-01

Adolescent future values – beliefs about what will matter to them in the future – may shape their adult behavior. Utilizing a national longitudinal British sample, this study examined whether adolescent future values in six domains (i.e., family responsibility, full-time job, personal responsibility, autonomy, civic responsibility, and hedonistic privilege) predicted adult social roles, civic behaviors, and alcohol use. Future values positively predicted behaviors within the same domain; fewer cross-domain associations were evident. Civic responsibility positively predicted adult civic behaviors, but negatively predicted having children. Hedonistic privilege positively predicted adult alcohol use and negatively predicted civic behaviors. Results suggest that attention should be paid to how adolescents are thinking about their futures due to the associated links with long-term social and health behaviors. PMID:26279595

Development of a predictive model for lead, cadmium and fluorine soil-water partition coefficients using sparse multiple linear regression analysis.

PubMed

Nakamura, Kengo; Yasutaka, Tetsuo; Kuwatani, Tatsu; Komai, Takeshi

2017-11-01

In this study, we applied sparse multiple linear regression (SMLR) analysis to clarify the relationships between soil properties and adsorption characteristics for a range of soils across Japan and identify easily-obtained physical and chemical soil properties that could be used to predict K and n values of cadmium, lead and fluorine. A model was first constructed that can easily predict the K and n values from nine soil parameters (pH, cation exchange capacity, specific surface area, total carbon, soil organic matter from loss on ignition and water holding capacity, the ratio of sand, silt and clay). The K and n values of cadmium, lead and fluorine of 17 soil samples were used to verify the SMLR models by the root mean square error values obtained from 512 combinations of soil parameters. The SMLR analysis indicated that fluorine adsorption to soil may be associated with organic matter, whereas cadmium or lead adsorption to soil is more likely to be influenced by soil pH, IL. We found that an accurate K value can be predicted from more than three soil parameters for most soils. Approximately 65% of the predicted values were between 33 and 300% of their measured values for the K value; 76% of the predicted values were within ±30% of their measured values for the n value. Our findings suggest that adsorption properties of lead, cadmium and fluorine to soil can be predicted from the soil physical and chemical properties using the presented models. Copyright © 2017 Elsevier Ltd. All rights reserved.

Markovian prediction of future values for food grains in the economic survey

NASA Astrophysics Data System (ADS)

Sathish, S.; Khadar Babu, S. K.

2017-11-01

Now-a-days prediction and forecasting are plays a vital role in research. For prediction, regression is useful to predict the future value and current value on production process. In this paper, we assume food grain production exhibit Markov chain dependency and time homogeneity. The economic generative performance evaluation the balance time artificial fertilization different level in Estrusdetection using a daily Markov chain model. Finally, Markov process prediction gives better performance compare with Regression model.

Comparison of predictability for human pharmacokinetics parameters among monkeys, rats, and chimeric mice with humanised liver.

PubMed

Miyamoto, Maki; Iwasaki, Shinji; Chisaki, Ikumi; Nakagawa, Sayaka; Amano, Nobuyuki; Hirabayashi, Hideki

2017-12-01

1. The aim of the present study was to evaluate the usefulness of chimeric mice with humanised liver (PXB mice) for the prediction of clearance (CL t ) and volume of distribution at steady state (Vd ss ), in comparison with monkeys, which have been reported as a reliable model for human pharmacokinetics (PK) prediction, and with rats, as a conventional PK model. 2. CL t and Vd ss values in PXB mice, monkeys and rats were determined following intravenous administration of 30 compounds known to be mainly eliminated in humans via the hepatic metabolism by various drug-metabolising enzymes. Using single-species allometric scaling, human CL t and Vd ss values were predicted from the three animal models. 3. Predicted CL t values from PXB mice exhibited the highest predictability: 25 for PXB mice, 21 for monkeys and 14 for rats were predicted within a three-fold range of actual values among 30 compounds. For predicted human Vd ss values, the number of compounds falling within a three-fold range was 23 for PXB mice, 24 for monkeys, and 16 for rats among 29 compounds. PXB mice indicated a higher predictability for CL t and Vd ss values than the other animal models. 4. These results demonstrate the utility of PXB mice in predicting human PK parameters.

Predicting driving performance in older adults: we are not there yet!

PubMed

Bédard, Michel; Weaver, Bruce; Darzins, Peteris; Porter, Michelle M

2008-08-01

We set up this study to determine the predictive value of approaches for which a statistical association with driving performance has been documented. We determined the statistical association (magnitude of association and probability of occurrence by chance alone) between four different predictors (the Mini-Mental State Examination, Trails A test, Useful Field of View [UFOV], and a composite measure of past driving incidents) and driving performance. We then explored the predictive value of these measures with receiver operating characteristic (ROC) curves and various cutoff values. We identified associations between the predictors and driving performance well beyond the play of chance (p < .01). Nonetheless, the predictors had limited predictive value with areas under the curve ranging from .51 to .82. Statistical associations are not sufficient to infer adequate predictive value, especially when crucial decisions such as whether one can continue driving are at stake. The predictors we examined have limited predictive value if used as stand-alone screening tests.

Does the Value of Dynamic Assessment in Predicting End-of-First-Grade Mathematics Performance Differ as a Function of English Language Proficiency?

PubMed Central

Seethaler, Pamela M.; Fuchs, Lynn S.; Fuchs, Douglas; Compton, Donald L.

2015-01-01

The purpose of this study was to assess the added value of dynamic assessment (DA) beyond more conventional static measures for predicting individual differences in year-end 1st-grade calculation (CA) and word-problem (WP) performance, as a function of limited English proficiency (LEP) status. At the start of 1st grade, students (129 LEP; 163 non-LEP) were assessed on a brief static mathematics test, an extended static mathematics test, static tests of domain-general abilities associated with CAs and WPs (vocabulary; reasoning), and DA. Near end of 1st grade, they were assessed on CA and WP. Regression analyses indicated that the value of the predictor depends on the predicted outcome and LEP status. In predicting CAs, the extended mathematics test and DA uniquely explained variance for LEP children, with stronger predictive value for the extended mathematics test; for non-LEP children, the extended mathematics test was the only significant predictor. However, in predicting WPs, only DA and vocabulary were uniquely predictive for LEP children, with stronger value for DA; for non-LEP children, the extended mathematics test and DA were comparably uniquely predictive. Neither the brief static mathematics test nor reasoning was significant in predicting either outcome. The potential value of a gated screening process, using an extended mathematics assessment to predict CAs and using DA to predict WPs, is discussed. PMID:26523068

Cardiovascular risk scores for coronary atherosclerosis.

PubMed

Yalcin, Murat; Kardesoglu, Ejder; Aparci, Mustafa; Isilak, Zafer; Uz, Omer; Yiginer, Omer; Ozmen, Namik; Cingozbay, Bekir Yilmaz; Uzun, Mehmet; Cebeci, Bekir Sitki

2012-10-01

The objective of this study was to compare frequently used cardiovascular risk scores in predicting the presence of coronary artery disease (CAD) and 3-vessel disease. In 350 consecutive patients (218 men and 132 women) who underwent coronary angiography, the cardiovascular risk level was determined using the Framingham Risk Score (FRS), the Modified Framingham Risk Score (MFRS), the Prospective Cardiovascular Münster (PROCAM) score, and the Systematic Coronary Risk Evaluation (SCORE). The area under the curve for receiver operating characteristic curves showed that FRS had more predictive value than the other scores for CAD (area under curve, 0.76, P < or = 0.001), but all scores had good specificity and positive predictive value. For 3-vessel disease, the FRS had better predictive value than the other scores (area under curve, 0.74, P < or = 0.001), but all scores had good specificity and negative predictive value. The risk scores (FRS, MFRS, PROCAM, and SCORE) may predict the presence and severity of coronary atherosclerosis.The FRS had better predictive value than the other scores.

Can blood and semen presepsin levels in males predict pregnancy in couples undergoing intra-cytoplasmic sperm injection?

PubMed Central

Ovayolu, Ali; Arslanbuğa, Cansev Yilmaz; Gun, Ismet; Devranoglu, Belgin; Ozdemir, Arman; Cakar, Sule Eren

2016-01-01

Objective: To determine whether semen and plasma presepsin values measured in men with normozoospermia and oligoasthenospermia undergoing invitro-fertilization would be helpful in predicting ongoing pregnancy and live birth. Methods: Group-I was defined as patients who had pregnancy after treatment and Group-II comprised those with no pregnancy. Semen and blood presepsin values were subsequently compared between the groups. Parametric comparisons were performed using Student’s t-test, and non-parametric comparisons were conducted using the Mann-Whitney U test. Results: There were 42 patients in Group-I and 72 in Group-II. In the context of successful pregnancy and live birth, semen presepsin values were statistically significantly higher in Group-I than in Group-II (p= 0.004 and p= 0.037, respectively). The most appropriate semen presepsin cut-off value for predicting both ongoing pregnancy and live birth was calculated as 199 pg/mL. Accordingly, their sensitivity was 64.5% to 59.3%, their specificity was 57.0% to 54.2%, and their positive predictive value was 37.0% to 29.6%, respectively; their negative predictive value was 80.4% in both instances. Conclusion: Semen presepsin values could be a new marker that may enable the prediction of successful pregnancy and/or live birth. Its negative predictive values are especially high. PMID:27882005

Predicting Jakarta composite index using hybrid of fuzzy time series and support vector regression models

NASA Astrophysics Data System (ADS)

Febrian Umbara, Rian; Tarwidi, Dede; Budi Setiawan, Erwin

2018-03-01

The paper discusses the prediction of Jakarta Composite Index (JCI) in Indonesia Stock Exchange. The study is based on JCI historical data for 1286 days to predict the value of JCI one day ahead. This paper proposes predictions done in two stages., The first stage using Fuzzy Time Series (FTS) to predict values of ten technical indicators, and the second stage using Support Vector Regression (SVR) to predict the value of JCI one day ahead, resulting in a hybrid prediction model FTS-SVR. The performance of this combined prediction model is compared with the performance of the single stage prediction model using SVR only. Ten technical indicators are used as input for each model.

First trimester prediction of maternal glycemic status.

PubMed

Gabbay-Benziv, Rinat; Doyle, Lauren E; Blitzer, Miriam; Baschat, Ahmet A

2015-05-01

To predict gestational diabetes mellitus (GDM) or normoglycemic status using first trimester maternal characteristics. We used data from a prospective cohort study. First trimester maternal characteristics were compared between women with and without GDM. Association of these variables with sugar values at glucose challenge test (GCT) and subsequent GDM was tested to identify key parameters. A predictive algorithm for GDM was developed and receiver operating characteristics (ROC) statistics was used to derive the optimal risk score. We defined normoglycemic state, when GCT and all four sugar values at oral glucose tolerance test, whenever obtained, were normal. Using same statistical approach, we developed an algorithm to predict the normoglycemic state. Maternal age, race, prior GDM, first trimester BMI, and systolic blood pressure (SBP) were all significantly associated with GDM. Age, BMI, and SBP were also associated with GCT values. The logistic regression analysis constructed equation and the calculated risk score yielded sensitivity, specificity, positive predictive value, and negative predictive value of 85%, 62%, 13.8%, and 98.3% for a cut-off value of 0.042, respectively (ROC-AUC - area under the curve 0.819, CI - confidence interval 0.769-0.868). The model constructed for normoglycemia prediction demonstrated lower performance (ROC-AUC 0.707, CI 0.668-0.746). GDM prediction can be achieved during the first trimester encounter by integration of maternal characteristics and basic measurements while normoglycemic status prediction is less effective.

Predictive Value of Parkinsonian Primates in Pharmacologic Studies: A Comparison between the Macaque, Marmoset, and Squirrel Monkey.

PubMed

Veyres, Nicolas; Hamadjida, Adjia; Huot, Philippe

2018-05-01

The 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-lesioned primate is the gold-standard animal model of Parkinson disease (PD) and has been used to assess the effectiveness of experimental drugs on dyskinesia, parkinsonism, and psychosis. Three species have been used in most studies-the macaque, marmoset, and squirrel monkey-the last much less so than the first two species; however, the predictive value of each species at forecasting clinical efficacy, or lack thereof, is poorly documented. Here, we have reviewed all the published literature detailing pharmacologic studies that assessed the effects of experimental drugs on dyskinesia, parkinsonism, and psychosis in each of these species and have calculated their predictive value of success and failure at the clinical level. We found that, for dyskinesia, the macaque has a positive predictive value of 87.5% and a false-positive rate of 38.1%, whereas the marmoset has a positive predictive value of 76.9% and a false-positive rate of 15.6%. For parkinsonism, the macaque has a positive predictive value of 68.2% and a false-positive rate of 44.4%, whereas the marmoset has a positive predictive value of 86.9% and a false-positive rate of 41.7%. No drug that alleviates psychosis in the clinic has shown efficacy at doing so in the macaque, whereas the marmoset has 100% positive predictive value. The small number of studies conducted in the squirrel monkey precluded us from calculating its predictive efficacy. We hope our results will help in the design of pharmacologic experiments and will facilitate the drug discovery and development process in PD. Copyright © 2018 by The American Society for Pharmacology and Experimental Therapeutics.

Interleukin (IL)-1A and IL-6: Applications to the predictive diagnostic testing of radiation pneumonitis

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

Chen Yuhchyau; Hyrien, Ollivier; Williams, Jacqueline

2005-05-01

Purpose: To explore the application of interleukin (IL)-1{alpha} and IL-6 measurements in the predictive diagnostic testing for symptomatic radiation pneumonitis (RP). Methods and materials: In a prospective protocol investigating RP and cytokines, IL-1{alpha} and IL-6 values were analyzed by enzyme-linked immunosorbent assay from serial weekly blood samples of patients receiving chest radiation. We analyzed sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) over selected threshold values for both cytokines in the application to diagnostic testing. Results: The average coefficient of variation was 51% of the weekly mean IL-1{alpha} level and 39% of the weekly mean IL-6 value.more » Interleukin 1{alpha} and IL-6 became positively correlated with time. Specificity for both cytokines was better than sensitivity. IL-6 globally outperformed IL-1{alpha} in predicting RP, with higher PPV and NPV. Conclusions: Our data demonstrate the feasibility of applying IL-1{alpha} and IL-6 measurements of blood specimens to predict RP. Interleukin-6 measurements offer stronger positive predictive value than IL-1{alpha}. This application might be further explored in a larger sample of patients.« less

Quantitative computed tomography for the prediction of pulmonary function after lung cancer surgery: a simple method using simulation software.

PubMed

Ueda, Kazuhiro; Tanaka, Toshiki; Li, Tao-Sheng; Tanaka, Nobuyuki; Hamano, Kimikazu

2009-03-01

The prediction of pulmonary functional reserve is mandatory in therapeutic decision-making for patients with resectable lung cancer, especially those with underlying lung disease. Volumetric analysis in combination with densitometric analysis of the affected lung lobe or segment with quantitative computed tomography (CT) helps to identify residual pulmonary function, although the utility of this modality needs investigation. The subjects of this prospective study were 30 patients with resectable lung cancer. A three-dimensional CT lung model was created with voxels representing normal lung attenuation (-600 to -910 Hounsfield units). Residual pulmonary function was predicted by drawing a boundary line between the lung to be preserved and that to be resected, directly on the lung model. The predicted values were correlated with the postoperative measured values. The predicted and measured values corresponded well (r=0.89, p<0.001). Although the predicted values corresponded with values predicted by simple calculation using a segment-counting method (r=0.98), there were two outliers whose pulmonary functional reserves were predicted more accurately by CT than by segment counting. The measured pulmonary functional reserves were significantly higher than the predicted values in patients with extensive emphysematous areas (<-910 Hounsfield units), but not in patients with chronic obstructive pulmonary disease. Quantitative CT yielded accurate prediction of functional reserve after lung cancer surgery and helped to identify patients whose functional reserves are likely to be underestimated. Hence, this modality should be utilized for patients with marginal pulmonary function.

Correcting the anion gap for hypoalbuminaemia does not improve detection of hyperlactataemia

PubMed Central

Dinh, C H; Ng, R; Grandinetti, A; Joffe, A; Chow, D C

2006-01-01

Background An elevated lactate level reflects impaired tissue oxygenation and is a predictor of mortality. Studies have shown that the anion gap is inadequate as a screen for hyperlactataemia, particularly in critically ill and trauma patients. A proposed explanation for the anion gap's poor sensitivity and specificity in detecting hyperlactataemia is that the serum albumin is frequently low. This study therefore, sought to compare the predictive values of the anion gap and the anion gap corrected for albumin (cAG) as an indicator of hyperlactataemia as defined by a lactate ⩾2.5 mmol/l. Methods A retrospective review of 639 sets of laboratory values from a tertiary care hospital. Patients' laboratory results were included in the study if serum chemistries and lactate were drawn consecutively. The sensitivity, specificity, and predictive values were obtained. A receiver operator characteristics curve (ROC) was drawn and the area under the curve (AUC) was calculated. Results An anion gap ⩾12 provided a sensitivity, specificity, positive predictive value, and negative predictive value of 39%, 89%, 79%, and 58%, respectively, and a cAG ⩾12 provided a sensitivity, specificity, positive predictive value, and negative predictive value of 75%, 59%, 66%, and 69%, respectively. The ROC curves between anion gap and cAG as a predictor of hyperlactataemia were almost identical. The AUC was 0.757 and 0.750, respectively. Conclusions The sensitivities, specificities, and predictive values of the anion gap and cAG were inadequate in predicting the presence of hyperlactataemia. The cAG provides no additional advantage over the anion gap in the detection of hyperlactataemia. PMID:16858097

Biases associated with genotype and sex in prediction of fat-free lean mass and carcass value in hogs.

PubMed

Hicks, C; Schinckel, A P; Forrest, J C; Akridge, J T; Wagner, J R; Chen, W

1998-09-01

Carcass and live measurements of 165 market hogs that represented seven genotypes were used to investigate genotype and sex biases associated with the prediction of fat-free lean mass (FFLM) and carcass value. Carcass value was determined as the sum of the product of weight of individual cuts and their average unit prices adjusted for slaughter and processing costs. Independent variables used in the prediction equations included carcass measurements, such as optical probe, midline ruler, ribbed carcass measurements, and electromagnetic scanning (EMSCAN), and live animal ultrasonic scanning. The effect of including subpopulation mean values of independent variables in the prediction equations for FFLM and carcass value was also investigated. Genotype and sex biases were found in equations in which midline backfat, ribbed carcass, EMSCAN, and live ultrasonic scanning were used as single technology sets of measurements. The prediction equations generally undervalued genotypes with above-average carcass value. Biases were reduced when measurements of combined technologies and mean adjusted variables were used. The FFLM and carcass value of gilts were underestimated, and they were overestimated of barrows. Equations that combined OP and EMSCAN technologies were the most accurate and least biased for both FFLM and carcass value. Equations that included carcass weight and midline last-rib backfat thickness measurements were the least accurate and most biased. Genotype and sex biases must be considered when predicting FFLM and carcass value.

[Serum PTH levels as a predictive factor of hypocalcaemia after total thyroidectomy].

PubMed

Díez Alonso, Manuel; Sánchez López, José Daniel; Sánchez-Seco Peña, María Isabel; Ratia Jiménez, Tomás; Arribas Gómez, Ignacio; Rodríguez Pascual, Angel; Martín-Duce, Antonio; Guadalix Hidalgo, Gregorio; Hernández Domínguez, Sara; Granell Vicent, Javier

2009-02-01

Postoperative parathyroid hormone (PTH) levels as a predictor of hypocalcaemia in patients subjected to total thyroidectomy is analyzed. Prospective study involving 67 patients who underwent total thyroidectomy due to a benign disease. Serum PTH and ionised calcium were measured 20 h after surgery. Sensitivity, specificity and predictive values of PTH and ionised calcium levels were calculated to predict clinical and analytical hypocalcaemia. A total of 42 (62.7%) patients developed hypocalcaemia (ionised calcium<0.95 mmol/l), but only 20 (29.9%) presented with symptoms. PTH concentration the day after surgery was significantly lower in the group that developed symptomatic hypocalcaemia (5.57+/-6.4 pg/ml) than in the asymptomatic (21.5+/-15.3 pg/ml) or normocalcaemic (26.8+/-24.9 pg/ml) groups (p=0.001). Taking the value of 13 pg/ml as a cut-off point of PTH levels, sensitivity, specificity, positive predictive value and negative predictive value were 54%, 72%, 76% and 48%, respectively. On the other hand, sensitivity for predicting symptomatic hypocalcaemia was 95% and specificity was 76%. The test showed a high incidence of false positives (11/30, 36%). Negative predictive value was 97% and positive predictive value was 65%. In multivariate analysis, PTH and ionised calcium were the only perioperative factors that showed an independent predictive value as risk indicators of symptomatic hypocalcaemia. Normal PTH levels 20 h after surgery practically rule out the subsequent appearance of hypocalcaemia symptoms. On the other hand, low PTH levels are not necessarily associated to symptomatic hypocalcaemia due to the high number of false positives.

[Predictive value of breast imaging report and database system (BIRADS) to detect cancer in a reference regional hospital].

PubMed

Bellolio, Enrique; Pineda, Viviana; Burgos, María Eugenia; Iriarte, M José; Becker, Renato; Araya, Juan Carlos; Villaseca, Miguel; Mardones, Noldy

2015-12-01

To validate the BIRADS in mammography, the calculation of its predictive value in each center is required, as recommended by the American College of Radiology. To determine the predictive value of the BIRADS system in our center. All ultrasound guided needle percutaneous biopsies, performed at our center between 2006 and 2010 were reviewed. Predictive value, sensitivity, specificity and diagnostic accuracy of BIRADS were calculated, with a confidence interval of 95%. Of 1,313 biopsies available, 1,058 met the inclusion criteria. Fifty eight percent of biopsies were performed to women with mammographies classified as BIRADS 4 or 5. The presence of cancer in mammographies classified as BIRADS 0 was 4%. The prevalence of cancer for mammographies BIRADS 1, 2, 3, 4 and 5 were 0, 3, 2.7, 17.7 and 72.4% respectively. The positive and negative predictive values of BIRADS classification were 55 and 92 % respectively. In our institution BIRADS classification 4 and 5 has a high positive predictive value for detecting cancer as in developed countries.

Application of an airfoil stall flutter computer prediction program to a three-dimensional wing: Prediction versus experiment. M.S. Thesis

NASA Technical Reports Server (NTRS)

Muffoletto, A. J.

1982-01-01

An aerodynamic computer code, capable of predicting unsteady and C sub m values for an airfoil undergoing dynamic stall, is used to predict the amplitudes and frequencies of a wing undergoing torsional stall flutter. The code, developed at United Technologies Research Corporation (UTRC), is an empirical prediction method designed to yield unsteady values of normal force and moment, given the airfoil's static coefficient characteristics and the unsteady aerodynamic values, alpha, A and B. In this experiment, conducted in the PSU 4' x 5' subsonic wind tunnel, the wing's elastic axis, torsional spring constant and initial angle of attack are varied, and the oscillation amplitudes and frequencies of the wing, while undergoing torsional stall flutter, are recorded. These experimental values show only fair comparisons with the predicted responses. Predictions tend to be good at low velocities and rather poor at higher velocities.

Memorable Messages as Guides to Self-Assessment of Behavior: The Role of Instrumental Values.

ERIC Educational Resources Information Center

Smith, Sandi W.; Ellis, Jennifer Butler; Yoo, Hyo-Jin

2001-01-01

Uses control theory to predict how important instrumental values and internalized memorable messages work together when undergraduate students self-assess their previous behavior. Finds none of the four higher-order value factors predicted the hypothesized relationships among values, messages, and behaviors; but the value of…

FEV1/FVC and FEV1 for the assessment of chronic airflow obstruction in prevalence studies: do prediction equations need revision?

PubMed

Roche, Nicolas; Dalmay, François; Perez, Thierry; Kuntz, Claude; Vergnenègre, Alain; Neukirch, Françoise; Giordanella, Jean-Pierre; Huchon, Gérard

2008-11-01

Little is known on the long-term validity of reference equations used in the calculation of FEV(1) and FEV(1)/FVC predicted values. This survey assessed the prevalence of chronic airflow obstruction in a population-based sample and how it is influenced by: (i) the definition of airflow obstruction; and (ii) equations used to calculate predicted values. Subjects aged 45 or more were recruited in health prevention centers, performed spirometry and fulfilled a standardized ECRHS-derived questionnaire. Previously diagnosed cases and risk factors were identified. Prevalence of airflow obstruction was calculated using: (i) ATS-GOLD definition (FEV(1)/FVC<0.70); and (ii) ERS definition (FEV(1)/FVC

Overview of Heat Addition and Efficiency Predictions for an Advanced Stirling Convertor

NASA Technical Reports Server (NTRS)

Wilson, Scott D.; Reid, Terry; Schifer, Nicholas; Briggs, Maxwell

2011-01-01

Past methods of predicting net heat input needed to be validated. Validation effort pursued with several paths including improving model inputs, using test hardware to provide validation data, and validating high fidelity models. Validation test hardware provided direct measurement of net heat input for comparison to predicted values. Predicted value of net heat input was 1.7 percent less than measured value and initial calculations of measurement uncertainty were 2.1 percent (under review). Lessons learned during validation effort were incorporated into convertor modeling approach which improved predictions of convertor efficiency.

Limited diagnostic accuracy of magnetic resonance imaging and clinical tests for detecting partial-thickness tears of the rotator cuff.

PubMed

Brockmeyer, Matthias; Schmitt, Cornelia; Haupert, Alexander; Kohn, Dieter; Lorbach, Olaf

2017-12-01

The reliable diagnosis of partial-thickness tears of the rotator cuff is still elusive in clinical practise. Therefore, the purpose of the study was to determine the diagnostic accuracy of MR imaging and clinical tests for detecting partial-thickness tears of the rotator cuff as well as the combination of these parameters. 334 consecutive shoulder arthroscopies for rotator cuff pathologies performed during the time period between 2010 and 2012 were analyzed retrospectively for the findings of common clinical signs for rotator cuff lesions and preoperative MR imaging. These were compared with the intraoperative arthroscopic findings as "gold standard". The reports of the MR imaging were evaluated with regard to the integrity of the rotator cuff. The Ellman Classification was used to define partial-thickness tears of the rotator cuff in accordance with the arthroscopic findings. Descriptive statistics, sensitivity, specificity, positive and negative predictive value were calculated. MR imaging showed 80 partial-thickness and 70 full-thickness tears of the rotator cuff. The arthroscopic examination confirmed 64 partial-thickness tears of which 52 needed debridement or refixation of the rotator cuff. Sensitivity for MR imaging to identify partial-thickness tears was 51.6%, specificity 77.2%, positive predictive value 41.3% and negative predictive value 83.7%. For the Jobe-test, sensitivity was 64.1%, specificity 43.2%, positive predictive value 25.9% and negative predictive value 79.5%. Sensitivity for the Impingement-sign was 76.7%, specificity 46.6%, positive predictive value 30.8% and negative predictive value 86.5%. For the combination of MR imaging, Jobe-test and Impingement-sign sensitivity was 46.9%, specificity 85.4%, positive predictive value 50% and negative predictive value 83.8%. The diagnostic accuracy of MR imaging and clinical tests (Jobe-test and Impingement-sign) alone is limited for detecting partial-thickness tears of the rotator cuff. Additionally, the combination of MR imaging and clinical tests does not improve diagnostic accuracy. Level II, Diagnostic study.

Novel and conventional serum biomarkers predicting acute kidney injury in adult cardiac surgery--a prospective cohort study.

PubMed

Haase-Fielitz, Anja; Bellomo, Rinaldo; Devarajan, Prasad; Story, David; Matalanis, George; Dragun, Duska; Haase, Michael

2009-02-01

To compare the value of novel with conventional serum biomarkers in the prediction of acute kidney injury (AKI) in adult cardiac surgical patients according to preoperative renal function. Single-center, prospective observational study. Tertiary hospital. One hundred adult cardiac surgical patients. We measured concentrations of plasma neutrophil gelatinase-associated lipocalin (NGAL), and serum cystatin C, and creatinine and urea at baseline, on arrival in the intensive care unit (ICU) and at 24 hours postoperatively. We assessed such biomarkers in relation to the development of AKI (>50% increase in creatinine from baseline) and to a composite end point (need for renal replacement therapy and in-hospital mortality). We defined an area under the receiver operating characteristic curve of 0.60-0.69 as poor, 0.70-0.79 as fair, 0.80-0.89 as good, and 0.90-1.00 as excellent in terms of predictive value. On arrival in ICU, plasma NGAL and serum cystatin C were of good predictive value, but creatinine and urea were of poor predictive value. After exclusion of patients with preoperative renal impairment (estimated glomerular filtration rate <60 mL/min), the predictive performance for AKI of all renal biomarkers on arrival in ICU remained unchanged except for cystatin C, which was of fair value in such patients. At 24 hours postoperatively, all renal biomarkers were of good predictive value. On arrival in ICU, novel biomarkers were superior to conventional biomarkers (p < 0.05). Plasma NGAL (p = 0.015) and serum cystatin C (p = 0.007) were independent predictors of AKI and of excellent value in the prediction of the composite end point. Early postoperative measurement of plasma NGAL was of good value in identifying patients who developed AKI after adult cardiac surgery. Plasma NGAL and serum cystatin C were superior to conventional biomarkers in the prediction of AKI and were also of prognostic value in this setting.

Application of Neural Network Optimized by Mind Evolutionary Computation in Building Energy Prediction

NASA Astrophysics Data System (ADS)

Song, Chen; Zhong-Cheng, Wu; Hong, Lv

2018-03-01

Building Energy forecasting plays an important role in energy management and plan. Using mind evolutionary algorithm to find the optimal network weights and threshold, to optimize the BP neural network, can overcome the problem of the BP neural network into a local minimum point. The optimized network is used for time series prediction, and the same month forecast, to get two predictive values. Then two kinds of predictive values are put into neural network, to get the final forecast value. The effectiveness of the method was verified by experiment with the energy value of three buildings in Hefei.

Dopamine prediction error responses integrate subjective value from different reward dimensions

PubMed Central

Lak, Armin; Stauffer, William R.; Schultz, Wolfram

2014-01-01

Prediction error signals enable us to learn through experience. These experiences include economic choices between different rewards that vary along multiple dimensions. Therefore, an ideal way to reinforce economic choice is to encode a prediction error that reflects the subjective value integrated across these reward dimensions. Previous studies demonstrated that dopamine prediction error responses reflect the value of singular reward attributes that include magnitude, probability, and delay. Obviously, preferences between rewards that vary along one dimension are completely determined by the manipulated variable. However, it is unknown whether dopamine prediction error responses reflect the subjective value integrated from different reward dimensions. Here, we measured the preferences between rewards that varied along multiple dimensions, and as such could not be ranked according to objective metrics. Monkeys chose between rewards that differed in amount, risk, and type. Because their choices were complete and transitive, the monkeys chose “as if” they integrated different rewards and attributes into a common scale of value. The prediction error responses of single dopamine neurons reflected the integrated subjective value inferred from the choices, rather than the singular reward attributes. Specifically, amount, risk, and reward type modulated dopamine responses exactly to the extent that they influenced economic choices, even when rewards were vastly different, such as liquid and food. This prediction error response could provide a direct updating signal for economic values. PMID:24453218

Very-short-term wind power prediction by a hybrid model with single- and multi-step approaches

NASA Astrophysics Data System (ADS)

Mohammed, E.; Wang, S.; Yu, J.

2017-05-01

Very-short-term wind power prediction (VSTWPP) has played an essential role for the operation of electric power systems. This paper aims at improving and applying a hybrid method of VSTWPP based on historical data. The hybrid method is combined by multiple linear regressions and least square (MLR&LS), which is intended for reducing prediction errors. The predicted values are obtained through two sub-processes:1) transform the time-series data of actual wind power into the power ratio, and then predict the power ratio;2) use the predicted power ratio to predict the wind power. Besides, the proposed method can include two prediction approaches: single-step prediction (SSP) and multi-step prediction (MSP). WPP is tested comparatively by auto-regressive moving average (ARMA) model from the predicted values and errors. The validity of the proposed hybrid method is confirmed in terms of error analysis by using probability density function (PDF), mean absolute percent error (MAPE) and means square error (MSE). Meanwhile, comparison of the correlation coefficients between the actual values and the predicted values for different prediction times and window has confirmed that MSP approach by using the hybrid model is the most accurate while comparing to SSP approach and ARMA. The MLR&LS is accurate and promising for solving problems in WPP.

Building and verifying a severity prediction model of acute pancreatitis (AP) based on BISAP, MEWS and routine test indexes.

PubMed

Ye, Jiang-Feng; Zhao, Yu-Xin; Ju, Jian; Wang, Wei

2017-10-01

To discuss the value of the Bedside Index for Severity in Acute Pancreatitis (BISAP), Modified Early Warning Score (MEWS), serum Ca2+, similarly hereinafter, and red cell distribution width (RDW) for predicting the severity grade of acute pancreatitis and to develop and verify a more accurate scoring system to predict the severity of AP. In 302 patients with AP, we calculated BISAP and MEWS scores and conducted regression analyses on the relationships of BISAP scoring, RDW, MEWS, and serum Ca2+ with the severity of AP using single-factor logistics. The variables with statistical significance in the single-factor logistic regression were used in a multi-factor logistic regression model; forward stepwise regression was used to screen variables and build a multi-factor prediction model. A receiver operating characteristic curve (ROC curve) was constructed, and the significance of multi- and single-factor prediction models in predicting the severity of AP using the area under the ROC curve (AUC) was evaluated. The internal validity of the model was verified through bootstrapping. Among 302 patients with AP, 209 had mild acute pancreatitis (MAP) and 93 had severe acute pancreatitis (SAP). According to single-factor logistic regression analysis, we found that BISAP, MEWS and serum Ca2+ are prediction indexes of the severity of AP (P-value<0.001), whereas RDW is not a prediction index of AP severity (P-value>0.05). The multi-factor logistic regression analysis showed that BISAP and serum Ca2+ are independent prediction indexes of AP severity (P-value<0.001), and MEWS is not an independent prediction index of AP severity (P-value>0.05); BISAP is negatively related to serum Ca2+ (r=-0.330, P-value<0.001). The constructed model is as follows: ln()=7.306+1.151*BISAP-4.516*serum Ca2+. The predictive ability of each model for SAP follows the order of the combined BISAP and serum Ca2+ prediction model>Ca2+>BISAP. There is no statistical significance for the predictive ability of BISAP and serum Ca2+ (P-value>0.05); however, there is remarkable statistical significance for the predictive ability using the newly built prediction model as well as BISAP and serum Ca2+ individually (P-value<0.01). Verification of the internal validity of the models by bootstrapping is favorable. BISAP and serum Ca2+ have high predictive value for the severity of AP. However, the model built by combining BISAP and serum Ca2+ is remarkably superior to those of BISAP and serum Ca2+ individually. Furthermore, this model is simple, practical and appropriate for clinical use. Copyright © 2016. Published by Elsevier Masson SAS.

Polar body based aneuploidy screening is poorly predictive of embryo ploidy and reproductive potential.

PubMed

Salvaggio, C N; Forman, E J; Garnsey, H M; Treff, N R; Scott, R T

2014-09-01

Polar body (polar body) biopsy represents one possible solution to performing comprehensive chromosome screening (CCS). This study adds to what is known about the predictive value of polar body based testing for the genetic status of the resulting embryo, but more importantly, provides the first evaluation of the predictive value for actual clinical outcomes after embryo transfer. SNP array was performed on first polar body, second polar body, and either a blastomere or trophectoderm biopsy, or the entire arrested embryo. Concordance of the polar body-based prediction with the observed diagnoses in the embryos was assessed. In addition, the predictive value of the polar body -based diagnosis for the specific clinical outcome of transferred embryos was evaluated through the use of DNA fingerprinting to track individual embryos. There were 459 embryos analyzed from 96 patients with a mean maternal age of 35.3. The polar body-based predictive value for the embryo based diagnosis was 70.3%. The blastocyst implantation predictive value of a euploid trophectoderm was higher than from euploid polar bodies (51% versus 40%). The cleavage stage embryo implantation predictive value of a euploid blastomere was also higher than from euploid polar bodies (31% versus 22%). Polar body based aneuploidy screening results were less predictive of actual clinical outcomes than direct embryo assessment and may not be adequate to improve sustained implantation rates. In nearly one-third of cases the polar body based analysis failed to predict the ploidy of the embryo. This imprecision may hinder efforts for polar body based CCS to improve IVF clinical outcomes.

Does Spontaneous Favorability to Power (vs. Universalism) Values Predict Spontaneous Prejudice and Discrimination?

PubMed

Souchon, Nicolas; Maio, Gregory R; Hanel, Paul H P; Bardin, Brigitte

2017-10-01

We conducted five studies testing whether an implicit measure of favorability toward power over universalism values predicts spontaneous prejudice and discrimination. Studies 1 (N = 192) and 2 (N = 86) examined correlations between spontaneous favorability toward power (vs. universalism) values, achievement (vs. benevolence) values, and a spontaneous measure of prejudice toward ethnic minorities. Study 3 (N = 159) tested whether conditioning participants to associate power values with positive adjectives and universalism values with negative adjectives (or inversely) affects spontaneous prejudice. Study 4 (N = 95) tested whether decision bias toward female handball players could be predicted by spontaneous attitude toward power (vs. universalism) values. Study 5 (N = 123) examined correlations between spontaneous attitude toward power (vs. universalism) values, spontaneous importance toward power (vs. universalism) values, and spontaneous prejudice toward Black African people. Spontaneous positivity toward power (vs. universalism) values was associated with spontaneous negativity toward minorities and predicted gender bias in a decision task, whereas the explicit measures did not. These results indicate that the implicit assessment of evaluative responses attached to human values helps to model value-attitude-behavior relations. © 2016 The Authors. Journal of Personality Published by Wiley Periodicals, Inc.

Sensitivity, specificity, and predictive values of pediatric metabolic syndrome components in relation to adult metabolic syndrome: the Princeton LRC follow-up study.

PubMed

Huang, Terry T-K; Nansel, Tonja R; Belsheim, Allen R; Morrison, John A

2008-02-01

To estimate the sensitivity, specificity, and predictive values of pediatric metabolic syndrome (MetS) components (obesity, fasting glucose, triglycerides, high-density lipoprotein, and blood pressure) at various cutoff points in relation to adult MetS. Data from the National Heart, Lung, and Blood Institute Lipid Research Clinics Princeton Prevalence Study (1973-1976) and the Princeton Follow-up Study (2000-2004) were used to calculate sensitivity, specificity, and positive and negative predictive values for each component at a given cutoff point and for aggregates of components. Individual pediatric components alone showed low to moderate sensitivity, high specificity, and moderate predictive values in relation to adult MetS. When all 5 pediatric MetS components were considered, the presence of at least 1 abnormality had higher sensitivity for adult MetS than individual components alone. When multiple abnormalities were mandatory for MetS, positive predictive value was high and sensitivity was low. Childhood body mass alone showed neither high sensitivity nor high positive predictive value for adult MetS. Considering multiple metabolic variables in childhood can improve the predictive usefulness for adult MetS, compared with each component or body mass alone. MetS variables may be useful for identifying some children who are at risk for prevention interventions.

Gender Attributions of Science and Academic Attributes: AN Examination of Undergraduate Science, Mathematics, and Technology Majors

NASA Astrophysics Data System (ADS)

Hughes, W. Jay

Questionnaire data (n = 297) examined the relationship between gender attributions of science and academic attributes for undergraduate science, mathematics, and technology majors from the perspective of gender schema theory. Female and male respondents perceived that (a) the role of scientist was sex typed as masculine, (b) their majors were more valuable for members of their gender than for those of the opposite gender, (c) their majors were more valuable for themselves than for members of their gender in general. Androgynous attributions of scientists and the value of one's major for women predicted value for oneself, major confidence, and career confidence, and masculine attributions of scientists predicted class participation for female respondents. Feminine attributions of scientists predicted graduate school intent; value for women predicted major confidence and subjective achievement, and value for men predicted value for oneself, course confidence, and career confidence for male respondents.

Integration of multi-array sensors and support vector machines for the detection and classification of organophosphate nerve agents

NASA Astrophysics Data System (ADS)

Land, Walker H., Jr.; Sadik, Omowunmi A.; Embrechts, Mark J.; Leibensperger, Dale; Wong, Lut; Wanekaya, Adam; Uematsu, Michiko

2003-08-01

Due to the increased threats of chemical and biological weapons of mass destruction (WMD) by international terrorist organizations, a significant effort is underway to develop tools that can be used to detect and effectively combat biochemical warfare. Furthermore, recent events have highlighted awareness that chemical and biological agents (CBAs) may become the preferred, cheap alternative WMD, because these agents can effectively attack large populations while leaving infrastructures intact. Despite the availability of numerous sensing devices, intelligent hybrid sensors that can detect and degrade CBAs are virtually nonexistent. This paper reports the integration of multi-array sensors with Support Vector Machines (SVMs) for the detection of organophosphates nerve agents using parathion and dichlorvos as model stimulants compounds. SVMs were used for the design and evaluation of new and more accurate data extraction, preprocessing and classification. Experimental results for the paradigms developed using Structural Risk Minimization, show a significant increase in classification accuracy when compared to the existing AromaScan baseline system. Specifically, the results of this research has demonstrated that, for the Parathion versus Dichlorvos pair, when compared to the AromaScan baseline system: (1) a 23% improvement in the overall ROC Az index using the S2000 kernel, with similar improvements with the Gaussian and polynomial (of degree 2) kernels, (2) a significant 173% improvement in specificity with the S2000 kernel. This means that the number of false negative errors were reduced by 173%, while making no false positive errors, when compared to the AromaScan base line performance. (3) The Gaussian and polynomial kernels demonstrated similar specificity at 100% sensitivity. All SVM classifiers provided essentially perfect classification performance for the Dichlorvos versus Trichlorfon pair. For the most difficult classification task, the Parathion versus Paraoxon pair, the following results were achieved (using the three SVM kernels: (1) ROC Az indices from approximately 93% to greater than 99%, (2) partial Az values from ~79% to 93%, (3) specificities from 76% to ~84% at 100 and 98% sensitivity, and (4) PPVs from 73% to ~84% at 100% and 98% sensitivities. These are excellent results, considering only one atom differentiates these nerve agents.

Development of Interpretable Predictive Models for BPH and Prostate Cancer.

PubMed

Bermejo, Pablo; Vivo, Alicia; Tárraga, Pedro J; Rodríguez-Montes, J A

2015-01-01

Traditional methods for deciding whether to recommend a patient for a prostate biopsy are based on cut-off levels of stand-alone markers such as prostate-specific antigen (PSA) or any of its derivatives. However, in the last decade we have seen the increasing use of predictive models that combine, in a non-linear manner, several predictives that are better able to predict prostate cancer (PC), but these fail to help the clinician to distinguish between PC and benign prostate hyperplasia (BPH) patients. We construct two new models that are capable of predicting both PC and BPH. An observational study was performed on 150 patients with PSA ≥3 ng/mL and age >50 years. We built a decision tree and a logistic regression model, validated with the leave-one-out methodology, in order to predict PC or BPH, or reject both. Statistical dependence with PC and BPH was found for prostate volume (P-value < 0.001), PSA (P-value < 0.001), international prostate symptom score (IPSS; P-value < 0.001), digital rectal examination (DRE; P-value < 0.001), age (P-value < 0.002), antecedents (P-value < 0.006), and meat consumption (P-value < 0.08). The two predictive models that were constructed selected a subset of these, namely, volume, PSA, DRE, and IPSS, obtaining an area under the ROC curve (AUC) between 72% and 80% for both PC and BPH prediction. PSA and volume together help to build predictive models that accurately distinguish among PC, BPH, and patients without any of these pathologies. Our decision tree and logistic regression models outperform the AUC obtained in the compared studies. Using these models as decision support, the number of unnecessary biopsies might be significantly reduced.

South African and international reference values for lung function and its relationship with blood pressure in Africans.

PubMed

van Rooyen, Yolandi; Huisman, Hugo W; Schutte, Aletta E; Eloff, Fritz C; Du Plessis, Johan L; Kruger, Annamarie; Van Rooyen, Johannes M

2015-06-01

In South Africa respiratory diseases are highly prevalent, with cardiovascular disease being a manifestation. However, international reference values for lung function are commonly used, which may not be appropriate to correctly identify reduced lung function. An inverse relationship exists between lung function and blood pressure (BP) but is not investigated extensively in black South Africans. We included 2010 Africans from the PURE (Prospective Urban Rural Epidemiology) study (aged > 35 years) in the North West Province. Spirometry was performed and predicted values for forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) were calculated from South African, European and United States prediction equations. With the exception of the European predicted values, all other predicted mean FEV1 and FVC were above 80%. South African reference values displayed the highest percentages of the predicted values for FEV1 and FVC (87.9 and 99.7%, respectively.) BP increased from quintiles five to one for both FEV1 and FVC, (p for trend <0.001). After adjustment the differences remained (p<0.05). South African reference values yielded higher percentages of predicted FEV1 and FVC values than European and US equations suggesting that South African prediction equations may be more useful when investigating lung function in black South Africans. Elevated BP is related to reduced lung function, highlighting the importance in managing both respiratory- and cardiovascular disease. Copyright © 2015 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

Health Value and Self-Esteem as Predictors of Wellness Behavior.

ERIC Educational Resources Information Center

Abood, Doris A.; Conway, Terry L.

1992-01-01

Study examined relationships between self-esteem, health values, specific health behaviors, and general practice of wellness behaviors in Navy personnel. Lifestyle surveys indicated health values predicted specific health behaviors and general practice of wellness behaviors. After controlling for health values, self-esteem predicted general…

Sensitivity, specificity and predictive values of anterior chamber tap in cases of bacterial endophthalmitis.

PubMed

Sjoholm-Gomez de Liano, Carl; Soberon-Ventura, Vidal F; Salcedo-Villanueva, Guillermo; Santos-Palacios, Abril; Guerrero-Naranjo, Jose Luis; Fromow-Guerra, Jans; García-Aguirre, Gerardo; Morales-Canton, Virgilio; Velez-Montoya, Raul

2017-01-01

To assess the sensitivity, specificity, positive predictive value and negative predictive value of anterior chamber tap for the diagnosis of bacterial endophthalmitis on a population with high prevalence. Retrospective, single centre, case series study. We reviewed all medical records with clinical diagnosis of bacterial endophthalmitis in our hospital from January 1st, 2000 to December 31st 2014. From each record, we documented general demographic data, best corrected visual acuity and vitreous and aqueous tap microbiological results. All cases were further divided according to the endophthalmitis aetiology to perform individual calculations of sensitivity, specificity, positive predictive value, negative predictive value, accuracy and prevalence. We used the results of the vitreous tap as the gold standard for diagnosis of bacterial endophthalmitis. We excluded those records in which the aqueous and vitreous samples were not taken simultaneously or had an incomplete microbiological report. Significance were assessed with chi squared statistics, with an alpha value of 0.05 for statistical significance. A total of 190 cases fulfilled the inclusion/exclusion criteria. Positive culture rate from vitreous samples was 64.74%. Positive culture rate from aqueous sample was 32.11%. Bacteria isolated from aqueous samples matched those isolated from vitreous samples 78.68% of the time. The overall sensitivity was 38.21%, specificity: 75.51%, positive predictive value: 79.66%, negative predictive value: 32.74% ( p  = 0.08). Subgroup analysis showed that anterior chamber taps in cases of post-surgical endophthalmitis had a moderate to low sensitivity (37.73%), high specificity (93%) and high positive predictive value (95%) ( p  < 0.04). The sensitivity and specificity of anterior chamber tap are low and should not be used for critical therapeutic decisions in patients with suspected bacterial endophthalmitis. In cases of post-surgical endophthalmitis, the result of an anterior chamber tap could be used for therapeutic guidance, but only in conjunction with clinical presentation and in the absence of a better method for diagnosis.

[Study of the predictive value of detection tests for silent aspirations].

PubMed

Woisard, V; Réhault, E; Brouard, C; Fichaux-Bourin, P; Puech, M; Grand, S

2009-01-01

Screening for aspiration in patients with swallowing disorders is important in preventing complications. The tests used in this regard are insufficient due to silent aspiration relating to abnormal protective reflexes in many patients with swallowing problems. The aim of this study is to determine the predictive values of simple tests in screening for silent aspiration. The reference test used was videofluoroscopic examination on swallowing. In the presence of aspiration (FR+) the presence (ME+) or not (ME-) of a cough of throat clearing was noted. The tests being studied were a nasal test with isotonic saline and swallowing according to a set time. For screening for aspiration the presence of a "wet voice" was considered to be a sign of reduced protective reflexes. 1) During the nasal test, the results are 100% for the positive predictive value (VPp) and 83.3% for the negative predictive value (VPn); 2) These results are respectively 84.6% and 35.9% during the swallowing test. Regarding screening for silent aspiration, 1) during the nasal test, the results are 62.5% for the positive predictive value (VPp) and 36.3% for the negative predictive value (VPn); 2) These results are respectively 54.5% and 26.6% during the swallowing test. This preliminary study points out the lack of predictive value of the nasal test and the swallow test for the silent aspirations. However the results could be useful for other researchers developing other tests in this area.

Bit selection using field drilling data and mathematical investigation

NASA Astrophysics Data System (ADS)

Momeni, M. S.; Ridha, S.; Hosseini, S. J.; Meyghani, B.; Emamian, S. S.

2018-03-01

A drilling process will not be complete without the usage of a drill bit. Therefore, bit selection is considered to be an important task in drilling optimization process. To select a bit is considered as an important issue in planning and designing a well. This is simply because the cost of drilling bit in total cost is quite high. Thus, to perform this task, aback propagation ANN Model is developed. This is done by training the model using several wells and it is done by the usage of drilling bit records from offset wells. In this project, two models are developed by the usage of the ANN. One is to find predicted IADC bit code and one is to find Predicted ROP. Stage 1 was to find the IADC bit code by using all the given filed data. The output is the Targeted IADC bit code. Stage 2 was to find the Predicted ROP values using the gained IADC bit code in Stage 1. Next is Stage 3 where the Predicted ROP value is used back again in the data set to gain Predicted IADC bit code value. The output is the Predicted IADC bit code. Thus, at the end, there are two models that give the Predicted ROP values and Predicted IADC bit code values.

Use of visible and near-infrared spectroscopy to predict pork longissimus lean color stability.

PubMed

King, D A; Shackelford, S D; Wheeler, T L

2011-12-01

This study evaluated the use of visible and near-infrared (VISNIR) spectroscopy to predict lean color stability in pork loin chops. Spectra were collected immediately after and approximately 1 h after rib removal on 1,208 loins. Loins were aged for 14 d before a 2.54-cm chop was placed in simulated retail display. Spectra were collected on aged loins immediately after removal from the vacuum package and on chops 10 min after cutting. Instrumental color measurements [L*, a*, b*, hue angle, chroma, and E (overall color change)] were determined on d 0, 1, 7, 11, and 14 of display. Principal components analysis of display d 0 and 14 values of these traits identified a factor (first principal component; PC1) explaining 67% of the variance that was related to color change. Partial least squares regression was used to develop 3 models to predict PC1 values by using VISNIR spectra collected in the plant, on aged loins, and on chops. Loins with predicted PC1 values less than 0 were classified as having a stable color, whereas values greater than 0 were classified as having a labile lean color. Loins classified as stable by the in-plant model had smaller (P < 0.05) L* values than those classified as labile. Hue angle and ΔE values were less (P < 0.05) and a* and chroma values were greater (P < 0.05) after d 7 of display in loins predicted to have a stable color than in loins predicted to have a labile lean color. Similarly, chops from loins classified as stable using the aged loin model had smaller (P < 0.05) L* values than those from loins classified as labile. Furthermore, loins predicted to be stable had smaller (P < 0.05) hue angle and ΔE values and greater (P < 0.05) a* and chroma values after d 7 of display than did loins predicted to be labile. Results for the chop model were similar to those from the 2 loin models. Chops predicted to have a stable lean color had smaller (P < 0.05) L* values than did those predicted to have a labile lean color. Chops classified as stable had smaller (P < 0.05) hue angle and ΔE values and greater (P < 0.05) a* and chroma values after d 7 of display compared with chops classified as labile. All 3 models effectively segregated chops based on color stability, particularly with regard to redness. Regardless of the model being used, d 14 display values for a*, hue angle, and ΔE in loins classified as stable were similar to the d 7 values of loins classified as labile. Thus, these results suggest that VISNIR spectroscopy would be an effective technology for sorting pork loins with regard to lean color stability.

A Value Model for Depressive Symptoms and Hopelessness among University Students in Turkey

ERIC Educational Resources Information Center

Bilican, F. Isil; Yapici, Asim; Kutlu, M. Oguz

2016-01-01

This study aimed to examine which values predicted depressive symptoms and hopelessness in Turkey. While it was hypothesized that values emphasizing universalism, benevolence, conformity, security, tradition, spirituality, self-direction, and achievement would predict lower levels of depressive symptoms and hopelessness, those values emphasizing…

Limited Sampling Strategy for the Prediction of Area Under the Curve (AUC) of Statins: Reliability of a Single Time Point for AUC Prediction for Pravastatin and Simvastatin.

PubMed

Srinivas, N R

2016-02-01

Statins are widely prescribed medicines and are also available in fixed dose combinations with other drugs to treat several chronic ailments. Given the safety issues associated with statins it may be important to assess feasibility of a single time concentration strategy for prediction of exposure (area under the curve; AUC). The peak concentration (Cmax) was used to establish relationship with AUC separately for pravastatin and simvastatin using published pharmacokinetic data. The regression equations generated for statins were used to predict the AUC values from various literature references. The fold difference of the observed divided by predicted values along with correlation coefficient (r) were used to judge the feasibility of the single time point approach. Both pravastatin and simvastatin showed excellent correlation of Cmax vs. AUC values with r value ≥ 0.9638 (p<0.001). The fold difference was within 0.5-fold to 2-fold for 220 out of 227 AUC predictions and >81% of the predicted values were in a narrower range of >0.75-fold but <1.5-fold difference. Predicted vs. observed AUC values showed excellent correlation for pravastatin (r=0.9708, n=115; p<0.001) and simvastatin (r=0.9810; n=117; p<0.001) suggesting the utility of Cmax for AUC predictions. On the basis of the present work, it is feasible to develop a single concentration time point strategy that coincides with Cmax occurrence for both pravastatin and simvastatin from a therapeutic drug monitoring perspective. © Georg Thieme Verlag KG Stuttgart · New York.

Need for Affect and Attitudes Toward Drugs: The Mediating Role of Values.

PubMed

Lins de Holanda Coelho, Gabriel; H P Hanel, Paul; Vilar, Roosevelt; P Monteiro, Renan; Gouveia, Valdiney V; R Maio, Gregory

2018-05-04

Human values and affective traits were found to predict attitudes toward the use of different types of drugs (e.g., alcohol, marijuana, and other illegal drugs). In this study (N = 196, M age = 23.09), we aimed to gain a more comprehensive understanding of those predictors of attitudes toward drug use in a mediated structural equation model, providing a better overview of a possible motivational path that drives to such a risky behavior. Specifically, we predicted and found that the relations between need for affect and attitudes toward drug use were mediated by excitement values. Also, results showed that excitement values and need for affect positively predicted attitudes toward the use of drugs, whereas normative values predicted it negatively. The pattern of results remained the same when we investigated attitudes toward alcohol, marijuana, or illegal drugs separately. Overall, the findings indicate that emotions operate via excitement and normative values to influence risk behavior.

The predictive value of MRI in detecting thyroid gland invasion in patients with advanced laryngeal or hypopharyngeal carcinoma.

PubMed

Lin, Peiliang; Huang, Xiaoming; Zheng, Chushan; Cai, Qian; Guan, Zhong; Liang, Faya; Zheng, Yiqing

2017-01-01

The aim of this study was to evaluate the predictive value of magnetic resonance imaging (MRI) in detecting thyroid gland invasion (TGI) in patients with advanced laryngeal or hypopharyngeal carcinoma. In a retrospective chart review, 41 patients with advanced laryngeal or hypopharyngeal carcinoma underwent MRI scan before total laryngectomy and ipsilateral or bilateral thyroidectomy during the past 5 years. The MRI findings were compared with the postoperative pathological results. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated. Among the 41 patients, 3 had thyroid gland invasion in postoperative pathological results. MRI correctly predicted the absence of TGI in 37 of 38 patients and TGI in all 3 patients. The sensitivity, specificity, PPV, and NPV of MRI were 100.0, 97.4, 75.0, and 100 %, respectively, with the diagnostic accuracy of 97.6 %. In consideration of the high negative predictive value of MRI, it may help surgeons selectively preserve thyroid gland in total laryngectomy and reduce the incidence of hypothyroidism and hypoparathyroidism postoperatively.

Domestic estimated breeding values and genomic enhanced breeding values of bulls in comparison with their foreign genomic enhanced breeding values.

PubMed

Přibyl, J; Bauer, J; Čermák, V; Pešek, P; Přibylová, J; Šplíchal, J; Vostrá-Vydrová, H; Vostrý, L; Zavadilová, L

2015-10-01

Estimated breeding values (EBVs) and genomic enhanced breeding values (GEBVs) for milk production of young genotyped Holstein bulls were predicted using a conventional BLUP - Animal Model, a method fitting regression coefficients for loci (RRBLUP), a method utilizing the realized genomic relationship matrix (GBLUP), by a single-step procedure (ssGBLUP) and by a one-step blending procedure. Information sources for prediction were the nation-wide database of domestic Czech production records in the first lactation combined with deregressed proofs (DRP) from Interbull files (August 2013) and domestic test-day (TD) records for the first three lactations. Data from 2627 genotyped bulls were used, of which 2189 were already proven under domestic conditions. Analyses were run that used Interbull values for genotyped bulls only or that used Interbull values for all available sires. Resultant predictions were compared with GEBV of 96 young foreign bulls evaluated abroad and whose proofs were from Interbull method GMACE (August 2013) on the Czech scale. Correlations of predictions with GMACE values of foreign bulls ranged from 0.33 to 0.75. Combining domestic data with Interbull EBVs improved prediction of both EBV and GEBV. Predictions by Animal Model (traditional EBV) using only domestic first lactation records and GMACE values were correlated by only 0.33. Combining the nation-wide domestic database with all available DRP for genotyped and un-genotyped sires from Interbull resulted in an EBV correlation of 0.60, compared with 0.47 when only Interbull data were used. In all cases, GEBVs had higher correlations than traditional EBVs, and the highest correlations were for predictions from the ssGBLUP procedure using combined data (0.75), or with all available DRP from Interbull records only (one-step blending approach, 0.69). The ssGBLUP predictions using the first three domestic lactation records in the TD model were correlated with GMACE predictions by 0.69, 0.64 and 0.61 for milk yield, protein yield and fat yield, respectively.

Validating proposed migration equation and parameters' values as a tool to reproduce and predict 137Cs vertical migration activity in Spanish soils.

PubMed

Olondo, C; Legarda, F; Herranz, M; Idoeta, R

2017-04-01

This paper shows the procedure performed to validate the migration equation and the migration parameters' values presented in a previous paper (Legarda et al., 2011) regarding the migration of 137 Cs in Spanish mainland soils. In this paper, this model validation has been carried out checking experimentally obtained activity concentration values against those predicted by the model. This experimental data come from the measured vertical activity profiles of 8 new sampling points which are located in northern Spain. Before testing predicted values of the model, the uncertainty of those values has been assessed with the appropriate uncertainty analysis. Once establishing the uncertainty of the model, both activity concentration values, experimental versus model predicted ones, have been compared. Model validation has been performed analyzing its accuracy, studying it as a whole and also at different depth intervals. As a result, this model has been validated as a tool to predict 137 Cs behaviour in a Mediterranean environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Sensitivity, Specificity, and Predictive Values of Pediatric Metabolic Syndrome Components in Relation to Adult Metabolic Syndrome: The Princeton LRC Follow-up Study

PubMed Central

Huang, Terry T-K; Nansel, Tonja R.; Belsheim, Allen R.; Morrison, John A.

2008-01-01

Objective To estimate the sensitivity, specificity, and predictive values of pediatric metabolic syndrome (MetS) components (obesity, fasting glucose, triglycerides, high-density lipoprotein, and blood pressure) at various cutoffs in relation to adult MetS. Study design Data from the NHLBI Lipid Research Clinics (LRC) Princeton Prevalence Study (1973–76) and the Princeton Follow-up Study (PFS, 2000-4) were used to calculate sensitivity, specificity, and positive and negative predictive values for each component at a given cutoff, as well as for aggregates of components. Results Individual pediatric components alone showed low to moderate sensitivity, high specificity, and moderate predictive values in relation to adult MetS. When all five pediatric MetS components were considered, the presence of at least one abnormality had higher sensitivity for adult MetS than individual components alone. When multiple abnormalities were mandatory for MetS, positive predictive value was high and sensitivity was low. Childhood body mass alone showed neither high sensitivity nor high positive predictive value for adult MetS. Conclusions Considering multiple metabolic variables in childhood can improve the predictive utility for adult MetS, compared to each component or body mass alone. MetS variables may be useful for identifying some at risk children for prevention interventions. PMID:18206687

Diagnostic performance of dual-energy CT stress myocardial perfusion imaging: direct comparison with cardiovascular MRI.

PubMed

Ko, Sung Min; Song, Meong Gun; Chee, Hyun Kun; Hwang, Hweung Kon; Feuchtner, Gudrun Maria; Min, James K

2014-12-01

The purpose of this study was to assess the diagnostic performance of stress perfusion dual-energy CT (DECT) and its incremental value when used with coronary CT angiography (CTA) for identifying hemodynamically significant coronary artery disease. One hundred patients with suspected or known coronary artery disease without chronic myocardial infarction detected with coronary CTA underwent stress perfusion DECT, stress cardiovascular perfusion MRI, and invasive coronary angiography (ICA). Stress perfusion DECT and cardiovascular stress perfusion MR images were used for detecting perfusion defects. Coronary CTA and ICA were evaluated in the detection of ≥50% coronary stenosis. The diagnostic performance of coronary CTA for detecting hemo-dynamically significant stenosis was assessed before and after stress perfusion DECT on a per-vessel basis with ICA and cardiovascular stress perfusion MRI as the reference standard. The performance of stress perfusion DECT compared with cardiovascular stress perfusion MRI on a per-vessel basis in the detection of perfusion defects was sensitivity, 89%; specificity, 74%; positive predictive value, 73%; negative predictive value, 90%. Per segment, these values were sensitivity, 76%; specificity, 80%; positive predictive value, 63%; and negative predictive value, 88%. Compared with ICA and cardiovascular stress perfusion MRI per vessel territory the sensitivity, specificity, positive predictive value, and negative predictive value of coronary CTA were 95%, 61%, 61%, and 95%. The values for stress perfusion DECT were 92%, 72%, 68%, and 94%. The values for coronary CTA and stress perfusion DECT were 88%, 79%, 73%, and 91%. The ROC AUC increased from 0.78 to 0.84 (p=0.02) with the use of coronary CTA and stress perfusion DECT compared with coronary CTA alone. Stress perfusion DECT plays a complementary role in enhancing the accuracy of coronary CTA for identifying hemodynamically significant coronary stenosis.

Predictive value of general movements' quality in low-risk infants for minor neurological dysfunction and behavioural problems at preschool age.

PubMed

Bennema, Anne N; Schendelaar, Pamela; Seggers, Jorien; Haadsma, Maaike L; Heineman, Maas Jan; Hadders-Algra, Mijna

2016-03-01

General movement (GM) assessment is a well-established tool to predict cerebral palsy in high-risk infants. Little is known on the predictive value of GM assessment in low-risk populations. To assess the predictive value of GM quality in early infancy for the development of the clinically relevant form of minor neurological dysfunction (complex MND) and behavioral problems at preschool age. Prospective cohort study. A total of 216 members of the prospective Groningen Assisted Reproductive Techniques (ART) cohort study were included in this study. ART did not affect neurodevelopmental outcome of these relatively low-risk infants born to subfertile parents. GM quality was determined at 2 weeks and 3 months. At 18 months and 4 years, the Hempel neurological examination was used to assess MND. At 4 years, parents completed the Child Behavior Checklist; this resulted in the total problem score (TPS), internalizing problem score (IPS), and externalizing problem score (EPS). Predictive values of definitely (DA) and mildly (MA) abnormal GMs were calculated. DA GMs at 2 weeks were associated with complex MND at 18 months and atypical TPS and IPS at 4 years (all p<0.05). Sensitivity and positive predictive value of DA GMs at 2 weeks were rather low (13%-60%); specificity and negative predictive value were excellent (92%-99%). DA GMs at 3 months occurred too infrequently to calculate prediction. MA GMs were not associated with outcome. GM quality as a single predictor for complex MND and behavioral problems at preschool age has limited clinical value in children at low risk for developmental disorders. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

The predictive value of single-photon emission computed tomography/computed tomography for sentinel lymph node localization in head and neck cutaneous malignancy.

PubMed

Remenschneider, Aaron K; Dilger, Amanda E; Wang, Yingbing; Palmer, Edwin L; Scott, James A; Emerick, Kevin S

2015-04-01

Preoperative localization of sentinel lymph nodes in head and neck cutaneous malignancies can be aided by single-photon emission computed tomography/computed tomography (SPECT/CT); however, its true predictive value for identifying lymph nodes intraoperatively remains unquantified. This study aims to understand the sensitivity, specificity, and positive and negative predictive values of SPECT/CT in sentinel lymph node biopsy for cutaneous malignancies of the head and neck. Blinded retrospective imaging review with comparison to intraoperative gamma probe confirmed sentinel lymph nodes. A consecutive series of patients with a head and neck cutaneous malignancy underwent preoperative SPECT/CT followed by sentinel lymph node biopsy with a gamma probe. Two nuclear medicine physicians, blinded to clinical data, independently reviewed each SPECT/CT. Activity within radiographically defined nodal basins was recorded and compared to intraoperative gamma probe findings. Sensitivity, specificity, and negative and positive predictive values were calculated with subgroup stratification by primary tumor site. Ninety-two imaging reads were performed on 47 patients with cutaneous malignancy who underwent SPECT/CT followed by sentinel lymph node biopsy. Overall sensitivity was 73%, specificity 92%, positive predictive value 54%, and negative predictive value 96%. The predictive ability of SPECT/CT to identify the basin or an adjacent basin containing the single hottest node was 92%. SPECT/CT overestimated uptake by an average of one nodal basin. In the head and neck, SPECT/CT has higher reliability for primary lesions of the eyelid, scalp, and cheek. SPECT/CT has high sensitivity, specificity, and negative predictive value, but may overestimate relevant nodal basins in sentinel lymph node biopsy. © 2014 The American Laryngological, Rhinological and Otological Society, Inc.

[Comparison of two quantitative methods of endobronchial ultrasound real-time elastography for evaluating intrathoracic lymph nodes].

PubMed

Mao, X W; Yang, J Y; Zheng, X X; Wang, L; Zhu, L; Li, Y; Xiong, H K; Sun, J Y

2017-06-12

Objective: To compare the clinical value of two quantitative methods in analyzing endobronchial ultrasound real-time elastography (EBUS-RTE) images for evaluating intrathoracic lymph nodes. Methods: From January 2014 to April 2014, EBUS-RTE examination was performed in patients who received EBUS-TBNA examination in Shanghai Chest Hospital. Each intrathoracic lymph node had a selected EBUS-RTE image. Stiff area ratio and mean hue value of region of interest (ROI) in each image were calculated respectively. The final diagnosis of lymph node was based on the pathologic/microbiologic results of EBUS-TBNA, pathologic/microbiologic results of other examinations and clinical following-up. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy were evaluated for distinguishing malignant and benign lesions. Results: Fifty-six patients and 68 lymph nodes were enrolled in this study, of which 35 lymph nodes were malignant and 33 lymph nodes were benign. The stiff area ratio and mean hue value of benign and malignant lesions were 0.32±0.29, 0.62±0.20 and 109.99±28.13, 141.62±17.52, respectively, and statistical differences were found in both of those two methods ( t =-5.14, P <0.01; t =-5.53, P <0.01). The area under curves was 0.813, 0.814 in stiff area ratio and mean hue value, respectively. The optimal diagnostic cut-off value of stiff area ratio was 0.48, and the sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 82.86%, 81.82%, 82.86%, 81.82% and 82.35%, respectively. The optimal diagnostic cut-off value of mean hue value was 126.28, and the sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 85.71%, 75.76%, 78.95%, 83.33% and 80.88%, respectively. Conclusion: Both the stiff area ratio and mean hue value methods can be used for analyzing EBUS-RTE images quantitatively, having the value of differentiating benign and malignant intrathoracic lymph nodes, and the stiff area ratio is better than the mean hue value between the two methods.

In monkeys making value-based decisions, amygdala neurons are sensitive to cue value as distinct from cue salience.

PubMed

Leathers, Marvin L; Olson, Carl R

2017-04-01

Neurons in the lateral intraparietal (LIP) area of macaque monkey parietal cortex respond to cues predicting rewards and penalties of variable size in a manner that depends on the motivational salience of the predicted outcome (strong for both large reward and large penalty) rather than on its value (positive for large reward and negative for large penalty). This finding suggests that LIP mediates the capture of attention by salient events and does not encode value in the service of value-based decision making. It leaves open the question whether neurons elsewhere in the brain encode value in the identical task. To resolve this issue, we recorded neuronal activity in the amygdala in the context of the task employed in the LIP study. We found that responses to reward-predicting cues were similar between areas, with the majority of reward-sensitive neurons responding more strongly to cues that predicted large reward than to those that predicted small reward. Responses to penalty-predicting cues were, however, markedly different. In the amygdala, unlike LIP, few neurons were sensitive to penalty size, few penalty-sensitive neurons favored large over small penalty, and the dependence of firing rate on penalty size was negatively correlated with its dependence on reward size. These results indicate that amygdala neurons encoded cue value under circumstances in which LIP neurons exhibited sensitivity to motivational salience. However, the representation of negative value, as reflected in sensitivity to penalty size, was weaker than the representation of positive value, as reflected in sensitivity to reward size. NEW & NOTEWORTHY This is the first study to characterize amygdala neuronal responses to cues predicting rewards and penalties of variable size in monkeys making value-based choices. Manipulating reward and penalty size allowed distinguishing activity dependent on motivational salience from activity dependent on value. This approach revealed in a previous study that neurons of the lateral intraparietal (LIP) area encode motivational salience. Here, it reveals that amygdala neurons encode value. The results establish a sharp functional distinction between the two areas. Copyright © 2017 the American Physiological Society.

Predictions of the pathological response to neoadjuvant chemotherapy in patients with primary breast cancer using a data mining technique.

PubMed

Takada, M; Sugimoto, M; Ohno, S; Kuroi, K; Sato, N; Bando, H; Masuda, N; Iwata, H; Kondo, M; Sasano, H; Chow, L W C; Inamoto, T; Naito, Y; Tomita, M; Toi, M

2012-07-01

Nomogram, a standard technique that utilizes multiple characteristics to predict efficacy of treatment and likelihood of a specific status of an individual patient, has been used for prediction of response to neoadjuvant chemotherapy (NAC) in breast cancer patients. The aim of this study was to develop a novel computational technique to predict the pathological complete response (pCR) to NAC in primary breast cancer patients. A mathematical model using alternating decision trees, an epigone of decision tree, was developed using 28 clinicopathological variables that were retrospectively collected from patients treated with NAC (n = 150), and validated using an independent dataset from a randomized controlled trial (n = 173). The model selected 15 variables to predict the pCR with yielding area under the receiver operating characteristics curve (AUC) values of 0.766 [95 % confidence interval (CI)], 0.671-0.861, P value < 0.0001) in cross-validation using training dataset and 0.787 (95 % CI 0.716-0.858, P value < 0.0001) in the validation dataset. Among three subtypes of breast cancer, the luminal subgroup showed the best discrimination (AUC = 0.779, 95 % CI 0.641-0.917, P value = 0.0059). The developed model (AUC = 0.805, 95 % CI 0.716-0.894, P value < 0.0001) outperformed multivariate logistic regression (AUC = 0.754, 95 % CI 0.651-0.858, P value = 0.00019) of validation datasets without missing values (n = 127). Several analyses, e.g. bootstrap analysis, revealed that the developed model was insensitive to missing values and also tolerant to distribution bias among the datasets. Our model based on clinicopathological variables showed high predictive ability for pCR. This model might improve the prediction of the response to NAC in primary breast cancer patients.

Phase angle assessment by bioelectrical impedance analysis and its predictive value for malnutrition risk in hospitalized geriatric patients.

PubMed

Varan, Hacer Dogan; Bolayir, Basak; Kara, Ozgur; Arik, Gunes; Kizilarslanoglu, Muhammet Cemal; Kilic, Mustafa Kemal; Sumer, Fatih; Kuyumcu, Mehmet Emin; Yesil, Yusuf; Yavuz, Burcu Balam; Halil, Meltem; Cankurtaran, Mustafa

2016-12-01

Phase angle (PhA) value determined by bioelectrical impedance analysis (BIA) is an indicator of cell membrane damage and body cell mass. Recent studies have shown that low PhA value is associated with increased nutritional risk in various group of patients. However, there have been only a few studies performed globally assessing the relationship between nutritional risk and PhA in hospitalized geriatric patients. The aim of the study is to evaluate the predictive value of the PhA for malnutrition risk in hospitalized geriatric patients. One hundred and twenty-two hospitalized geriatric patients were included in this cross-sectional study. Comprehensive geriatric assessment tests and BIA measurements were performed within the first 48 h after admission. Nutritional risk state of the patients was determined with NRS-2002. Phase angle values of the patients with malnutrition risk were compared with the patients that did not have the same risk. The independent variables for predicting malnutrition risk were determined. SPSS version 15 was utilized for the statistical analyzes. The patients with malnutrition risk had significantly lower phase angle values than the patients without malnutrition risk (p = 0.003). ROC curve analysis suggested that the optimum PhA cut-off point for malnutrition risk was 4.7° with 79.6 % sensitivity, 64.6 % specificity, 73.9 % positive predictive value, and 73.9 % negative predictive value. BMI, prealbumin, PhA, and Mini Mental State Examination Test scores were the independent variables for predicting malnutrition risk. PhA can be a useful, independent indicator for predicting malnutrition risk in hospitalized geriatric patients.

Validation of Water Erosion Prediction Project (WEPP) model for low-volume forest roads

Treesearch

William Elliot; R. B. Foltz; Charlie Luce

1995-01-01

Erosion rates of recently graded nongravel forest roads were measured under rainfall simulation on five different soils. The erosion rates observed on 24 forest road erosion plots were compared with values predicted by the Water Erosion Prediction Project (WEPP) Model, Version 93.1. Hydraulic conductivity and soil erodibility values were predicted from methods...

Sensitivity and positive predictive values of presurgical clinical diagnosis of excised benign and malignant skin tumors: a prospective study of 835 lesions in 778 patients.

PubMed

Har-Shai, Y; Hai, N; Taran, A; Mayblum, S; Barak, A; Tzur, E; Schafer, I; David, R; David, E; Linn, S

2001-12-01

This article reports on the sensitivity and positive predictive value of clinical diagnosis of benign and malignant skin tumors by expert plastic surgeons in an Israeli clinic. Most published reports have focused on the sensitivity of clinicians' diagnoses, a general measure of the physician's skill that does not predict the rate of accuracy of a physician's diagnoses. Our study of 835 lesions in 778 patients, one of the largest Israeli series, assesses the clinical diagnosis of malignant and benign skin tumors and is one of the few that provide information on the positive predictive value, the measure that is of interest to both physicians and patients. The majority of tumors were benign (56.8 percent), 31.6 percent were malignant, and 11.6 percent were premalignant. Among the 474 benign lesions, 46 percent were nevi. The most common nevi subclass was compound nevi (53 percent), 9 percent of the nevi were dysplastic, and 5 percent were blue nevi. The most common malignant tumor was basal cell carcinoma, accounting for 78 percent of malignant tumors. Although sensitivity for clinical diagnosis of malignancy was 91.3 percent, the positive predictive value for clinical diagnosis of malignancy was 71.3 percent. The sensitivity rate for clinically diagnosing premalignant tumors was 42.3 percent, whereas the positive predictive value for these diagnoses was higher (64.1 percent). The sensitivity rate for diagnosis of all benign lesions was 85.9 percent, and the positive predictive value was 94.2 percent. The sensitivity rate for diagnosis of all nevi was 87.6 percent, and the positive predictive value was 85.7 percent: i.e., only seven of the 218 pathologically proven diagnoses of nevi (3.2 percent) were falsely diagnosed as malignant lesions. Even more interestingly, five of the 223 clinical diagnoses of nevi (2.2 percent) were pathologically proven to be malignant melanomas, and seven were found to be premalignant lesions (3.1 percent). It was concluded that publications which report only on the sensitivity neglect to provide information of interest regarding the positive predictive value. Often, positive predictive value is qualitatively different from the sensitivity, and thus relying only on the sensitivity may lead to incorrect evaluation of a clinical judgment, which may result in erroneous surgical decisions.

Predictive value of serum sST2 in preschool wheezers for development of asthma with high FeNO.

PubMed

Ketelaar, M E; van de Kant, K D; Dijk, F N; Klaassen, E M; Grotenboer, N S; Nawijn, M C; Dompeling, E; Koppelman, G H

2017-11-01

Wheezing is common in childhood. However, current prediction models of pediatric asthma have only modest accuracy. Novel biomarkers and definition of subphenotypes may improve asthma prediction. Interleukin-1-receptor-like-1 (IL1RL1 or ST2) is a well-replicated asthma gene and associates with eosinophilia. We investigated whether serum sST2 predicts asthma and asthma with elevated exhaled NO (FeNO), compared to the commonly used Asthma Prediction Index (API). Using logistic regression modeling, we found that serum sST2 levels in 2-3 years-old wheezers do not predict doctors' diagnosed asthma at age 6 years. Instead, sST2 predicts a subphenotype of asthma characterized by increased levels of FeNO, a marker for eosinophilic airway inflammation. Herein, sST2 improved the predictive value of the API (AUC=0.70, 95% CI 0.56-0.84), but had also significant predictive value on its own (AUC=0.65, 95% CI 0.52-0.79). Our study indicates that sST2 in preschool wheezers has predictive value for the development of eosinophilic airway inflammation in asthmatic children at school age. © 2017 EAACI and John Wiley and Sons A/S. Published by John Wiley and Sons Ltd.

[Validation of the abbreviated Zarit scales for measuring burden syndrome in the primary caregiver of an elderly patient].

PubMed

Vélez Lopera, Johana María; Berbesí Fernández, Dedsy; Cardona Arango, Doris; Segura Cardona, Angela; Ordóñez Molina, Jaime

2012-07-01

To determine which abbreviated Zarit Scale (ZS) better evaluates the burden of the caregiver of an elderly patient in Medellin, Colombia. Validation study. Primary Care setting in the city of Medellin. Primary caregiver of dependent elderly patients over 65 years old. Sensitivity, specificity, positive predictive value, and negative predictive value for the different abbreviated Zarit scales, plus performing a reliability analysis using the Cronbach Alpha coefficient. The abbreviated scales obtained a sensitivity of between 36.84 and 81.58%, specificity between 95.99 and 100%, positive predictive values between 71.05 and 100%, and negative predictive values of between 91.64 and 97.42%. The scale that better determined caregiver burden in Primary Care was the Bedard Screening scale, with a sensitivity of 81.58%, a specificity of 96.35% and positive and negative predictive values of 75.61% and 97.42%, respectively. Copyright © 2010 Elsevier España, S.L. All rights reserved.

Interspecies scaling of a camptothecin analogue: human predictions for intravenous topotecan using animal data.

PubMed

Ahlawat, P; Srinivas, N R

2008-11-01

As a class, camptothecin analogues via market entry of topotecan and irinotecan, have shown promise for the treatment of various solid tumours. Topotecan, in particular, was chosen as the substrate for allometric scaling and prediction of human parameter values for both total clearance (CL) and volume of distribution (V(ss)). The availability of published data in mouse, rat, dog, and monkey paved the way for interspecies scaling via allometry. Although it appeared that at a minimum mouse, rat, and dog would reasonably fit in a three-species allometry scale-up, the inclusion of monkey data enabled a better prediction of the human parameter values for total topotecan-e.g., CL: allometric equation: 1.5234W(0.7865); predicted value = 43.04 l h(-1): observed CL = 24-53 l h(-1); V(ss): allometric equation: 1.1939W(1.0208); predicted value = 91.29 litres: observed V(ss) = 66-146 litres. The proximity of the allometric exponent values of CL (0.7885) and V(ss) (1.0208) to the suggested values of 0.75 and 1.00 was not only encouraging, but also confirmed the applicability of interspecies scaling approach for topotecan. The data suggest that allometric scaling approaches with suitable correction factors could potentially be used to predict the human pharmacokinetics of novel CPT analogues prospectively.

Unchained Melody: Revisiting the Estimation of SF-6D Values

PubMed Central

Craig, Benjamin M.

2015-01-01

Purpose In the original SF-6D valuation study, the analytical design inherited conventions that detrimentally affected its ability to predict values on a quality-adjusted life year (QALY) scale. Our objective is to estimate UK values for SF-6D states using the original data and multi-attribute utility (MAU) regression after addressing its limitations and to compare the revised SF-6D and EQ-5D value predictions. Methods Using the unaltered data (611 respondents, 3503 SG responses), the parameters of the original MAU model were re-estimated under 3 alternative error specifications, known as the instant, episodic, and angular random utility models. Value predictions on a QALY scale were compared to EQ-5D3L predictions using the 1996 Health Survey for England. Results Contrary to the original results, the revised SF-6D value predictions range below 0 QALYs (i.e., worse than death) and agree largely with EQ-5D predictions after adjusting for scale. Although a QALY is defined as a year in optimal health, the SF-6D sets a higher standard for optimal health than the EQ-5D-3L; therefore, it has larger units on a QALY scale by construction (20.9% more). Conclusions Much of the debate in health valuation has focused on differences between preference elicitation tasks, sampling, and instruments. After correcting errant econometric practices and adjusting for differences in QALY scale between the EQ-5D and SF-6D values, the revised predictions demonstrate convergent validity, making them more suitable for UK economic evaluations compared to original estimates. PMID:26359242

[Development and validation of an algorithm to identify cancer recurrences from hospital data bases].

PubMed

Manzanares-Laya, S; Burón, A; Murta-Nascimento, C; Servitja, S; Castells, X; Macià, F

2014-01-01

Hospital cancer registries and hospital databases are valuable and efficient sources of information for research into cancer recurrences. The aim of this study was to develop and validate algorithms for the detection of breast cancer recurrence. A retrospective observational study was conducted on breast cancer cases from the cancer registry of a third level university hospital diagnosed between 2003 and 2009. Different probable cancer recurrence algorithms were obtained by linking the hospital databases and the construction of several operational definitions, with their corresponding sensitivity, specificity, positive predictive value and negative predictive value. A total of 1,523 patients were diagnosed of breast cancer between 2003 and 2009. A request for bone gammagraphy after 6 months from the first oncological treatment showed the highest sensitivity (53.8%) and negative predictive value (93.8%), and a pathology test after 6 months after the diagnosis showed the highest specificity (93.8%) and negative predictive value (92.6%). The combination of different definitions increased the specificity and the positive predictive value, but decreased the sensitivity. Several diagnostic algorithms were obtained, and the different definitions could be useful depending on the interest and resources of the researcher. A higher positive predictive value could be interesting for a quick estimation of the number of cases, and a higher negative predictive value for a more exact estimation if more resources are available. It is a versatile and adaptable tool for other types of tumors, as well as for the needs of the researcher. Copyright © 2014 SECA. Published by Elsevier Espana. All rights reserved.

Double dissociation of value computations in orbitofrontal and anterior cingulate neurons

PubMed Central

Kennerley, Steven W.; Behrens, Timothy E. J.; Wallis, Jonathan D.

2011-01-01

Damage to prefrontal cortex (PFC) impairs decision-making, but the underlying value computations that might cause such impairments remain unclear. Here we report that value computations are doubly dissociable within PFC neurons. While many PFC neurons encoded chosen value, they used opponent encoding schemes such that averaging the neuronal population eliminated value coding. However, a special population of neurons in anterior cingulate cortex (ACC) - but not orbitofrontal cortex (OFC) - multiplex chosen value across decision parameters using a unified encoding scheme, and encoded reward prediction errors. In contrast, neurons in OFC - but not ACC - encoded chosen value relative to the recent history of choice values. Together, these results suggest complementary valuation processes across PFC areas: OFC neurons dynamically evaluate current choices relative to recent choice values, while ACC neurons encode choice predictions and prediction errors using a common valuation currency reflecting the integration of multiple decision parameters. PMID:22037498

Does Enjoying Friendship Help or Impede Academic Achievement? Academic and Social Intrinsic Value Profiles Predict Academic Achievement

ERIC Educational Resources Information Center

Seo, Eunjin; Lee, You-kyung

2018-01-01

We examine the intrinsic value students placed on schoolwork (i.e. academic intrinsic value) and social relationships (i.e. social intrinsic value). We then look at how these values predict middle and high school achievement. To do this, we came up with four profiles based on cluster analyses of 6,562 South Korean middle school students. The four…

[Predictive value of qualitative assessment of general movements for adverse outcomes at 24 months of age in infants with asphyxia].

PubMed

Chen, Nan; Wen, Xiao-Hong; Huang, Jin-Hua; Wang, Shui-Yun; Zhu, Yue-E

2015-12-01

To investigate the predictive value of the qualitative assessment of general movements (GMs) for adverse outcomes at 24 months of age in full-term infants with asphyxia. A total of 114 full-term asphyxiated infants, who were admitted to the neonatal intensive care unit between 2009 and 2012 and took part in follow-ups after discharge were included in the study. All of them received the qualitative assessment of GMs within 3 months after birth. The development quotient was determined with the Bayley Scales of Infant Development at 24 months of age. The results of the qualitative assessment of GMs within 3 months after birth showed that among 114 infants, 20 (17.5%) had poor repertoire movements and 7 (6.1%) had cramped-synchronized movements during the writhing movements period; 8 infants (7.0%) had the absence of fidgety movements during the fidgety movements period. The results of development quotient at 24 months of age showed that 7 infants (6.1%) had adverse developmental outcomes: 6 cases of cerebral palsy and mental retardation and 1 case of mental retardation. There was a poor consistency between poor repertoire movements during the writhing movements period and the developmental outcomes at 24 months of age (Kappa=-0.019; P>0.05). There was a high consistency between cramped-synchronized movements during the writhing movements period and the developmental outcomes at 24 months of age (Kappa=0.848; P<0.05), and the results of predictive values of cramped-synchronized movements were shown as follows: predictive validity 98.2%, sensitivity 85.7%, specificity 99.1%, positive predictive value 85.7%, and negative predictive value 99.1%. There was a high consistency between the absence of fidgety movements during the fidgety movements period and the developmental outcomes at 24 months of age (Kappa=0.786; P<0.05), and its predictive values were expressed as follows: predictive validity 97.4%, sensitivity 85.7%, specificity 98.1%, positive predictive value 75.0%, and negative predictive value 99.1%. Cramped-synchronized movements and absence of fidgety movements can predict adverse developmental outcomes at 24 months of age in full-term infants with asphyxia.

The importance of information on relatives for the prediction of genomic breeding values and the implications for the makeup of reference data sets in livestock breeding schemes.

PubMed

Clark, Samuel A; Hickey, John M; Daetwyler, Hans D; van der Werf, Julius H J

2012-02-09

The theory of genomic selection is based on the prediction of the effects of genetic markers in linkage disequilibrium with quantitative trait loci. However, genomic selection also relies on relationships between individuals to accurately predict genetic value. This study aimed to examine the importance of information on relatives versus that of unrelated or more distantly related individuals on the estimation of genomic breeding values. Simulated and real data were used to examine the effects of various degrees of relationship on the accuracy of genomic selection. Genomic Best Linear Unbiased Prediction (gBLUP) was compared to two pedigree based BLUP methods, one with a shallow one generation pedigree and the other with a deep ten generation pedigree. The accuracy of estimated breeding values for different groups of selection candidates that had varying degrees of relationships to a reference data set of 1750 animals was investigated. The gBLUP method predicted breeding values more accurately than BLUP. The most accurate breeding values were estimated using gBLUP for closely related animals. Similarly, the pedigree based BLUP methods were also accurate for closely related animals, however when the pedigree based BLUP methods were used to predict unrelated animals, the accuracy was close to zero. In contrast, gBLUP breeding values, for animals that had no pedigree relationship with animals in the reference data set, allowed substantial accuracy. An animal's relationship to the reference data set is an important factor for the accuracy of genomic predictions. Animals that share a close relationship to the reference data set had the highest accuracy from genomic predictions. However a baseline accuracy that is driven by the reference data set size and the overall population effective population size enables gBLUP to estimate a breeding value for unrelated animals within a population (breed), using information previously ignored by pedigree based BLUP methods.

The Socialization of Culturally Related Values and Prosocial Tendencies among Mexican American Adolescents

PubMed Central

Knight, George P.; Carlo, Gustavo; Mahrer, Nicole E.; Davis, Alexandra N.

2016-01-01

The socialization of cultural values, ethnic identity, and prosocial behaviors is examined in a sample of 749 Mexican American adolescents [age 9–12 at the 5th grade; M(SD) = 10.42(.55); 49% female], their mothers, and fathers at the 5th, 7th and 10th grades. Parents’ familism values positively predicted their ethnic socialization practices. Mothers’ ethnic socialization positively predicted adolescents’ ethnic identity, which positively predicted adolescents’ familism. Familism was associated with several types of prosocial tendencies. Adolescents’ material success and personal achievement values were negatively associated with altruistic helping and positively associated with public helping, but not their parents’ corresponding values. Findings support cultural socialization models, asserting that parents’ traditional cultural values influence their socialization practices, youth cultural values, and youth prosocial behaviors. PMID:28262940

Performance of the dipstick screening test as a predictor of negative urine culture

PubMed Central

Marques, Alexandre Gimenes; Doi, André Mario; Pasternak, Jacyr; Damascena, Márcio dos Santos; França, Carolina Nunes; Martino, Marinês Dalla Valle

2017-01-01

ABSTRACT Objective To investigate whether the urine dipstick screening test can be used to predict urine culture results. Methods A retrospective study conducted between January and December 2014 based on data from 8,587 patients with a medical order for urine dipstick test, urine sediment analysis and urine culture. Sensitivity, specificity, positive and negative predictive values were determined and ROC curve analysis was performed. Results The percentage of positive cultures was 17.5%. Nitrite had 28% sensitivity and 99% specificity, with positive and negative predictive values of 89% and 87%, respectively. Leukocyte esterase had 79% sensitivity and 84% specificity, with positive and negative predictive values of 51% and 95%, respectively. The combination of positive nitrite or positive leukocyte esterase tests had 85% sensitivity and 84% specificity, with positive and negative predictive values of 53% and 96%, respectively. Positive urinary sediment (more than ten leukocytes per microliter) had 92% sensitivity and 71% specificity, with positive and negative predictive values of 40% and 98%, respectively. The combination of nitrite positive test and positive urinary sediment had 82% sensitivity and 99% specificity, with positive and negative predictive values of 91% and 98%, respectively. The combination of nitrite or leukocyte esterase positive tests and positive urinary sediment had the highest sensitivity (94%) and specificity (84%), with positive and negative predictive values of 58% and 99%, respectively. Based on ROC curve analysis, the best indicator of positive urine culture was the combination of positives leukocyte esterase or nitrite tests and positive urinary sediment, followed by positives leukocyte and nitrite tests, positive urinary sediment alone, positive leukocyte esterase test alone, positive nitrite test alone and finally association of positives nitrite and urinary sediment (AUC: 0.845, 0.844, 0.817, 0.814, 0.635 and 0.626, respectively). Conclusion A negative urine culture can be predicted by negative dipstick test results. Therefore, this test may be a reliable predictor of negative urine culture. PMID:28444086

Clinical value of CT-based preoperative software assisted lung lobe volumetry for predicting postoperative pulmonary function after lung surgery

NASA Astrophysics Data System (ADS)

Wormanns, Dag; Beyer, Florian; Hoffknecht, Petra; Dicken, Volker; Kuhnigk, Jan-Martin; Lange, Tobias; Thomas, Michael; Heindel, Walter

2005-04-01

This study was aimed to evaluate a morphology-based approach for prediction of postoperative forced expiratory volume in one second (FEV1) after lung resection from preoperative CT scans. Fifteen Patients with surgically treated (lobectomy or pneumonectomy) bronchogenic carcinoma were enrolled in the study. A preoperative chest CT and pulmonary function tests before and after surgery were performed. CT scans were analyzed by prototype software: automated segmentation and volumetry of lung lobes was performed with minimal user interaction. Determined volumes of different lung lobes were used to predict postoperative FEV1 as percentage of the preoperative values. Predicted FEV1 values were compared to the observed postoperative values as standard of reference. Patients underwent lobectomy in twelve cases (6 upper lobes; 1 middle lobe; 5 lower lobes; 6 right side; 6 left side) and pneumonectomy in three cases. Automated calculation of predicted postoperative lung function was successful in all cases. Predicted FEV1 ranged from 54% to 95% (mean 75% +/- 11%) of the preoperative values. Two cases with obviously erroneous LFT were excluded from analysis. Mean error of predicted FEV1 was 20 +/- 160 ml, indicating absence of systematic error; mean absolute error was 7.4 +/- 3.3% respective 137 +/- 77 ml/s. The 200 ml reproducibility criterion for FEV1 was met in 11 of 13 cases (85%). In conclusion, software-assisted prediction of postoperative lung function yielded a clinically acceptable agreement with the observed postoperative values. This method might add useful information for evaluation of functional operability of patients with lung cancer.

Model-free and model-based reward prediction errors in EEG.

PubMed

Sambrook, Thomas D; Hardwick, Ben; Wills, Andy J; Goslin, Jeremy

2018-05-24

Learning theorists posit two reinforcement learning systems: model-free and model-based. Model-based learning incorporates knowledge about structure and contingencies in the world to assign candidate actions with an expected value. Model-free learning is ignorant of the world's structure; instead, actions hold a value based on prior reinforcement, with this value updated by expectancy violation in the form of a reward prediction error. Because they use such different learning mechanisms, it has been previously assumed that model-based and model-free learning are computationally dissociated in the brain. However, recent fMRI evidence suggests that the brain may compute reward prediction errors to both model-free and model-based estimates of value, signalling the possibility that these systems interact. Because of its poor temporal resolution, fMRI risks confounding reward prediction errors with other feedback-related neural activity. In the present study, EEG was used to show the presence of both model-based and model-free reward prediction errors and their place in a temporal sequence of events including state prediction errors and action value updates. This demonstration of model-based prediction errors questions a long-held assumption that model-free and model-based learning are dissociated in the brain. Copyright © 2018 Elsevier Inc. All rights reserved.

The value of negative Chlamydia trachomatis antibody in prediction of normal tubes in infertile women.

PubMed

Raoofi, Z; Barchinegad, M; Haghighi, L

2013-01-01

To evaluate the value of Chlamydia trachomatis antibody testing in prediction of at least one normal tube in infertile women. Eighty infertile women without any history of abdominal or pelvic surgery, pelvic inflammatory disease, and endometriosis were recruited in this cross-sectional study from 2009 to 2010. The patients underwent hysterosalpingography, laparoscopy, and anti Chlamydia trachomatis IgG antibody (CAT) testing. We compared laparoscopy findings and CAT regarding sensitivity, specificity, accuracy, and predicting value of tubal conditions. The CAT was positive in 50 patients (62.5%) and laparoscopy was positive in 32 patients (40%). The CAT was significantly higher in women with tubal disease (1.88 +/- 0.34) versus in women with normal tubes (1.21 +/- 0.28) (p = 0.003). Five out of 30 sero-negative women had unilateral tubal abnormality and none of them had bilateral tubal obstruction or severe pelvic adhesion. The sensitivity, specificity, positive and negative predictive value, and accuracy of the CAT in prediction of one normal tube were 100%, 42.25%, 18%, 100%, and 48.75%, respectively. The negative predictive value of CAT to predict at least one normal tube in infertile women without history of abdominal or pelvic surgery, pelvic inflammatory disease, and endometriosis was 100%.

Predictive Performance Assessment: Trait and State Dimensions Should not be Confused

NASA Astrophysics Data System (ADS)

Pattyn, N.; Migeotte, P.-F.; Morais, J.; Cluydts, R.; Soetens, E.; Meeusen, R.; de Schutter, G.; Nederhof, E.; Kolinsky, R.

2008-06-01

One of the major aims of performance investigation is to obtain a measure predicting real-life performance, in order to prevent consequences of a potential decrement. Whereas the predictive validity of such assessment has been extensively described for long-term outcomes, as is the case for testing in selection context, equivalent evidence is lacking regarding the short-term predictive value of cognitive testing, i.e., whether these results reflect real-life performance on an immediately subsequent task. In this series of experiments, we investigated both medium-term and short-term predictive value of psychophysiological testing with regard to real-life performance in two operational settings: military student pilots with regard to their success on an evaluation flight, and special forces candidates with regard to their performance on their training course. Our results showed some relationships between test performance and medium-term outcomes. However, no short-term predictive value could be identified for cognitive testing, despite the fact physiological data showed interesting trends. We recommend a critical distinction between "state" and "trait" dimensions of performance with regard to the predictive value of testing.

Intranasal Pharmacokinetic Data for Triptans Such as Sumatriptan and Zolmitriptan Can Render Area Under the Curve (AUC) Predictions for the Oral Route: Strategy Development and Application.

PubMed

Srinivas, Nuggehally R; Syed, Muzeeb

2016-01-01

Limited pharmacokinetic sampling strategy may be useful for predicting the area under the curve (AUC) for triptans and may have clinical utility as a prospective tool for prediction. Using appropriate intranasal pharmacokinetic data, a Cmax vs. AUC relationship was established by linear regression models for sumatriptan and zolmitriptan. The predictions of the AUC values were performed using published mean/median Cmax data and appropriate regression lines. The quotient of observed and predicted values rendered fold-difference calculation. The mean absolute error (MAE), mean positive error (MPE), mean negative error (MNE), root mean square error (RMSE), correlation coefficient (r), and the goodness of the AUC fold prediction were used to evaluate the two triptans. Also, data from the mean concentration profiles at time points of 1 hour (sumatriptan) and 3 hours (zolmitriptan) were used for the AUC prediction. The Cmax vs. AUC models displayed excellent correlation for both sumatriptan (r = .9997; P < .001) and zolmitriptan (r = .9999; P < .001). Irrespective of the two triptans, the majority of the predicted AUCs (83%-85%) were within 0.76-1.25-fold difference using the regression model. The prediction of AUC values for sumatriptan or zolmitriptan using the concentration data that reflected the Tmax occurrence were in the proximity of the reported values. In summary, the Cmax vs. AUC models exhibited strong correlations for sumatriptan and zolmitriptan. The usefulness of the prediction of the AUC values was established by a rigorous statistical approach.

The Predictive Validity of the ABFM's In-Training Examination.

PubMed

O'Neill, Thomas R; Li, Zijia; Peabody, Michael R; Lybarger, Melanie; Royal, Kenneth; Puffer, James C

2015-05-01

Our objective was to examine the predictive validity of the American Board of Family Medicine's (ABFM) In-Training Examination (ITE) with regard to predicting outcomes on the ABFM certification examination. This study used a repeated measures design across three levels of medical training (PGY1--PGY2, PGY2--PGY3, and PGY3--initial certification) with three different cohorts (2010--2011, 2011--2012, and 2012--2013) to examine: (1) how well the residents' ITE scores correlated with their test scores in the following year, (2) what the typical score increase was across training years, and (3) what was the sensitivity, specificity, positive predictive value, and negative predictive value of the PGY3 scores with regard to predicting future results on the MC-FP Examination. ITE scores generally correlate at about .7 with the following year's ITE or with the following year's certification examination. The mean growth from PGY1 to PGY2 was 52 points, from PGY2 to PGY3 was 34 points, and from PGY3 to initial certification was 27 points. The sensitivity, specificity, positive predictive value, and negative predictive value were .91, .47, .96, and .27, respectively. The ITE is a useful predictor of future ITE and initial certification examination performance.

Muscle Synergies May Improve Optimization Prediction of Knee Contact Forces During Walking

PubMed Central

Walter, Jonathan P.; Kinney, Allison L.; Banks, Scott A.; D'Lima, Darryl D.; Besier, Thor F.; Lloyd, David G.; Fregly, Benjamin J.

2014-01-01

The ability to predict patient-specific joint contact and muscle forces accurately could improve the treatment of walking-related disorders. Muscle synergy analysis, which decomposes a large number of muscle electromyographic (EMG) signals into a small number of synergy control signals, could reduce the dimensionality and thus redundancy of the muscle and contact force prediction process. This study investigated whether use of subject-specific synergy controls can improve optimization prediction of knee contact forces during walking. To generate the predictions, we performed mixed dynamic muscle force optimizations (i.e., inverse skeletal dynamics with forward muscle activation and contraction dynamics) using data collected from a subject implanted with a force-measuring knee replacement. Twelve optimization problems (three cases with four subcases each) that minimized the sum of squares of muscle excitations were formulated to investigate how synergy controls affect knee contact force predictions. The three cases were: (1) Calibrate+Match where muscle model parameter values were calibrated and experimental knee contact forces were simultaneously matched, (2) Precalibrate+Predict where experimental knee contact forces were predicted using precalibrated muscle model parameters values from the first case, and (3) Calibrate+Predict where muscle model parameter values were calibrated and experimental knee contact forces were simultaneously predicted, all while matching inverse dynamic loads at the hip, knee, and ankle. The four subcases used either 44 independent controls or five synergy controls with and without EMG shape tracking. For the Calibrate+Match case, all four subcases closely reproduced the measured medial and lateral knee contact forces (R2 ≥ 0.94, root-mean-square (RMS) error < 66 N), indicating sufficient model fidelity for contact force prediction. For the Precalibrate+Predict and Calibrate+Predict cases, synergy controls yielded better contact force predictions (0.61 < R2 < 0.90, 83 N < RMS error < 161 N) than did independent controls (-0.15 < R2 < 0.79, 124 N < RMS error < 343 N) for corresponding subcases. For independent controls, contact force predictions improved when precalibrated model parameter values or EMG shape tracking was used. For synergy controls, contact force predictions were relatively insensitive to how model parameter values were calibrated, while EMG shape tracking made lateral (but not medial) contact force predictions worse. For the subject and optimization cost function analyzed in this study, use of subject-specific synergy controls improved the accuracy of knee contact force predictions, especially for lateral contact force when EMG shape tracking was omitted, and reduced prediction sensitivity to uncertainties in muscle model parameter values. PMID:24402438

Muscle synergies may improve optimization prediction of knee contact forces during walking.

PubMed

Walter, Jonathan P; Kinney, Allison L; Banks, Scott A; D'Lima, Darryl D; Besier, Thor F; Lloyd, David G; Fregly, Benjamin J

2014-02-01

The ability to predict patient-specific joint contact and muscle forces accurately could improve the treatment of walking-related disorders. Muscle synergy analysis, which decomposes a large number of muscle electromyographic (EMG) signals into a small number of synergy control signals, could reduce the dimensionality and thus redundancy of the muscle and contact force prediction process. This study investigated whether use of subject-specific synergy controls can improve optimization prediction of knee contact forces during walking. To generate the predictions, we performed mixed dynamic muscle force optimizations (i.e., inverse skeletal dynamics with forward muscle activation and contraction dynamics) using data collected from a subject implanted with a force-measuring knee replacement. Twelve optimization problems (three cases with four subcases each) that minimized the sum of squares of muscle excitations were formulated to investigate how synergy controls affect knee contact force predictions. The three cases were: (1) Calibrate+Match where muscle model parameter values were calibrated and experimental knee contact forces were simultaneously matched, (2) Precalibrate+Predict where experimental knee contact forces were predicted using precalibrated muscle model parameters values from the first case, and (3) Calibrate+Predict where muscle model parameter values were calibrated and experimental knee contact forces were simultaneously predicted, all while matching inverse dynamic loads at the hip, knee, and ankle. The four subcases used either 44 independent controls or five synergy controls with and without EMG shape tracking. For the Calibrate+Match case, all four subcases closely reproduced the measured medial and lateral knee contact forces (R2 ≥ 0.94, root-mean-square (RMS) error < 66 N), indicating sufficient model fidelity for contact force prediction. For the Precalibrate+Predict and Calibrate+Predict cases, synergy controls yielded better contact force predictions (0.61 < R2 < 0.90, 83 N < RMS error < 161 N) than did independent controls (-0.15 < R2 < 0.79, 124 N < RMS error < 343 N) for corresponding subcases. For independent controls, contact force predictions improved when precalibrated model parameter values or EMG shape tracking was used. For synergy controls, contact force predictions were relatively insensitive to how model parameter values were calibrated, while EMG shape tracking made lateral (but not medial) contact force predictions worse. For the subject and optimization cost function analyzed in this study, use of subject-specific synergy controls improved the accuracy of knee contact force predictions, especially for lateral contact force when EMG shape tracking was omitted, and reduced prediction sensitivity to uncertainties in muscle model parameter values.

The predictive ability of six pharmacokinetic models of rocuronium developed using a single bolus: evaluation with bolus and continuous infusion regimen.

PubMed

Sasakawa, Tomoki; Masui, Kenichi; Kazama, Tomiei; Iwasaki, Hiroshi

2016-08-01

Rocuronium concentration prediction using pharmacokinetic (PK) models would be useful for controlling rocuronium effects because neuromuscular monitoring throughout anesthesia can be difficult. This study assessed whether six different compartmental PK models developed from data obtained after bolus administration only could predict the measured plasma concentration (Cp) values of rocuronium delivered by bolus followed by continuous infusion. Rocuronium Cp values from 19 healthy subjects who received a bolus dose followed by continuous infusion in a phase III multicenter trial in Japan were used retrospectively as evaluation datasets. Six different compartmental PK models of rocuronium were used to simulate rocuronium Cp time course values, which were compared with measured Cp values. Prediction error (PE) derivatives of median absolute PE (MDAPE), median PE (MDPE), wobble, divergence absolute PE, and divergence PE were used to assess inaccuracy, bias, intra-individual variability, and time-related trends in APE and PE values. MDAPE and MDPE values were acceptable only for the Magorian and Kleijn models. The divergence PE value for the Kleijn model was lower than -10 %/h, indicating unstable prediction over time. The Szenohradszky model had the lowest divergence PE (-2.7 %/h) and wobble (5.4 %) values with negative bias (MDPE = -25.9 %). These three models were developed using the mixed-effects modeling approach. The Magorian model showed the best PE derivatives among the models assessed. A PK model developed from data obtained after single-bolus dosing can predict Cp values during bolus and continuous infusion. Thus, a mixed-effects modeling approach may be preferable in extrapolating such data.

How useful are ARFI elastography cut-off values proposed by meta-analysis for predicting the significant fibrosis and compensated liver cirrhosis?

PubMed

Bota, Simona; Sporea, Ioan; Sirli, Roxana; Popescu, Alina; Gradinaru-Tascau, Oana

2015-06-01

To evaluate how often do we "miss" chronic hepatitis C patients with at least significant fibrosis (F>/=2) and those with compensated cirrhosis, by using Acoustic Radiation Force Impulse (ARFI) elastography cut-off values proposed by meta-analysis. Our study included 132 patients with chronic hepatitis C, evaluated by means of ARFI and liver biopsy (LB), in the same session. Reliable measurements were defined as: median value of 10 liver stiffness (LS) measurements with a success rate>/=60% and an interquartile range interval<30%. For predicting F>/=2 and F=4 we used the LS cut-offs proposed in the last published meta-analysis: 1.35 m/s and 1.87 m/s, respectively. Reliable LS measurements by means of ARFI were obtained in 117 patients (87.9%). In our study, 58 patients (49.6%) had LS values <1.35 m/s; from these 75.8% had F>/=2 in LB. From the 59 patients (50.4%) with LS values>/=1.35 m/s, only 6.8% had F0 or F1 in LB. Also, in our study, 88 patients (75.3%) had LS values <1.87 m/s; from these only 2.2 % had F4 in LB. From the 29 patients (24.7%) with LS values>/=1.87 m/s, 41.3% had F4 in LB. Both for prediction of at least significant fibrosis and liver cirrhosis, higher aminotransferases levels were associated with wrongly classified patients, in univariate and multivariate analysis. ARFI elastography had a very good positive predictive value (93.2%) for predicting the presence of significant fibrosis and excellent negative predictive value (97.8%) for excluding the presence of compensated liver cirrhosis.

Stock price prediction using geometric Brownian motion

NASA Astrophysics Data System (ADS)

Farida Agustini, W.; Restu Affianti, Ika; Putri, Endah RM

2018-03-01

Geometric Brownian motion is a mathematical model for predicting the future price of stock. The phase that done before stock price prediction is determine stock expected price formulation and determine the confidence level of 95%. On stock price prediction using geometric Brownian Motion model, the algorithm starts from calculating the value of return, followed by estimating value of volatility and drift, obtain the stock price forecast, calculating the forecast MAPE, calculating the stock expected price and calculating the confidence level of 95%. Based on the research, the output analysis shows that geometric Brownian motion model is the prediction technique with high rate of accuracy. It is proven with forecast MAPE value ≤ 20%.

Lossless Compression of Data into Fixed-Length Packets

NASA Technical Reports Server (NTRS)

Kiely, Aaron B.; Klimesh, Matthew A.

2009-01-01

A computer program effects lossless compression of data samples from a one-dimensional source into fixed-length data packets. The software makes use of adaptive prediction: it exploits the data structure in such a way as to increase the efficiency of compression beyond that otherwise achievable. Adaptive linear filtering is used to predict each sample value based on past sample values. The difference between predicted and actual sample values is encoded using a Golomb code.

How long the singular value decomposed entropy predicts the stock market? - Evidence from the Dow Jones Industrial Average Index

NASA Astrophysics Data System (ADS)

Gu, Rongbao; Shao, Yanmin

2016-07-01

In this paper, a new concept of multi-scales singular value decomposition entropy based on DCCA cross correlation analysis is proposed and its predictive power for the Dow Jones Industrial Average Index is studied. Using Granger causality analysis with different time scales, it is found that, the singular value decomposition entropy has predictive power for the Dow Jones Industrial Average Index for period less than one month, but not for more than one month. This shows how long the singular value decomposition entropy predicts the stock market that extends Caraiani's result obtained in Caraiani (2014). On the other hand, the result also shows an essential characteristic of stock market as a chaotic dynamic system.

Optical coherence tomography in the diagnosis of dysplasia and adenocarcinoma in Barret's esophagus

NASA Astrophysics Data System (ADS)

Gladkova, N. D.; Zagaynova, E. V.; Zuccaro, G.; Kareta, M. V.; Feldchtein, F. I.; Balalaeva, I. V.; Balandina, E. B.

2007-02-01

Statistical analysis of endoscopic optical coherence tomography (EOCT) surveillance of 78 patients with Barrett's esophagus (BE) is presented in this study. The sensitivity of OCT device in retrospective open detection of early malignancy (including high grade dysplasia and intramucosal adenocarcinoma (IMAC)) was 75%, specificity 82%, diagnostic accuracy - 80%, positive predictive value- 60%, negative predictive value- 87%. In the open recognition of IMAC sensitivity was 81% and specificity were 85% each. Results of a blind recognition with the same material were similar: sensitivity - 77%, specificity 85%, diagnostic accuracy - 82%, positive predictive value- 70%, negative predictive value- 87%. As the endoscopic detection of early malignancy is problematic, OCT holds great promise in enhancing the diagnostic capability of clinical GI endoscopy.

Estimating cross-validatory predictive p-values with integrated importance sampling for disease mapping models.

PubMed

Li, Longhai; Feng, Cindy X; Qiu, Shi

2017-06-30

An important statistical task in disease mapping problems is to identify divergent regions with unusually high or low risk of disease. Leave-one-out cross-validatory (LOOCV) model assessment is the gold standard for estimating predictive p-values that can flag such divergent regions. However, actual LOOCV is time-consuming because one needs to rerun a Markov chain Monte Carlo analysis for each posterior distribution in which an observation is held out as a test case. This paper introduces a new method, called integrated importance sampling (iIS), for estimating LOOCV predictive p-values with only Markov chain samples drawn from the posterior based on a full data set. The key step in iIS is that we integrate away the latent variables associated the test observation with respect to their conditional distribution without reference to the actual observation. By following the general theory for importance sampling, the formula used by iIS can be proved to be equivalent to the LOOCV predictive p-value. We compare iIS and other three existing methods in the literature with two disease mapping datasets. Our empirical results show that the predictive p-values estimated with iIS are almost identical to the predictive p-values estimated with actual LOOCV and outperform those given by the existing three methods, namely, the posterior predictive checking, the ordinary importance sampling, and the ghosting method by Marshall and Spiegelhalter (2003). Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Discrimination and prediction of the origin of Chinese and Korean soybeans using Fourier transform infrared spectrometry (FT-IR) with multivariate statistical analysis

PubMed Central

Lee, Byeong-Ju; Zhou, Yaoyao; Lee, Jae Soung; Shin, Byeung Kon; Seo, Jeong-Ah; Lee, Doyup; Kim, Young-Suk

2018-01-01

The ability to determine the origin of soybeans is an important issue following the inclusion of this information in the labeling of agricultural food products becoming mandatory in South Korea in 2017. This study was carried out to construct a prediction model for discriminating Chinese and Korean soybeans using Fourier-transform infrared (FT-IR) spectroscopy and multivariate statistical analysis. The optimal prediction models for discriminating soybean samples were obtained by selecting appropriate scaling methods, normalization methods, variable influence on projection (VIP) cutoff values, and wave-number regions. The factors for constructing the optimal partial-least-squares regression (PLSR) prediction model were using second derivatives, vector normalization, unit variance scaling, and the 4000–400 cm–1 region (excluding water vapor and carbon dioxide). The PLSR model for discriminating Chinese and Korean soybean samples had the best predictability when a VIP cutoff value was not applied. When Chinese soybean samples were identified, a PLSR model that has the lowest root-mean-square error of the prediction value was obtained using a VIP cutoff value of 1.5. The optimal PLSR prediction model for discriminating Korean soybean samples was also obtained using a VIP cutoff value of 1.5. This is the first study that has combined FT-IR spectroscopy with normalization methods, VIP cutoff values, and selected wave-number regions for discriminating Chinese and Korean soybeans. PMID:29689113

Thermodynamic characterization of tandem mismatches found in naturally occurring RNA

PubMed Central

Christiansen, Martha E.; Znosko, Brent M.

2009-01-01

Although all sequence symmetric tandem mismatches and some sequence asymmetric tandem mismatches have been thermodynamically characterized and a model has been proposed to predict the stability of previously unmeasured sequence asymmetric tandem mismatches [Christiansen,M.E. and Znosko,B.M. (2008) Biochemistry, 47, 4329–4336], experimental thermodynamic data for frequently occurring tandem mismatches is lacking. Since experimental data is preferred over a predictive model, the thermodynamic parameters for 25 frequently occurring tandem mismatches were determined. These new experimental values, on average, are 1.0 kcal/mol different from the values predicted for these mismatches using the previous model. The data for the sequence asymmetric tandem mismatches reported here were then combined with the data for 72 sequence asymmetric tandem mismatches that were published previously, and the parameters used to predict the thermodynamics of previously unmeasured sequence asymmetric tandem mismatches were updated. The average absolute difference between the measured values and the values predicted using these updated parameters is 0.5 kcal/mol. This updated model improves the prediction for tandem mismatches that were predicted rather poorly by the previous model. This new experimental data and updated predictive model allow for more accurate calculations of the free energy of RNA duplexes containing tandem mismatches, and, furthermore, should allow for improved prediction of secondary structure from sequence. PMID:19509311

The reliability, validity, sensitivity, specificity and predictive values of the Chinese version of the Rowland Universal Dementia Assessment Scale.

PubMed

Chen, Chia-Wei; Chu, Hsin; Tsai, Chia-Fen; Yang, Hui-Ling; Tsai, Jui-Chen; Chung, Min-Huey; Liao, Yuan-Mei; Chi, Mei-Ju; Chou, Kuei-Ru

2015-11-01

The purpose of this study was to translate the Rowland Universal Dementia Assessment Scale into Chinese and to evaluate the psychometric properties (reliability and validity) and the diagnostic properties (sensitivity, specificity and predictive values) of the Chinese version of the Rowland Universal Dementia Assessment Scale. The accurate detection of early dementia requires screening tools with favourable cross-cultural linguistic and appropriate sensitivity, specificity, and predictive values, particularly for Chinese-speaking populations. This was a cross-sectional, descriptive study. Overall, 130 participants suspected to have cognitive impairment were enrolled in the study. A test-retest for determining reliability was scheduled four weeks after the initial test. Content validity was determined by five experts, whereas construct validity was established by using contrasted group technique. The participants' clinical diagnoses were used as the standard in calculating the sensitivity, specificity, positive predictive value and negative predictive value. The study revealed that the Chinese version of the Rowland Universal Dementia Assessment Scale exhibited a test-retest reliability of 0.90, an internal consistency reliability of 0.71, an inter-rater reliability (kappa value) of 0.88 and a content validity index of 0.97. Both the patients and healthy contrast group exhibited significant differences in their cognitive ability. The optimal cut-off points for the Chinese version of the Rowland Universal Dementia Assessment Scale in the test for mild cognitive impairment and dementia were 24 and 22, respectively; moreover, for these two conditions, the sensitivities of the scale were 0.79 and 0.76, the specificities were 0.91 and 0.81, the areas under the curve were 0.85 and 0.78, the positive predictive values were 0.99 and 0.83 and the negative predictive values were 0.96 and 0.91 respectively. The Chinese version of the Rowland Universal Dementia Assessment Scale exhibited sound reliability, validity, sensitivity, specificity and predictive values. This scale can help clinical staff members to quickly and accurately diagnose cognitive impairment and provide appropriate treatment as early as possible. © 2015 John Wiley & Sons Ltd.

Forecasting the Value of Training

ERIC Educational Resources Information Center

Basarab, Dave

2011-01-01

The Predictive Evaluation (PE) model is a training and evaluation approach with the element of prediction. PE allows trainers and business leaders to predict the results, value, intention, adoption, and impact of training, allowing them to make smarter, more strategic training and evaluation investments. PE is invaluable for companies that…

Prediction of human dietary δ15N intake from standardised food records: validity and precision of single meal and 24-h diet data.

PubMed

Hülsemann, Frank; Koehler, Karsten; Wittsiepe, Jürgen; Wilhelm, Michael; Hilbig, Annett; Kersting, Mathilde; Braun, Hans; Flenker, Ulrich; Schänzer, Wilhelm

2017-08-01

Natural stable isotope ratios (δ 15 N) of humans can be used for nutritional analyses and dietary reconstruction of modern and historic individuals and populations. Information about an individual's metabolic state can be obtained by comparison of tissue and dietary δ 15 N. Different methods have been used to estimate dietary δ 15 N in the past; however, the validity of such predictions has not been compared to experimental values. For a total of 56 meals and 21 samples of 24-h diets, predicted and experimental δ 15 N values were compared. The δ 15 N values were predicted from self-recorded food intake and compared with experimental δ 15 N values. Predicted and experimental δ 15 N values were in good agreement for meals and preparations (r = 0.89, p < .001) as well as for the 24-h diets (r = 0.76, p < .001). Dietary δ 15 N was mainly determined by the amount of fish, whereas the contribution of meat to dietary δ 15 N values was less pronounced. Prediction of human dietary δ 15 N values using standardised food records and representative δ 15 N data sets yields reliable data for dietary δ 15 N intake. A differentiated analysis of the primary protein sources is necessary when relating the proportion of animal-derived protein in the diet by δ 15 N analysis.

Prediction of anaerobic power values from an abbreviated WAnT protocol.

PubMed

Stickley, Christopher D; Hetzler, Ronald K; Kimura, Iris F

2008-05-01

The traditional 30-second Wingate anaerobic test (WAnT) is a widely used anaerobic power assessment protocol. An abbreviated protocol has been shown to decrease the mild to severe physical discomfort often associated with the WAnT. Therefore, the purpose of this study was to determine whether a 20-second WAnT protocol could be used to accurately predict power values of a standard 30-second WAnT. In 96 college females, anaerobic power variables were assessed using a standard 30-second WAnT protocol. Maximum power values as well as instantaneous power at 10, 15, and 20 seconds were recorded. Based on these results, stepwise regression analysis was performed to determine the accuracy with which mean power, minimum power, 30-second power, and percentage of fatigue for a standard 30-second WAnT could be predicted from values obtained during the first 20 seconds of testing. Mean power values showed the highest level of predictability (R2 = 0.99) from the 20-second values. Minimum power, 30-second power, and percentage of fatigue also showed high levels of predictability (R2 = 0.91, 0.84, and 0.84, respectively) using only values obtained during the first 20 seconds of the protocol. An abbreviated (20-second) WAnT protocol appears to effectively predict results of a standard 30-second WAnT in college-age females, allowing for comparison of data to published norms. A shortened test may allow for a decrease in unwanted side effects associated with the traditional WAnT protocol.

Selected SNARE proteins are essential for the polarized membrane insertion of igf-1 receptor and the regulation of initial axonal outgrowth in neurons.

PubMed

Grassi, Diego; Plonka, Florentyna Bustos; Oksdath, Mariana; Guil, Alvaro Nieto; Sosa, Lucas J; Quiroga, Santiago

2015-01-01

The establishment of polarity necessitates initial axonal outgrowth and, therefore, the addition of new membrane to the axon's plasmalemma. Axolemmal expansion occurs by exocytosis of plasmalemmal precursor vesicles (PPVs) primarily at the neuronal growth cone. Little is known about the SNAREs family proteins involved in the regulation of PPV fusion with the neuronal plasmalemma at early stages of differentiation. We show here that five SNARE proteins (VAMP2, VAMP4, VAMP7, Syntaxin6 and SNAP23) were expressed by hippocampal pyramidal neurons before polarization. Expression silencing of three of these proteins (VAMP4, Syntaxin6 and SNAP23) repressed axonal outgrowth and the establishment of neuronal polarity, by inhibiting IGF-1 receptor exocytotic polarized insertion, necessary for neuronal polarization. In addition, stimulation with IGF-1 triggered the association of VAMP4, Syntaxin6 and SNAP23 to vesicular structures carrying the IGF-1 receptor and overexpression of a negative dominant form of Syntaxin6 significantly inhibited exocytosis of IGF-1 receptor containing vesicles at the neuronal growth cone. Taken together, our results indicated that VAMP4, Syntaxin6 and SNAP23 functions are essential for regulation of PPV exocytosis and the polarized insertion of IGF-1 receptor and, therefore, required for initial axonal elongation and the establishment of neuronal polarity.

Direct cost of pars plana vitrectomy for the treatment of macular hole, epiretinal membrane and vitreomacular traction: a bottom-up approach.

PubMed

Nicod, Elena; Jackson, Timothy L; Grimaccia, Federico; Angelis, Aris; Costen, Marc; Haynes, Richard; Hughes, Edward; Pringle, Edward; Zambarakji, Hadi; Kanavos, Panos

2016-11-01

The direct cost to the National Health Service (NHS) in England of pars plana vitrectomy (PPV) is unknown since a bottom-up costing exercise has not been undertaken. Healthcare resource group (HRG) costing relies on a top-down approach. We aimed to quantify the direct cost of intermediate complexity PPV. Five NHS vitreoretinal units prospectively recorded all consumables, equipment and staff salaries during PPV undertaken for vitreomacular traction, epiretinal membrane and macular hole. Out-of-surgery costs between admission and discharge were estimated using a representative accounting method. The average patient time in theatre for 57 PPVs was 72 min. The average in-surgery cost for staff was £297, consumables £619, and equipment £82 (total £997). The average out-of-surgery costs were £260, including nursing and medical staff, other consumables, eye drops and hospitalisation. The total cost was therefore £1634, including 30 % overheads. This cost estimate was an under-estimate because it did not include out-of-theatre consumables or equipment. The average reimbursed HRG tariff was £1701. The cost of undertaking PPV of intermediate complexity is likely to be higher than the reimbursed tariff, except for hospitals with high throughput, where amortisation costs benefit from economies of scale. Although this research was set in England, the methodology may provide a useful template for other countries.

Characterizing Decision-Analysis Performances of Risk Prediction Models Using ADAPT Curves.

PubMed

Lee, Wen-Chung; Wu, Yun-Chun

2016-01-01

The area under the receiver operating characteristic curve is a widely used index to characterize the performance of diagnostic tests and prediction models. However, the index does not explicitly acknowledge the utilities of risk predictions. Moreover, for most clinical settings, what counts is whether a prediction model can guide therapeutic decisions in a way that improves patient outcomes, rather than to simply update probabilities.Based on decision theory, the authors propose an alternative index, the "average deviation about the probability threshold" (ADAPT).An ADAPT curve (a plot of ADAPT value against the probability threshold) neatly characterizes the decision-analysis performances of a risk prediction model.Several prediction models can be compared for their ADAPT values at a chosen probability threshold, for a range of plausible threshold values, or for the whole ADAPT curves. This should greatly facilitate the selection of diagnostic tests and prediction models.

Diagnostic accuracy of 3.0 T magnetic resonance imaging for the detection of meniscus posterior root pathology.

PubMed

LaPrade, Robert F; Ho, Charles P; James, Evan; Crespo, Bernardo; LaPrade, Christopher M; Matheny, Lauren M

2015-01-01

The purpose of this study was to determine the diagnostic accuracy of 3 T MRI, including sensitivity, specificity, negative and positive predictive values, for detection of posterior medial and lateral meniscus root tears and avulsions. All patients who had a 3 T MRI of the knee, followed by arthroscopic surgery, were included in this study. Arthroscopy was considered the gold standard. Meniscus root tears diagnosed at arthroscopy and on MRI were defined as a complete meniscus root detachment within 9 mm of the root. All surgical data were collected prospectively and stored in a data registry. MRI exams were reported prospectively by a musculoskeletal radiologist and reviewed retrospectively. There were 287 consecutive patients (156 males, 131 females; mean age 41.7 years) in this study. Prevalence of meniscus posterior root tears identified at arthroscopy was 9.1, 5.9% for medial and 3.5% for lateral root tears (one patient had both). Sensitivity was 0.770 (95% CI 0.570, 0.901), specificity was 0.729 (95% CI 0.708, 0.741), positive predictive value was 0.220 (95% CI 0.163, 0.257) and negative predictive value was 0.970 (95% CI 0.943, 0.987). For medial root tears, sensitivity was 0.824 (95% CI 0.569, 0.953), specificity was 0.800 (95% CI 0.784, 0.808), positive predictive value was 0.206 (95% CI 0.142, 0.238) and negative predictive value was 0.986 (95% CI 0.967, 0.996). For lateral meniscus posterior root tears, sensitivity was 0.600 (95% CI 0.281, 0.860), specificity was 0.903 (95% CI 0.891, 0.912), positive predictive value was 0.181 (95% CI 0.085, 0.261) and negative predictive value was 0.984 (95% CI 0.972, 0.994). This study demonstrated moderate sensitivity and specificity of 3 T MRI to detect posterior meniscus root tears. The negative predictive value of 3 T MRI to detect posterior meniscus root tears was high; however, the positive predictive value was low. Sensitivity was higher for medial root tears, indicating a higher risk of missing lateral root tears on MRI. Imaging has an important role in identifying meniscus posterior horn root tears; however, some root tears may not be identified until arthroscopy. Prognostic study (diagnostic), Level II.

Does a Dynamic Test of Phonological Awareness Predict Early Reading Difficulties? A Longitudinal Study from Kindergarten through Grade 1

ERIC Educational Resources Information Center

Gellert, Anna S.; Elbro, Carsten

2017-01-01

A few studies have indicated that dynamic measures of phonological awareness may contribute uniquely to the prediction of early reading development. However, standard control measures have been few and limited by floor effects, thus limiting their predictive value. The purpose of the present study was to examine the predictive value of a dynamic…

Charting the Eccles' Expectancy-Value Model from Mothers' Beliefs in Childhood to Youths' Activities in Adolescence

ERIC Educational Resources Information Center

Simpkins, Sandra D.; Fredricks, Jennifer A.; Eccles, Jacquelynne S.

2012-01-01

The Eccles' expectancy-value model posits that a cascade of mechanisms explain associations between parents' beliefs and youths' achievement-related behaviors. Specifically, parents' beliefs predict parents' behaviors; in turn, parents' behaviors predict youths' motivational beliefs, and youths' motivational beliefs predict their behaviors. This…

Predicting Air Quality at First Ingress into Vehicles Visiting the International Space Station.

PubMed

Romoser, Amelia A; Scully, Robert R; Limero, Thomas F; De Vera, Vanessa; Cheng, Patti F; Hand, Jennifer J; James, John T; Ryder, Valerie E

2017-02-01

NASA regularly performs ground-based offgas tests (OGTs), which allow prediction of accumulated volatile pollutant concentrations at first entry on orbit, on whole modules and vehicles scheduled to connect to the International Space Station (ISS). These data guide crew safety operations and allow for estimation of ISS air revitalization systems impact from additional pollutant load. Since volatiles released from vehicle, module, and payload materials can affect crew health and performance, prediction of first ingress air quality is important. To assess whether toxicological risk is typically over or underpredicted, OGT and first ingress samples from 10 vehicles and modules were compared. Samples were analyzed by gas chromatography and gas chromatography-mass spectrometry. The rate of pollutant accumulation was extrapolated over time. Ratios of analytical values and Spacecraft Maximum Allowable Concentrations were used to predict total toxicity values (T-values) at first entry. Results were also compared by compound. Frequently overpredicted was 2-butanone (9/10), whereas propanal (6/10) and ethanol (8/10) were typically underpredicted, but T-values were not substantially affected. Ingress sample collection delay (estimated by octafluoropropane introduced from ISS atmosphere) and T-value prediction accuracy correlated well (R2 = 0.9008), highlighting the importance of immediate air sample collection and accounting for ISS air dilution. Importantly, T-value predictions were conservative 70% of the time. Results also suggest that T-values can be normalized to octafluoropropane levels to adjust for ISS air dilution at first ingress. Finally, OGT and ingress sampling has allowed small leaks in vehicle fluid systems to be recognized and addressed.Romoser AA, Scully RR, Limero TF, De Vera V, Cheng PF, Hand JJ, James JT, Ryder VE. Predicting air quality at first ingress into vehicles visiting the International Space Station. Aerosp Med Hum Perform. 2017; 88(2):104-113.

Parametric response mapping cut-off values that predict survival of hepatocellular carcinoma patients after TACE.

PubMed

Nörthen, Aventinus; Asendorf, Thomas; Shin, Hoen-Oh; Hinrichs, Jan B; Werncke, Thomas; Vogel, Arndt; Kirstein, Martha M; Wacker, Frank K; Rodt, Thomas

2018-04-21

Parametric response mapping (PRM) is a novel image-analysis technique applicable to assess tumor viability and predict intrahepatic recurrence of hepatocellular carcinoma (HCC) patients treated with transarterial chemoembolization (TACE). However, to date, the prognostic value of PRM for prediction of overall survival in HCC patients undergoing TACE is unclear. The objective of this explorative, single-center study was to identify cut-off values for voxel-specific PRM parameters that predict the post TACE overall survival in HCC patients. PRM was applied to biphasic CT data obtained at baseline and following 3 TACE treatments of 20 patients with HCC tumors ≥ 2 cm. The individual portal venous phases were registered to the arterial phases followed by segmentation of the largest lesion, i.e., the region of interest (ROI). Segmented voxels with their respective arterial and portal venous phase density values were displayed as a scatter plot. Voxel-specific PRM parameters were calculated and compared to patients' survival at 1, 2, and 3 years post treatment to identify the maximal predictive parameters. The hypervascularized tissue portion of the ROI was found to represent an independent predictor of the post TACE overall survival. For this parameter, cut-off values of 3650, 2057, and 2057 voxels, respectively, were determined to be optimal to predict overall survival at 1, 2, and 3 years after TACE. Using these cut points, patients were correctly classified as having died with a sensitivity of 80, 92, and 86% and as still being alive with a specificity of 60, 75, and 83%, respectively. The prognostic accuracy measured by area under the curve (AUC) values ranged from 0.73 to 0.87. PRM may have prognostic value to predict post TACE overall survival in HCC patients.

Implicit Theories, Expectancies, and Values Predict Mathematics Motivation and Behavior across High School and College.

PubMed

Priess-Groben, Heather A; Hyde, Janet Shibley

2017-06-01

Mathematics motivation declines for many adolescents, which limits future educational and career options. The present study sought to identify predictors of this decline by examining whether implicit theories assessed in ninth grade (incremental/entity) predicted course-taking behaviors and utility value in college. The study integrated implicit theory with variables from expectancy-value theory to examine potential moderators and mediators of the association of implicit theories with college mathematics outcomes. Implicit theories and expectancy-value variables were assessed in 165 American high school students (47 % female; 92 % White), who were then followed into their college years, at which time mathematics courses taken, course-taking intentions, and utility value were assessed. Implicit theories predicted course-taking intentions and utility value, but only self-concept of ability predicted courses taken, course-taking intentions, and utility value after controlling for prior mathematics achievement and baseline values. Expectancy for success in mathematics mediated associations between self-concept of ability and college outcomes. This research identifies self-concept of ability as a stronger predictor than implicit theories of mathematics motivation and behavior across several years: math self-concept is critical to sustained engagement in mathematics.

Can adaptive threshold-based metabolic tumor volume (MTV) and lean body mass corrected standard uptake value (SUL) predict prognosis in head and neck cancer patients treated with definitive radiotherapy/chemoradiotherapy?

PubMed

Akagunduz, Ozlem Ozkaya; Savas, Recep; Yalman, Deniz; Kocacelebi, Kenan; Esassolak, Mustafa

2015-11-01

To evaluate the predictive value of adaptive threshold-based metabolic tumor volume (MTV), maximum standardized uptake value (SUVmax) and maximum lean body mass corrected SUV (SULmax) measured on pretreatment positron emission tomography and computed tomography (PET/CT) imaging in head and neck cancer patients treated with definitive radiotherapy/chemoradiotherapy. Pretreatment PET/CT of the 62 patients with locally advanced head and neck cancer who were treated consecutively between May 2010 and February 2013 were reviewed retrospectively. The maximum FDG uptake of the primary tumor was defined according to SUVmax and SULmax. Multiple threshold levels between 60% and 10% of the SUVmax and SULmax were tested with intervals of 5% to 10% in order to define the most suitable threshold value for the metabolic activity of each patient's tumor (adaptive threshold). MTV was calculated according to this value. We evaluated the relationship of mean values of MTV, SUVmax and SULmax with treatment response, local recurrence, distant metastasis and disease-related death. Receiver-operating characteristic (ROC) curve analysis was done to obtain optimal predictive cut-off values for MTV and SULmax which were found to have a predictive value. Local recurrence-free (LRFS), disease-free (DFS) and overall survival (OS) were examined according to these cut-offs. Forty six patients had complete response, 15 had partial response, and 1 had stable disease 6 weeks after the completion of treatment. Median follow-up of the entire cohort was 18 months. Of 46 complete responders 10 had local recurrence, and of 16 partial or no responders 10 had local progression. Eighteen patients died. Adaptive threshold-based MTV had significant predictive value for treatment response (p=0.011), local recurrence/progression (p=0.050), and disease-related death (p=0.024). SULmax had a predictive value for local recurrence/progression (p=0.030). ROC curves analysis revealed a cut-off value of 14.00 mL for MTV and 10.15 for SULmax. Three-year LRFS and DFS rates were significantly lower in patients with MTV ≥ 14.00 mL (p=0.026, p=0.018 respectively), and SULmax≥10.15 (p=0.017, p=0.022 respectively). SULmax did not have a significant predictive value for OS whereas MTV had (p=0.025). Adaptive threshold-based MTV and SULmax could have a role in predicting local control and survival in head and neck cancer patients. Copyright © 2015 Elsevier Inc. All rights reserved.

Can overt diabetes mellitus be predicted by an early A1C value in gestational diabetics?

PubMed

Granada, Catalina; Forbes, Joanna; Sangi-Haghpeykar, Haleh; Davidson, Christina

2014-01-01

To test the hypothesis that a hemoglobin A1C value (A1C) in early pregnancy is predictive of overt diabetes mellitus (DM) postpartum in women with gestational diabetes (GDM). In this case-control analysis of women with an early pregnancy diagnosis of GDM, we estimated the association between an early pregnancy A1C and subsequent diagnosis of DM. Women with a normal postpartum diabetic screen (controls) were compared against those with confirmed postpartum DM (cases). Ability of A1C levels to predict DM was examined via logistic regression analysis and corresponding receiver operating characteristic values. During the 10-year study period 166 women met the inclusion criteria: 140 (84%) had normal postpartum testing (controls), and 26 (16%) were diagnosed with DM (cases). The mean A1C value was significantly higher among cases than controls (6.7 vs. 5.6, p < 0.0001, SD 1.3-5). Cases had A1Cs ranging from 5.5- 11.7%, while controls had A1Cs ranging from 4.3-7.8%. The best discriminatory cut point for postpartum DM was an A1C > 5.9% (sensitivity 81%, specificity 83%, positive predictive value 47%, negative predictive value Our findings suggest that an elevated early pregnancy A1C may be predictive of overt DM. Larger studies are needed to further validate this association.

[Formulation of combined predictive indicators using logistic regression model in predicting sepsis and prognosis].

PubMed

Duan, Liwei; Zhang, Sheng; Lin, Zhaofen

2017-02-01

To explore the method and performance of using multiple indices to diagnose sepsis and to predict the prognosis of severe ill patients. Critically ill patients at first admission to intensive care unit (ICU) of Changzheng Hospital, Second Military Medical University, from January 2014 to September 2015 were enrolled if the following conditions were satisfied: (1) patients were 18-75 years old; (2) the length of ICU stay was more than 24 hours; (3) All records of the patients were available. Data of the patients was collected by searching the electronic medical record system. Logistic regression model was formulated to create the new combined predictive indicator and the receiver operating characteristic (ROC) curve for the new predictive indicator was built. The area under the ROC curve (AUC) for both the new indicator and original ones were compared. The optimal cut-off point was obtained where the Youden index reached the maximum value. Diagnostic parameters such as sensitivity, specificity and predictive accuracy were also calculated for comparison. Finally, individual values were substituted into the equation to test the performance in predicting clinical outcomes. A total of 362 patients (218 males and 144 females) were enrolled in our study and 66 patients died. The average age was (48.3±19.3) years old. (1) For the predictive model only containing categorical covariants [including procalcitonin (PCT), lipopolysaccharide (LPS), infection, white blood cells count (WBC) and fever], increased PCT, increased WBC and fever were demonstrated to be independent risk factors for sepsis in the logistic equation. The AUC for the new combined predictive indicator was higher than that of any other indictor, including PCT, LPS, infection, WBC and fever (0.930 vs. 0.661, 0.503, 0.570, 0.837, 0.800). The optimal cut-off value for the new combined predictive indicator was 0.518. Using the new indicator to diagnose sepsis, the sensitivity, specificity and diagnostic accuracy rate were 78.00%, 93.36% and 87.47%, respectively. One patient was randomly selected, and the clinical data was substituted into the probability equation for prediction. The calculated value was 0.015, which was less than the cut-off value (0.518), indicating that the prognosis was non-sepsis at an accuracy of 87.47%. (2) For the predictive model only containing continuous covariants, the logistic model which combined acute physiology and chronic health evaluation II (APACHE II) score and sequential organ failure assessment (SOFA) score to predict in-hospital death events, both APACHE II score and SOFA score were independent risk factors for death. The AUC for the new predictive indicator was higher than that of APACHE II score and SOFA score (0.834 vs. 0.812, 0.813). The optimal cut-off value for the new combined predictive indicator in predicting in-hospital death events was 0.236, and the corresponding sensitivity, specificity and diagnostic accuracy for the combined predictive indicator were 73.12%, 76.51% and 75.70%, respectively. One patient was randomly selected, and the APACHE II score and SOFA score was substituted into the probability equation for prediction. The calculated value was 0.570, which was higher than the cut-off value (0.236), indicating that the death prognosis at an accuracy of 75.70%. The combined predictive indicator, which is formulated by logistic regression models, is superior to any single indicator in predicting sepsis or in-hospital death events.

Spatial Pattern of Standing Timber Value across the Brazilian Amazon

PubMed Central

Ahmed, Sadia E.; Ewers, Robert M.

2012-01-01

The Amazon is a globally important system, providing a host of ecosystem services from climate regulation to food sources. It is also home to a quarter of all global diversity. Large swathes of forest are removed each year, and many models have attempted to predict the spatial patterns of this forest loss. The spatial patterns of deforestation are determined largely by the patterns of roads that open access to frontier areas and expansion of the road network in the Amazon is largely determined by profit seeking logging activities. Here we present predictions for the spatial distribution of standing value of timber across the Amazon. We show that the patterns of timber value reflect large-scale ecological gradients, determining the spatial distribution of functional traits of trees which are, in turn, correlated with timber values. We expect that understanding the spatial patterns of timber value across the Amazon will aid predictions of logging movements and thus predictions of potential future road developments. These predictions in turn will be of great use in estimating the spatial patterns of deforestation in this globally important biome. PMID:22590520

[Role of parathyroid hormone measurement in prediction for symptomatic hypocalcaemia after total thyroidectomy].

PubMed

An, Chang-ming; Tang, Ping-zhang; Xu, Zhen-gang; Zhang, Bin; Zhang, Zong-min; Yan, Dan-gui; Li, Zheng-jiang

2010-03-01

To evaluate the role of parathyroid hormone (PTH) and serum calcium in prediction for hypocalcaemia after total thyroidectomy. One hundred and sixty-five patients undergoing total or complete total thyroidectomy were reviewed retrospectively. The indications included bilateral carcinoma, undifferential carcinoma, surroundings invasion, distant metastasis and huge benign lesions. Preoperative and postoperative PTH, calcium concentrations and their decline levels were compared between Jan. 2005 and May 2009. The role of PTH value and decline level predicting for symptomatic hypocalcaemia were analyzed by receiver operator characteristics (ROC) curve. After total thyroidectomy, 85 patients (51.5%) developed hypocalcemia. Symptoms were reported by 36 patients (21.8%). The mean concentration of PTH for normocalcaemia (80 cases), asymptomatic hypocalcaemia (49 cases) and symptomatic patients (36 cases) were 31.0 ng/L, 19.6 ng/L and 11.9 ng/L, respectively. The mean decline level for the three groups were 28.6%, 52.6% and 78.0%, respectively. PTH value and its decline level had a poor predicting value for symptomatic hypocalcaemia and high negative predicting value for asymptomatic patients. The serum calcium concentration more than 2.0 mmol/L, PTH level higher than 15 ng/L and PTH decline less than 50% had the good negative predicting value of 97.6%, 90.3% and 96.5%, respectively. Postoperative PTH and its decline level were significantly correlated with postoperative serum calcium concentration but had a low accuracy for predicting symptomatic hypocalcaemia. The serum calcium concentration more than 2.0 mmol/L, PTH level higher than 15 ng/L and PTH decline less than 50% had the good predicting value for asymptomatic patients. Calcium should be routinely supplemented in the first 24 h after total thyroidectomy to reduce the rate of hypocalcemia and the severity of hypocalcemia symptoms.

Ottawa Ankle Rules and Subjective Surgeon Perception to Evaluate Radiograph Necessity Following Foot and Ankle Sprain

PubMed Central

Pires, RES; Pereira, AA; Abreu-e-Silva, GM; Labronici, PJ; Figueiredo, LB; Godoy-Santos, AL; Kfuri, M

2014-01-01

Background: Foot and ankle injuries are frequent in emergency departments. Although only a few patients with foot and ankle sprain present fractures and the fracture patterns are almost always simple, lack of fracture diagnosis can lead to poor functional outcomes. Aim: The present study aims to evaluate the reliability of the Ottawa ankle rules and the orthopedic surgeon subjective perception to assess foot and ankle fractures after sprains. Subjects and Methods: A cross-sectional study was conducted from July 2012 to December 2012. Ethical approval was granted. Two hundred seventy-four adult patients admitted to the emergency department with foot and/or ankle sprain were evaluated by an orthopedic surgeon who completed a questionnaire prior to radiographic assessment. The Ottawa ankle rules and subjective perception of foot and/or ankle fractures were evaluated on the questionnaire. Results: Thirteen percent (36/274) patients presented fracture. Orthopedic surgeon subjective analysis showed 55.6% sensitivity, 90.1% specificity, 46.5% positive predictive value and 92.9% negative predictive value. The general orthopedic surgeon opinion accuracy was 85.4%. The Ottawa ankle rules presented 97.2% sensitivity, 7.8% specificity, 13.9% positive predictive value, 95% negative predictive value and 19.9% accuracy respectively. Weight-bearing inability was the Ottawa ankle rule item that presented the highest reliability, 69.4% sensitivity, 61.6% specificity, 63.1% accuracy, 21.9% positive predictive value and 93% negative predictive value respectively. Conclusion: The Ottawa ankle rules showed high reliability for deciding when to take radiographs in foot and/or ankle sprains. Weight-bearing inability was the most important isolated item to predict fracture presence. Orthopedic surgeon subjective analysis to predict fracture possibility showed a high specificity rate, representing a confident method to exclude unnecessary radiographic exams. PMID:24971221

Basal CD34+ Cell Count Predicts Peripheral Blood Stem Cell Mobilization in Healthy Donors after Administration of Granulocyte Colony-Stimulating Factor: A Longitudinal, Prospective, Observational, Single-Center, Cohort Study.

PubMed

Martino, Massimo; Gori, Mercedes; Pitino, Annalisa; Gentile, Massimo; Dattola, Antonia; Pontari, Antonella; Vigna, Ernesto; Moscato, Tiziana; Recchia, Anna Grazia; Barilla', Santina; Tripepi, Giovanni; Morabito, Fortunato

2017-07-01

A longitudinal, prospective, observational, single-center, cohort study on healthy donors (HDs) was designed to identify predictors of CD34 + cells on day 5 with emphasis on the predictive value of the basal CD34 + cell count. As potential predictors of mobilization, age, sex, body weight, height, blood volume as well as white blood cell count, peripheral blood (PB) mononuclear cells, platelet count, hematocrit, and hemoglobin levels were considered. Two different evaluations of CD34 + cell counts were determined for each donor: baseline (before granulocyte colony-stimulating factor [G-CSF] administration) and in PB after G-CSF administration on the morning of the fifth day (day 5). A total of 128 consecutive HDs (66 males) with a median age of 43 years were enrolled. CD34 + levels on day 5 displayed a non-normal distribution, with a median value of 75.5 cells/µL. To account for the non-normal distribution of the dependent variable, a quantile regression analysis to predict CD34 + on day 5 using the baseline value of CD34 + as the key predictor was performed. On crude analysis, a baseline value of CD34 + ranging from .5 cells/µL to 1 cells/µL predicts a median value of 50 cells/µL on day 5; a value of 2 cells/µL predicts a median value of 70.7 cells/µL; a value of 3 cells/µL to 4 cells/µL predicts a median value of 91.3 cells/µL, and a value ≥ 5 predicts a median value of 112 cells/µL. In conclusion, the baseline PB CD34 + cell count correlates with the effectiveness of allogeneic PB stem cell mobilization and could be useful to plan the collection. Copyright © 2017 The American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

Predictive value of Tokuhashi scoring systems in spinal metastases, focusing on various primary tumor groups: evaluation of 448 patients in the Aarhus spinal metastases database.

PubMed

Wang, Miao; Bünger, Cody Eric; Li, Haisheng; Wu, Chunsen; Høy, Kristian; Niedermann, Bent; Helmig, Peter; Wang, Yu; Jensen, Anders Bonde; Schättiger, Katrin; Hansen, Ebbe Stender

2012-04-01

We conducted a prospective cohort study of 448 patients with spinal metastases from a variety of cancer groups. To determine the specific predictive value of the Tokuhashi scoring system (T12) and its revised version (T15) in spinal metastases of various primary tumors. The life expectancy of patients with spinal metastases is one of the most important factors in selecting the treatment modality. Tokuhashi et al formulated a prognostic scoring system with a total sum of 12 points for preoperative prediction of life expectancy in 1990 and revised it in 2005 to a total sum of 15 points. There is a lack of knowledge about the specific predictive value of those scoring systems in patients with spinal metastases from a variety of cancer groups. We included 448 patients with vertebral metastases who underwent surgical treatment during November 1992 to November 2009 in Aarhus University Hospital NBG. Data were retrieved from Aarhus Metastases Database. Scores based on T12 and T15 were calculated prospectively for each patient. We divided all the patients into different groups dictated by the site of their primary tumor. Predictive value and accuracy rate of the 2 scoring systems were compared in each cancer group. Both the T12 and T15 scoring systems showed statistically significant predictive value when the 448 patients were analyzed in total (T12, P < 0.0001; T15, P < 0.0001). The accuracy rate was significantly higher in T15 (P < 0.0001) than in T12. The further analyses by primary cancer groups showed that the predictive value of T12 and T15 was primarily determined by the prostate (P = 0.0003) and breast group (P = 0.0385). Only T12 displayed predictive value in the colon group (P = 0.0011). Neither of the scoring systems showed significant predictive value in the lung (P > 0.05), renal (P > 0.05), or miscellaneous primary tumor groups (P > 0.05). The accuracy rate of prognosis in T15 was significantly improved in the prostate (P = 0.0032) and breast group (P < 0.0001). Both T12 and T15 showed significant predictive value in patients with spinal metastases. T15 has a statistically higher accuracy rate than T12. Among the various cancer groups, the 2 scoring systems are especially reliable in prostate and breast metastases groups. T15 is recommended as superior to T12 because of its higher accuracy rate.

[A Retrospective Study of Mean Computed Tomography Value to Predict 
the Tumor Invasiveness in AAH and Clinical Stage Ia Lung Cancer].

PubMed

Wu, Hanran; Liu, Changqing; Xu, Meiqing; Xiong, Ran; Xu, Guangwen; Li, Caiwei; Xie, Mingran

2018-03-20

Recently, the detectable rate of ground-glass opacity (GGO ) was significantly increased, a appropriate diagnosis before clinic treatment tends to be important for patients with GGO lesions. The aim of this study is to validate the ability of the mean computed tomography (m-CT) value to predict tumor invasiveness, and compared with other measurements such as Max CT value, GGO size, solid size of GGO and C/T ratio (consolid/tumor ratio, C/T) to find out the best measurement to predict tumor invasiveness. A retrospective study was conducted of 129 patients who recieved lobectomy and were pathological confirmed as atypical adenomatous pyperplasia (AAH) or clinical stage Ia lung cance in our center between January 2012 and December 2013. Of those 129 patients, the number of patients of AAH, AIS, AIS and invasive adenocarcinoma were 43, 26, 17 and 43, respectively. We defined AAH and AIS as noninvasive cancer (NC), MIA and invasive adenocarcinoma were categorized as invasive cancer(IC). We used receiver operating characteristic (ROC) curve analysis to compare the ability to predict tumor invasiveness between m-CT value, consolidation/tumor ratio, tumor size and solid size of tumor. Multiple logistic regression analyses were performed to determine the independent variables for prediction of pathologic more invasive lung cancer. 129 patients were enrolled in our study (59 male and 70 female), the patients were a median age of (62.0±8.6) years (range, 44 to 82 years). The two groups were similar in terms of age, sex, differentiation (P>0.05). ROC curve analysis was performed to determine the appropriate cutoff value and area under the cure (AUC). The cutoff value of solid tumor size, tumor size, C/T ratio, m-CT value and Max CT value were 9.4 mm, 15.3 mm, 47.5%, -469.0 HU and -35.0 HU, respectively. The AUC of those variate were 0.89, 0.79, 0.82, 0.90, 0.85, respectively. When compared the clinical and radiologic data between two groups, we found the IC group was strongly associated with a high m-CT value, high Max CT value, high C/T ratio and large tumor size. Gender, solid tumor size, tumor size, C/T ratio, m-CT value and MaxCT value were selected factor for multivariate analysis, when using the preoperatively determined variables to predict the tumor invasiveness, revealed that tumor size, C/T ratio, m-CT value and Max CT value were independent predictive factors of IC. The musurements of Max CT value, GGO size, solid size of GGO and C/T ratio were significantly correlated with tumor invasiveness, and the evaluation of m-CT value is most useful musurement in predicting more invasive lung cancer.

Predictive models of alcohol use based on attitudes and individual values.

PubMed

García del Castillo Rodríguez, José A; López-Sánchez, Carmen; Quiles Soler, M Carmen; García del Castillo-López, Alvaro; Gázquez Pertusa, Mónica; Marzo Campos, Juan Carlos; Inglés, Candido J

2013-01-01

Two predictive models are developed in this article: the first is designed to predict people's attitudes to alcoholic drinks, while the second sets out to predict the use of alcohol in relation to selected individual values. University students (N = 1,500) were recruited through stratified sampling based on sex and academic discipline. The questionnaire used obtained information on participants' alcohol use, attitudes and personal values. The results show that the attitudes model correctly classifies 76.3% of cases. Likewise, the model for level of alcohol use correctly classifies 82% of cases. According to our results, we can conclude that there are a series of individual values that influence drinking and attitudes to alcohol use, which therefore provides us with a potentially powerful instrument for developing preventive intervention programs.

Diagnostic value of contrast-enhanced ultrasound in thyroid nodules with calcification.

PubMed

Jiang, Jue; Shang, Xu; Wang, Hua; Xu, Yong-Bo; Gao, Ya; Zhou, Qi

2015-03-01

The aim of this study was to investigate the diagnostic values of conventional ultrasound and contrast-enhanced ultrasound (CEUS) in benign and malignant thyroid nodules with calcification. Conventional ultrasound and CEUS were performed in 122 patients with thyroid nodules with calcification. The thyroid nodules were characterized as benign or malignant by pathological diagnosis. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accordance rate of the two imaging methods were determined. The area under the receiver operating characteristics curve (AUC) was used to assess the diagnostic values of the two imaging methods. In 122 cases of thyroid nodules with calcification, 73 benign nodules and 49 malignant nodules were verified by pathological diagnosis. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accordance rate of conventional ultrasound were 50%, 77%, 59%, 69%, and 66%, respectively, and those of CEUS were 90%, 92%, 88%, 93%, and 91%, respectively. There were significant differences between the two imaging methods. AUCs of conventional ultrasound and CEUS were 0.628 ± 0.052 and 0.908 ± 0.031, suggesting low and high diagnostic values, respectively. CEUS has high diagnostic values, being significantly greater than those of conventional ultrasound, in differential diagnosis of benign and malignant thyroid nodules with calcification. Copyright © 2014. Published by Elsevier Taiwan.

Predicting the rate of change in timber value for forest stands infested with gypsy moth

Treesearch

David A. Gansner; Owen W. Herrick

1982-01-01

Presents a method for estimating the potential impact of gypsy moth attacks on forest-stand value. Robust regression analysis is used to develop an equation for predicting the rate of change in timber value from easy-to-measure key characteristics of stand condition.

Personality and Values as Predictors of Medical Specialty Choice

ERIC Educational Resources Information Center

Taber, Brian J.; Hartung, Paul J.; Borges, Nicole J.

2011-01-01

Research rarely considers the combined influence of personality traits and values in predicting behavioral outcomes. We aimed to advance a germinal line of inquiry that addresses this gap by separately and simultaneously examining personality traits and physician work values to predict medical specialty choice. First-year medical students (125…

The predictive power of Japanese candlestick charting in Chinese stock market

NASA Astrophysics Data System (ADS)

Chen, Shi; Bao, Si; Zhou, Yu

2016-09-01

This paper studies the predictive power of 4 popular pairs of two-day bullish and bearish Japanese candlestick patterns in Chinese stock market. Based on Morris' study, we give the quantitative details of definition of long candlestick, which is important in two-day candlestick pattern recognition but ignored by several previous researches, and we further give the quantitative definitions of these four pairs of two-day candlestick patterns. To test the predictive power of candlestick patterns on short-term price movement, we propose the definition of daily average return to alleviate the impact of correlation among stocks' overlap-time returns in statistical tests. To show the robustness of our result, two methods of trend definition are used for both the medium-market-value and large-market-value sample sets. We use Step-SPA test to correct for data snooping bias. Statistical results show that the predictive power differs from pattern to pattern, three of the eight patterns provide both short-term and relatively long-term prediction, another one pair only provide significant forecasting power within very short-term period, while the rest three patterns present contradictory results for different market value groups. For all the four pairs, the predictive power drops as predicting time increases, and forecasting power is stronger for stocks with medium market value than those with large market value.

The efficacy of the reverse contrast mode in digital radiography for the detection of proximal dentinal caries

PubMed Central

Miri, Shimasadat; Mehralizadeh, Sandra; Sadri, Donya; Motamedi, Mahmood Reza Kalantar

2015-01-01

Purpose This study evaluated the diagnostic accuracy of the reverse contrast mode in intraoral digital radiography for the detection of proximal dentinal caries, in comparison with the original digital radiographs. Materials and Methods Eighty extracted premolars with no clinically apparent caries were selected, and digital radiographs of them were taken separately in standard conditions. Four observers examined the original radiographs and the same radiographs in the reverse contrast mode with the goal of identifying proximal dentinal caries. Microscopic sections 5 µm in thickness were prepared from the teeth in the mesiodistal direction. Four slides prepared from each sample used as the diagnostic gold standard. The data were analyzed using SPSS (α=0.05). Results Our results showed that the original radiographs in order to identify proximal dentinal caries had the following values for sensitivity, specificity, positive predictive value, negative predictive value, and accuracy, respectively: 72.5%, 90%, 87.2%, 76.5%, and 80.9%. For the reverse contrast mode, however, the corresponding values were 63.1%, 89.4%, 87.1%, 73.5%, and 78.8%, respectively. The sensitivity of original digital radiograph for detecting proximal dentinal caries was significantly higher than that of reverse contrast mode (p<0.05). However, no statistically significant differences were found regarding specificity, positive predictive value, negative predictive value, or accuracy (p>0.05). Conclusion The sensitivity of the original digital radiograph for detecting proximal dentinal caries was significantly higher than that of the reversed contrast images. However, no statistically significant differences were found between these techniques regarding specificity, positive predictive value, negative predictive value, or accuracy. PMID:26389055

A threshold-free summary index of prediction accuracy for censored time to event data.

PubMed

Yuan, Yan; Zhou, Qian M; Li, Bingying; Cai, Hengrui; Chow, Eric J; Armstrong, Gregory T

2018-05-10

Prediction performance of a risk scoring system needs to be carefully assessed before its adoption in clinical practice. Clinical preventive care often uses risk scores to screen asymptomatic population. The primary clinical interest is to predict the risk of having an event by a prespecified future time t 0 . Accuracy measures such as positive predictive values have been recommended for evaluating the predictive performance. However, for commonly used continuous or ordinal risk score systems, these measures require a subjective cutoff threshold value that dichotomizes the risk scores. The need for a cutoff value created barriers for practitioners and researchers. In this paper, we propose a threshold-free summary index of positive predictive values that accommodates time-dependent event status and competing risks. We develop a nonparametric estimator and provide an inference procedure for comparing this summary measure between 2 risk scores for censored time to event data. We conduct a simulation study to examine the finite-sample performance of the proposed estimation and inference procedures. Lastly, we illustrate the use of this measure on a real data example, comparing 2 risk score systems for predicting heart failure in childhood cancer survivors. Copyright © 2018 John Wiley & Sons, Ltd.

The Accuracy of the Spot Sign and the Blend Sign for Predicting Hematoma Expansion in Patients with Spontaneous Intracerebral Hemorrhage.

PubMed

Zheng, Jun; Yu, Zhiyuan; Xu, Zhao; Li, Mou; Wang, Xiaoze; Lin, Sen; Li, Hao; You, Chao

2017-05-12

BACKGROUND Hematoma expansion is associated with poor outcome in intracerebral hemorrhage (ICH) patients. The spot sign and the blend sign are reliable tools for predicting hematoma expansion in ICH patients. The aim of this study was to compare the accuracy of the two signs in the prediction of hematoma expansion. MATERIAL AND METHODS Patients with spontaneous ICH were screened for the presence of the computed tomography angiography (CTA) spot sign and the non-contrast CT (NCCT) blend sign within 6 hours after onset of symptoms. The sensitivity, specificity, and positive and negative predictive values of the spot sign and the blend sign in predicting hematoma expansion were calculated. The accuracy of the spot sign and the blend sign in predicting hematoma expansion was analyzed by receiver-operator analysis. RESULTS A total of 115 patients were enrolled in this study. The spot sign was observed in 25 (21.74%) patients, whereas the blend sign was observed in 22 (19.13%) patients. Of the 28 patients with hematoma expansion, the CTA spot sign was found on admission CT scans in 16 (57.14%) and the NCCT blend sign in 12 (42.86%), respectively. The sensitivity, specificity, positive predictive value, and negative predictive value of the spot sign for predicting hematoma expansion were 57.14%, 89.66%, 64.00%, and 86.67%, respectively. In contrast, the sensitivity, specificity, positive predictive value, and negative predictive value of the blend sign were 42.86%, 88.51%, 54.55%, and 82.80%, respectively. The area under the curve (AUC) of the spot sign was 0.734, which was higher than that of the blend sign (0.657). CONCLUSIONS Both the spot sign and the blend sign seemed to be good predictors for hematoma expansion, and the spot sign appeared to have better predictive accuracy.

The Accuracy of the Spot Sign and the Blend Sign for Predicting Hematoma Expansion in Patients with Spontaneous Intracerebral Hemorrhage

PubMed Central

Zheng, Jun; Yu, Zhiyuan; Xu, Zhao; Li, Mou; Wang, Xiaoze; Lin, Sen; Li, Hao; You, Chao

2017-01-01

Background Hematoma expansion is associated with poor outcome in intracerebral hemorrhage (ICH) patients. The spot sign and the blend sign are reliable tools for predicting hematoma expansion in ICH patients. The aim of this study was to compare the accuracy of the two signs in the prediction of hematoma expansion. Material/Methods Patients with spontaneous ICH were screened for the presence of the computed tomography angiography (CTA) spot sign and the non-contrast CT (NCCT) blend sign within 6 hours after onset of symptoms. The sensitivity, specificity, and positive and negative predictive values of the spot sign and the blend sign in predicting hematoma expansion were calculated. The accuracy of the spot sign and the blend sign in predicting hematoma expansion was analyzed by receiver-operator analysis. Results A total of 115 patients were enrolled in this study. The spot sign was observed in 25 (21.74%) patients, whereas the blend sign was observed in 22 (19.13%) patients. Of the 28 patients with hematoma expansion, the CTA spot sign was found on admission CT scans in 16 (57.14%) and the NCCT blend sign in 12 (42.86%), respectively. The sensitivity, specificity, positive predictive value, and negative predictive value of the spot sign for predicting hematoma expansion were 57.14%, 89.66%, 64.00%, and 86.67%, respectively. In contrast, the sensitivity, specificity, positive predictive value, and negative predictive value of the blend sign were 42.86%, 88.51%, 54.55%, and 82.80%, respectively. The area under the curve (AUC) of the spot sign was 0.734, which was higher than that of the blend sign (0.657). Conclusions Both the spot sign and the blend sign seemed to be good predictors for hematoma expansion, and the spot sign appeared to have better predictive accuracy. PMID:28498827

Computational prediction of ionic liquid 1-octanol/water partition coefficients.

PubMed

Kamath, Ganesh; Bhatnagar, Navendu; Baker, Gary A; Baker, Sheila N; Potoff, Jeffrey J

2012-04-07

Wet 1-octanol/water partition coefficients (log K(ow)) predicted for imidazolium-based ionic liquids using adaptive bias force-molecular dynamics (ABF-MD) simulations lie in excellent agreement with experimental values. These encouraging results suggest prospects for this computational tool in the a priori prediction of log K(ow) values of ionic liquids broadly with possible screening implications as well (e.g., prediction of CO(2)-philic ionic liquids).

An accurate and efficient method to predict the electronic excitation energies of BODIPY fluorescent dyes.

PubMed

Wang, Jia-Nan; Jin, Jun-Ling; Geng, Yun; Sun, Shi-Ling; Xu, Hong-Liang; Lu, Ying-Hua; Su, Zhong-Min

2013-03-15

Recently, the extreme learning machine neural network (ELMNN) as a valid computing method has been proposed to predict the nonlinear optical property successfully (Wang et al., J. Comput. Chem. 2012, 33, 231). In this work, first, we follow this line of work to predict the electronic excitation energies using the ELMNN method. Significantly, the root mean square deviation of the predicted electronic excitation energies of 90 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) derivatives between the predicted and experimental values has been reduced to 0.13 eV. Second, four groups of molecule descriptors are considered when building the computing models. The results show that the quantum chemical descriptions have the closest intrinsic relation with the electronic excitation energy values. Finally, a user-friendly web server (EEEBPre: Prediction of electronic excitation energies for BODIPY dyes), which is freely accessible to public at the web site: http://202.198.129.218, has been built for prediction. This web server can return the predicted electronic excitation energy values of BODIPY dyes that are high consistent with the experimental values. We hope that this web server would be helpful to theoretical and experimental chemists in related research. Copyright © 2012 Wiley Periodicals, Inc.

On prediction of genetic values in marker-assisted selection.

PubMed Central

Lange, C; Whittaker, J C

2001-01-01

We suggest a new approximation for the prediction of genetic values in marker-assisted selection. The new approximation is compared to the standard approach. It is shown that the new approach will often provide substantially better prediction of genetic values; furthermore the new approximation avoids some of the known statistical problems of the standard approach. The advantages of the new approach are illustrated by a simulation study in which the new approximation outperforms both the standard approach and phenotypic selection. PMID:11729177

Chain pooling to minimize prediction error in subset regression. [Monte Carlo studies using population models

NASA Technical Reports Server (NTRS)

Holms, A. G.

1974-01-01

Monte Carlo studies using population models intended to represent response surface applications are reported. Simulated experiments were generated by adding pseudo random normally distributed errors to population values to generate observations. Model equations were fitted to the observations and the decision procedure was used to delete terms. Comparison of values predicted by the reduced models with the true population values enabled the identification of deletion strategies that are approximately optimal for minimizing prediction errors.

Estimating the Accuracy of the Chedoke-McMaster Stroke Assessment Predictive Equations for Stroke Rehabilitation.

PubMed

Dang, Mia; Ramsaran, Kalinda D; Street, Melissa E; Syed, S Noreen; Barclay-Goddard, Ruth; Stratford, Paul W; Miller, Patricia A

2011-01-01

To estimate the predictive accuracy and clinical usefulness of the Chedoke-McMaster Stroke Assessment (CMSA) predictive equations. A longitudinal prognostic study using historical data obtained from 104 patients admitted post cerebrovascular accident was undertaken. Data were abstracted for all patients undergoing rehabilitation post stroke who also had documented admission and discharge CMSA scores. Published predictive equations were used to determine predicted outcomes. To determine the accuracy and clinical usefulness of the predictive model, shrinkage coefficients and predictions with 95% confidence bands were calculated. Complete data were available for 74 patients with a mean age of 65.3±12.4 years. The shrinkage values for the six Impairment Inventory (II) dimensions varied from -0.05 to 0.09; the shrinkage value for the Activity Inventory (AI) was 0.21. The error associated with predictive values was greater than ±1.5 stages for the II dimensions and greater than ±24 points for the AI. This study shows that the large error associated with the predictions (as defined by the confidence band) for the CMSA II and AI limits their clinical usefulness as a predictive measure. Further research to establish predictive models using alternative statistical procedures is warranted.

Novel Applications of Multi-task Learning and Multiple Output Regression to Multiple Genetic Trait Prediction

USDA-ARS?s Scientific Manuscript database

Given a set of biallelic molecular markers, such as SNPs, with genotype values encoded numerically on a collection of plant, animal or human samples, the goal of genetic trait prediction is to predict the quantitative trait values by simultaneously modeling all marker effects. Genetic trait predicti...

Development of an evidence-based approach to external quality assurance for breast cancer hormone receptor immunohistochemistry: comparison of reference values.

PubMed

Makretsov, Nikita; Gilks, C Blake; Alaghehbandan, Reza; Garratt, John; Quenneville, Louise; Mercer, Joel; Palavdzic, Dragana; Torlakovic, Emina E

2011-07-01

External quality assurance and proficiency testing programs for breast cancer predictive biomarkers are based largely on traditional ad hoc design; at present there is no universal consensus on definition of a standard reference value for samples used in external quality assurance programs. To explore reference values for estrogen receptor and progesterone receptor immunohistochemistry in order to develop an evidence-based analytic platform for external quality assurance. There were 31 participating laboratories, 4 of which were previously designated as "expert" laboratories. Each participant tested a tissue microarray slide with 44 breast carcinomas for estrogen receptor and progesterone receptor and submitted it to the Canadian Immunohistochemistry Quality Control Program for analysis. Nuclear staining in 1% or more of the tumor cells was a positive score. Five methods for determining reference values were compared. All reference values showed 100% agreement for estrogen receptor and progesterone receptor scores, when indeterminate results were excluded. Individual laboratory performance (agreement rates, test sensitivity, test specificity, positive predictive value, negative predictive value, and κ value) was very similar for all reference values. Identification of suboptimal performance by all methods was identical for 30 of 31 laboratories. Estrogen receptor assessment of 1 laboratory was discordant: agreement was less than 90% for 3 of 5 reference values and greater than 90% with the use of 2 other reference values. Various reference values provide equivalent laboratory rating. In addition to descriptive feedback, our approach allows calculation of technical test sensitivity and specificity, positive and negative predictive values, agreement rates, and κ values to guide corrective actions.

Influence of Temperature, Relative Humidity, and Soil Properties on the Soil-Air Partitioning of Semivolatile Pesticides: Laboratory Measurements and Predictive Models.

PubMed

Davie-Martin, Cleo L; Hageman, Kimberly J; Chin, Yu-Ping; Rougé, Valentin; Fujita, Yuki

2015-09-01

Soil-air partition coefficient (Ksoil-air) values are often employed to investigate the fate of organic contaminants in soils; however, these values have not been measured for many compounds of interest, including semivolatile current-use pesticides. Moreover, predictive equations for estimating Ksoil-air values for pesticides (other than the organochlorine pesticides) have not been robustly developed, due to a lack of measured data. In this work, a solid-phase fugacity meter was used to measure the Ksoil-air values of 22 semivolatile current- and historic-use pesticides and their degradation products. Ksoil-air values were determined for two soils (semiarid and volcanic) under a range of environmentally relevant temperature (10-30 °C) and relative humidity (30-100%) conditions, such that 943 Ksoil-air measurements were made. Measured values were used to derive a predictive equation for pesticide Ksoil-air values based on temperature, relative humidity, soil organic carbon content, and pesticide-specific octanol-air partition coefficients. Pesticide volatilization losses from soil, calculated with the newly derived Ksoil-air predictive equation and a previously described pesticide volatilization model, were compared to previous results and showed that the choice of Ksoil-air predictive equation mainly affected the more-volatile pesticides and that the way in which relative humidity was accounted for was the most critical difference.

Periprosthetic infection: where do we stand with regard to Gram stain?

PubMed

Ghanem, Elie; Ketonis, Constantinos; Restrepo, Camilo; Joshi, Ashish; Barrack, Robert; Parvizi, Javad

2009-02-01

One of the routinely used intraoperative tests for diagnosis of periprosthetic infection (PPI) is the Gram stain. It is not known if the result of this test can vary according to the type of joint affected or the number of specimen samples collected. We examined the role of this diagnostic test in a large cohort of patients from a single institution. A positive gram stain was defined as the visualization of bacterial cells or "many neutrophils" (> 5 per high-power field) in the smear. The sensitivity, specificity, and predictive values of each individual diagnostic arm of Gram stain were determined. Combinations were performed in series, which required both tests to be positive to confirm infection, and also in parallel, which necessitated both tests to be negative to rule out infection. The presence of organisms and "many" neutrophils on a Gram smear had high specificity (98-100%) and positive predictive value (89-100%) in both THA and TKA. The sensitivities (30-50%) and negative predictive values (70-79%) of the 2 tests were low for both joint types. When the 2 tests were combined in series, the specificity and positive predictive value were absolute (100%). The sensitivity and the negative predictive value improved for both THA and TKA (43-64% and 82%, respectively). Although the 2 diagnostic arms of Gram staining can be combined to achieve improved negative predictive value (82%), Gram stain continues to have little value in ruling out PPI. With the advances in the field of molecular biology, novel diagnostic modalities need to be designed that can replace these traditional and poor tests.

Conditional Toxicity Value (CTV) Predictor: An In Silico Approach for Generating Quantitative Risk Estimates for Chemicals.

PubMed

Wignall, Jessica A; Muratov, Eugene; Sedykh, Alexander; Guyton, Kathryn Z; Tropsha, Alexander; Rusyn, Ivan; Chiu, Weihsueh A

2018-05-01

Human health assessments synthesize human, animal, and mechanistic data to produce toxicity values that are key inputs to risk-based decision making. Traditional assessments are data-, time-, and resource-intensive, and they cannot be developed for most environmental chemicals owing to a lack of appropriate data. As recommended by the National Research Council, we propose a solution for predicting toxicity values for data-poor chemicals through development of quantitative structure-activity relationship (QSAR) models. We used a comprehensive database of chemicals with existing regulatory toxicity values from U.S. federal and state agencies to develop quantitative QSAR models. We compared QSAR-based model predictions to those based on high-throughput screening (HTS) assays. QSAR models for noncancer threshold-based values and cancer slope factors had cross-validation-based Q 2 of 0.25-0.45, mean model errors of 0.70-1.11 log 10 units, and applicability domains covering >80% of environmental chemicals. Toxicity values predicted from QSAR models developed in this study were more accurate and precise than those based on HTS assays or mean-based predictions. A publicly accessible web interface to make predictions for any chemical of interest is available at http://toxvalue.org. An in silico tool that can predict toxicity values with an uncertainty of an order of magnitude or less can be used to quickly and quantitatively assess risks of environmental chemicals when traditional toxicity data or human health assessments are unavailable. This tool can fill a critical gap in the risk assessment and management of data-poor chemicals. https://doi.org/10.1289/EHP2998.

Fetal nasal bone hypoplasia in the second trimester: Comparison of diagnostic methods for predicting trisomy 21 (Down syndrome).

PubMed

Has, Recep; Akel, Esra Gilbaz; Kalelioglu, Ibrahim H; Dural, Ozlem; Yasa, Cenk; Esmer, Aytül Corbacioglu; Yuksel, Atıl; Yildirim, Alkan; Ibrahimoglu, Lemi; Ermis, Hayri

2016-02-01

The aim of this prospective observational study was to identify the best method for use in diagnosing fetal nasal bone (NB) hypoplasia in the second trimester as a means of predicting trisomy 21 (Down syndrome). The NB length (NBL), NBL percentiles, and NBL multiple-of-median (MoM) values and the biparietal diameter-to-NBL ratios were calculated and compared in an attempt to identify the best predictive method and most appropriate cutoff value. Predictive values for several cutoff points were calculated. Receiver operating characteristic curves at a fixed 5% false-positive rate were used to compare the four methods. NBL measurements were obtained from 2,211 (95.6%) of a total of 2,314 fetuses. Data from 1,689 of those 2,211 fetuses were used to obtain reference ranges, derive a linear regression equation, and calculate NBL percentiles and MoM values. Using a fixed 5% false-positive rate, we found 25.5% sensitivity for NBL (95% confidence interval [CI], 15-39.1) and 23.5% sensitivity for NBL percentiles (95% CI, 13.4-37), NBL MoM values (95% CI, 13.4-37), and biparietal diameter-to-NBL ratios (95% CI, 13.4-37). Our study demonstrated that all four methods can be used in the second trimester for diagnosing fetal NB hypoplasia as a means of predicting trisomy 21 because their predictive values are similar at a fixed 5% false-positive rate. For simplicity of use, we recommend using 3 mm as the NBL cutoff value. © 2015 Wiley Periodicals, Inc.

Three-dimensional computed tomographic volumetry precisely predicts the postoperative pulmonary function.

PubMed

Kobayashi, Keisuke; Saeki, Yusuke; Kitazawa, Shinsuke; Kobayashi, Naohiro; Kikuchi, Shinji; Goto, Yukinobu; Sakai, Mitsuaki; Sato, Yukio

2017-11-01

It is important to accurately predict the patient's postoperative pulmonary function. The aim of this study was to compare the accuracy of predictions of the postoperative residual pulmonary function obtained with three-dimensional computed tomographic (3D-CT) volumetry with that of predictions obtained with the conventional segment-counting method. Fifty-three patients scheduled to undergo lung cancer resection, pulmonary function tests, and computed tomography were enrolled in this study. The postoperative residual pulmonary function was predicted based on the segment-counting and 3D-CT volumetry methods. The predicted postoperative values were compared with the results of postoperative pulmonary function tests. Regarding the linear correlation coefficients between the predicted postoperative values and the measured values, those obtained using the 3D-CT volumetry method tended to be higher than those acquired using the segment-counting method. In addition, the variations between the predicted and measured values were smaller with the 3D-CT volumetry method than with the segment-counting method. These results were more obvious in COPD patients than in non-COPD patients. Our findings suggested that the 3D-CT volumetry was able to predict the residual pulmonary function more accurately than the segment-counting method, especially in patients with COPD. This method might lead to the selection of appropriate candidates for surgery among patients with a marginal pulmonary function.

Accuracy of stroke volume variation in predicting fluid responsiveness: a systematic review and meta-analysis.

PubMed

Zhang, Zhongheng; Lu, Baolong; Sheng, Xiaoyan; Jin, Ni

2011-12-01

Stroke volume variation (SVV) appears to be a good predictor of fluid responsiveness in critically ill patients. However, a wide range of its predictive values has been reported in recent years. We therefore undertook a systematic review and meta-analysis of clinical trials that investigated the diagnostic value of SVV in predicting fluid responsiveness. Clinical investigations were identified from several sources, including MEDLINE, EMBASE, WANFANG, and CENTRAL. Original articles investigating the diagnostic value of SVV in predicting fluid responsiveness were considered to be eligible. Participants included critically ill patients in the intensive care unit (ICU) or operating room (OR) who require hemodynamic monitoring. A total of 568 patients from 23 studies were included in our final analysis. Baseline SVV was correlated to fluid responsiveness with a pooled correlation coefficient of 0.718. Across all settings, we found a diagnostic odds ratio of 18.4 for SVV to predict fluid responsiveness at a sensitivity of 0.81 and specificity of 0.80. The SVV was of diagnostic value for fluid responsiveness in OR or ICU patients monitored with the PiCCO or the FloTrac/Vigileo system, and in patients ventilated with tidal volume greater than 8 ml/kg. SVV is of diagnostic value in predicting fluid responsiveness in various settings.

Predictive Validity of a Cigarette Purchase Task in a Randomized Controlled Trial of Contingent Vouchers for Smoking in Individuals With Substance Use Disorders

PubMed Central

Mackillop, James; Murphy, Cara M.; Martin, Rosemarie A.; Stojek, Monika; Tidey, Jennifer W.; Colby, Suzanne M.

2016-01-01

Abstract Introduction: A cigarette purchase task (CPT) is a behavioral economic measure of the reinforcing value of smoking in monetary terms (ie, cigarette demand). This study investigated whether cigarette demand predicted response to contingent monetary rewards for abstinence among individuals with substance use disorders. It also sought to replicate evidence for greater price sensitivity at whole-dollar pack price transitions (ie, left-digit effects). Methods: Participants ( N = 338) were individuals in residential substance use disorder treatment who participated in a randomized controlled trial that compared contingent vouchers to noncontingent vouchers for smoking abstinence. Baseline demand indices were used to predict number of abstinent days during the 14-day voucher period (after the reduction lead-in) and at 1 and 3 months afterward. Results: Demand indices correlated with measures of smoking and nicotine dependence. As measured by elasticity, intensity and Omax , higher demand significantly predicted fewer abstinent exhaled carbon monoxide readings during voucher period for individuals in the noncontingent vouchers condition. Breakpoint exhibited a trend-level association with abstinent exhaled carbon monoxide readings. Demand indices did not predict abstinence in the contingent vouchers group, and did not predict abstinence at 1- and 3-month follow-ups. Left-digit price transitions were associated with significantly greater reductions in consumption. Conclusions: The association of cigarette demand with smoking behavior only in the group for whom abstinence was not incentivized indicates that CPT assesses the value of smoking more than the value of money per se and that vouchers counteract the effects of the intrinsic reinforcing value of cigarettes. Results provide initial short-term evidence of predictive validity for the CPT indices. Implications: This study provides the first evidence of the validity of the CPT for predicting early response to brief advice for smoking cessation plus nicotine replacement in smokers with substance dependence. However, demand for cigarettes did not predict voucher-based treatment response, indicating that incentives serve as a powerful motivator not to smoke that acts in opposition to the intrinsic reinforcing value of cigarettes and that the indices reflect the value of smoking more than the value of money per se. PMID:26498173

Addendum to the article: Misuse of null hypothesis significance testing: Would estimation of positive and negative predictive values improve certainty of chemical risk assessment?

PubMed

Bundschuh, Mirco; Newman, Michael C; Zubrod, Jochen P; Seitz, Frank; Rosenfeldt, Ricki R; Schulz, Ralf

2015-03-01

We argued recently that the positive predictive value (PPV) and the negative predictive value (NPV) are valuable metrics to include during null hypothesis significance testing: They inform the researcher about the probability of statistically significant and non-significant test outcomes actually being true. Although commonly misunderstood, a reported p value estimates only the probability of obtaining the results or more extreme results if the null hypothesis of no effect was true. Calculations of the more informative PPV and NPV require a priori estimate of the probability (R). The present document discusses challenges of estimating R.

Getting off on the right foot: subjective value versus economic value in predicting longitudinal job outcomes from job offer negotiations.

PubMed

Curhan, Jared R; Elfenbein, Hillary Anger; Kilduff, Gavin J

2009-03-01

Although negotiation experiences can affect a negotiator's ensuing attitudes and behavior, little is known about their long-term consequences. Using a longitudinal survey design, the authors tested the degree to which economic and subjective value achieved in job offer negotiations predicts employees' subsequent job attitudes and intentions concerning turnover. Results indicate that subjective value predicts greater compensation satisfaction and job satisfaction and lower turnover intention measured 1 year later. Surprisingly, the economic outcomes that negotiators achieved had no apparent effects on these factors. Implications, limitations, and future directions are discussed. (c) 2009 APA, all rights reserved.

Combination of serum angiopoietin-2 and uterine artery Doppler for prediction of preeclampsia.

PubMed

Puttapitakpong, Ploynin; Phupong, Vorapong

2016-02-01

The aim of this study was to determine the predictive value of the combination of serum angiopoietin-2 (Ang-2) levels and uterine artery Doppler for the detection of preeclampsia in women at 16-18 weeks of gestation and to identify other pregnancy complications that could be predicted with these combined tests. Maternal serum Ang-2 levels were measured, and uterine artery Doppler was performed in 400 pregnant women. The main outcome was preeclampsia. The predictive values of this combination were calculated. Twenty-five women (6.3%) developed preeclampsia. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of uterine artery Doppler combined with serum Ang-2 levels for the prediction of preeclampsia were 24.0%, 94.4%, 22.2% and 94.9%, respectively. For the prediction of early-onset preeclampsia, the sensitivity, specificity, PPV and NPV were 57.1%, 94.1%, 14.8% and 99.2%, respectively. Patients with abnormal uterine artery Doppler and abnormal serum Ang-2 levels (above 19.5 ng ml(-1)) were at higher risk for preterm delivery (relative risk=2.7, 95% confidence interval 1.2-5.8). Our findings revealed that the combination of uterine artery Doppler and serum Ang-2 levels at 16-18 weeks of gestation can be used to predict early-onset preeclampsia but not overall preeclampsia. Thus, this combination may be a useful early second trimester screening test for the prediction of early-onset preeclampsia.

Predicting drug-induced liver injury in human with Naïve Bayes classifier approach.

PubMed

Zhang, Hui; Ding, Lan; Zou, Yi; Hu, Shui-Qing; Huang, Hai-Guo; Kong, Wei-Bao; Zhang, Ji

2016-10-01

Drug-induced liver injury (DILI) is one of the major safety concerns in drug development. Although various toxicological studies assessing DILI risk have been developed, these methods were not sufficient in predicting DILI in humans. Thus, developing new tools and approaches to better predict DILI risk in humans has become an important and urgent task. In this study, we aimed to develop a computational model for assessment of the DILI risk with using a larger scale human dataset and Naïve Bayes classifier. The established Naïve Bayes prediction model was evaluated by 5-fold cross validation and an external test set. For the training set, the overall prediction accuracy of the 5-fold cross validation was 94.0 %. The sensitivity, specificity, positive predictive value and negative predictive value were 97.1, 89.2, 93.5 and 95.1 %, respectively. The test set with the concordance of 72.6 %, sensitivity of 72.5 %, specificity of 72.7 %, positive predictive value of 80.4 %, negative predictive value of 63.2 %. Furthermore, some important molecular descriptors related to DILI risk and some toxic/non-toxic fragments were identified. Thus, we hope the prediction model established here would be employed for the assessment of human DILI risk, and the obtained molecular descriptors and substructures should be taken into consideration in the design of new candidate compounds to help medicinal chemists rationally select the chemicals with the best prospects to be effective and safe.

Towards a chromatographic similarity index to establish localised quantitative structure-retention relationships for retention prediction. II Use of Tanimoto similarity index in ion chromatography.

PubMed

Park, Soo Hyun; Talebi, Mohammad; Amos, Ruth I J; Tyteca, Eva; Haddad, Paul R; Szucs, Roman; Pohl, Christopher A; Dolan, John W

2017-11-10

Quantitative Structure-Retention Relationships (QSRR) are used to predict retention times of compounds based only on their chemical structures encoded by molecular descriptors. The main concern in QSRR modelling is to build models with high predictive power, allowing reliable retention prediction for the unknown compounds across the chromatographic space. With the aim of enhancing the prediction power of the models, in this work, our previously proposed QSRR modelling approach called "federation of local models" is extended in ion chromatography to predict retention times of unknown ions, where a local model for each target ion (unknown) is created using only structurally similar ions from the dataset. A Tanimoto similarity (TS) score was utilised as a measure of structural similarity and training sets were developed by including ions that were similar to the target ion, as defined by a threshold value. The prediction of retention parameters (a- and b-values) in the linear solvent strength (LSS) model in ion chromatography, log k=a - blog[eluent], allows the prediction of retention times under all eluent concentrations. The QSRR models for a- and b-values were developed by a genetic algorithm-partial least squares method using the retention data of inorganic and small organic anions and larger organic cations (molecular mass up to 507) on four Thermo Fisher Scientific columns (AS20, AS19, AS11HC and CS17). The corresponding predicted retention times were calculated by fitting the predicted a- and b-values of the models into the LSS model equation. The predicted retention times were also plotted against the experimental values to evaluate the goodness of fit and the predictive power of the models. The application of a TS threshold of 0.6 was found to successfully produce predictive and reliable QSRR models (Q ext(F2) 2 >0.8 and Mean Absolute Error<0.1), and hence accurate retention time predictions with an average Mean Absolute Error of 0.2min. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

Class-Related Emotions in Secondary Physical Education: A Control-Value Theory Approach

ERIC Educational Resources Information Center

Simonton, Kelly L.; Garn, Alex C.; Solmon, Melinda Ann

2017-01-01

Purpose: Grounded in control-value theory, a model of students' achievement emotions in physical education (PE) was investigated. Methods: A path analysis tested hypotheses that students' (N = 529) perceptions of teacher responsiveness, assertiveness, and clarity predict control and value beliefs which, in turn, predict enjoyment and boredom.…

Predictive value of first fasting plasma glucose compared with admission plasma glucose for undiagnosed diabetes in a stable cardiology population.

PubMed

Wen, Zhu-zhi; Zhang, Xin-mei; Mai, Zun; Geng, Deng-feng; Wang, Jing-feng

2012-09-01

The study compared the predictive value of admission plasma glucose (APG) and first fasting plasma glucose (FPG) in stratifying patients meriting an oral glucose tolerance test (OGTT). Characteristics of APG, FPG and OGTT 2-hour glucose as well as other blood measurements, physical examinations and medical information were assessed in 994 patients without known diabetes. The prevalences of diabetes and impaired glucose tolerance were 24.6% and 37.9%, according to an OGTT, respectively. The first FPG demonstrated stronger predictive value in diagnosing diabetes than APG did both in overall and in patients with less clinical value. Compared to the first FPG, APG provided less value to coronary artery disease, hypertension and high-sensitivity C-reactive protein for diabetes screening. The first FPG exerted more predictive value than APG did and was still a preferable reference prior to APG in stratifying patients for undiagnosed diabetes by an OGTT. Copyright © 2012 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Hierarchical time series bottom-up approach for forecast the export value in Central Java

NASA Astrophysics Data System (ADS)

Mahkya, D. A.; Ulama, B. S.; Suhartono

2017-10-01

The purpose of this study is Getting the best modeling and predicting the export value of Central Java using a Hierarchical Time Series. The export value is one variable injection in the economy of a country, meaning that if the export value of the country increases, the country’s economy will increase even more. Therefore, it is necessary appropriate modeling to predict the export value especially in Central Java. Export Value in Central Java are grouped into 21 commodities with each commodity has a different pattern. One approach that can be used time series is a hierarchical approach. Hierarchical Time Series is used Buttom-up. To Forecast the individual series at all levels using Autoregressive Integrated Moving Average (ARIMA), Radial Basis Function Neural Network (RBFNN), and Hybrid ARIMA-RBFNN. For the selection of the best models used Symmetric Mean Absolute Percentage Error (sMAPE). Results of the analysis showed that for the Export Value of Central Java, Bottom-up approach with Hybrid ARIMA-RBFNN modeling can be used for long-term predictions. As for the short and medium-term predictions, it can be used a bottom-up approach RBFNN modeling. Overall bottom-up approach with RBFNN modeling give the best result.

Predictive genetic testing for the identification of high-risk groups: a simulation study on the impact of predictive ability

PubMed Central

2011-01-01

Background Genetic risk models could potentially be useful in identifying high-risk groups for the prevention of complex diseases. We investigated the performance of this risk stratification strategy by examining epidemiological parameters that impact the predictive ability of risk models. Methods We assessed sensitivity, specificity, and positive and negative predictive value for all possible risk thresholds that can define high-risk groups and investigated how these measures depend on the frequency of disease in the population, the frequency of the high-risk group, and the discriminative accuracy of the risk model, as assessed by the area under the receiver-operating characteristic curve (AUC). In a simulation study, we modeled genetic risk scores of 50 genes with equal odds ratios and genotype frequencies, and varied the odds ratios and the disease frequency across scenarios. We also performed a simulation of age-related macular degeneration risk prediction based on published odds ratios and frequencies for six genetic risk variants. Results We show that when the frequency of the high-risk group was lower than the disease frequency, positive predictive value increased with the AUC but sensitivity remained low. When the frequency of the high-risk group was higher than the disease frequency, sensitivity was high but positive predictive value remained low. When both frequencies were equal, both positive predictive value and sensitivity increased with increasing AUC, but higher AUC was needed to maximize both measures. Conclusions The performance of risk stratification is strongly determined by the frequency of the high-risk group relative to the frequency of disease in the population. The identification of high-risk groups with appreciable combinations of sensitivity and positive predictive value requires higher AUC. PMID:21797996

Mapping the EORTC QLQ-C30 onto the EQ-5D-3L: assessing the external validity of existing mapping algorithms.

PubMed

Doble, Brett; Lorgelly, Paula

2016-04-01

To determine the external validity of existing mapping algorithms for predicting EQ-5D-3L utility values from EORTC QLQ-C30 responses and to establish their generalizability in different types of cancer. A main analysis (pooled) sample of 3560 observations (1727 patients) and two disease severity patient samples (496 and 93 patients) with repeated observations over time from Cancer 2015 were used to validate the existing algorithms. Errors were calculated between observed and predicted EQ-5D-3L utility values using a single pooled sample and ten pooled tumour type-specific samples. Predictive accuracy was assessed using mean absolute error (MAE) and standardized root-mean-squared error (RMSE). The association between observed and predicted EQ-5D utility values and other covariates across the distribution was tested using quantile regression. Quality-adjusted life years (QALYs) were calculated using observed and predicted values to test responsiveness. Ten 'preferred' mapping algorithms were identified. Two algorithms estimated via response mapping and ordinary least-squares regression using dummy variables performed well on number of validation criteria, including accurate prediction of the best and worst QLQ-C30 health states, predicted values within the EQ-5D tariff range, relatively small MAEs and RMSEs, and minimal differences between estimated QALYs. Comparison of predictive accuracy across ten tumour type-specific samples highlighted that algorithms are relatively insensitive to grouping by tumour type and affected more by differences in disease severity. Two of the 'preferred' mapping algorithms suggest more accurate predictions, but limitations exist. We recommend extensive scenario analyses if mapped utilities are used in cost-utility analyses.

Prediction of wastewater treatment plants performance based on artificial fish school neural network

NASA Astrophysics Data System (ADS)

Zhang, Ruicheng; Li, Chong

2011-10-01

A reliable model for wastewater treatment plant is essential in providing a tool for predicting its performance and to form a basis for controlling the operation of the process. This would minimize the operation costs and assess the stability of environmental balance. For the multi-variable, uncertainty, non-linear characteristics of the wastewater treatment system, an artificial fish school neural network prediction model is established standing on actual operation data in the wastewater treatment system. The model overcomes several disadvantages of the conventional BP neural network. The results of model calculation show that the predicted value can better match measured value, played an effect on simulating and predicting and be able to optimize the operation status. The establishment of the predicting model provides a simple and practical way for the operation and management in wastewater treatment plant, and has good research and engineering practical value.

Prediction of venous wound healing with laser speckle imaging.

PubMed

van Vuuren, Timme Maj; Van Zandvoort, Carina; Doganci, Suat; Zwiers, Ineke; tenCate-Hoek, Arina J; Kurstjens, Ralph Lm; Wittens, Cees Ha

2017-12-01

Introduction Laser speckle imaging is used for noninvasive assessment of blood flow of cutaneous wounds. The aim of this study was to assess if laser speckle imaging can be used as a predictor of venous ulcer healing. Methods After generating the flux speckle images, three regions of interest (ROI) were identified to measure the flow. Sensitivity, specificity, negative predictive value, and positive predictive value for ulcer healing were calculated. Results In total, 17 limbs were included. A sensitivity of 92.3%, specificity of 75.0%, PPV of 80.0%, and NPV 75.0% were found in predicting wound healing based on laser speckle images. Mean flux values were lowest in the center (ROI I) and showed an increase at the wound edge (ROI II, p = 0.03). Conclusion Laser speckle imaging shows acceptable sensitivity and specificity rates in predicting venous ulcer healing. The wound edge proved to be the best probability for the prediction of wound healing.

Raman spectroscopy compared against traditional predictors of shear force in lamb m. longissimus lumborum.

PubMed

Fowler, Stephanie M; Schmidt, Heinar; van de Ven, Remy; Wynn, Peter; Hopkins, David L

2014-12-01

A Raman spectroscopic hand held device was used to predict shear force (SF) of 80 fresh lamb m. longissimus lumborum (LL) at 1 and 5days post mortem (PM). Traditional predictors of SF including sarcomere length (SL), particle size (PS), cooking loss (CL), percentage myofibrillar breaks and pH were also measured. SF values were regressed against Raman spectra using partial least squares regression and against the traditional predictors using linear regression. The best prediction of shear force values used spectra at 1day PM to predict shear force at 1day which gave a root mean square error of prediction (RMSEP) of 13.6 (Null=14.0) and the R(2) between observed and cross validated predicted values was 0.06 (R(2)cv). Overall, for fresh LL, the predictability SF, by either the Raman hand held probe or traditional predictors was low. Copyright © 2014 Elsevier Ltd. All rights reserved.

Signal-averaged P wave in patients with paroxysmal atrial fibrillation.

PubMed

Rosenheck, S

1997-10-01

The theoretical and experimental rational of atrial signal-averaged ECG in patients with AF is delay in the intra-atrial and interatrial conduction. Similar to the ventricular signal-averaged ECG, the atrial signal-averaged ECG is an averaging of a high number of consecutive P waves that match the template created earlier P wave triggering is preferred over QRS triggering because of more accurate aligning. However, the small amplitude of the atrial ECG and its gradual increase from the isoelectric line may create difficulties in defining the start point if P wave triggering is used. Studies using P wave triggering and those using QRS triggering demonstrate a prolonged P wave duration in patients with paroxysmal AF. The negative predictive value of this test is relatively high at 60%-80%. The positive predictive value of atrial signal-averaged ECGs in predicting the risk of AF is considerably lower than the negative predictive value. All the data accumulated prospectively on the predictive value of P wave signal-averaging was determined only in patients undergoing coronary bypass surgery or following MI; its value in other patients with paroxysmal AF is still not determined. The clinical role of frequency-domain analysis (alone or added to time-domain analysis) remains undefined. Because of this limited knowledge on the predictive value of P wave signal-averaging, it is still not clinical medicine, and further research is needed before atrial signal-averaged ECG will be part of clinical testing.

Diagnostic accuracy of APRI and FIB-4 for predicting hepatitis B virus-related liver fibrosis accompanied with hepatocellular carcinoma.

PubMed

Xiao, Guangqin; Zhu, Feng; Wang, Min; Zhang, Hang; Ye, Dawei; Yang, Jiayin; Jiang, Li; Liu, Chang; Yan, Lunan; Qin, Renyi

2016-10-01

Aspartate aminotransferase to platelet ratio index (APRI) and the fibrosis index based on four factors (FIB-4) are the two most focused non-invasive models to assess liver fibrosis. We aimed to examine the validity of these two models for predicting hepatitis B virus (HBV)-related liver fibrosis accompanied with hepatocellular carcinoma (HCC). We enrolled HBV-infected patients with liver cancer who had received hepatectomy. The accuracy of APRI and FIB-4 for diagnosing liver fibrosis was assessed based on their sensitivity, specificity, diagnostic efficiency, positive predictive value (PPV), negative predictive value (NPV), kappa (κ) value and area under the receiver-operating characteristic curve (AUC). Finally 2176 patients were included, with 1682 retrospective subjects and 494 prospective subjects. APRI (rs=0.310) and FIB-4 (rs=0.278) were positively correlated with liver fibrosis. And χ(2) analysis demonstrated that APRI and FIB-4 values correlated with different levels of liver fibrosis with all P values less than 0.01. The AUC values for APRI and FIB-4 were 0.685 and 0.626 (P=0.73) for predicting significant fibrosis, 0.681 and 0.648 (P=0.81) for differentiation of advanced fibrosis and 0.676 and 0.652 (P=0.77) for diagnosing cirrhosis. APRI and FIB-4 correlate with liver fibrosis. However these two models have low accuracy for predicting HBV-related liver fibrosis in HCC patients. Copyright © 2016. Published by Elsevier Ltd.

Sirc-cvs cytotoxicity test: an alternative for predicting rodent acute systemic toxicity.

PubMed

Kitagaki, Masato; Wakuri, Shinobu; Hirota, Morihiko; Tanaka, Noriho; Itagaki, Hiroshi

2006-10-01

An in vitro crystal violet staining method using the rabbit cornea-derived cell line (SIRC-CVS) has been developed as an alternative to predict acute systemic toxicity in rodents. Seventy-nine chemicals, the in vitro cytotoxicity of which was already reported by the Multicenter Evaluation of In vitro Toxicity (MEIC) and ICCVAM/ECVAM, were selected as test compounds. The cells were incubated with the chemicals for 72 hrs and the IC(50) and IC(35) values (microg/mL) were obtained. The results were compared to the in vivo (rat or mouse) "most toxic" oral, intraperitoneal, subcutaneous and intravenous LD(50) values (mg/kg) taken from the RTECS database for each of the chemicals by using Pearson's correlation statistics. The following parameters were calculated: accuracy, sensitivity, specificity, prevalence, positive predictability, and negative predictability. Good linear correlations (Pearson's coefficient; r>0.6) were observed between either the IC(50) or the IC(35) values and all the LD(50) values. Among them, a statistically significant high correlation (r=0.8102, p<0.001) required for acute systemic toxicity prediction was obtained between the IC(50) values and the oral LD(50) values. By using the cut-off concentrations of 2,000 mg/kg (LD(50)) and 4,225 microg/mL (IC(50)), no false negatives were observed, and the accuracy was 84.8%. From this, it is concluded that this method could be used to predict the acute systemic toxicity potential of chemicals in rodents.

The utility of QSARs in predicting acute fish toxicity of pesticide metabolites: A retrospective validation approach.

PubMed

Burden, Natalie; Maynard, Samuel K; Weltje, Lennart; Wheeler, James R

2016-10-01

The European Plant Protection Products Regulation 1107/2009 requires that registrants establish whether pesticide metabolites pose a risk to the environment. Fish acute toxicity assessments may be carried out to this end. Considering the total number of pesticide (re-) registrations, the number of metabolites can be considerable, and therefore this testing could use many vertebrates. EFSA's recent "Guidance on tiered risk assessment for plant protection products for aquatic organisms in edge-of-field surface waters" outlines opportunities to apply non-testing methods, such as Quantitative Structure Activity Relationship (QSAR) models. However, a scientific evidence base is necessary to support the use of QSARs in predicting acute fish toxicity of pesticide metabolites. Widespread application and subsequent regulatory acceptance of such an approach would reduce the numbers of animals used. The work presented here intends to provide this evidence base, by means of retrospective data analysis. Experimental fish LC50 values for 150 metabolites were extracted from the Pesticide Properties Database (http://sitem.herts.ac.uk/aeru/ppdb/en/atoz.htm). QSAR calculations were performed to predict fish acute toxicity values for these metabolites using the US EPA's ECOSAR software. The most conservative predicted LC50 values generated by ECOSAR were compared with experimental LC50 values. There was a significant correlation between predicted and experimental fish LC50 values (Spearman rs = 0.6304, p < 0.0001). For 62% of metabolites assessed, the QSAR predicted values are equal to or lower than their respective experimental values. Refined analysis, taking into account data quality and experimental variation considerations increases the proportion of sufficiently predictive estimates to 91%. For eight of the nine outliers, there are plausible explanation(s) for the disparity between measured and predicted LC50 values. Following detailed consideration of the robustness of this non-testing approach, it can be concluded there is a strong data driven rationale for the applicability of QSAR models in the metabolite assessment scheme recommended by EFSA. As such there is value in further refining this approach, to improve the method and enable its future incorporation into regulatory guidance and practice. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

A performance test of the log and tree grades for eastern white pine

Treesearch

Robert L. Brisbin

1972-01-01

The results of testing the Forest Service standard tree grades and sawlog grades for eastern white pine on an independent sample of 75 trees and 299 logs in southwestern Maine. The total predicted value of the 75 trees was 3 percent higher than the actual value. The total predicted value of the 299 logs was 2 percent higher than the actual value. The differences...

Combined panel of serum human tissue kallikreins and CA-125 for the detection of epithelial ovarian cancer.

PubMed

Koh, Stephen Chee Liang; Huak, Chan Yiong; Lutan, Delfi; Marpuang, Johny; Ketut, Suwiyoga; Budiana, Nyoma Gede; Saleh, Agustria Zainu; Aziz, Mohamad Farid; Winarto, Hariyono; Pradjatmo, Heru; Hoan, Nguyen Khac Han; Thanh, Pham Viet; Choolani, Mahesh

2012-07-01

To determine the predictive accuracy of the combined panels of serum human tissue kallikreins (hKs) and CA-125 for the detection of epithelial ovarian cancer. Serum specimens collected from 5 Indonesian centers and 1 Vietnamese center were analyzed for CA-125, hK6, and hK10 levels. A total of 375 specimens from patients presenting with ovarian tumors, which include 156 benign cysts, 172 epithelial ovarian cancers (stage I/II, n=72; stage III/IV, n=100), 36 germ cell tumors and 11 borderline tumors, were included in the study analysis. Receiver operating characteristic analysis were performed to determine the cutoffs for age, CA-125, hK6, and hK10. Sensitivity, specificity, negative, and positive predictive values were determined for various combinations of the biomarkers. The levels of hK6 and hK10 were significantly elevated in ovarian cancer cases compared to benign cysts. Combination of 3 markers, age/CA-125/hk6 or CA-125/hk6/hk10, showed improved specificity (100%) and positive predictive value (100%) for prediction of ovarian cancer, when compared to the performance of single markers having 80-92% specificity and 74-87% positive predictive value. Four-marker combination, age/CA-125/hK6/hK10 also showed 100% specificity and 100% positive predictive value, although it demonstrated low sensitivity (11.9%) and negative predictive value (52.8%). The combination of human tissue kallikreins and CA-125 showed potential for improving prediction of epithelial ovarian cancer in patients presenting with ovarian tumors.

A novel clinical index for the assessment of RVD in acute pulmonary embolism: Blood pressure index.

PubMed

Ates, Hale; Ates, Ihsan; Kundi, Harun; Arikan, Mehmet Fettah; Yilmaz, Fatma Meric

2017-10-01

This study aims to investigate the role of the blood pressure index (BPI), which is a new index that we developed, in detection of right ventricular dysfunction (RVD) in acute pulmonary embolism (APE). A total of 539 patients, (253 males and 286 females), diagnosed with APE using computer tomography pulmonary angiography were included in the study. The BPI was obtained by dividing systolic blood pressure (SBP) by diastolic blood pressure (DBP). Mean DBP (75±11mmHg vs 63±15mmHg; p<0.001, respectively) was found to be higher in RVD patients compared to those without RVD, whereas BPI (1.5±0.1 vs 1.9±0.2; p<0.001, respectively) was lower. Examining the performance of BPI in prediction of RVD using receiver operating characteristic curve analysis (area under curve±SE=0.975±0.006; p<0.001), it was found that BPI could predict RVD with very high sensitivity (92.8%) and specificity (100%) and had a positive predictive value of 100% and a negative predictive value of 42.1%. According to the analysis, the highest youden index for the optimal prediction value was found to be 0.478 and the BPI≤1.4 was found to predict mortality 68.6% sensitivity and 80.8% specificity (Area under curve±SE=0.777±0.051; p<0.001). We found that BPI was an index with high positive predictive value and low negative predictive value in detection of RVD. Copyright © 2017 Elsevier Inc. All rights reserved.

Focal Low and Global High Permeability Predict the Possibility, Risk, and Location of Hemorrhagic Transformation following Intra-Arterial Thrombolysis Therapy in Acute Stroke.

PubMed

Li, Y; Xia, Y; Chen, H; Liu, N; Jackson, A; Wintermark, M; Zhang, Y; Hu, J; Wu, B; Zhang, W; Tu, J; Su, Z; Zhu, G

2017-09-01

The contrast volume transfer coefficient ( K trans ), which reflects blood-brain barrier permeability, is influenced by circulation and measurement conditions. We hypothesized that focal low BBB permeability values can predict the spatial distribution of hemorrhagic transformation and global high BBB permeability values can predict the likelihood of hemorrhagic transformation. We retrospectively enrolled 106 patients with hemispheric stroke who received intra-arterial thrombolytic treatment. K trans maps were obtained with first-pass perfusion CT data. The K trans values at the region level, obtained with the Alberta Stroke Program Early CT Score system, were compared to determine the differences between the hemorrhagic transformation and nonhemorrhagic transformation regions. The K trans values of the whole ischemic region based on baseline perfusion CT were obtained as a variable to hemorrhagic transformation possibility at the global level. Forty-eight (45.3%) patients had hemorrhagic transformation, and 21 (19.8%) had symptomatic intracranial hemorrhage. At the region level, there were 82 ROIs with hemorrhagic transformation and parenchymal hemorrhage with a mean K trans , 0.5 ± 0.5/min, which was significantly lower than that in the nonhemorrhagic transformation regions ( P < .01). The mean K trans value of 615 nonhemorrhagic transformation ROIs was 0.7 ± 0.6/min. At the global level, there was a significant difference ( P = .01) between the mean K trans values of patients with symptomatic intracranial hemorrhage (1.3 ± 0.9) and those without symptomatic intracranial hemorrhage (0.8 ± 0.4). Only a high K trans value at the global level could predict the occurrence of symptomatic intracranial hemorrhage ( P < .01; OR = 5.04; 95% CI, 2.01-12.65). Global high K trans values can predict the likelihood of hemorrhagic transformation or symptomatic intracranial hemorrhage at the patient level, whereas focal low K trans values can predict the spatial distributions of hemorrhagic transformation at the region level. © 2017 by American Journal of Neuroradiology.

[Evaluation of thermal comfort in a student population: predictive value of an integrated index (Fanger's predicted mean value].

PubMed

Catenacci, G; Terzi, R; Marcaletti, G; Tringali, S

1989-01-01

Practical applications and predictive values of a thermal comfort index (Fanger's PRV) were verified on a sample school population (1236 subjects) by studying the relationships between thermal sensations (subjective analysis), determined by means of an individual questionnaire, and the values of thermal comfort index (objective analysis) obtained by calculating the PMV index individually in the subjects under study. In homogeneous conditions of metabolic expenditure rate and thermal impedence from clothing, significant differences were found between the two kinds of analyses. At 22 degrees C mean radiant and operative temperature, the PMV values averaged 0 and the percentage of subjects who experienced thermal comfort did not exceed 60%. The high level of subjects who were dissatisfied with their environmental thermal conditions confirms the doubts regarding the use of the PMV index as a predictive indicator of thermal comfort, especially considering that the negative answers were not homogeneous nor attributable to the small thermal fluctuations (less than 0.5 degree C) measured in the classrooms.

Prediction of monthly-seasonal precipitation using coupled SVD patterns between soil moisture and subsequent precipitation

Treesearch

Yongqiang Liu

2003-01-01

It was suggested in a recent statistical correlation analysis that predictability of monthly-seasonal precipitation could be improved by using coupled singular value decomposition (SVD) pattems between soil moisture and precipitation instead of their values at individual locations. This study provides predictive evidence for this suggestion by comparing skills of two...

Disentangling neural representations of value and salience in the human brain

PubMed Central

Kahnt, Thorsten; Park, Soyoung Q; Haynes, John-Dylan; Tobler, Philippe N.

2014-01-01

A large body of evidence has implicated the posterior parietal and orbitofrontal cortex in the processing of value. However, value correlates perfectly with salience when appetitive stimuli are investigated in isolation. Accordingly, considerable uncertainty has remained about the precise nature of the previously identified signals. In particular, recent evidence suggests that neurons in the primate parietal cortex signal salience instead of value. To investigate neural signatures of value and salience, here we apply multivariate (pattern-based) analyses to human functional MRI data acquired during a noninstrumental outcome-prediction task involving appetitive and aversive outcomes. Reaction time data indicated additive and independent effects of value and salience. Critically, we show that multivoxel ensemble activity in the posterior parietal cortex encodes predicted value and salience in superior and inferior compartments, respectively. These findings reinforce the earlier reports of parietal value signals and reconcile them with the recent salience report. Moreover, we find that multivoxel patterns in the orbitofrontal cortex correlate with value. Importantly, the patterns coding for the predicted value of appetitive and aversive outcomes are similar, indicating a common neural scale for appetite and aversive values in the orbitofrontal cortex. Thus orbitofrontal activity patterns satisfy a basic requirement for a neural value signal. PMID:24639493

Evaluation of the Predictive Validity of Thermography in Identifying Extravasation With Intravenous Chemotherapy Infusions.

PubMed

Matsui, Yuko; Murayama, Ryoko; Tanabe, Hidenori; Oe, Makoto; Motoo, Yoshiharu; Wagatsuma, Takanori; Michibuchi, Michiko; Kinoshita, Sachiko; Sakai, Keiko; Konya, Chizuko; Sugama, Junko; Sanada, Hiromi

Early detection of extravasation is important, but conventional methods of detection lack objectivity and reliability. This study evaluated the predictive validity of thermography for identifying extravasation during intravenous antineoplastic therapy. Of 257 patients who received chemotherapy through peripheral veins, extravasation was identified in 26. Thermography was performed every 15 to 30 minutes during the infusions. Sensitivity, specificity, positive predictive value, and negative predictive value using thermography were 84.6%, 94.8%, 64.7%, and 98.2%, respectively. This study showed that thermography offers an accurate prediction of extravasation.

Comparison of measured efficiencies of nine turbine designs with efficiencies predicted by two empirical methods

NASA Technical Reports Server (NTRS)

English, Robert E; Cavicchi, Richard H

1951-01-01

Empirical methods of Ainley and Kochendorfer and Nettles were used to predict performances of nine turbine designs. Measured and predicted performances were compared. Appropriate values of blade-loss parameter were determined for the method of Kochendorfer and Nettles. The measured design-point efficiencies were lower than predicted by as much as 0.09 (Ainley and 0.07 (Kochendorfer and Nettles). For the method of Kochendorfer and Nettles, appropriate values of blade-loss parameter ranged from 0.63 to 0.87 and the off-design performance was accurately predicted.

Severe community-acquired pneumonia. Assessment of severity criteria.

PubMed

Ewig, S; Ruiz, M; Mensa, J; Marcos, M A; Martinez, J A; Arancibia, F; Niederman, M S; Torres, A

1998-10-01

The purpose of the study was to validate the criteria used in the guidelines of the American Thoracic Society (ATS) for severe community-acquired pneumonia (CAP). Severe pneumonia was defined as admission to the intensive care unit (ICU). Overall 331 nonsevere (84%) and 64 severe cases (16%) of CAP were prospectively studied. Mortality was 19 of 395 (5%) and 19 of 64 (30%), respectively. Single severity criteria as well as the ATS definition of severe pneumonia were assessed calculating the operative indices. A modified prediction rule including minor (baseline) and major (baseline or evolutionary) criteria was derived. Single minor criteria at admission had a low sensitivity and positive predictive value. Defining severe pneumonia according to the ATS guidelines had a high sensitivity (98%). However, specificity and positive predictive value were low (32% and 24%, respectively). A modified prediction rule (presence of two or three minor criteria [systolic blood pressure < 90 mm Hg, multilobar involvement, PaO2/FIO2 < 250] or one of two major criteria [requirement of mechanical ventilation, presence of septic shock]) had a sensitivity of 78%, a specificity of 94%, a positive predictive value of 75%, and a negative predictive value of 95%. The ATS definition of severe pneumonia was highly sensitive but insufficiently specific and had a low positive predictive value. Our suggested modified rule had a more balanced performance and, if validated in an independent population, may represent a more accurate definition of severe CAP.

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

Delmau, L.H.; Haverlock, T.J.; Sloop, F.V., Jr.

This report presents the work that followed the CSSX model development completed in FY2002. The developed cesium and potassium extraction model was based on extraction data obtained from simple aqueous media. It was tested to ensure the validity of the prediction for the cesium extraction from actual waste. Compositions of the actual tank waste were obtained from the Savannah River Site personnel and were used to prepare defined simulants and to predict cesium distribution ratios using the model. It was therefore possible to compare the cesium distribution ratios obtained from the actual waste, the simulant, and the predicted values. Itmore » was determined that the predicted values agree with the measured values for the simulants. Predicted values also agreed, with three exceptions, with measured values for the tank wastes. Discrepancies were attributed in part to the uncertainty in the cation/anion balance in the actual waste composition, but likely more so to the uncertainty in the potassium concentration in the waste, given the demonstrated large competing effect of this metal on cesium extraction. It was demonstrated that the upper limit for the potassium concentration in the feed ought to not exceed 0.05 M in order to maintain suitable cesium distribution ratios.« less

Sensitivity, Specificity, and Predictive Values: Foundations, Pliabilities, and Pitfalls in Research and Practice.

PubMed

Trevethan, Robert

2017-01-01

Within the context of screening tests, it is important to avoid misconceptions about sensitivity, specificity, and predictive values. In this article, therefore, foundations are first established concerning these metrics along with the first of several aspects of pliability that should be recognized in relation to those metrics. Clarification is then provided about the definitions of sensitivity, specificity, and predictive values and why researchers and clinicians can misunderstand and misrepresent them. Arguments are made that sensitivity and specificity should usually be applied only in the context of describing a screening test's attributes relative to a reference standard; that predictive values are more appropriate and informative in actual screening contexts, but that sensitivity and specificity can be used for screening decisions about individual people if they are extremely high; that predictive values need not always be high and might be used to advantage by adjusting the sensitivity and specificity of screening tests; that, in screening contexts, researchers should provide information about all four metrics and how they were derived; and that, where necessary, consumers of health research should have the skills to interpret those metrics effectively for maximum benefit to clients and the healthcare system.

Sensitivity, Specificity, and Predictive Values: Foundations, Pliabilities, and Pitfalls in Research and Practice

PubMed Central

Trevethan, Robert

2017-01-01

Within the context of screening tests, it is important to avoid misconceptions about sensitivity, specificity, and predictive values. In this article, therefore, foundations are first established concerning these metrics along with the first of several aspects of pliability that should be recognized in relation to those metrics. Clarification is then provided about the definitions of sensitivity, specificity, and predictive values and why researchers and clinicians can misunderstand and misrepresent them. Arguments are made that sensitivity and specificity should usually be applied only in the context of describing a screening test’s attributes relative to a reference standard; that predictive values are more appropriate and informative in actual screening contexts, but that sensitivity and specificity can be used for screening decisions about individual people if they are extremely high; that predictive values need not always be high and might be used to advantage by adjusting the sensitivity and specificity of screening tests; that, in screening contexts, researchers should provide information about all four metrics and how they were derived; and that, where necessary, consumers of health research should have the skills to interpret those metrics effectively for maximum benefit to clients and the healthcare system. PMID:29209603

Cytomegalovirus frequency in neonatal intrahepatic cholestasis determined by serology, histology, immunohistochemistry and PCR

PubMed Central

Bellomo-Brandao, Maria Angela; Andrade, Paula D; Costa, Sandra CB; Escanhoela, Cecilia AF; Vassallo, Jose; Porta, Gilda; De Tommaso, Adriana MA; Hessel, Gabriel

2009-01-01

AIM: To determine cytomegalovirus (CMV) frequency in neonatal intrahepatic cholestasis by serology, histological revision (searching for cytomegalic cells), immunohistochemistry, and polymerase chain reaction (PCR), and to verify the relationships among these methods. METHODS: The study comprised 101 non-consecutive infants submitted for hepatic biopsy between March 1982 and December 2005. Serological results were obtained from the patient’s files and the other methods were performed on paraffin-embedded liver samples from hepatic biopsies. The following statistical measures were calculated: frequency, sensibility, specific positive predictive value, negative predictive value, and accuracy. RESULTS: The frequencies of positive results were as follows: serology, 7/64 (11%); histological revision, 0/84; immunohistochemistry, 1/44 (2%), and PCR, 6/77 (8%). Only one patient had positive immunohistochemical findings and a positive PCR. The following statistical measures were calculated between PCR and serology: sensitivity, 33.3%; specificity, 88.89%; positive predictive value, 28.57%; negative predictive value, 90.91%; and accuracy, 82.35%. CONCLUSION: The frequency of positive CMV varied among the tests. Serology presented the highest positive frequency. When compared to PCR, the sensitivity and positive predictive value of serology were low. PMID:19610143

[Determination of prognostic value of the OESIL risk score at 6 months in a Colombian cohort with syncope evaluated in the emergency department; first Latin American experience].

PubMed

Díaz-Tribaldos, Diana Carolina; Mora, Guillermo; Olaya, Alejandro; Marín, Jorge; Sierra Matamoros, Fabio

2017-07-14

To establish the prognostic value, with sensitivity, specificity, positive predictive value, and negative predictive value for the OESIL syncope risk score to predict the presentation of severe outcomes (death, invasive interventions, and readmission) after 6 months of observation in adults who consulted the emergency department due to syncope. Observational, prospective, and multicentre study with enrolment of subjects older than 18 years, who consulted in the emergency department due to syncope. A record was mad of the demographic and clinical information of all patients. The OESIL risk score was calculated, and severe patient outcomes were followed up during a 6 month period using telephone contact. A total of 161 patients met the inclusion criteria and were followed up for 6 months. A score above or equal to 2 in the risk score, classified as high risk, was present in 72% of the patients. The characteristics of the risk score to predict the combined outcome of mortality, invasive interventions, and readmission for a score above or equal to 2 were 75.7, 30.5, 43.1, and 64.4% for sensitivity, specificity, positive predictive value, and negative predictive value, respectively. A score above or equal to 2 in the OESIL risk score applied in Colombian population was of limited use to predict the studied severe outcomes. This score will be unable to discriminate between patients that benefit of early admission and further clinical studies. Copyright © 2017 Instituto Nacional de Cardiología Ignacio Chávez. Publicado por Masson Doyma México S.A. All rights reserved.

Predictive value of painful popping for a posterior root tear of the medial meniscus in middle-aged to older Asian patients.

PubMed

Bae, Ji-Hoon; Paik, Nak Hwan; Park, Gyu-Won; Yoon, Jung-Ro; Chae, Dong-Ju; Kwon, Jae Ho; Kim, Jong In; Nha, Kyung-Wook

2013-03-01

The purpose of this study was to determine the accuracy, sensitivity, specificity, and predictive values of a single event of painful popping in the presence of a posterior root tear of the medial meniscus in middle-aged to older Asian patients. We conducted a retrospective review of medical records of 936 patients who underwent arthroscopic surgeries for an isolated medial meniscus tear between January 2000 and December 2010. There were 332 men and 604 women with a mean age of 41 years (range, 25 to 66 years). The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of a painful popping sensation for a posterior root tear of the medial meniscus were calculated. Arthroscopy confirmed the presence of posterior root tears of the medial menisci in 237 of 936 patients (25.3%). A single event of a painful popping sensation was present in 86 of these 936 patients (9.1%). Of these 86 patients with a painful popping sensation, 83 (96.5%) were categorized as having an isolated posterior root tear of the medial meniscus. The positive predictive value of a painful popping sensation in identifying a posterior root tear of the medial meniscus was 96.5%, the negative predictive value was 81.8%, the sensitivity was 35.0%, the specificity was 99.5%, and the diagnostic accuracy was 77.9%. A single event of painful popping can be a highly predictive clinical sign of a posterior root tear of the medial meniscus in the middle-aged to older Asian population. However, it has low sensitivity for the detection of a posterior root tear of the medial meniscus. Level IV, therapeutic case series. Copyright © 2013 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Magnetic resonance spectroscopy and brain volumetry in mild cognitive impairment. A prospective study.

PubMed

Fayed, Nicolás; Modrego, Pedro J; García-Martí, Gracián; Sanz-Requena, Roberto; Marti-Bonmatí, Luis

2017-05-01

To assess the accuracy of magnetic resonance spectroscopy (1H-MRS) and brain volumetry in mild cognitive impairment (MCI) to predict conversion to probable Alzheimer's disease (AD). Forty-eight patients fulfilling the criteria of amnestic MCI who underwent a conventional magnetic resonance imaging (MRI) followed by MRS, and T1-3D on 1.5 Tesla MR unit. At baseline the patients underwent neuropsychological examination. 1H-MRS of the brain was carried out by exploring the left medial occipital lobe and ventral posterior cingulated cortex (vPCC) using the LCModel software. A high resolution T1-3D sequence was acquired to carry out the volumetric measurement. A cortical and subcortical parcellation strategy was used to obtain the volumes of each area within the brain. The patients were followed up to detect conversion to probable AD. After a 3-year follow-up, 15 (31.2%) patients converted to AD. The myo-inositol in the occipital cortex and glutamate+glutamine (Glx) in the posterior cingulate cortex predicted conversion to probable AD at 46.1% sensitivity and 90.6% specificity. The positive predictive value was 66.7%, and the negative predictive value was 80.6%, with an overall cross-validated classification accuracy of 77.8%. The volume of the third ventricle, the total white matter and entorhinal cortex predict conversion to probable AD at 46.7% sensitivity and 90.9% specificity. The positive predictive value was 70%, and the negative predictive value was 78.9%, with an overall cross-validated classification accuracy of 77.1%. Combining volumetric measures in addition to the MRS measures the prediction to probable AD has a 38.5% sensitivity and 87.5% specificity, with a positive predictive value of 55.6%, a negative predictive value of 77.8% and an overall accuracy of 73.3%. Either MRS or brain volumetric measures are markers separately of cognitive decline and may serve as a noninvasive tool to monitor cognitive changes and progression to dementia in patients with amnestic MCI, but the results do not support the routine use in the clinical settings. Copyright © 2016 Elsevier Inc. All rights reserved.

NASA-Langley Research Center's participation in a round-robin comparison between some current crack-propagation prediction methods

NASA Technical Reports Server (NTRS)

Hudson, C. M.; Lewis, P. E.

1979-01-01

A round-robin study was conducted which evaluated and compared different methods currently in practice for predicting crack growth in surface-cracked specimens. This report describes the prediction methods used by the Fracture Mechanics Engineering Section, at NASA-Langley Research Center, and presents a comparison between predicted crack growth and crack growth observed in laboratory experiments. For tests at higher stress levels, the correlation between predicted and experimentally determined crack growth was generally quite good. For tests at lower stress levels, the predicted number of cycles to reach a given crack length was consistently higher than the experimentally determined number of cycles. This consistent overestimation of the number of cycles could have resulted from a lack of definition of crack-growth data at low values of the stress intensity range. Generally, the predicted critical flaw sizes were smaller than the experimentally determined critical flaw sizes. This underestimation probably resulted from using plane-strain fracture toughness values to predict failure rather than the more appropriate values based on maximum load.

Predicting the solubility and lability of Zn, Cd, and Pb in soils from a minespoil-contaminated catchment by stable isotopic exchange

NASA Astrophysics Data System (ADS)

Marzouk, E. R.; Chenery, S. R.; Young, S. D.

2013-12-01

The Rookhope catchment of Weardale, England, has a diverse legacy of contaminated soils due to extensive lead mining activity over four centuries. We measured the isotopically exchangeable content of Pb, Cd and Zn (E-values) in a large representative subset of the catchment soils (n = 246) using stable isotope dilution. All three metals displayed a wide range of %E-values (c. 1-100%) but relative lability followed the sequence Cd > Pb > Zn. A refinement of the stable isotope dilution approach also enabled detection of non-reactive metal contained within suspended sub-micron (<0.22 μm) colloidal particles (SCP-metal). For most soils, the presence of non-labile SCP-metal caused only minor over-estimation of E-values (<2%) but the effect was greater for soils with particularly large humus or carbonate contents. Approximately 80%, 53% and 66% of the variability in Zn, Cd and Pb %E-values (respectively) could be explained by pH, loss on ignition and total metal content. E-values were affected by the presence of ore minerals at high metal contents leading to an inconsistent trend in the relationship between %E-value and soil metal concentration. Metal solubility, in the soil suspensions used to measure E-values, was predicted using the WHAM geochemical speciation model (versions VI and VII). The use of total and isotopically exchangeable metal as alternative input variables was compared; the latter provided significantly better predictions of solubility, especially in the case of Zn. Lead solubility was less well predicted by either version of WHAM, with over-prediction at low pH and under-prediction at high soil pH values. Quantify the isotopically exchangeable fractions of Zn, Cd and Pb (E-values), and assess their local and regional variability, using multi-element stable isotope dilution, in a diverse range of soil ecosystems within the catchment of an old Pb/Zn mining area. Assess the controlling influences of soil properties on metal lability and develop predictive algorithms for metal lability in the contaminated catchment based on simple soil properties (such as pH, organic matter (LOI), and total metal content). Examine the incidence of non-isotopically-exchangeable metal held within suspended colloidal particles (SCP-metal) in filtered soil solutions (<0.22 μm) by comparing E-values from isotopic abundance in solutions equilibrated with soil and in a resin phase equilibrated with the separated solution. Assess the ability of a geochemical speciation model, WHAM(VII), to predict metal solubility using isotopically exchangeable metal as an input variable.

[Forest lighting fire forecasting for Daxing'anling Mountains based on MAXENT model].

PubMed

Sun, Yu; Shi, Ming-Chang; Peng, Huan; Zhu, Pei-Lin; Liu, Si-Lin; Wu, Shi-Lei; He, Cheng; Chen, Feng

2014-04-01

Daxing'anling Mountains is one of the areas with the highest occurrence of forest lighting fire in Heilongjiang Province, and developing a lightning fire forecast model to accurately predict the forest fires in this area is of importance. Based on the data of forest lightning fires and environment variables, the MAXENT model was used to predict the lightning fire in Daxing' anling region. Firstly, we studied the collinear diagnostic of each environment variable, evaluated the importance of the environmental variables using training gain and the Jackknife method, and then evaluated the prediction accuracy of the MAXENT model using the max Kappa value and the AUC value. The results showed that the variance inflation factor (VIF) values of lightning energy and neutralized charge were 5.012 and 6.230, respectively. They were collinear with the other variables, so the model could not be used for training. Daily rainfall, the number of cloud-to-ground lightning, and current intensity of cloud-to-ground lightning were the three most important factors affecting the lightning fires in the forest, while the daily average wind speed and the slope was of less importance. With the increase of the proportion of test data, the max Kappa and AUC values were increased. The max Kappa values were above 0.75 and the average value was 0.772, while all of the AUC values were above 0.5 and the average value was 0. 859. With a moderate level of prediction accuracy being achieved, the MAXENT model could be used to predict forest lightning fire in Daxing'anling Mountains.

Quantitative structure-activity relationships (QSARs) for the transformation of organic micropollutants during oxidative water treatment.

PubMed

Lee, Yunho; von Gunten, Urs

2012-12-01

Various oxidants such as chlorine, chlorine dioxide, ferrate(VI), ozone, and hydroxyl radicals can be applied for eliminating organic micropollutant by oxidative transformation during water treatment in systems such as drinking water, wastewater, and water reuse. Over the last decades, many second-order rate constants (k) have been determined for the reaction of these oxidants with model compounds and micropollutants. Good correlations (quantitative structure-activity relationships or QSARs) are often found between the k-values for an oxidation reaction of closely related compounds (i.e. having a common organic functional group) and substituent descriptor variables such as Hammett or Taft sigma constants. In this study, we developed QSARs for the oxidation of organic and some inorganic compounds and organic micropollutants transformation during oxidative water treatment. A number of 18 QSARs were developed based on overall 412 k-values for the reaction of chlorine, chlorine dioxide, ferrate, and ozone with organic compounds containing electron-rich moieties such as phenols, anilines, olefins, and amines. On average, 303 out of 412 (74%) k-values were predicted by these QSARs within a factor of 1/3-3 compared to the measured values. For HO(·) reactions, some principles and estimation methods of k-values (e.g. the Group Contribution Method) are discussed. The developed QSARs and the Group Contribution Method could be used to predict the k-values for various emerging organic micropollutants. As a demonstration, 39 out of 45 (87%) predicted k-values were found within a factor 1/3-3 compared to the measured values for the selected emerging micropollutants. Finally, it is discussed how the uncertainty in the predicted k-values using the QSARs affects the accuracy of prediction for micropollutant elimination during oxidative water treatment. Copyright © 2012 Elsevier Ltd. All rights reserved.

SIM_ADJUST -- A computer code that adjusts simulated equivalents for observations or predictions

USGS Publications Warehouse

Poeter, Eileen P.; Hill, Mary C.

2008-01-01

This report documents the SIM_ADJUST computer code. SIM_ADJUST surmounts an obstacle that is sometimes encountered when using universal model analysis computer codes such as UCODE_2005 (Poeter and others, 2005), PEST (Doherty, 2004), and OSTRICH (Matott, 2005; Fredrick and others (2007). These codes often read simulated equivalents from a list in a file produced by a process model such as MODFLOW that represents a system of interest. At times values needed by the universal code are missing or assigned default values because the process model could not produce a useful solution. SIM_ADJUST can be used to (1) read a file that lists expected observation or prediction names and possible alternatives for the simulated values; (2) read a file produced by a process model that contains space or tab delimited columns, including a column of simulated values and a column of related observation or prediction names; (3) identify observations or predictions that have been omitted or assigned a default value by the process model; and (4) produce an adjusted file that contains a column of simulated values and a column of associated observation or prediction names. The user may provide alternatives that are constant values or that are alternative simulated values. The user may also provide a sequence of alternatives. For example, the heads from a series of cells may be specified to ensure that a meaningful value is available to compare with an observation located in a cell that may become dry. SIM_ADJUST is constructed using modules from the JUPITER API, and is intended for use on any computer operating system. SIM_ADJUST consists of algorithms programmed in Fortran90, which efficiently performs numerical calculations.

[Prognostic prediction of the functional capacity and effectiveness of functional improvement program of the musculoskeletal system among users of preventive care service under long-term care insurance].

PubMed

Sone, Toshimasa; Nakaya, Naoki; Tomata, Yasutake; Aida, Jun; Okubo, Ichiro; Ohara, Satoko; Obuchi, Shuichi; Sugiyama, Michiko; Yasumura, Seiji; Suzuki, Takao; Tsuji, Ichiro

2013-01-01

The purpose of this study was to examine the effectiveness of the Functional Improvement Program of the Musculoskeletal System among users of Preventive Care Service under Long-Term Care Insurance. A total of 3,073 subjects were analyzed. We used the prediction formula to estimate the predicted value of the Kihon Checklist after one year, and calculated the measured value minus the predicted value. The subjects were divided into two groups according to the measured value minus predicted value tertiles: the lowest and middle tertile (good-to-fair measured value) and the highest tertile (poor measured value). We used a multiple logistic regression model to calculate the odds ratio (OR) and 95% confidence interval (CI) of the good-to-fair measured values of the Kihon Checklist after one year, according to the Functional Improvement Program of the Musculoskeletal System. In potentially dependent elderly, the multivariate adjusted ORs (95% CI) of the good-to-fair measured values were 2.4 (1.3-4.4) for those who attended the program eight times or more in a month (vs those who attended it three times or less in a month), 1.3 (1.0-1.8) for those who engaged in strength training using machines (vs those who did not train), and 1.4 (1.0-1.9) for those who engaged in endurance training. In this study, among potentially dependent elderly, those who attended the program eight times or more in a month and those who engaged in strength training using machines or endurance training showed a significant improvement of their functional capacity.

Predicting Success in an Online Course Using Expectancies, Values, and Typical Mode of Instruction

ERIC Educational Resources Information Center

Zimmerman, Whitney Alicia

2017-01-01

Expectancies of success and values were used to predict success in an online undergraduate-level introductory statistics course. Students who identified as primarily face-to-face learners were compared to students who identified as primarily online learners. Expectancy value theory served as a model. Expectancies of success were operationalized as…

Prediction of major complications after hepatectomy using liver stiffness values determined by magnetic resonance elastography.

PubMed

Sato, N; Kenjo, A; Kimura, T; Okada, R; Ishigame, T; Kofunato, Y; Shimura, T; Abe, K; Ohira, H; Marubashi, S

2018-04-23

Liver fibrosis is a risk factor for hepatectomy but cannot be determined accurately before hepatectomy because diagnostic procedures are too invasive. Magnetic resonance elastography (MRE) can determine liver stiffness (LS), a surrogate marker for assessing liver fibrosis, non-invasively. The aim of this study was to investigate whether the LS value determined by MRE is predictive of major complications after hepatectomy. This prospective study enrolled consecutive patients who underwent hepatic resection between April 2013 and August 2016. LS values were measured by imaging shear waves by MRE in the liver before hepatectomy. The primary endpoint was major complications, defined as Clavien-Dindo grade IIIa or above. Logistic regression analysis identified independent predictive factors, from which a logistic model to estimate the probability of major complications was constructed. A total of 96 patients were included in the study. Major complications were observed in 15 patients (16 per cent). Multivariable logistic analysis confirmed that higher LS value (P = 0·021) and serum albumin level (P = 0·009) were independent predictive factors for major complications after hepatectomy. Receiver operating characteristic (ROC) analysis showed that the best LS cut-off value was 4·3 kPa for detecting major complications, comparable to liver fibrosis grade F4, with a sensitivity of 80 per cent and specificity of 82 per cent. A logistic model using the LS value and serum albumin level to estimate the probability of major complications was constructed; the area under the ROC curve for predicting major complications was 0·84. The LS value determined by MRE in patients undergoing hepatectomy was an independent predictive factor for major complications. © 2018 BJS Society Ltd Published by John Wiley & Sons Ltd.

Diagnostic value and cost utility analysis for urine Gram stain and urine microscopic examination as screening tests for urinary tract infection.

PubMed

Wiwanitkit, Viroj; Udomsantisuk, Nibhond; Boonchalermvichian, Chaiyaporn

2005-06-01

The aim of this study was to evaluate the diagnostic properties of urine Gram stain and urine microscopic examination for screening for urinary tract infection (UTI), and to perform an additional cost utility analysis. This descriptive study was performed on 95 urine samples sent for urine culture to the Department of Microbiology, Faculty of Medicine, Chulalongkorn University. The first part of the study was to determine the diagnostic properties of two screening tests (urine Gram stain and urine microscopic examination). Urine culture was set as the gold standard and the results from both methods were compared to this. The second part of this study was to perform a cost utility analysis. The sensitivity of urine Gram stain was 96.2%, the specificity 93.0%, the positive predictive value 94.3% and the negative predictive value 95.2%. False positives occurred with a frequency of 7.0% and false negatives 3.8%. For the microscopic examination, the sensitivity was 65.4%, specificity 74.4%, positive predictive value 75.6% and negative predictive value 64.0%. False positives occurred with a frequency of 25.6% and false negatives 34.6%. Combining urine Gram stain and urine microscopic examination, the sensitivity was 98.1%, specificity 74.4%, positive predictive value 82.3% and negative predictive value 97.0%. False positives occurred with a frequency of 25.6% and false negatives 1.9%. However, the cost per utility of the combined method was higher than either urine microscopic examination or urine Gram stain alone. Urine Gram stain provided the lowest cost per utility. Economically, urine Gram stain is the proper screening tool for presumptive diagnosis of UTI.

Periprosthetic infection: where do we stand with regard to Gram stain?

PubMed Central

Ghanem, Elie; Ketonis, Constantinos; Restrepo, Camilo; Joshi, Ashish; Barrack, Robert

2009-01-01

Background and purpose One of the routinely used intraoperative tests for diagnosis of periprosthetic infection (PPI) is the Gram stain. It is not known if the result of this test can vary according to the type of joint affected or the number of specimen samples collected. We examined the role of this diagnostic test in a large cohort of patients from a single institution. Materials and methods A positive gram stain was defined as the visualization of bacterial cells or “many neutrophils” (> 5 per high-power field) in the smear. The sensitivity, specificity, and predictive values of each individual diagnostic arm of Gram stain were determined. Combinations were performed in series, which required both tests to be positive to confirm infection, and also in parallel, which necessitated both tests to be negative to rule out infection. Results The presence of organisms and “many” neutrophils on a Gram smear had high specificity (98–100%) and positive predictive value (89–100%) in both THA and TKA. The sensitivities (30–50%) and negative predictive values (70–79%) of the 2 tests were low for both joint types. When the 2 tests were combined in series, the specificity and positive predictive value were absolute (100%). The sensitivity and the negative predictive value improved for both THA and TKA (43–64% and 82%, respectively). Interpretation Although the 2 diagnostic arms of Gram staining can be combined to achieve improved negative predictive value (82%), Gram stain continues to have little value in ruling out PPI. With the advances in the field of molecular biology, novel diagnostic modalities need to be designed that can replace these traditional and poor tests. PMID:19297787

Distinct prediction errors in mesostriatal circuits of the human brain mediate learning about the values of both states and actions: evidence from high-resolution fMRI.

PubMed

Colas, Jaron T; Pauli, Wolfgang M; Larsen, Tobias; Tyszka, J Michael; O'Doherty, John P

2017-10-01

Prediction-error signals consistent with formal models of "reinforcement learning" (RL) have repeatedly been found within dopaminergic nuclei of the midbrain and dopaminoceptive areas of the striatum. However, the precise form of the RL algorithms implemented in the human brain is not yet well determined. Here, we created a novel paradigm optimized to dissociate the subtypes of reward-prediction errors that function as the key computational signatures of two distinct classes of RL models-namely, "actor/critic" models and action-value-learning models (e.g., the Q-learning model). The state-value-prediction error (SVPE), which is independent of actions, is a hallmark of the actor/critic architecture, whereas the action-value-prediction error (AVPE) is the distinguishing feature of action-value-learning algorithms. To test for the presence of these prediction-error signals in the brain, we scanned human participants with a high-resolution functional magnetic-resonance imaging (fMRI) protocol optimized to enable measurement of neural activity in the dopaminergic midbrain as well as the striatal areas to which it projects. In keeping with the actor/critic model, the SVPE signal was detected in the substantia nigra. The SVPE was also clearly present in both the ventral striatum and the dorsal striatum. However, alongside these purely state-value-based computations we also found evidence for AVPE signals throughout the striatum. These high-resolution fMRI findings suggest that model-free aspects of reward learning in humans can be explained algorithmically with RL in terms of an actor/critic mechanism operating in parallel with a system for more direct action-value learning.

Prognosis of Pregnant Women with One Abnormal Value on 75g OGTT.

PubMed

Kozuma, Yutaka; Inoue, Shigeru; Horinouchi, Takashi; Shinagawa, Takaaki; Nakayama, Hitomi; Kawaguchi, Atsushi; Hori, Daizo; Kamura, Toshiharu; Yamada, Kentaro; Ushijima, Kimio

2015-01-01

The aim of this study was to identify risk factors to allow us to detect patients at high risk of requiring insulin therapy, among Japanese pregnant women with one abnormal value (OAV) on a 75-g oral glucose tolerance test (75-g OGTT). A total of 118 pregnant women with OAV on a previous 75-g OGTT between 1997 and 2010 were studied. We identified the factors which can predict patients at high risk of requiring insulin therapy among Japanese pregnant women with OAV, by comparing severe abnormal glucose tolerance (insulin treatment; n=17) with mild glucose tolerance patients (diet only; n=101). The following factors were examined; plasma level of glucose (PG) and immunoreactive insulin (IRI) at fasting, 0.5, 1 and 2 hours after loading glucose, insulinogenic index, homeostasis model assessment insulin resistance (HOMA-IR), insulin sensitivity index-composite (ISI composite), and HbA1c at the time of the 75-g OGTT. Univariate analysis showed a positive correlation between insulin therapy and 2-h PG value, 0.5-h and 1-h IRI values, AUC-IRI and insulinogenic index (p<0.05). Multivariate analysis showed that the PG 2-h value and insulinogenic index were independent predictive factors of insulin therapy. A 2-h PG ≥153 mg / dl and an insulinogenic index of <0.42 had a sensitivity of 81.8%, a specificity of 83.8%, a positive predictive value of 60.0% and a negative predictive value of 93.9% for the prediction of patients who required insulin therapy among pregnant women with OAV. These results suggest that a level of 2-h PG ≥153 mg/dl and an insulinogenic index of <0.42 on 75-g OGTT are predictive factors for insulin therapy in Japanese pregnant women with OAV.

Distinct prediction errors in mesostriatal circuits of the human brain mediate learning about the values of both states and actions: evidence from high-resolution fMRI

PubMed Central

Pauli, Wolfgang M.; Larsen, Tobias; Tyszka, J. Michael; O’Doherty, John P.

2017-01-01

Prediction-error signals consistent with formal models of “reinforcement learning” (RL) have repeatedly been found within dopaminergic nuclei of the midbrain and dopaminoceptive areas of the striatum. However, the precise form of the RL algorithms implemented in the human brain is not yet well determined. Here, we created a novel paradigm optimized to dissociate the subtypes of reward-prediction errors that function as the key computational signatures of two distinct classes of RL models—namely, “actor/critic” models and action-value-learning models (e.g., the Q-learning model). The state-value-prediction error (SVPE), which is independent of actions, is a hallmark of the actor/critic architecture, whereas the action-value-prediction error (AVPE) is the distinguishing feature of action-value-learning algorithms. To test for the presence of these prediction-error signals in the brain, we scanned human participants with a high-resolution functional magnetic-resonance imaging (fMRI) protocol optimized to enable measurement of neural activity in the dopaminergic midbrain as well as the striatal areas to which it projects. In keeping with the actor/critic model, the SVPE signal was detected in the substantia nigra. The SVPE was also clearly present in both the ventral striatum and the dorsal striatum. However, alongside these purely state-value-based computations we also found evidence for AVPE signals throughout the striatum. These high-resolution fMRI findings suggest that model-free aspects of reward learning in humans can be explained algorithmically with RL in terms of an actor/critic mechanism operating in parallel with a system for more direct action-value learning. PMID:29049406

Prediction of parenteral nutrition osmolarity by digital refractometry.

PubMed

Chang, Wei-Kuo; Yeh, Ming-Kung

2011-05-01

Infusion of high-osmolarity parenteral nutrition (PN) formulations into a peripheral vein will damage the vessel. In this study, the authors developed a refractometric method to predict PN formulation osmolarity for patients receiving PN. Nutrients in PN formulations were prepared for Brix value and osmolality measurement. Brix value and osmolality measurement of the dextrose, amino acids, and electrolytes were used to evaluate the limiting factor of PN osmolarity prediction. A best-fit equation was generated to predict PN osmolarity (mOsm/L): 81.05 × Brix value--116.33 (R(2) > 0.99). To validate the PN osmolarity prediction by these 4 equations, a total of 500 PN admixtures were tested. The authors found strong linear relationships between the Brix values and the osmolality measurement of dextrose (R(2) = 0.97), amino acids (R(2) = 0.99), and electrolytes (R(2) > 0.96). When PN-measured osmolality was between 600 and 900 mOsm/kg, approximately 43%, 29%, 43%, and 0% of the predicted osmolarity obtained by equations 1, 2, 3, and 4 were outside the acceptable 90% to 110% confidence interval range, respectively. When measured osmolality was between 900 and 1,500 mOsm/kg, 31%, 100%, 85%, and 15% of the predicted osmolarity by equations 1, 2, 3, and 4 were outside the acceptable 90% to 110% confidence interval range, respectively. The refractive method permits accurate PN osmolarity prediction and reasonable quality assurance before PN formulation administration.

Predicting Hydrologic Function With Aquatic Gene Fragments

NASA Astrophysics Data System (ADS)

Good, S. P.; URycki, D. R.; Crump, B. C.

2018-03-01

Recent advances in microbiology techniques, such as genetic sequencing, allow for rapid and cost-effective collection of large quantities of genetic information carried within water samples. Here we posit that the unique composition of aquatic DNA material within a water sample contains relevant information about hydrologic function at multiple temporal scales. In this study, machine learning was used to develop discharge prediction models trained on the relative abundance of bacterial taxa classified into operational taxonomic units (OTUs) based on 16S rRNA gene sequences from six large arctic rivers. We term this approach "genohydrology," and show that OTU relative abundances can be used to predict river discharge at monthly and longer timescales. Based on a single DNA sample from each river, the average Nash-Sutcliffe efficiency (NSE) for predicted mean monthly discharge values throughout the year was 0.84, while the NSE for predicted discharge values across different return intervals was 0.67. These are considerable improvements over predictions based only on the area-scaled mean specific discharge of five similar rivers, which had average NSE values of 0.64 and -0.32 for seasonal and recurrence interval discharge values, respectively. The genohydrology approach demonstrates that genetic diversity within the aquatic microbiome is a large and underutilized data resource with benefits for prediction of hydrologic function.

Predictive value of diminutive colonic adenoma trial: the PREDICT trial.

PubMed

Schoenfeld, Philip; Shad, Javaid; Ormseth, Eric; Coyle, Walter; Cash, Brooks; Butler, James; Schindler, William; Kikendall, Walter J; Furlong, Christopher; Sobin, Leslie H; Hobbs, Christine M; Cruess, David; Rex, Douglas

2003-05-01

Diminutive adenomas (1-9 mm in diameter) are frequently found during colon cancer screening with flexible sigmoidoscopy (FS). This trial assessed the predictive value of these diminutive adenomas for advanced adenomas in the proximal colon. In a multicenter, prospective cohort trial, we matched 200 patients with normal FS and 200 patients with diminutive adenomas on FS for age and gender. All patients underwent colonoscopy. The presence of advanced adenomas (adenoma >or= 10 mm in diameter, villous adenoma, adenoma with high grade dysplasia, and colon cancer) and adenomas (any size) was recorded. Before colonoscopy, patients completed questionnaires about risk factors for adenomas. The prevalence of advanced adenomas in the proximal colon was similar in patients with diminutive adenomas and patients with normal FS (6% vs. 5.5%, respectively) (relative risk, 1.1; 95% confidence interval [CI], 0.5-2.6). Diminutive adenomas on FS did not accurately predict advanced adenomas in the proximal colon: sensitivity, 52% (95% CI, 32%-72%); specificity, 50% (95% CI, 49%-51%); positive predictive value, 6% (95% CI, 4%-8%); and negative predictive value, 95% (95% CI, 92%-97%). Male gender (odds ratio, 1.63; 95% CI, 1.01-2.61) was associated with an increased risk of proximal colon adenomas. Diminutive adenomas on sigmoidoscopy may not accurately predict advanced adenomas in the proximal colon.

[Evaluation of performance of five bioinformatics software for the prediction of missense mutations].

PubMed

Chen, Qianting; Dai, Congling; Zhang, Qianjun; Du, Juan; Li, Wen

2016-10-01

To study the prediction performance evaluation with five kinds of bioinformatics software (SIFT, PolyPhen2, MutationTaster, Provean, MutationAssessor). From own database for genetic mutations collected over the past five years, Chinese literature database, Human Gene Mutation Database, and dbSNP, 121 missense mutations confirmed by functional studies, and 121 missense mutations suspected to be pathogenic by pedigree analysis were used as positive gold standard, while 242 missense mutations with minor allele frequency (MAF)>5% in dominant hereditary diseases were used as negative gold standard. The selected mutations were predicted with the five software. Based on the results, the performance of the five software was evaluated for their sensitivity, specificity, positive predict value, false positive rate, negative predict value, false negative rate, false discovery rate, accuracy, and receiver operating characteristic curve (ROC). In terms of sensitivity, negative predictive value and false negative rate, the rank was MutationTaster, PolyPhen2, Provean, SIFT, and MutationAssessor. For specificity and false positive rate, the rank was MutationTaster, Provean, MutationAssessor, SIFT, and PolyPhen2. For positive predict value and false discovery rate, the rank was MutationTaster, Provean, MutationAssessor, PolyPhen2, and SIFT. For area under the ROC curve (AUC) and accuracy, the rank was MutationTaster, Provean, PolyPhen2, MutationAssessor, and SIFT. The prediction performance of software may be different when using different parameters. Among the five software, MutationTaster has the best prediction performance.

The Dopamine Prediction Error: Contributions to Associative Models of Reward Learning

PubMed Central

Nasser, Helen M.; Calu, Donna J.; Schoenbaum, Geoffrey; Sharpe, Melissa J.

2017-01-01

Phasic activity of midbrain dopamine neurons is currently thought to encapsulate the prediction-error signal described in Sutton and Barto’s (1981) model-free reinforcement learning algorithm. This phasic signal is thought to contain information about the quantitative value of reward, which transfers to the reward-predictive cue after learning. This is argued to endow the reward-predictive cue with the value inherent in the reward, motivating behavior toward cues signaling the presence of reward. Yet theoretical and empirical research has implicated prediction-error signaling in learning that extends far beyond a transfer of quantitative value to a reward-predictive cue. Here, we review the research which demonstrates the complexity of how dopaminergic prediction errors facilitate learning. After briefly discussing the literature demonstrating that phasic dopaminergic signals can act in the manner described by Sutton and Barto (1981), we consider how these signals may also influence attentional processing across multiple attentional systems in distinct brain circuits. Then, we discuss how prediction errors encode and promote the development of context-specific associations between cues and rewards. Finally, we consider recent evidence that shows dopaminergic activity contains information about causal relationships between cues and rewards that reflect information garnered from rich associative models of the world that can be adapted in the absence of direct experience. In discussing this research we hope to support the expansion of how dopaminergic prediction errors are thought to contribute to the learning process beyond the traditional concept of transferring quantitative value. PMID:28275359

Climate predictability and prediction skill on seasonal time scales over South America from CHFP models

NASA Astrophysics Data System (ADS)

Osman, Marisol; Vera, C. S.

2017-10-01

This work presents an assessment of the predictability and skill of climate anomalies over South America. The study was made considering a multi-model ensemble of seasonal forecasts for surface air temperature, precipitation and regional circulation, from coupled global circulation models included in the Climate Historical Forecast Project. Predictability was evaluated through the estimation of the signal-to-total variance ratio while prediction skill was assessed computing anomaly correlation coefficients. Both indicators present over the continent higher values at the tropics than at the extratropics for both, surface air temperature and precipitation. Moreover, predictability and prediction skill for temperature are slightly higher in DJF than in JJA while for precipitation they exhibit similar levels in both seasons. The largest values of predictability and skill for both variables and seasons are found over northwestern South America while modest but still significant values for extratropical precipitation at southeastern South America and the extratropical Andes. The predictability levels in ENSO years of both variables are slightly higher, although with the same spatial distribution, than that obtained considering all years. Nevertheless, predictability at the tropics for both variables and seasons diminishes in both warm and cold ENSO years respect to that in all years. The latter can be attributed to changes in signal rather than in the noise. Predictability and prediction skill for low-level winds and upper-level zonal winds over South America was also assessed. Maximum levels of predictability for low-level winds were found were maximum mean values are observed, i.e. the regions associated with the equatorial trade winds, the midlatitudes westerlies and the South American Low-Level Jet. Predictability maxima for upper-level zonal winds locate where the subtropical jet peaks. Seasonal changes in wind predictability are observed that seem to be related to those associated with the signal, especially at the extratropics.

Estimating the Accuracy of the Chedoke–McMaster Stroke Assessment Predictive Equations for Stroke Rehabilitation

PubMed Central

Dang, Mia; Ramsaran, Kalinda D.; Street, Melissa E.; Syed, S. Noreen; Barclay-Goddard, Ruth; Miller, Patricia A.

2011-01-01

ABSTRACT Purpose: To estimate the predictive accuracy and clinical usefulness of the Chedoke–McMaster Stroke Assessment (CMSA) predictive equations. Method: A longitudinal prognostic study using historical data obtained from 104 patients admitted post cerebrovascular accident was undertaken. Data were abstracted for all patients undergoing rehabilitation post stroke who also had documented admission and discharge CMSA scores. Published predictive equations were used to determine predicted outcomes. To determine the accuracy and clinical usefulness of the predictive model, shrinkage coefficients and predictions with 95% confidence bands were calculated. Results: Complete data were available for 74 patients with a mean age of 65.3±12.4 years. The shrinkage values for the six Impairment Inventory (II) dimensions varied from −0.05 to 0.09; the shrinkage value for the Activity Inventory (AI) was 0.21. The error associated with predictive values was greater than ±1.5 stages for the II dimensions and greater than ±24 points for the AI. Conclusions: This study shows that the large error associated with the predictions (as defined by the confidence band) for the CMSA II and AI limits their clinical usefulness as a predictive measure. Further research to establish predictive models using alternative statistical procedures is warranted. PMID:22654239

Incremental Value of Repeated Risk Factor Measurements for Cardiovascular Disease Prediction in Middle-Aged Korean Adults: Results From the NHIS-HEALS (National Health Insurance System-National Health Screening Cohort).

PubMed

Cho, In-Jeong; Sung, Ji Min; Chang, Hyuk-Jae; Chung, Namsik; Kim, Hyeon Chang

2017-11-01

Increasing evidence suggests that repeatedly measured cardiovascular disease (CVD) risk factors may have an additive predictive value compared with single measured levels. Thus, we evaluated the incremental predictive value of incorporating periodic health screening data for CVD prediction in a large nationwide cohort with periodic health screening tests. A total of 467 708 persons aged 40 to 79 years and free from CVD were randomly divided into development (70%) and validation subcohorts (30%). We developed 3 different CVD prediction models: a single measure model using single time point screening data; a longitudinal average model using average risk factor values from periodic screening data; and a longitudinal summary model using average values and the variability of risk factors. The development subcohort included 327 396 persons who had 3.2 health screenings on average and 25 765 cases of CVD over 12 years. The C statistics (95% confidence interval [CI]) for the single measure, longitudinal average, and longitudinal summary models were 0.690 (95% CI, 0.682-0.698), 0.695 (95% CI, 0.687-0.703), and 0.752 (95% CI, 0.744-0.760) in men and 0.732 (95% CI, 0.722-0.742), 0.735 (95% CI, 0.725-0.745), and 0.790 (95% CI, 0.780-0.800) in women, respectively. The net reclassification index from the single measure model to the longitudinal average model was 1.78% in men and 1.33% in women, and the index from the longitudinal average model to the longitudinal summary model was 32.71% in men and 34.98% in women. Using averages of repeatedly measured risk factor values modestly improves CVD predictability compared with single measurement values. Incorporating the average and variability information of repeated measurements can lead to great improvements in disease prediction. URL: https://www.clinicaltrials.gov. Unique identifier: NCT02931500. © 2017 American Heart Association, Inc.

Thoracic computed tomography is an effective screening modality in patients with penetrating injuries to the chest.

PubMed

Strumwasser, Aaron; Chong, Vincent; Chu, Eveline; Victorino, Gregory P

2016-09-01

The precise role of thoracic CT in penetrating chest trauma remains to be defined. We hypothesized that thoracic CT effectively screens hemodynamically normal patients with penetrating thoracic trauma to surgery vs. expectant management (NOM). A ten-year review of all penetrating torso cases was retrospectively analyzed from our urban University-based trauma center. We included hemodynamically normal patients (systolic blood pressure ≥90) with penetrating chest injuries that underwent screening thoracic CT. Hemodynamically unstable patients and diaphragmatic injuries were excluded. The sensitivity, specificity, positive predictive value and negative predictive value were calculated. A total of 212 patients (mean injury severity score=24, Abbreviated Injury Score for Chest=3.9) met inclusion criteria. Of these, 84.3% underwent NOM, 9.1% necessitated abdominal exploration, 6.6% underwent exploration for retained hemothorax/empyema, 6.6% underwent immediate thoracic exploration for significant injuries on chest CT, and 1.0% underwent delayed thoracic exploration for missed injuries. Thoracic CT had a sensitivity of 82%, specificity of 99%, positive predictive value of 90%, a negative predictive value of 99%, and an accuracy of 99% in predicting surgery vs. NOM. Thoracic CT has a negative predictive value of 99% in triaging hemodynamically normal patients with penetrating chest trauma. Screening thoracic CT successfully excludes surgery in patients with non-significant radiologic findings. Copyright © 2016. Published by Elsevier Ltd.

Real-ear-to-coupler difference predictions as a function of age for two coupling procedures.

PubMed

Bagatto, Marlene P; Scollie, Susan D; Seewald, Richard C; Moodie, K Shane; Hoover, Brenda M

2002-09-01

The predicted real-ear-to-coupler difference (RECD) values currently used in pediatric hearing instrument prescription methods are based on 12-month age range categories and were derived from measures using standard acoustic immittance probe tips. Consequently, the purpose of this study was to develop normative RECD predicted values for foam/acoustic immittance tips and custom earmolds across the age continuum. To this end, RECD data were collected on 392 infants and children (141 with acoustic immittance tips, 251 with earmolds) to develop normative regression equations for use in deriving continuous age predictions of RECDs for foam/acoustic immittance tips and earmolds. Owing to the substantial between-subject variability observed in the data, the predictive equations of RECDs by age (in months) resulted in only gross estimates of RECD values (i.e., within +/- 4.4 dB for 95% of acoustic immittance tip measures; within +/- 5.4 dB in 95% of measures with custom earmolds) across frequency. Thus, it is concluded that the estimates derived from this study should not be used to replace the more precise individual RECD measurements. Relative to previously available normative RECD values for infants and young children, however, the estimates derived through this study provide somewhat more accurate predicted values for use under those circumstances for which individual RECD measurements cannot be made.

[Diagnostic value of a predictive model for complete ruptures of the rotator cuff associated to subacromial impingement].

PubMed

Águila-Ledesma, I R; Córdova-Fonseca, J L; Medina-Pontaza, O; Núñez-Gómez, D A; Calvache-García, C; Pérez-Atanasio, J M; Torres-González, R

2017-01-01

Pathology related to the rotator cuff remains among the most prevalent musculoskeletal diseases. There is an increasing need for imaging studies (MRI, US, arthroscopy) to test the diagnostic performance of the medical history and physical examination. To prove the diagnostic value of a clinical-radiographic predictive model to find complete ruptures of the rotator cuff. Descriptive, observational, prospective, transversal and analytical study. Fifty-five patients with preoperative shoulder pain were evaluated with 13 predictive variables: age > 50 years, nocturnal pain, muscle weakness, clinical signs of Neer, Hawkins, Jobe, external rotation lag (ERLS), belly-press, bear hug, and lift-off, radiographic measurement of subacromial space, acromial index and critical shoulder angle. Sensitivity, specificity, and positive and negative predictive values were measured in each variable, comparing the results of each one against the postoperative findings. Of the 55 patients evaluated, 42 had a complete rupture of the rotator cuff in the postoperative period. The eight variables with a higher diagnostic value were selected and a ROC curve was performed, providing an area under the curve of 0.88. This predictive model uses eight variables (age > 50 years, nocturnal pain, muscle weakness, Jobe, Hawkins, ERLS, subacromial space ≤ 6 mm, and critical shoulder angle > 35°), which together add the predictive value of 0.88 (AUC) to diagnose complete ruptures of the supraspinatus tendon.

[How reliable is the monitoring for doping?].

PubMed

Hüsler, J

1990-12-01

The reliability of the dope control, of the chemical analysis of the urine probes in the accredited laboratories and their decisions, is discussed using probabilistic and statistical methods. Basically, we evaluated and estimated the positive predictive value which means the probability that an urine probe contains prohibited dope substances given a positive test decision. Since there are not statistical data and evidence for some important quantities in relation to the predictive value, an exact evaluation is not possible, only conservative, lower bounds can be given. We found that the predictive value is at least 90% or 95% with respect to the analysis and decision based on the A-probe only, and at least 99% with respect to both A- and B-probes. A more realistic observation, but without sufficient statistical confidence, points to the fact that the true predictive value is significantly larger than these lower estimates.

Learning-Induced Plasticity in Medial Prefrontal Cortex Predicts Preference Malleability

PubMed Central

Garvert, Mona M.; Moutoussis, Michael; Kurth-Nelson, Zeb; Behrens, Timothy E.J.; Dolan, Raymond J.

2015-01-01

Summary Learning induces plasticity in neuronal networks. As neuronal populations contribute to multiple representations, we reasoned plasticity in one representation might influence others. We used human fMRI repetition suppression to show that plasticity induced by learning another individual’s values impacts upon a value representation for oneself in medial prefrontal cortex (mPFC), a plasticity also evident behaviorally in a preference shift. We show this plasticity is driven by a striatal “prediction error,” signaling the discrepancy between the other’s choice and a subject’s own preferences. Thus, our data highlight that mPFC encodes agent-independent representations of subjective value, such that prediction errors simultaneously update multiple agents’ value representations. As the resulting change in representational similarity predicts interindividual differences in the malleability of subjective preferences, our findings shed mechanistic light on complex human processes such as the powerful influence of social interaction on beliefs and preferences. PMID:25611512

Analysis and comparison of nonlinear tree height prediction strategies for Douglas-fir forest.

Treesearch

H. Temesgen; V.J. Monleon; D.W. Hann

2008-01-01

Using an extensive Douglas-fir data set from southwest Oregon, we examined the (I) performance and suitability of selected prediction strategies, (2) contribution of relative position and stand-density measures in improving tree height (h) prediction values, and (3) effect of different subsampling designs to fill in missing h values in a new stand using a regional...

Prediction of beta-turns from amino acid sequences using the residue-coupled model.

PubMed

Guruprasad, K; Shukla, S

2003-04-01

We evaluated the prediction of beta-turns from amino acid sequences using the residue-coupled model with an enlarged representative protein data set selected from the Protein Data Bank. Our results show that the probability values derived from a data set comprising 425 protein chains yielded an overall beta-turn prediction accuracy 68.74%, compared with 94.7% reported earlier on a data set of 30 proteins using the same method. However, we noted that the overall beta-turn prediction accuracy using probability values derived from the 30-protein data set reduces to 40.74% when tested on the data set comprising 425 protein chains. In contrast, using probability values derived from the 425 data set used in this analysis, the overall beta-turn prediction accuracy yielded consistent results when tested on either the 30-protein data set (64.62%) used earlier or a more recent representative data set comprising 619 protein chains (64.66%) or on a jackknife data set comprising 476 representative protein chains (63.38%). We therefore recommend the use of probability values derived from the 425 representative protein chains data set reported here, which gives more realistic and consistent predictions of beta-turns from amino acid sequences.

Numerical weather prediction model tuning via ensemble prediction system

NASA Astrophysics Data System (ADS)

Jarvinen, H.; Laine, M.; Ollinaho, P.; Solonen, A.; Haario, H.

2011-12-01

This paper discusses a novel approach to tune predictive skill of numerical weather prediction (NWP) models. NWP models contain tunable parameters which appear in parameterizations schemes of sub-grid scale physical processes. Currently, numerical values of these parameters are specified manually. In a recent dual manuscript (QJRMS, revised) we developed a new concept and method for on-line estimation of the NWP model parameters. The EPPES ("Ensemble prediction and parameter estimation system") method requires only minimal changes to the existing operational ensemble prediction infra-structure and it seems very cost-effective because practically no new computations are introduced. The approach provides an algorithmic decision making tool for model parameter optimization in operational NWP. In EPPES, statistical inference about the NWP model tunable parameters is made by (i) generating each member of the ensemble of predictions using different model parameter values, drawn from a proposal distribution, and (ii) feeding-back the relative merits of the parameter values to the proposal distribution, based on evaluation of a suitable likelihood function against verifying observations. In the presentation, the method is first illustrated in low-order numerical tests using a stochastic version of the Lorenz-95 model which effectively emulates the principal features of ensemble prediction systems. The EPPES method correctly detects the unknown and wrongly specified parameters values, and leads to an improved forecast skill. Second, results with an atmospheric general circulation model based ensemble prediction system show that the NWP model tuning capacity of EPPES scales up to realistic models and ensemble prediction systems. Finally, a global top-end NWP model tuning exercise with preliminary results is published.

Developing a computer-controlled simulated digestion system to predict the concentration of metabolizable energy of feedstuffs for rooster.

PubMed

Zhao, F; Ren, L Q; Mi, B M; Tan, H Z; Zhao, J T; Li, H; Zhang, H F; Zhang, Z Y

2014-04-01

Four experiments were conducted to evaluate the effectiveness of a computer-controlled simulated digestion system (CCSDS) for predicting apparent metabolizable energy (AME) and true metabolizable energy (TME) using in vitro digestible energy (IVDE) content of feeds for roosters. In Exp. 1, the repeatability of the IVDE assay was tested in corn, wheat, rapeseed meal, and cottonseed meal with 3 assays of each sample and each with 5 replicates of the same sample. In Exp. 2, the additivity of IVDE concentration in corn, soybean meal, and cottonseed meal was tested by comparing determined IVDE values of the complete diet with values predicted from measurements on individual ingredients. In Exp. 3, linear models to predict AME and TME based on IVDE were developed with 16 calibration samples. In Exp. 4, the accuracy of prediction models was tested by the differences between predicted and determined values for AME or TME of 6 ingredients and 4 diets. In Exp. 1, the mean CV of IVDE was 0.88% (range = 0.20 to 2.14%) for corn, wheat, rapeseed meal, and cottonseed meal. No difference in IVDE was observed between 3 assays of an ingredient, indicating that the IVDE assay is repeatable under these conditions. In Exp. 2, minimal differences (<21 kcal/kg) were observed between determined and calculated IVDE of 3 complete diets formulated with corn, soybean meal, and cottonseed meal, demonstrating that the IVDE values are additive in a complete diet. In Exp. 3, linear relationships between AME and IVDE and between TME and IVDE were observed in 16 calibration samples: AME = 1.062 × IVDE - 530 (R(2) = 0.97, residual standard deviation [RSD] = 146 kcal/kg, P < 0.001) and TME = 1.050 × IVDE - 16 (R(2) = 0.97, RSD = 148 kcal/kg, P < 0.001). Differences of less than 100 kcal/kg were observed between determined and predicted values in 10 and 9 of the 16 calibration samples for AME and TME, respectively. In Exp. 4, differences of less than 100 kcal/kg between determined and predicted values were observed in 3 and 4 of the 6 ingredient samples for AME and TME, respectively, and all 4 diets showed the differences of less than 25 kcal/kg between determined and predicted AME or TME. Our results indicate that the CCSDS is repeatable and additive. This system accurately predicted AME or TME on 17 of the 26 samples and may be a promising method to predict the energetic values of feed for poultry.

Evaluation of a method of estimating low-flow frequencies from base-flow measurements at Indiana streams

USGS Publications Warehouse

Wilson, John Thomas

2000-01-01

A mathematical technique of estimating low-flow frequencies from base-flow measurements was evaluated by using data for streams in Indiana. Low-flow frequencies at low- flow partial-record stations were estimated by relating base-flow measurements to concurrent daily flows at nearby streamflow-gaging stations (index stations) for which low-flowfrequency curves had been developed. A network of long-term streamflow-gaging stations in Indiana provided a sample of sites with observed low-flow frequencies. Observed values of 7-day, 10-year low flow and 7-day, 2-year low flow were compared to predicted values to evaluate the accuracy of the method. Five test cases were used to evaluate the method under a variety of conditions in which the location of the index station and its drainage area varied relative to the partial-record station. A total of 141 pairs of streamflow-gaging stations were used in the five test cases. Four of the test cases used one index station, the fifth test case used two index stations. The number of base-flow measurements was varied for each test case to see if the accuracy of the method was affected by the number of measurements used. The most accurate and least variable results were produced when two index stations on the same stream or tributaries of the partial-record station were used. All but one value of the predicted 7-day, 10-year low flow were within 15 percent of the values observed for the long-term continuous record, and all of the predicted values of the 7-day, 2-year lowflow were within 15 percent of the observed values. This apparent accuracy, to some extent, may be a result of the small sample set of 15. Of the four test cases that used one index station, the most accurate and least variable results were produced in the test case where the index station and partial-record station were on the same stream or on streams tributary to each other and where the index station had a larger drainage area than the partial-record station. In that test case, the method tended to over predict, based on the median relative error. In 23 of 28 test pairs, the predicted 7-day, 10-year low flow was within 15 percent of the observed value; in 26 of 28 test pairs, the predicted 7-day, 2-year low flow was within 15 percent of the observed value. When the index station and partial-record station were on the same stream or streams tributary to each other and the index station had a smaller drainage area than the partial-record station, the method tended to under predict the low-flow frequencies. Nineteen of 28 predicted values of the 7-day, 10-year low flow were within 15 percent of the observed values. Twenty-five of 28 predicted values of the 7-day, 2-year low flow were within 15 percent of the observed values. When the index station and the partial-record station were on different streams, the method tended to under predict regardless of whether the index station had a larger or smaller drainage area than that of the partial-record station. Also, the variability of the relative error of estimate was greatest for the test cases that used index stations and partial-record stations from different streams. This variability, in part, may be caused by using more streamflow-gaging stations with small low-flow frequencies in these test cases. A small difference in the predicted and observed values can equate to a large relative error when dealing with stations that have small low-flow frequencies. In the test cases that used one index station, the method tended to predict smaller low-flow frequencies as the number of base-flow measurements was reduced from 20 to 5. Overall, the average relative error of estimate and the variability of the predicted values increased as the number of base-flow measurements was reduced.

An integrated approach to evaluating alternative risk prediction strategies: a case study comparing alternative approaches for preventing invasive fungal disease.

PubMed

Sadique, Z; Grieve, R; Harrison, D A; Jit, M; Allen, E; Rowan, K M

2013-12-01

This article proposes an integrated approach to the development, validation, and evaluation of new risk prediction models illustrated with the Fungal Infection Risk Evaluation study, which developed risk models to identify non-neutropenic, critically ill adult patients at high risk of invasive fungal disease (IFD). Our decision-analytical model compared alternative strategies for preventing IFD at up to three clinical decision time points (critical care admission, after 24 hours, and end of day 3), followed with antifungal prophylaxis for those judged "high" risk versus "no formal risk assessment." We developed prognostic models to predict the risk of IFD before critical care unit discharge, with data from 35,455 admissions to 70 UK adult, critical care units, and validated the models externally. The decision model was populated with positive predictive values and negative predictive values from the best-fitting risk models. We projected lifetime cost-effectiveness and expected value of partial perfect information for groups of parameters. The risk prediction models performed well in internal and external validation. Risk assessment and prophylaxis at the end of day 3 was the most cost-effective strategy at the 2% and 1% risk threshold. Risk assessment at each time point was the most cost-effective strategy at a 0.5% risk threshold. Expected values of partial perfect information were high for positive predictive values or negative predictive values (£11 million-£13 million) and quality-adjusted life-years (£11 million). It is cost-effective to formally assess the risk of IFD for non-neutropenic, critically ill adult patients. This integrated approach to developing and evaluating risk models is useful for informing clinical practice and future research investment. © 2013 International Society for Pharmacoeconomics and Outcomes Research (ISPOR) Published by International Society for Pharmacoeconomics and Outcomes Research (ISPOR) All rights reserved.

Demands, values, and burnout

PubMed Central

Leiter, Michael P.; Frank, Erica; Matheson, Timothy J.

2009-01-01

OBJECTIVE T o explore the interaction between workload and values congruence (personal values with health care system values) in the context of burnout and physician engagement and to explore the relative importance of these factors by sex, given the distinct work patterns of male and female physicians. DESIGN National mailed survey. SETTING Canada. PARTICIPANTS A random sample of 8100 Canadian physicians (response rate 40%, N = 3213); 2536 responses (from physicians working more than 35 hours per week) were analyzed. MAIN OUTCOME MEASURES Levels of burnout, values congruence, and workload, by sex, measured by the Maslach Burnout Inventory—General Scale and the Areas of Worklife Scale. RESULTS Results showed a moderate level of burnout among Canadian physicians, with relatively positive scores on exhaustion, average scores on cynicism, and mildly negative scores on professional efficacy. A series of multiple regression analyses confirmed parallel main effect contributions from manageable workload and values congruence. Both workload and values congruence predicted exhaustion and cynicism for men and women (P = .001). Only values congruence provided a significant prediction of professional efficacy for both men and women (P = .001) These predictors interacted for women on all 3 aspects of burnout (exhaustion, cynicism, and diminished efficacy). Howevever, overall levels of the burnout indicators departed only modestly from normative levels. CONCLUSION W orkload and values congruence make distinct contributions to physician burnout. Work overload contributes to predicting exhaustion and cynicism; professional values crises contribute to predicting exhaustion, cynicism, and low professional efficacy. The interaction of values and workload for women in particular has implications for the distinct work-life patterns of male and female physicians. Specifically, the congruence of individual values with values inherent in the health care system appeared to be of greater consequence for women than for men. PMID:20008605

Autocorrelation structure at rest predicts value correlates of single neurons during reward-guided choice

PubMed Central

Cavanagh, Sean E; Wallis, Joni D; Kennerley, Steven W; Hunt, Laurence T

2016-01-01

Correlates of value are routinely observed in the prefrontal cortex (PFC) during reward-guided decision making. In previous work (Hunt et al., 2015), we argued that PFC correlates of chosen value are a consequence of varying rates of a dynamical evidence accumulation process. Yet within PFC, there is substantial variability in chosen value correlates across individual neurons. Here we show that this variability is explained by neurons having different temporal receptive fields of integration, indexed by examining neuronal spike rate autocorrelation structure whilst at rest. We find that neurons with protracted resting temporal receptive fields exhibit stronger chosen value correlates during choice. Within orbitofrontal cortex, these neurons also sustain coding of chosen value from choice through the delivery of reward, providing a potential neural mechanism for maintaining predictions and updating stored values during learning. These findings reveal that within PFC, variability in temporal specialisation across neurons predicts involvement in specific decision-making computations. DOI: http://dx.doi.org/10.7554/eLife.18937.001 PMID:27705742

Personal spiritual values and quality of life: evidence from Chinese college students.

PubMed

Zhang, Kaili Chen; Hui, C Harry; Lam, Jasmine; Lau, Esther Yuet Ying; Cheung, Shu-Fai; Mok, Doris Shui Ying

2014-08-01

Values are guiding principles in our life. While some studies found spiritual values to be "healthier," Sagiv and Schwartz (Eur J Soc Psychol 30:177-198, 2000) showed that people holding non-spiritual values were higher on affective well-being. We examined the predictive power of these two types of values with a longitudinal data set collected from Chinese students mainly in Hong Kong. Structural equation modeling revealed that spiritual values (as well as family income) positively predicted quality of life a year later. Non-spiritual, self-enhancement values, did not show any association. Results suggest that developing spiritual values may promote well-being through enabling individuals to find meaning and purpose in life.

Use of risk assessment instruments to predict violence and antisocial behaviour in 73 samples involving 24 827 people: systematic review and meta-analysis.

PubMed

Fazel, Seena; Singh, Jay P; Doll, Helen; Grann, Martin

2012-07-24

To investigate the predictive validity of tools commonly used to assess the risk of violence, sexual, and criminal behaviour. Systematic review and tabular meta-analysis of replication studies following PRISMA guidelines. PsycINFO, Embase, Medline, and United States Criminal Justice Reference Service Abstracts. We included replication studies from 1 January 1995 to 1 January 2011 if they provided contingency data for the offending outcome that the tools were designed to predict. We calculated the diagnostic odds ratio, sensitivity, specificity, area under the curve, positive predictive value, negative predictive value, the number needed to detain to prevent one offence, as well as a novel performance indicator-the number safely discharged. We investigated potential sources of heterogeneity using metaregression and subgroup analyses. Risk assessments were conducted on 73 samples comprising 24,847 participants from 13 countries, of whom 5879 (23.7%) offended over an average of 49.6 months. When used to predict violent offending, risk assessment tools produced low to moderate positive predictive values (median 41%, interquartile range 27-60%) and higher negative predictive values (91%, 81-95%), and a corresponding median number needed to detain of 2 (2-4) and number safely discharged of 10 (4-18). Instruments designed to predict violent offending performed better than those aimed at predicting sexual or general crime. Although risk assessment tools are widely used in clinical and criminal justice settings, their predictive accuracy varies depending on how they are used. They seem to identify low risk individuals with high levels of accuracy, but their use as sole determinants of detention, sentencing, and release is not supported by the current evidence. Further research is needed to examine their contribution to treatment and management.

Incorporating Psychological Predictors of Treatment Response into Health Economic Simulation Models: A Case Study in Type 1 Diabetes.

PubMed

Kruger, Jen; Pollard, Daniel; Basarir, Hasan; Thokala, Praveen; Cooke, Debbie; Clark, Marie; Bond, Rod; Heller, Simon; Brennan, Alan

2015-10-01

. Health economic modeling has paid limited attention to the effects that patients' psychological characteristics have on the effectiveness of treatments. This case study tests 1) the feasibility of incorporating psychological prediction models of treatment response within an economic model of type 1 diabetes, 2) the potential value of providing treatment to a subgroup of patients, and 3) the cost-effectiveness of providing treatment to a subgroup of responders defined using 5 different algorithms. . Multiple linear regressions were used to investigate relationships between patients' psychological characteristics and treatment effectiveness. Two psychological prediction models were integrated with a patient-level simulation model of type 1 diabetes. Expected value of individualized care analysis was undertaken. Five different algorithms were used to provide treatment to a subgroup of predicted responders. A cost-effectiveness analysis compared using the algorithms to providing treatment to all patients. . The psychological prediction models had low predictive power for treatment effectiveness. Expected value of individualized care results suggested that targeting education at responders could be of value. The cost-effectiveness analysis suggested, for all 5 algorithms, that providing structured education to a subgroup of predicted responders would not be cost-effective. . The psychological prediction models tested did not have sufficient predictive power to make targeting treatment cost-effective. The psychological prediction models are simple linear models of psychological behavior. Collection of data on additional covariates could potentially increase statistical power. . By collecting data on psychological variables before an intervention, we can construct predictive models of treatment response to interventions. These predictive models can be incorporated into health economic models to investigate more complex service delivery and reimbursement strategies. © The Author(s) 2015.

Should bedside sonography be used first to diagnose pneumothorax secondary to blunt trauma?

PubMed

Donmez, Halil; Tokmak, Turgut Tursem; Yildirim, Afra; Buyukoglan, Hakan; Ozturk, Mehmet; Yaşar Ayaz, Umit; Mavili, Ertugrul

2012-01-01

BACKGROUND.: Our purpose was to evaluate the effectiveness of bedside sonography (US) in the detection of pneumothorax secondary to blunt thoracic trauma. METHODS.: In this prospective study, 240 hemithoraces of 120 consecutive patients with multiple trauma were evaluated with chest radiographs (CXR) and bedside thoracic US for the diagnosis of pneumothorax. CT examinations were performed in 68 patients. Fifty-two patients who did not undergo CT examinations were excluded from the study. US examinations were performed independently at bedside by two radiologists who were not informed about CXR and CT findings. CXRs were interpreted by two radiologists who were unaware of the US and CT results. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of CXR and US were calculated. RESULTS.: One hundred thirty-six hemithoraces were assessed in 68 patients. A total of 35 pneumothoraces were detected in 33 patients. On US, the diagnosis of pneumothorax was correct in 32 hemithoraces. In 98 hemithoraces without pneumothorax, US was normal. With US examination, there were three false-positive and three false-negative results. The sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy of US were 91.4%, 97%, 91.4%, 97%, and 97%, respectively. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of CXR were 82.7%, 89.7%, 68.5%, 95%, and 89.5%, respectively. CONCLUSIONS.: Bedside thoracic US is an accurate method that can be used in trauma patients instead of CXR for the detection of pneumothorax. Copyright © 2012 Wiley Periodicals, Inc.

Association between Gallbladder Ultrasound Findings and Bacterial Culture of Bile in 70 Cats and 202 Dogs.

PubMed

Policelli Smith, R; Gookin, J L; Smolski, W; Di Cicco, M F; Correa, M; Seiler, G S

2017-09-01

Bacterial cholecystitis often is diagnosed by combination of gallbladder ultrasound (US) findings and positive results of bile culture. The value of gallbladder US in determining the likelihood of bile bacterial infection in cats and dogs with suspected biliary disease is unknown. To determine the value of gallbladder US in predicting bile bacterial culture results, identify most common bacterial isolates from bile, and describe complications after cholecystocentesis in cats and dogs with suspected hepatobiliary disease. Cats (70) and dogs (202) that underwent an abdominal US and submission of bile for culture were included in the study. A cross-sectional study design was used to determine the association of gallbladder US abnormalities and the results of bile cultures, and complications of cholecystocentesis. Abnormal gallbladder US had high sensitivity (96%) but low specificity (49%) in cats with positive and negative results of bile bacterial culture, respectively. Cats with normal gallbladder US findings were unlikely to have positive bile bacterial culture (negative predictive value of 96%). Gallbladder US had lower sensitivity (81%), specificity (31%), positive predictive value (20%), and negative predictive value (88%) in dogs. The most common bacterial isolates were of enteric origin, the prevalence being higher in cats. Incidence of complications after cholecystocentesis was 3.4%. Gallbladder US has a high negative predictive value for bile culture results in cats. This modality is less predictive of infection in dogs. Percutaneous US-guided cholecystocentesis has a low complication rate. Copyright © 2017 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

Ovarian response to 150 µg corifollitropin alfa in a GnRH-antagonist multiple-dose protocol: a prospective cohort study.

PubMed

Lerman, Tamara; Depenbusch, Marion; Schultze-Mosgau, Askan; von Otte, Soeren; Scheinhardt, Markus; Koenig, Inke; Kamischke, Axel; Macek, Milan; Schwennicke, Arne; Segerer, Sabine; Griesinger, Georg

2017-05-01

The incidence of low (<6 oocytes) and high (>18 oocytes) ovarian response to 150 µg corifollitropin alfa in relation to anti-Müllerian hormone (AMH) and other biomarkers was studied in a multi-centre (n = 5), multi-national, prospective, investigator-initiated, observational cohort study. Infertile women (n = 212), body weight >60 kg, underwent controlled ovarian stimulation in a gonadotrophin-releasing hormone-antagonist multiple-dose protocol. Demographic, sonographic and endocrine parameters were prospectively assessed on cycle day 2 or 3 of a spontaneous menstruation before the administration of 150 µg corifollitropin alfa. Serum AMH showed the best correlation with the number of oocytes obtained among all predictor variables. In receiver-operating characteristic analysis, AMH at a threshold of 0.91 ng/ml showed a sensitivity of 82.4%, specificity of 82.4%, positive predictive value 52.9%and negative predictive value 95.1% for predicting low response (area under the curve [AUC], 95% CI; P-value: 0.853, 0.769-0.936; <0.0001). For predicting high response, the optimal threshold for AMH was 2.58 ng/ml, relating to a sensitivity of 80.0%, specificity 82.1%, positive predictive value 42.5% and negative predictive value 96.1% (AUC, 95% CI; P-value: 0.871, 0.787-0.955; <0.0001). In conclusion, patients with serum AMH concentrations between approximately 0.9 and 2.6 ng/ml were unlikely to show extremes of response. Copyright © 2017. Published by Elsevier Ltd.

Predictive value of T2 relative signal intensity for response to somatostatin analogs in newly diagnosed acromegaly.

PubMed

Shen, Ming; Zhang, Qilin; Liu, Wenjuan; Wang, Meng; Zhu, Jingjing; Ma, Zengyi; He, Wenqiang; Li, Shiqi; Shou, Xuefei; Li, Yiming; Zhang, Zhaoyun; Ye, Hongying; He, Min; Lu, Bin; Yao, Zhenwei; Lu, Yun; Qiao, Nidan; Ye, Zhao; Zhang, Yichao; Yang, Yeping; Zhao, Yao; Wang, Yongfei

2016-11-01

The difficulty of predicting the efficacy of somatostatin analogs (SSA) is not fully resolved. Here, we quantitatively evaluated the predictive value of relative signal intensity (rSI) on T1- and T2-weighted magnetic resonance imaging (MRI) for the short-term efficacy (3 months) of SSA therapy in patients with active acromegaly and assessed the correlation between MRI rSI and expression of somatostatin receptors (SSTR). This was a retrospective review of prospectively recorded data. Ninety-two newly diagnosed patients (37 males and 55 females) with active acromegaly were recruited. All patients were treated with pre-surgical SSA, followed by reassessment and transspenoidal surgery. rSI values were generated by calculating the ratio of SI in the tumor to the SI of normal frontal white matter. The Youden indices were calculated to determine the optimal cutoff of rSI to determine the efficacy of SSA. The correlation between rSI and expression of SSTR2/5 was analyzed by the Spearman rank correlation coefficient. T2 rSI was strongly correlated with biochemical sensitivity to SSA. The cutoff value of T2 rSI to distinguish biochemical sensitivity was 1.205, with a positive predictive value (PPV) of 81.5 % and a negative predictive value (NPV) of 77.3 %. No correlation was found between MRI and tumor size sensitivity. Moreover, T2 rSI was negatively correlated with the expression of SSTR5. T2 rSI correlates with the expression of SSTR5 and quantitatively predicts the biochemical efficacy of SSA in acromegaly.

A weighted generalized score statistic for comparison of predictive values of diagnostic tests.

PubMed

Kosinski, Andrzej S

2013-03-15

Positive and negative predictive values are important measures of a medical diagnostic test performance. We consider testing equality of two positive or two negative predictive values within a paired design in which all patients receive two diagnostic tests. The existing statistical tests for testing equality of predictive values are either Wald tests based on the multinomial distribution or the empirical Wald and generalized score tests within the generalized estimating equations (GEE) framework. As presented in the literature, these test statistics have considerably complex formulas without clear intuitive insight. We propose their re-formulations that are mathematically equivalent but algebraically simple and intuitive. As is clearly seen with a new re-formulation we presented, the generalized score statistic does not always reduce to the commonly used score statistic in the independent samples case. To alleviate this, we introduce a weighted generalized score (WGS) test statistic that incorporates empirical covariance matrix with newly proposed weights. This statistic is simple to compute, always reduces to the score statistic in the independent samples situation, and preserves type I error better than the other statistics as demonstrated by simulations. Thus, we believe that the proposed WGS statistic is the preferred statistic for testing equality of two predictive values and for corresponding sample size computations. The new formulas of the Wald statistics may be useful for easy computation of confidence intervals for difference of predictive values. The introduced concepts have potential to lead to development of the WGS test statistic in a general GEE setting. Copyright © 2012 John Wiley & Sons, Ltd.

A weighted generalized score statistic for comparison of predictive values of diagnostic tests

PubMed Central

Kosinski, Andrzej S.

2013-01-01

Positive and negative predictive values are important measures of a medical diagnostic test performance. We consider testing equality of two positive or two negative predictive values within a paired design in which all patients receive two diagnostic tests. The existing statistical tests for testing equality of predictive values are either Wald tests based on the multinomial distribution or the empirical Wald and generalized score tests within the generalized estimating equations (GEE) framework. As presented in the literature, these test statistics have considerably complex formulas without clear intuitive insight. We propose their re-formulations which are mathematically equivalent but algebraically simple and intuitive. As is clearly seen with a new re-formulation we present, the generalized score statistic does not always reduce to the commonly used score statistic in the independent samples case. To alleviate this, we introduce a weighted generalized score (WGS) test statistic which incorporates empirical covariance matrix with newly proposed weights. This statistic is simple to compute, it always reduces to the score statistic in the independent samples situation, and it preserves type I error better than the other statistics as demonstrated by simulations. Thus, we believe the proposed WGS statistic is the preferred statistic for testing equality of two predictive values and for corresponding sample size computations. The new formulas of the Wald statistics may be useful for easy computation of confidence intervals for difference of predictive values. The introduced concepts have potential to lead to development of the weighted generalized score test statistic in a general GEE setting. PMID:22912343

Analysis of the Sensitivity and Specificity of Noninvasive Imaging Tests for the Diagnosis of Renal Artery Stenosis

PubMed Central

Borelli, Flavio Antonio de Oliveira; Pinto, Ibraim M. F.; Amodeo, Celso; Smanio, Paola E. P.; Kambara, Antonio M.; Petisco, Ana Claudia G.; Moreira, Samuel M.; Paiva, Ricardo Calil; Lopes, Hugo Belotti; Sousa, Amanda G. M. R.

2013-01-01

Background Aging and atherosclerosis are related to renovascular hypertension in elderly individuals. Regardless of comorbidities, renal artery stenosis is itself an important cause of cardiovascular morbidity and mortality. Objective To define the sensitivity, specificity, positive predictive value, and negative predictive value of noninvasive imaging tests used in the diagnosis of renal artery stenosis. Methods In a group of 61 patients recruited, 122 arteries were analized, thus permitting the definition of sensitivity, specificity, and the relative contribution of each imaging study performed (Doppler, scintigraphy and computed tomographic angiography in comparison to renal arteriography). Results The mean age was 65.43 years (standard deviation: 8.7). Of the variables related to the study population that were compared to arteriography, two correlated with renal artery stenosis, renal dysfunction and triglycerides. The median glomerular filtration rate was 52.8 mL/min/m2. Doppler showed sensitivity of 82.90%, specificity of 70%, a positive predictive value of 85% and negative predictive value of 66.70%. For tomography, sensitivity was 66.70%, specificity 80%, positive predictive value 87.50% and negative predictive value 55.20%. With these findings, we could identify the imaging tests that best detected stenosis. Conclusion Tomography and Doppler showed good quality and efficacy in the diagnosis of renal artery stenosis, with Doppler having the advantage of not requiring the use of contrast medium for the assessment of a disease that is common in diabetics and is associated with renal dysfunction and severe left ventricular dysfunction. PMID:24061685

Use of the International Classification of Diseases, 9th revision, coding in identifying chronic hepatitis B virus infection in health system data: implications for national surveillance.

PubMed

Mahajan, Reena; Moorman, Anne C; Liu, Stephen J; Rupp, Loralee; Klevens, R Monina

2013-05-01

With increasing use electronic health records (EHR) in the USA, we looked at the predictive values of the International Classification of Diseases, 9th revision (ICD-9) coding system for surveillance of chronic hepatitis B virus (HBV) infection. The chronic HBV cohort from the Chronic Hepatitis Cohort Study was created based on electronic health records (EHR) of adult patients who accessed services from 2006 to 2008 from four healthcare systems in the USA. Using the gold standard of abstractor review to confirm HBV cases, we calculated the sensitivity, specificity, positive and negative predictive values using one qualifying ICD-9 code versus using two qualifying ICD-9 codes separated by 6 months or greater. Of 1 652 055 adult patients, 2202 (0.1%) were confirmed as having chronic HBV. Use of one ICD-9 code had a sensitivity of 83.9%, positive predictive value of 61.0%, and specificity and negative predictive values greater than 99%. Use of two hepatitis B-specific ICD-9 codes resulted in a sensitivity of 58.4% and a positive predictive value of 89.9%. Use of one or two hepatitis B ICD-9 codes can identify cases with chronic HBV infection with varying sensitivity and positive predictive values. As the USA increases the use of EHR, surveillance using ICD-9 codes may be reliable to determine the burden of chronic HBV infection and would be useful to improve reporting by state and local health departments.

Ability of a 5-minute electrocardiography (ECG) for predicting arrhythmias in Doberman Pinschers with cardiomyopathy in comparison with a 24-hour ambulatory ECG.

PubMed

Wess, G; Schulze, A; Geraghty, N; Hartmann, K

2010-01-01

Ventricular premature contractions (VPCs) are common in the occult stage of cardiomyopathy in Doberman Pinschers. Although the gold standard for detecting arrhythmia is the 24-hour ambulatory electrocardiography (ECG) (Holter), this method is more expensive, time-consuming and often not as readily available as common ECG. Comparison of 5-minute ECGs with Holter examinations. Eight hundred and seventy-five 5-minute ECGs and Holter examinations of 431 Doberman Pinschers. Each examination included a 5-minute ECG and Holter examination. A cut-off value of > 100 VPCs/24 hours using Holter was considered diagnostic for the presence of cardiomyopathy. Statistical evaluation included calculation of sensitivity, specificity, positive predictive value, and negative predictive value. Holter examinations revealed > 100 VPCs/24 hours in 204/875 examinations. At least 1 VPC during a 5-minute ECG was detected in 131 (64.2%) of these 204 examinations. No VPCs were found in the 5-minute ECG in 73 (35.8%) examinations of affected Doberman Pinschers. A 5-minute ECG with at least 1 VPC as cut-off had a sensitivity of 64.2%, a specificity of 96.7%, a positive predictive value of 85.6% and a negative predictive value of 89.9% for the presence of > 100 VPCs/24 hours. A 5-minute ECG is a rather insensitive method for detecting arrhythmias in Doberman Pinschers. However, the occurrence of at least 1 VPC in 5 minutes strongly warrants further examination of the dog, because specificity (96.7%) and positive predictive value (85.6%) are high and could suggest occult cardiomyopathy.

Vasospasm on transcranial Doppler is predictive of delayed cerebral ischemia in aneurysmal subarachnoid hemorrhage: a systematic review and meta-analysis.

PubMed

Kumar, Gyanendra; Shahripour, Reza Bavarsad; Harrigan, Mark R

2016-05-01

OBJECT The impact of transcranial Doppler (TCD) ultrasonography evidence of vasospasm on patient-centered clinical outcomes following aneurysmal subarachnoid hemorrhage (aSAH) is unknown. Vasospasm is known to lead to delayed cerebral ischemia (DCI) and poor outcomes. This systematic review and meta-analysis evaluates the predictive value of vasospasm on DCI, as diagnosed on TCD. METHODS MEDLINE, Scopus, the Cochrane trial register, and clinicaltrials.gov were searched through September 2014 using key words and the terms "subarachnoid hemorrhage," "aneurysm," "aneurysmal," "cerebral vasospasm," "vasospasm," "transcranial Doppler," and "TCD." Sensitivities, specificities, and positive and negative predictive values were pooled by a DerSimonian and Laird random-effects model. RESULTS Seventeen studies (n = 2870 patients) met inclusion criteria. The amount of variance attributable to heterogeneity was significant (I(2) > 50%) for all syntheses. No studies reported the impact of TCD evidence of vasospasm on functional outcome or mortality. TCD evidence of vasospasm was found to be highly predictive of DCI. Pooled estimates for TCD diagnosis of vasospasm (for DCI) were sensitivity 90% (95% confidence interval [CI] 77%-96%), specificity 71% (95% CI 51%-84%), positive predictive value 57% (95% CI 38%-71%), and negative predictive value 92% (95% CI 83%-96%). CONCLUSIONS TCD evidence of vasospasm is predictive of DCI with high accuracy. Although high sensitivity and negative predictive value make TCD an ideal monitoring device, it is not a mandated standard of care in aSAH due to the paucity of evidence on clinically relevant outcomes, despite recommendation by national guidelines. High-quality randomized trials evaluating the impact of TCD monitoring on patient-centered and physician-relevant outcomes are needed.

[Analysis of energy expenditure in adults with cystic fibrosis: comparison of indirect calorimetry and prediction equations].

PubMed

Fuster, Casilda Olveira; Fuster, Gabriel Olveira; Galindo, Antonio Dorado; Galo, Alicia Padilla; Verdugo, Julio Merino; Lozano, Francisco Miralles

2007-07-01

Undernutrition, which implies an imbalance between energy intake and energy requirements, is common in patients with cystic fibrosis. The aim of this study was to compare resting energy expenditure determined by indirect calorimetry with that obtained with commonly used predictive equations in adults with cystic fibrosis and to assess the influence of clinical variables on the values obtained. We studied 21 patients with clinically stable cystic fibrosis, obtaining data on anthropometric variables, hand grip dynamometry, electrical bioimpedance, and resting energy expenditure by indirect calorimetry. We used the intraclass correlation coefficient (ICC) and the Bland-Altman method to assess agreement between the values obtained for resting energy expenditure measured by indirect calorimetry and those obtained with the World Health Organization (WHO) and Harris-Benedict prediction equations. The prediction equations underestimated resting energy expenditure in more than 90% of cases. The agreement between the value obtained by indirect calorimetry and that calculated with the prediction equations was poor (ICC for comparisons with the WHO and Harris-Benedict equations, 0.47 and 0.41, respectively). Bland-Altman analysis revealed a variable bias between the results of indirect calorimetry and those obtained with prediction equations, irrespective of the resting energy expenditure. The difference between the values measured by indirect calorimetry and those obtained with the WHO equation was significantly larger in patients homozygous for the DeltaF508 mutation and in those with exocrine pancreatic insufficiency. The WHO and Harris-Benedict prediction equations underestimate resting energy expenditure in adults with cystic fibrosis. There is poor agreement between the values for resting energy expenditure determined by indirect calorimetry and those estimated with prediction equations. Underestimation was greater in patients with exocrine pancreatic insufficiency and patients who were homozygous for DeltaF508.

Comparison of the Walz Nomogram and Presence of Secondary Circulating Prostate Cells for Predicting Early Biochemical Failure after Radical Prostatectomy for Prostate Cancer in Chilean Men.

PubMed

Murray, Nigel P; Reyes, Eduardo; Orellana, Nelson; Fuentealba, Cynthia; Jacob, Omar

2015-01-01

To determine the utility of secondary circulating prostate cells for predicting early biochemical failure after radical prostatectomy for prostate cancer and compare the results with the Walz nomagram. A single centre, prospective study of men with prostate cancer treated with radical prostatectomy between 2004 and 2014 was conducted, with registration of clinical-pathological details, total serum PSA pre-surgery, Gleason score, extracapsular extension, positive surgical margins, infiltration of lymph nodes, seminal vesicles and pathological stage. Secondary circulating prostate cells were obtained using differential gel centrifugation and assessed using standard immunocytochemistry with anti-PSA. Biochemical failure was defined as a PSA >0.2ng/ml, predictive values werecalculated using the Walz nomagram and CPC detection. A total of 326 men participated, with a median follow up of 5 years; 64 had biochemical failure within two years. Extracapsular extension, positive surgical margins, pathological stage, Gleason score ≥ 8, infiltration of seminal vesicles and lymph nodes were all associated with higher risk of biochemical failure. The discriminative value for the nomogram and circulating prostate cells was high (AUC >0.80), predictive values were higher for circulating prostate cell detection, with a negative predictive value of 99%, sensitivity of 96% and specificity of 75%. The nomagram had good predictive power to identify men with a high risk of biochemical failure within two years. The presence of circulating prostate cells had the same predictive power, with a higher sensitivity and negative predictive value. The presence of secondary circulating prostate cells identifies a group of men with a high risk of early biochemical failure. Those negative for secondary CPCs have a very low risk of early biochemical failure.

Bayesian model checking: A comparison of tests

NASA Astrophysics Data System (ADS)

Lucy, L. B.

2018-06-01

Two procedures for checking Bayesian models are compared using a simple test problem based on the local Hubble expansion. Over four orders of magnitude, p-values derived from a global goodness-of-fit criterion for posterior probability density functions agree closely with posterior predictive p-values. The former can therefore serve as an effective proxy for the difficult-to-calculate posterior predictive p-values.

Flight test evaluation of predicted light aircraft drag, performance, and stability

NASA Technical Reports Server (NTRS)

Smetana, F. O.; Fox, S. R.

1979-01-01

A technique was developed which permits simultaneous extraction of complete lift, drag, and thrust power curves from time histories of a single aircraft maneuver such as a pullup (from V sub max to V sub stall) and pushover (to sub V max for level flight.) The technique is an extension to non-linear equations of motion of the parameter identification methods of lliff and Taylor and includes provisions for internal data compatibility improvement as well. The technique was show to be capable of correcting random errors in the most sensitive data channel and yielding highly accurate results. This technique was applied to flight data taken on the ATLIT aircraft. The drag and power values obtained from the initial least squares estimate are about 15% less than the 'true' values. If one takes into account the rather dirty wing and fuselage existing at the time of the tests, however, the predictions are reasonably accurate. The steady state lift measurements agree well with the extracted values only for small values of alpha. The predicted value of the lift at alpha = 0 is about 33% below that found in steady state tests while the predicted lift slope is 13% below the steady state value.

Prediction of textural attributes using color values of banana (Musa sapientum) during ripening.

PubMed

Jaiswal, Pranita; Jha, Shyam Narayan; Kaur, Poonam Preet; Bhardwaj, Rishi; Singh, Ashish Kumar; Wadhawan, Vishakha

2014-06-01

Banana is an important sub-tropical fruit in international trade. It undergoes significant textural and color transformations during ripening process, which in turn influence the eating quality of the fruit. In present study, color ('L', 'a' and 'b' value) and textural attributes of bananas (peel, fruit and pulp firmness; pulp toughness; stickiness) were studied simultaneously using Hunter Color Lab and Texture Analyser, respectively, during ripening period of 10 days at ambient atmosphere. There was significant effect of ripening period on all the considered textural characteristics and color properties of bananas except color value 'b'. In general, textural descriptors (peel, fruit and pulp firmness; and pulp toughness) decreased during ripening except stickiness, while color values viz 'a' and 'b' increased with ripening barring 'L' value. Among various textural attributes, peel toughness and pulp firmness showed highest correlation (r) with 'a' value of banana peel. In order to predict textural properties using color values of banana, five types of equations (linear/polynomial/exponential/logarithmic/power) were fitted. Among them, polynomial equation was found to be the best fit (highest coefficient of determination, R(2)) for prediction of texture using color properties for bananas. The pulp firmness, peel toughness and pulp toughness showed R(2) above 0.84 with indicating its potentiality of the fitted equations for prediction of textural profile of bananas non-destructively using 'a' value.

Mortality risk prediction in burn injury: Comparison of logistic regression with machine learning approaches.

PubMed

Stylianou, Neophytos; Akbarov, Artur; Kontopantelis, Evangelos; Buchan, Iain; Dunn, Ken W

2015-08-01

Predicting mortality from burn injury has traditionally employed logistic regression models. Alternative machine learning methods have been introduced in some areas of clinical prediction as the necessary software and computational facilities have become accessible. Here we compare logistic regression and machine learning predictions of mortality from burn. An established logistic mortality model was compared to machine learning methods (artificial neural network, support vector machine, random forests and naïve Bayes) using a population-based (England & Wales) case-cohort registry. Predictive evaluation used: area under the receiver operating characteristic curve; sensitivity; specificity; positive predictive value and Youden's index. All methods had comparable discriminatory abilities, similar sensitivities, specificities and positive predictive values. Although some machine learning methods performed marginally better than logistic regression the differences were seldom statistically significant and clinically insubstantial. Random forests were marginally better for high positive predictive value and reasonable sensitivity. Neural networks yielded slightly better prediction overall. Logistic regression gives an optimal mix of performance and interpretability. The established logistic regression model of burn mortality performs well against more complex alternatives. Clinical prediction with a small set of strong, stable, independent predictors is unlikely to gain much from machine learning outside specialist research contexts. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

Evaluation of the Predictive Validity of Thermography in Identifying Extravasation With Intravenous Chemotherapy Infusions

PubMed Central

Murayama, Ryoko; Tanabe, Hidenori; Oe, Makoto; Motoo, Yoshiharu; Wagatsuma, Takanori; Michibuchi, Michiko; Kinoshita, Sachiko; Sakai, Keiko; Konya, Chizuko; Sugama, Junko; Sanada, Hiromi

2017-01-01

Early detection of extravasation is important, but conventional methods of detection lack objectivity and reliability. This study evaluated the predictive validity of thermography for identifying extravasation during intravenous antineoplastic therapy. Of 257 patients who received chemotherapy through peripheral veins, extravasation was identified in 26. Thermography was performed every 15 to 30 minutes during the infusions. Sensitivity, specificity, positive predictive value, and negative predictive value using thermography were 84.6%, 94.8%, 64.7%, and 98.2%, respectively. This study showed that thermography offers an accurate prediction of extravasation. PMID:29112585

Anticipatory Monitoring and Control of Complex Systems using a Fuzzy based Fusion of Support Vector Regressors

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

Miltiadis Alamaniotis; Vivek Agarwal

This paper places itself in the realm of anticipatory systems and envisions monitoring and control methods being capable of making predictions over system critical parameters. Anticipatory systems allow intelligent control of complex systems by predicting their future state. In the current work, an intelligent model aimed at implementing anticipatory monitoring and control in energy industry is presented and tested. More particularly, a set of support vector regressors (SVRs) are trained using both historical and observed data. The trained SVRs are used to predict the future value of the system based on current operational system parameter. The predicted values are thenmore » inputted to a fuzzy logic based module where the values are fused to obtain a single value, i.e., final system output prediction. The methodology is tested on real turbine degradation datasets. The outcome of the approach presented in this paper highlights the superiority over single support vector regressors. In addition, it is shown that appropriate selection of fuzzy sets and fuzzy rules plays an important role in improving system performance.« less

The utility of kindergarten teacher ratings for predicting low academic achievement in first grade.

PubMed

Teisl, J T; Mazzocco, M M; Myers, G F

2001-01-01

The purpose of this study was to assess the predictive value of kindergarten teachers' ratings of pupils for later first-grade academic achievement. Kindergarten students were rated by their teachers on a variety of variables, including math and reading performance, teacher concerns, and amount of learning relative to peers. These variables were then analyzed with respect to outcome measures for math and reading ability administered in the first grade. The teachers' ratings of academic performance were significantly correlated with scores on the outcome measures. Analyses were also carried out to determine sensitivity, specificity, and predictive values of the different teacher ratings. The results indicated high overall accuracy, sensitivity, specificity, and negative predictive value for the ratings. Positive predictive value tended to be lower. A recommendation to follow from these results is that teacher ratings of this sort be used to determine which children should receive cognitive screening measures to further enhance identification of children at risk for learning disability. However, this recommendation is limited by the lack of empirically supported screening measures for math disability versus well-supported screening tools for reading disability.

Impaction and Prediction: Does Ureteral Wall Thickness Affect the Success of Medical Expulsive Therapy in Pediatric Ureteral Stones?

PubMed

Tuerxun, Aierken; Batuer, Abudukahaer; Erturhan, Sakip; Eryildirim, Bilal; Camur, Emre; Sarica, Kemal

2017-01-01

The study aimed to evaluate the predictive value of ureteral wall thickness (UWT) and stone-related parameters for medical expulsive therapy (MET) success with an alpha blocker in pediatric upper ureteral stones. A total of 35 children receiving MET ureteral stones (<10 mm) were evaluated. Patients were divided into 2 subgroups where MET was successful in 18 children (51.4%) and unsuccessful in 17 children (48.6%). Prior to management, stone size, stone density (in Hounsfield unit), degree of hydronephrosis, and UWT were evaluated with patient demographics and recorded. The possible predictive value of these parameters in success rates and time to stone expulsion were evaluated in a comparative manner between the 2 groups. The overall mean patient age and stone size values were 5.40 ± 0.51 years and 6.24 ± 0.28 mm, respectively. Regarding the predictive values of these parameters for the success of MET, while stone size and UWT were found to be highly predictive for MET success, patients age, body mass index, stone density, and degree of hydronephrosis had no predictive value on this aspect. Our findings indicated that some stone and anatomical factors may be used to predict the success of MET in pediatric ureteral stones in an effective manner. With this approach, unnecessary use of these drugs that may cause a delay in removing the stone will be avoided, and the possible adverse effects of obstruction as well as stone-related clinical symptoms could be minimized. © 2017 S. Karger AG, Basel.

Carotid bruit for detection of hemodynamically significant carotid stenosis: the Northern Manhattan Study

PubMed Central

Ratchford, Elizabeth V.; Jin, Zhezhen; Di Tullio, Marco R.; Salameh, Maya J.; Homma, Shunichi; Gan, Robert; Boden-Albala, Bernadette; Sacco, Ralph L.; Rundek, Tatjana

2009-01-01

Objective The prevalence of carotid bruits and the utility of auscultation for predicting carotid stenosis are not well known. We aimed to establish the prevalence of carotid bruits and the diagnostic accuracy of auscultation for detection of hemodynamically significant carotid stenosis, using carotid duplex as the gold standard. Methods The Northern Manhattan Study (NOMAS) is a prospective multiethnic community-based cohort designed to examine the incidence of stroke and other vascular events and the association between various vascular risk factors and subclinical atherosclerosis. Of the stroke-free cohort (n=3298), 686 were examined for carotid bruits and underwent carotid duplex. Main outcome measures included prevalence of carotid bruits and sensitivity, specificity, positive predictive value, negative predictive value and accuracy of auscultation for prediction of ipsilateral carotid stenosis. Results Among 686 subjects with a mean age of 68.2 ± 9.4 years, the prevalence of ≥60% carotid stenosis as detected by ultrasound was 2.2% and the prevalence of carotid bruits was 4.1%. For detection of carotid stenosis, sensitivity of auscultation was 56%, specificity was 98%, positive predictive value was 25%, negative predictive value was 99% and overall accuracy was 97.5%. Discussion In this ethnically diverse cohort, the prevalence of carotid bruits and hemodynamically significant carotid stenosis was low. Sensitivity and positive predictive value were also low, and the 44% false-negative rate suggests that auscultation is not sufficient to exclude carotid stenosis. While the presence of a bruit may still warrant further evaluation with carotid duplex, ultrasonography may be considered in high-risk asymptomatic patients, irrespective of findings on auscultation. PMID:19133168

The Social Values of Aggressive-Prosocial Youth.

PubMed

McDonald, Kristina L; Benish-Weisman, Maya; O'Brien, Christopher T; Ungvary, Stephen

2015-12-01

Recent research has identified youth who utilize both aggressive and prosocial behavior with peers. Although the social values and motivations associated with aggression and prosocial behavior have been well studied, the values of youth who utilize both aggression and prosocial behavior are unknown. The current study identified groups of adolescents based on peer nominations of aggression and prosocial behavior from both Israel (n = 569; 56.94% Arab, 43.06% Jewish; 53.78% female) and the United States (n = 342; 67.54% African-American; 32.46% European-American; 50.88% female). Self-enhancement, self-transcendence, openness-to-change, and conservation values predicted behavioral group membership. Power values predicted membership in the aggressive group relative to the aggressive-prosocial, prosocial, and low-both groups. For Israeli boys, openness-to-change values predicted membership in the aggressive-prosocial group relative to the prosocial group. The values of aggressive-prosocial youth were more similar to the values of prosocial peers than to aggressive peers, suggesting that motivational interventions for aggressive-prosocial youth should differ in important ways than those for aggressive youth.

The multidirectional bending properties of the human lumbar intervertebral disc.

PubMed

Spenciner, David; Greene, David; Paiva, James; Palumbo, Mark; Crisco, Joseph

2006-01-01

While the biomechanical properties of the isolated intervertebral disc have been well studied in the three principal anatomic directions of flexion/extension, axial rotation, and lateral bending, there is little data on the properties in the more functional directions that are combinations of these principal anatomic directions. To determine the bending flexibility, range of motion (ROM), and neutral zone (NZ) of the human lumbar disc in multiple directions and to determine if the values about the combined moment axes can be predicted from the values about principal moment axes. Three-dimensional biomechanical analysis of the elastic bending properties of human lumbar discs about principal and combined moment axes. Pure, unconstrained moments were applied about multiple axes. The bending properties (flexibility, ROM, and NZ) of isolated lumbar discs (n=4 for L2/L3 and n=3 for L4/L5) were determined in the six principal directions and in 20 combined directions. The experimental values were compared with those predicted from the linear combination of the six principal moment axes. The maximum and minimum values of the biomechanical properties were found at the principal moment axes. Among combined moment axes, ROM and NZ (but not flexibility) values were predicted from the principal moment axis values. The principal moment axes coincide with the primary mechanical axes of the intervertebral disc and demonstrate significant differences in direction for values of flexibility, ROM, and NZ. Not all combined moment axis values can be predicted from principal moment axis values.

Predicting long-term absenteeism from work in construction industry: a longitudinal study.

PubMed

Hoonakker, Peter; van Duivenbooden, Cor

2012-01-01

In this study we examine whether the Work Ability Index (WAI) has additional value in predicting long-term absenteeism in construction industry. Results of the study show that the WAI has additional value in predicting absenteeism, but that the amount of explained variance is low. This is partly due to the definition of absenteeism in The Netherlands, where this study took place.

The interrelationship between preoperative anemia and N-terminal pro-B-type natriuretic peptide: the effect on predicting postoperative cardiac outcome in vascular surgery patients.

PubMed

Goei, Dustin; Flu, Willem-Jan; Hoeks, Sanne E; Galal, Wael; Dunkelgrun, Martin; Boersma, Eric; Kuijper, Ruud; van Kuijk, Jan-Peter; Winkel, Tamara A; Schouten, Olaf; Bax, Jeroen J; Poldermans, Don

2009-11-01

N-terminal pro-B-type natriuretic peptide (NT-proBNP) predicts adverse cardiac outcome in patients undergoing vascular surgery. However, several conditions might influence this prognostic value, including anemia. In this study, we evaluated whether anemia confounds the prognostic value of NT-proBNP for predicting cardiac events in patients undergoing vascular surgery. A detailed cardiac history, resting echocardiography, and hemoglobin and NT-proBNP levels were obtained in 666 patients before vascular surgery. Anemia was defined as serum hemoglobin <13 g/dL for men and <12 g/dL for women. Troponin T measurements and 12-lead electrocardiograms were performed on postoperative days 1, 3, 7, and 30 and whenever clinically indicated. The primary end point of the study was the composite of 30-day postoperative cardiovascular death, nonfatal myocardial infarction, and troponin T release. Receiver operating characteristic curve analysis was used to assess the optimal cutoff value of NT-proBNP for the prediction of the composite end point. Multivariable regression analysis was used to assess the additional value of NT-proBNP for the prediction of postoperative cardiac events in nonanemic and anemic patients. Anemia was present in 206 patients (31%) before surgery. Hemoglobin level was inversely related with the NT-proBNP levels (beta coefficient = -2.242; P = 0.025). The optimal predictive cutoff value of NT-proBNP for predicting the composite cardiovascular outcome was 350 pg/mL. After adjustment for clinical cardiac risk factors, both anemia (odds ratio [OR] 1.53; 95% confidence interval [CI]: 1.07-2.99) and increased levels of NT-proBNP (OR 4.09; 95% CI: 2.19-7.64) remained independent predictors for postoperative cardiac events. However, increased levels of NT-proBNP were not predictive for the risk of adverse cardiac events in the subgroup of anemic patients (OR 2.16; 95% CI: 0.90-5.21). Both anemia and NT-proBNP are independently associated with an increased risk for postoperative cardiac events in patients undergoing vascular surgery. NT-proBNP has less predictive value in anemic patients.

Use of Landsat data to predict the trophic state of Minnesota lakes

NASA Technical Reports Server (NTRS)

Lillesand, T. M.; Johnson, W. L.; Deuell, R. L.; Lindstrom, O. M.; Meisner, D. E.

1983-01-01

Near-concurrent Landsat Multispectral Scanner (MSS) and ground data were obtained for 60 lakes distributed in two Landsat scene areas. The ground data included measurement of secchi disk depth, chlorophyll-a, total phosphorous, turbidity, color, and total nitrogen, as well as Carlson Trophic State Index (TSI) values derived from the first three parameters. The Landsat data best correlated with the TSI values. Prediction models were developed to classify some 100 'test' lakes appearing in the two analysis scenes on the basis of TSI estimates. Clouds, wind, poor image data, small lake size, and shallow lake depth caused some problems in lake TSI prediction. Overall, however, the Landsat-predicted TSI estimates were judged to be very reliable for the secchi-derived TSI estimation, moderately reliable for prediction of the chlorophyll-a TSI, and unreliable for the phosphorous value. Numerous Landsat data extraction procedures were compared, and the success of the Landsat TSI prediction models was a strong function of the procedure employed.

Fast and simultaneous prediction of animal feed nutritive values using near infrared reflectance spectroscopy

NASA Astrophysics Data System (ADS)

Samadi; Wajizah, S.; Munawar, A. A.

2018-02-01

Feed plays an important factor in animal production. The purpose of this study is to apply NIRS method in determining feed values. NIRS spectra data were acquired for feed samples in wavelength range of 1000 - 2500 nm with 32 scans and 0.2 nm wavelength. Spectral data were corrected by de-trending (DT) and standard normal variate (SNV) methods. Prediction of in vitro dry matter digestibility (IVDMD) and in vitro organic matter digestibility (IVOMD) were established as model by using principal component regression (PCR) and validated using leave one out cross validation (LOOCV). Prediction performance was quantified using coefficient correlation (r) and residual predictive deviation (RPD) index. The results showed that IVDMD and IVOMD can be predicted by using SNV spectra data with r and RPD index: 0.93 and 2.78 for IVDMD ; 0.90 and 2.35 for IVOMD respectively. In conclusion, NIRS technique appears feasible to predict animal feed nutritive values.

Hydrogen and Oxygen Isotope Ratios in Body Water and Hair: Modeling Isotope Dynamics in Nonhuman Primates

PubMed Central

O’Grady, Shannon P.; Valenzuela, Luciano O.; Remien, Christopher H.; Enright, Lindsey E.; Jorgensen, Matthew J.; Kaplan, Jay R.; Wagner, Janice D.; Cerling, Thure E.; Ehleringer, James R.

2012-01-01

The stable isotopic composition of drinking water, diet, and atmospheric oxygen influence the isotopic composition of body water (2H/1H, 18O/16O expressed as δ2H and δ18O). In turn, body water influences the isotopic composition of organic matter in tissues, such as hair and teeth, which are often used to reconstruct historical dietary and movement patterns of animals and humans. Here, we used a nonhuman primate system (Macaca fascicularis) to test the robustness of two different mechanistic stable isotope models: a model to predict the δ2H and δ18O values of body water and a second model to predict the δ2H and δ18O values of hair. In contrast to previous human-based studies, use of nonhuman primates fed controlled diets allowed us to further constrain model parameter values and evaluate model predictions. Both models reliably predicted the δ2H and δ18O values of body water and of hair. Moreover, the isotope data allowed us to better quantify values for two critical variables in the models: the δ2H and δ18O values of gut water and the 18O isotope fractionation associated with a carbonyl oxygen-water interaction in the gut (αow). Our modeling efforts indicated that better predictions for body water and hair isotope values were achieved by making the isotopic composition of gut water approached that of body water. Additionally, the value of αow was 1.0164, in close agreement with the only other previously measured observation (microbial spore cell walls), suggesting robustness of this fractionation factor across different biological systems. PMID:22553163

Reference Values for Spirometry Derived Using Lambda, Mu, Sigma (LMS) Method in Korean Adults: in Comparison with Previous References.

PubMed

Jo, Bum Seak; Myong, Jun Pyo; Rhee, Chin Kook; Yoon, Hyoung Kyu; Koo, Jung Wan; Kim, Hyoung Ryoul

2018-01-15

The present study aimed to update the prediction equations for spirometry and their lower limits of normal (LLN) by using the lambda, mu, sigma (LMS) method and to compare the outcomes with the values of previous spirometric reference equations. Spirometric data of 10,249 healthy non-smokers (8,776 females) were extracted from the fourth and fifth versions of the Korea National Health and Nutrition Examination Survey (KNHANES IV, 2007-2009; V, 2010-2012). Reference equations were derived using the LMS method which allows modeling skewness (lambda [L]), mean (mu [M]), and coefficient of variation (sigma [S]). The outcome equations were compared with previous reference values. Prediction equations were presented in the following form: predicted value = e{a + b × ln(height) + c × ln(age) + M - spline}. The new predicted values for spirometry and their LLN derived using the LMS method were shown to more accurately reflect transitions in pulmonary function in young adults than previous prediction equations derived using conventional regression analysis in 2013. There were partial discrepancies between the new reference values and the reference values from the Global Lung Function Initiative in 2012. The results should be interpreted with caution for young adults and elderly males, particularly in terms of the LLN for forced expiratory volume in one second/forced vital capacity in elderly males. Serial spirometry follow-up, together with correlations with other clinical findings, should be emphasized in evaluating the pulmonary function of individuals. Future studies are needed to improve the accuracy of reference data and to develop continuous reference values for spirometry across all ages. © 2018 The Korean Academy of Medical Sciences.

Hydrogen and oxygen isotope ratios in body water and hair: modeling isotope dynamics in nonhuman primates.

PubMed

O'Grady, Shannon P; Valenzuela, Luciano O; Remien, Christopher H; Enright, Lindsey E; Jorgensen, Matthew J; Kaplan, Jay R; Wagner, Janice D; Cerling, Thure E; Ehleringer, James R

2012-07-01

The stable isotopic composition of drinking water, diet, and atmospheric oxygen influence the isotopic composition of body water ((2)H/(1)H, (18)O/(16)O expressed as δ(2) H and δ(18)O). In turn, body water influences the isotopic composition of organic matter in tissues, such as hair and teeth, which are often used to reconstruct historical dietary and movement patterns of animals and humans. Here, we used a nonhuman primate system (Macaca fascicularis) to test the robustness of two different mechanistic stable isotope models: a model to predict the δ(2)H and δ(18)O values of body water and a second model to predict the δ(2)H and δ(18)O values of hair. In contrast to previous human-based studies, use of nonhuman primates fed controlled diets allowed us to further constrain model parameter values and evaluate model predictions. Both models reliably predicted the δ(2)H and δ(18)O values of body water and of hair. Moreover, the isotope data allowed us to better quantify values for two critical variables in the models: the δ(2)H and δ(18)O values of gut water and the (18)O isotope fractionation associated with a carbonyl oxygen-water interaction in the gut (α(ow)). Our modeling efforts indicated that better predictions for body water and hair isotope values were achieved by making the isotopic composition of gut water approached that of body water. Additionally, the value of α(ow) was 1.0164, in close agreement with the only other previously measured observation (microbial spore cell walls), suggesting robustness of this fractionation factor across different biological systems. © 2012 Wiley Periodicals, Inc.

Medial Orbitofrontal Neurons Preferentially Signal Cues Predicting Changes in Reward during Unblocking

PubMed Central

Lopatina, Nina; McDannald, Michael A.; Styer, Clay V.; Peterson, Jacob F.; Sadacca, Brian F.; Cheer, Joseph F.

2016-01-01

The orbitofrontal cortex (OFC) has been broadly implicated in the ability to use the current value of expected outcomes to guide behavior. Although value correlates have been prominently reported in lateral OFC, they are more often associated with more medial areas. Further, recent studies in primates have suggested a dissociation in which the lateral OFC is involved in credit assignment and representation of reward identity and more medial areas are critical to representing value. Previously, we used unblocking to test more specifically what information about outcomes is represented by OFC neurons in rats; consistent with the proposed dichotomy between the lateral and medial OFC, we found relatively little linear value coding in the lateral OFC (Lopatina et al., 2015). Here we have repeated this experiment, recording in the medial OFC, to test whether such value signals might be found there. Neurons were recorded in an unblocking task as rats learned about cues that signaled either more, less, or the same amount of reward. We found that medial OFC neurons acquired responses to these cues; however, these responses did not signal different reward values across cues. Surprisingly, we found that cells developed responses to cues predicting a change, particularly a decrease, in reward value. This is consistent with a special role for medial OFC in representing current value to support devaluation/revaluation sensitive changes in behavior. SIGNIFICANCE STATEMENT This study uniquely examines encoding in rodent mOFC at the single-unit level in response to cues that predict more, less, or no change in reward in rats during training in a Pavlovian unblocking task, finding more cells responding to change-predictive cues and stronger activity in response to cues predictive of less reward. PMID:27511013

Predictive value of cognition for different domains of outcome in recent-onset schizophrenia.

PubMed

Holthausen, Esther A E; Wiersma, Durk; Cahn, Wiepke; Kahn, René S; Dingemans, Peter M; Schene, Aart H; van den Bosch, Robert J

2007-01-15

The aim of this study was to see whether and how cognition predicts outcome in recent-onset schizophrenia in a large range of domains such as course of illness, self-care, interpersonal functioning, vocational functioning and need for care. At inclusion, 115 recent-onset patients were tested on a cognitive battery and 103 patients participated in the follow-up 2 years after inclusion. Differences in outcome between cognitively normal and cognitively impaired patients were also analysed. Cognitive measures at inclusion did not predict number of relapses, activities of daily living and interpersonal functioning. Time in psychosis or in full remission, as well as need for care, were partly predicted by specific cognitive measures. Although statistically significant, the predictive value of cognition with regard to clinical outcome was limited. There was a significant difference between patients with and without cognitive deficits in competitive employment status and vocational functioning. The predictive value of cognition for different social outcome domains varies. It seems that cognition most strongly predicts work performance, where having a cognitive deficit, regardless of the nature of the deficit, acts as a rate-limiting factor.

Experimentally determined stiffness and damping of an inherently compensated air squeeze-film damper

NASA Technical Reports Server (NTRS)

Cunningham, R. E.

1975-01-01

Values of damping and stiffness were determined experimentally for an externally pressurized, inherently compensated, compressible squeeze-film damper up to excitation frequencies of 36,000 cycles per minute. Experimental damping values were higher than theory predicted at low squeeze numbers and less than predicted at high squeeze numbers. Experimental values of air film stiffness were less than theory predicted at low squeeze numbers and much greater at higher squeeze numbers. Results also indicate sufficient damping to attenuate amplitudes and forces at the critical speed when using three dampers in the flexible support system of a small, lightweight turborotor.

HIV RNA testing in the context of nonoccupational postexposure prophylaxis.

PubMed

Roland, Michelle E; Elbeik, Tarek A; Kahn, James O; Bamberger, Joshua D; Coates, Thomas J; Krone, Melissa R; Katz, Mitchell H; Busch, Michael P; Martin, Jeffrey N

2004-08-01

The specificity and positive predictive value of human immunodeficiency virus (HIV) RNA assays have not been evaluated in the setting of postexposure prophylaxis (PEP). Plasma from subjects enrolled in a nonoccupational PEP study was tested with 2 branched-chain DNA (bDNA) assays, 2 polymerase chain reaction (PCR) assays, and a transcription-mediated amplification (TMA) assay. Assay specificity and positive predictive value were determined for subjects who remained negative for HIV antibody for >or=3 months. In 329 subjects examined, the lowest specificities (90.1%-93.7%) were seen for bDNA testing performed in real time. The highest specificities were seen with batched bDNA version 3.0 (99.1%), standard PCR (99.4%), ultrasensitive PCR (100%), and TMA (99.6%) testing. Only the 2 assays with the highest specificities had positive predictive values >40%. For the bDNA assays, increasing the cutoff point at which a test is called positive (e.g., from 50 copies/mL to 500 copies/mL for version 3.0) increased both specificity and positive predictive values to 100%. The positive predictive value of HIV RNA assays in individuals presenting for PEP is unacceptably low for bDNA-based testing and possibly acceptable for PCR- and TMA-based testing. Routine use of HIV RNA assays in such individuals is not recommended.

Intra-Operative Frozen Sections for Ovarian Tumors – A Tertiary Center Experience

PubMed Central

Arshad, Nur Zaiti Md; Ng, Beng Kwang; Paiman, Noor Asmaliza Md; Mahdy, Zaleha Abdullah; Noor, Rushdan Mohd

2018-01-01

Background: Accuracy of diagnosis with intra-operative frozen sections is extremely important in the evaluation of ovarian tumors so that appropriate surgical procedures can be selected. Study design: All patients who with intra-operative frozen sections for ovarian masses in a tertiary center over nine years from June 2008 until April 2017 were reviewed. Frozen section diagnosis and final histopathological reports were compared. Main outcome measures: Sensitivity, specificity, positive and negative predictive values of intra-operative frozen section as compared to final histopathological results for ovarian tumors. Results: A total of 92 cases were recruited for final evaluation. The frozen section diagnoses were comparable with the final histopathological reports in 83.7% of cases. The sensitivity, specificity, positive predictive value and negative predictive value for benign and malignant ovarian tumors were 95.6%, 85.1%, 86.0% and 95.2% and 69.2%, 100%, 100% and 89.2% respectively. For borderline ovarian tumors, the sensitivity and specificity were 76.2% and 88.7%, respectively; the positive predictive value was 66.7% and the negative predictive value was 92.7%. Conclusion: The accuracy of intra-operative frozen section diagnoses for ovarian tumors is high and this approach remains a reliable option in assessing ovarian masses intra-operatively. PMID:29373916

Reward inference by primate prefrontal and striatal neurons.

PubMed

Pan, Xiaochuan; Fan, Hongwei; Sawa, Kosuke; Tsuda, Ichiro; Tsukada, Minoru; Sakagami, Masamichi

2014-01-22

The brain contains multiple yet distinct systems involved in reward prediction. To understand the nature of these processes, we recorded single-unit activity from the lateral prefrontal cortex (LPFC) and the striatum in monkeys performing a reward inference task using an asymmetric reward schedule. We found that neurons both in the LPFC and in the striatum predicted reward values for stimuli that had been previously well experienced with set reward quantities in the asymmetric reward task. Importantly, these LPFC neurons could predict the reward value of a stimulus using transitive inference even when the monkeys had not yet learned the stimulus-reward association directly; whereas these striatal neurons did not show such an ability. Nevertheless, because there were two set amounts of reward (large and small), the selected striatal neurons were able to exclusively infer the reward value (e.g., large) of one novel stimulus from a pair after directly experiencing the alternative stimulus with the other reward value (e.g., small). Our results suggest that although neurons that predict reward value for old stimuli in the LPFC could also do so for new stimuli via transitive inference, those in the striatum could only predict reward for new stimuli via exclusive inference. Moreover, the striatum showed more complex functions than was surmised previously for model-free learning.

Reward Inference by Primate Prefrontal and Striatal Neurons

PubMed Central

Pan, Xiaochuan; Fan, Hongwei; Sawa, Kosuke; Tsuda, Ichiro; Tsukada, Minoru

2014-01-01

The brain contains multiple yet distinct systems involved in reward prediction. To understand the nature of these processes, we recorded single-unit activity from the lateral prefrontal cortex (LPFC) and the striatum in monkeys performing a reward inference task using an asymmetric reward schedule. We found that neurons both in the LPFC and in the striatum predicted reward values for stimuli that had been previously well experienced with set reward quantities in the asymmetric reward task. Importantly, these LPFC neurons could predict the reward value of a stimulus using transitive inference even when the monkeys had not yet learned the stimulus–reward association directly; whereas these striatal neurons did not show such an ability. Nevertheless, because there were two set amounts of reward (large and small), the selected striatal neurons were able to exclusively infer the reward value (e.g., large) of one novel stimulus from a pair after directly experiencing the alternative stimulus with the other reward value (e.g., small). Our results suggest that although neurons that predict reward value for old stimuli in the LPFC could also do so for new stimuli via transitive inference, those in the striatum could only predict reward for new stimuli via exclusive inference. Moreover, the striatum showed more complex functions than was surmised previously for model-free learning. PMID:24453328

Interactions between the nucleus accumbens and auditory cortices predict music reward value.

PubMed

Salimpoor, Valorie N; van den Bosch, Iris; Kovacevic, Natasa; McIntosh, Anthony Randal; Dagher, Alain; Zatorre, Robert J

2013-04-12

We used functional magnetic resonance imaging to investigate neural processes when music gains reward value the first time it is heard. The degree of activity in the mesolimbic striatal regions, especially the nucleus accumbens, during music listening was the best predictor of the amount listeners were willing to spend on previously unheard music in an auction paradigm. Importantly, the auditory cortices, amygdala, and ventromedial prefrontal regions showed increased activity during listening conditions requiring valuation, but did not predict reward value, which was instead predicted by increasing functional connectivity of these regions with the nucleus accumbens as the reward value increased. Thus, aesthetic rewards arise from the interaction between mesolimbic reward circuitry and cortical networks involved in perceptual analysis and valuation.

Adaptation of clinical prediction models for application in local settings.

PubMed

Kappen, Teus H; Vergouwe, Yvonne; van Klei, Wilton A; van Wolfswinkel, Leo; Kalkman, Cor J; Moons, Karel G M

2012-01-01

When planning to use a validated prediction model in new patients, adequate performance is not guaranteed. For example, changes in clinical practice over time or a different case mix than the original validation population may result in inaccurate risk predictions. To demonstrate how clinical information can direct updating a prediction model and development of a strategy for handling missing predictor values in clinical practice. A previously derived and validated prediction model for postoperative nausea and vomiting was updated using a data set of 1847 patients. The update consisted of 1) changing the definition of an existing predictor, 2) reestimating the regression coefficient of a predictor, and 3) adding a new predictor to the model. The updated model was then validated in a new series of 3822 patients. Furthermore, several imputation models were considered to handle real-time missing values, so that possible missing predictor values could be anticipated during actual model use. Differences in clinical practice between our local population and the original derivation population guided the update strategy of the prediction model. The predictive accuracy of the updated model was better (c statistic, 0.68; calibration slope, 1.0) than the original model (c statistic, 0.62; calibration slope, 0.57). Inclusion of logistical variables in the imputation models, besides observed patient characteristics, contributed to a strategy to deal with missing predictor values at the time of risk calculation. Extensive knowledge of local, clinical processes provides crucial information to guide the process of adapting a prediction model to new clinical practices.

Predicting out-of-office blood pressure level using repeated measurements in the clinic: an observational cohort study

PubMed Central

Sheppard, James P.; Holder, Roger; Nichols, Linda; Bray, Emma; Hobbs, F.D. Richard; Mant, Jonathan; Little, Paul; Williams, Bryan; Greenfield, Sheila; McManus, Richard J.

2014-01-01

Objectives: Identification of people with lower (white-coat effect) or higher (masked effect) blood pressure at home compared to the clinic usually requires ambulatory or home monitoring. This study assessed whether changes in SBP with repeated measurement at a single clinic predict subsequent differences between clinic and home measurements. Methods: This study used an observational cohort design and included 220 individuals aged 35–84 years, receiving treatment for hypertension, but whose SBP was not controlled. The characteristics of change in SBP over six clinic readings were defined as the SBP drop, the slope and the quadratic coefficient using polynomial regression modelling. The predictive abilities of these characteristics for lower or higher home SBP readings were investigated with logistic regression and repeated operating characteristic analysis. Results: The single clinic SBP drop was predictive of the white-coat effect with a sensitivity of 90%, specificity of 50%, positive predictive value of 56% and negative predictive value of 88%. Predictive values for the masked effect and those of the slope and quadratic coefficient were slightly lower, but when the slope and quadratic variables were combined, the sensitivity, specificity, positive and negative predictive values for the masked effect were improved to 91, 48, 24 and 97%, respectively. Conclusion: Characteristics obtainable from multiple SBP measurements in a single clinic in patients with treated hypertension appear to reasonably predict those unlikely to have a large white-coat or masked effect, potentially allowing better targeting of out-of-office monitoring in routine clinical practice. PMID:25144295

Predictive equations for total lung capacity and residual volume calculated from radiographs in a random sample of the Michigan population.

PubMed Central

Kilburn, K H; Warshaw, R H; Thornton, J C; Thornton, K; Miller, A

1992-01-01

BACKGROUND: Published predicted values for total lung capacity and residual volume are often based on a small number of subjects and derive from different populations from predicted spirometric values. Equations from the only two large studies gave smaller predicted values for total lung capacity than the smaller studies. A large number of subjects have been studied from a population which has already provided predicted values for spirometry and transfer factor for carbon monoxide. METHODS: Total lung capacity was measured from standard posteroanterior and lateral chest radiographs and forced vital capacity by spirometry in a population sample of 771 subjects. Prediction equations were developed for total lung capacity (TLC), residual volume (RV) and RV/TLC in two groups--normal and total. Subjects with signs or symptoms of cardiopulmonary disease were combined with the normal subjects and equations for all subjects were also modelled. RESULTS: Prediction equations for TLC and RV in non-smoking normal men and women were square root transformations which included height and weight but not age. They included a coefficient for duration of smoking in current smokers. The predictive equation for RV/TLC included weight, age, age and duration of smoking for current smokers and ex-smokers of both sexes. For the total population the equations took the same form but the height coefficients and constants were slightly different. CONCLUSION: These population based prediction equations for TLC, RV and RV/TLC provide reference standards in a population that has provided reference standards for spirometry and single breath transfer factor for carbon monoxide. PMID:1412094

Utility of Clinical Parameters and Multiparametric MRI as Predictive Factors for Differentiating Uterine Sarcoma From Atypical Leiomyoma.

PubMed

Bi, Qiu; Xiao, Zhibo; Lv, Fajin; Liu, Yao; Zou, Chunxia; Shen, Yiqing

2018-02-05

The objective of this study was to find clinical parameters and qualitative and quantitative magnetic resonance imaging (MRI) features for differentiating uterine sarcoma from atypical leiomyoma (ALM) preoperatively and to calculate predictive values for uterine sarcoma. Data from 60 patients with uterine sarcoma and 88 patients with ALM confirmed by surgery and pathology were collected. Clinical parameters, qualitative MRI features, diffusion-weighted imaging with apparent diffusion coefficient values, and quantitative parameters of dynamic contrast-enhanced MRI of these two tumor types were compared. Predictive values for uterine sarcoma were calculated using multivariable logistic regression. Patient clinical manifestations, tumor locations, margins, T2-weighted imaging signals, mean apparent diffusion coefficient values, minimum apparent diffusion coefficient values, and time-signal intensity curves of solid tumor components were obvious significant parameters for distinguishing between uterine sarcoma and ALM (all P <.001). Abnormal vaginal bleeding, tumors located mainly in the uterine cavity, ill-defined tumor margins, and mean apparent diffusion coefficient values of <1.272 × 10 -3  mm 2 /s were significant preoperative predictors of uterine sarcoma. When the overall scores of these four predictors were greater than or equal to 7 points, the sensitivity, the specificity, the accuracy, and the positive and negative predictive values were 88.9%, 99.9%, 95.7%, 97.0%, and 95.1%, respectively. The use of clinical parameters and multiparametric MRI as predictive factors was beneficial for diagnosing uterine sarcoma preoperatively. These findings could be helpful for guiding treatment decisions. Copyright © 2018 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

Development of an enzyme-linked immunosorbent assay for serodiagnosis of ringworm infection in cattle.

PubMed

Bagut, Elena Tatiana; Cambier, Ludivine; Heinen, Marie-Pierre; Cozma, Vasile; Monod, Michel; Mignon, Bernard

2013-08-01

The aim of this study was to develop an in-house enzyme-linked immunosorbent assay (ELISA) for the serological diagnosis of ringworm infection in cattle. We used available recombinant forms of Trichophyton rubrum dipeptidyl peptidase V (TruDppV) and T. rubrum leucin aminopeptidase 2 (TruLap2), which are 98% identical to Trichophyton verrucosum orthologues. Field serum samples from 135 cattle with ringworm infection, as confirmed by direct microscopy, fluorescence microscopy, and PCR, and from 55 cattle without any apparent skin lesions or history of ringworm infection that served as negative controls were used. Sensitivities, specificities, and positive and negative predictive values were determined to evaluate the diagnostic value of our ELISA. Overall, the ELISAs based on recombinant TruDppV and TruLap2 discriminated well between infected animals and healthy controls. Highly significant differences (P < 0.0001, Mann-Whitney U test) were noted between optical density values obtained when sera from infected versus control cattle were tested. The ELISA developed for the detection of specific antibodies against DppV gave 89.6% sensitivity, 92.7% specificity, a 96.8% positive predictive value, and a 78.4% negative predictive value. The recombinant TruLap2-based ELISA displayed 88.1% sensitivity, 90.9% specificity, a 95.9% positive predictive value, and a 75.7% negative predictive value. To the best of our knowledge, this is the first ELISA based on recombinant antigens for assessing immune responses to ringworm infection in cattle; it is particularly suitable for epidemiological studies and also for the evaluation of vaccines and/or vaccination procedures.

Predictive value of CHADS2 and CHA2DS2-VASc scores for acute myocardial infarction in patients with atrial fibrillation.

PubMed

Pang, Hui; Han, Bing; Fu, Qiang; Zong, Zhenkun

2017-07-05

The presence of acute myocardial infarction (AMI) confers a poor prognosis in atrial fibrillation (AF), associated with increased mortality dramatically. This study aimed to evaluate the predictive value of CHADS 2 and CHA 2 DS 2 -VASc scores for AMI in patients with AF. This retrospective study enrolled 5140 consecutive nonvalvular AF patients, 300 patients with AMI and 4840 patients without AMI. We identified the optimal cut-off values of the CHADS 2 and CHA 2 DS 2 -VASc scores each based on receiver operating characteristic curves to predict the risk of AMI. Both CHADS 2 score and CHA 2 DS 2 -VASc score were associated with an increased odds ratio of the prevalence of AMI in patients with AF, after adjustment for hyperlipidaemia, hyperuricemia, hyperthyroidism, hypothyroidism and obstructive sleep apnea. The present results showed that the area under the curve (AUC) for CHADS 2 score was 0.787 with a similar accuracy of the CHA 2 DS 2 -VASc score (AUC 0.750) in predicting "high-risk" AF patients who developed AMI. However, the predictive accuracy of the two clinical-based risk scores was fair. The CHA 2 DS 2 -VASc score has fair predictive value for identifying high-risk patients with AF and is not significantly superior to CHADS 2 in predicting patients who develop AMI.

Evaluation of predictive capacities of biomarkers based on research synthesis.

PubMed

Hattori, Satoshi; Zhou, Xiao-Hua

2016-11-10

The objective of diagnostic studies or prognostic studies is to evaluate and compare predictive capacities of biomarkers. Suppose we are interested in evaluation and comparison of predictive capacities of continuous biomarkers for a binary outcome based on research synthesis. In analysis of each study, subjects are often classified into two groups of the high-expression and low-expression groups according to a cut-off value, and statistical analysis is based on a 2 × 2 table defined by the response and the high expression or low expression of the biomarker. Because the cut-off is study specific, it is difficult to interpret a combined summary measure such as an odds ratio based on the standard meta-analysis techniques. The summary receiver operating characteristic curve is a useful method for meta-analysis of diagnostic studies in the presence of heterogeneity of cut-off values to examine discriminative capacities of biomarkers. We develop a method to estimate positive or negative predictive curves, which are alternative to the receiver operating characteristic curve based on information reported in published papers of each study. These predictive curves provide a useful graphical presentation of pairs of positive and negative predictive values and allow us to compare predictive capacities of biomarkers of different scales in the presence of heterogeneity in cut-off values among studies. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Determination of polyparameter linear free energy relationship (pp-LFER) substance descriptors for established and alternative flame retardants.

PubMed

Stenzel, Angelika; Goss, Kai-Uwe; Endo, Satoshi

2013-02-05

Polyparameter linear free energy relationships (pp-LFERs) can predict partition coefficients for a multitude of environmental and biological phases with high accuracy. In this work, the pp-LFER substance descriptors of 40 established and alternative flame retardants (e.g., polybrominated diphenyl ethers, hexabromocyclododecane, bromobenzenes, trialkyl phosphates) were determined experimentally. In total, 251 data for gas-chromatographic (GC) retention times and liquid/liquid partition coefficients (K) were measured and used to calibrate the pp-LFER substance descriptors. Substance descriptors were validated through a comparison between predicted and experimental log K for the systems octanol/water (K(ow)), water/air (K(wa)), organic carbon/water (K(oc)) and liposome/water (K(lipw)), revealing a high reliability of pp-LFER predictions based on our descriptors. For instance, the difference between predicted and experimental log K(ow) was <0.3 log units for 17 out of 21 compounds for which experimental values were available. Moreover, we found an indication that the H-bond acceptor value (B) depends on the solvent for some compounds. Thus, for predicting environmentally relevant partition coefficients it is important to determine B values using measurements in aqueous systems. The pp-LFER descriptors calibrated in this study can be used to predict partition coefficients for which experimental data are unavailable, and the predicted values can serve as references for further experimental measurements.

Quantifying model-structure- and parameter-driven uncertainties in spring wheat phenology prediction with Bayesian analysis

DOE PAGES

Alderman, Phillip D.; Stanfill, Bryan

2016-10-06

Recent international efforts have brought renewed emphasis on the comparison of different agricultural systems models. Thus far, analysis of model-ensemble simulated results has not clearly differentiated between ensemble prediction uncertainties due to model structural differences per se and those due to parameter value uncertainties. Additionally, despite increasing use of Bayesian parameter estimation approaches with field-scale crop models, inadequate attention has been given to the full posterior distributions for estimated parameters. The objectives of this study were to quantify the impact of parameter value uncertainty on prediction uncertainty for modeling spring wheat phenology using Bayesian analysis and to assess the relativemore » contributions of model-structure-driven and parameter-value-driven uncertainty to overall prediction uncertainty. This study used a random walk Metropolis algorithm to estimate parameters for 30 spring wheat genotypes using nine phenology models based on multi-location trial data for days to heading and days to maturity. Across all cases, parameter-driven uncertainty accounted for between 19 and 52% of predictive uncertainty, while model-structure-driven uncertainty accounted for between 12 and 64%. Here, this study demonstrated the importance of quantifying both model-structure- and parameter-value-driven uncertainty when assessing overall prediction uncertainty in modeling spring wheat phenology. More generally, Bayesian parameter estimation provided a useful framework for quantifying and analyzing sources of prediction uncertainty.« less

Can history and exam alone reliably predict pneumonia?

PubMed

Graffelman, A W; le Cessie, S; Knuistingh Neven, A; Wilemssen, F E J A; Zonderland, H M; van den Broek, P J

2007-06-01

Prediction rules based on clinical information have been developed to support the diagnosis of pneumonia and help limit the use of expensive diagnostic tests. However, these prediction rules need to be validated in the primary care setting. Adults who met our definition of lower respiratory tract infection (LRTI) were recruited for a prospective study on the causes of LRTI, between November 15, 1998 and June 1, 2001 in the Leiden region of The Netherlands. Clinical information was collected and chest radiography was performed. A literature search was also done to find prediction rules for pneumonia. 129 patients--26 with pneumonia and 103 without--were included, and 6 prediction rules were applied. Only the model with the addition of a test for C-reactive protein had a significant area under the curve of 0.69 (95% confidence interval [CI], 0.58-0.80), with a positive predictive value of 47% (95% CI, 23-71) and a negative predictive value of 84% (95% CI, 77-91). The pretest probabilities for the presence and absence of pneumonia were 20% and 80%, respectively. Models based only on clinical information do not reliably predict the presence of pneumonia. The addition of an elevated C-reactive protein level seems of little value.

Predicting risk for portal vein thrombosis in acute pancreatitis patients: A comparison of radical basis function artificial neural network and logistic regression models.

PubMed

Fei, Yang; Hu, Jian; Gao, Kun; Tu, Jianfeng; Li, Wei-Qin; Wang, Wei

2017-06-01

To construct a radical basis function (RBF) artificial neural networks (ANNs) model to predict the incidence of acute pancreatitis (AP)-induced portal vein thrombosis. The analysis included 353 patients with AP who had admitted between January 2011 and December 2015. RBF ANNs model and logistic regression model were constructed based on eleven factors relevant to AP respectively. Statistical indexes were used to evaluate the value of the prediction in two models. The predict sensitivity, specificity, positive predictive value, negative predictive value and accuracy by RBF ANNs model for PVT were 73.3%, 91.4%, 68.8%, 93.0% and 87.7%, respectively. There were significant differences between the RBF ANNs and logistic regression models in these parameters (P<0.05). In addition, a comparison of the area under receiver operating characteristic curves of the two models showed a statistically significant difference (P<0.05). The RBF ANNs model is more likely to predict the occurrence of PVT induced by AP than logistic regression model. D-dimer, AMY, Hct and PT were important prediction factors of approval for AP-induced PVT. Copyright © 2017 Elsevier Inc. All rights reserved.

The accuracy of new wheelchair users' predictions about their future wheelchair use.

PubMed

Hoenig, Helen; Griffiths, Patricia; Ganesh, Shanti; Caves, Kevin; Harris, Frances

2012-06-01

This study examined the accuracy of new wheelchair user predictions about their future wheelchair use. This was a prospective cohort study of 84 community-dwelling veterans provided a new manual wheelchair. The association between predicted and actual wheelchair use was strong at 3 mos (ϕ coefficient = 0.56), with 90% of those who anticipated using the wheelchair at 3 mos still using it (i.e., positive predictive value = 0.96) and 60% of those who anticipated not using it indeed no longer using the wheelchair (i.e., negative predictive value = 0.60, overall accuracy = 0.92). Predictive accuracy diminished over time, with overall accuracy declining from 0.92 at 3 mos to 0.66 at 6 mos. At all time points, and for all types of use, patients better predicted use as opposed to disuse, with correspondingly higher positive than negative predictive values. Accuracy of prediction of use in specific indoor and outdoor locations varied according to location. This study demonstrates the importance of better understanding the potential mismatch between the anticipated and actual patterns of wheelchair use. The findings suggest that users can be relied upon to accurately predict their basic wheelchair-related needs in the short-term. Further exploration is needed to identify characteristics that will aid users and their providers in more accurately predicting mobility needs for the long-term.

The statistical properties and possible causes of polar motion prediction errors

NASA Astrophysics Data System (ADS)

Kosek, Wieslaw; Kalarus, Maciej; Wnek, Agnieszka; Zbylut-Gorska, Maria

2015-08-01

The pole coordinate data predictions from different prediction contributors of the Earth Orientation Parameters Combination of Prediction Pilot Project (EOPCPPP) were studied to determine the statistical properties of polar motion forecasts by looking at the time series of differences between them and the future IERS pole coordinates data. The mean absolute errors, standard deviations as well as the skewness and kurtosis of these differences were computed together with their error bars as a function of prediction length. The ensemble predictions show a little smaller mean absolute errors or standard deviations however their skewness and kurtosis values are similar as the for predictions from different contributors. The skewness and kurtosis enable to check whether these prediction differences satisfy normal distribution. The kurtosis values diminish with the prediction length which means that the probability distribution of these prediction differences is becoming more platykurtic than letptokurtic. Non zero skewness values result from oscillating character of these differences for particular prediction lengths which can be due to the irregular change of the annual oscillation phase in the joint fluid (atmospheric + ocean + land hydrology) excitation functions. The variations of the annual oscillation phase computed by the combination of the Fourier transform band pass filter and the Hilbert transform from pole coordinates data as well as from pole coordinates model data obtained from fluid excitations are in a good agreement.

Choosing the appropriate forecasting model for predictive parameter control.

PubMed

Aleti, Aldeida; Moser, Irene; Meedeniya, Indika; Grunske, Lars

2014-01-01

All commonly used stochastic optimisation algorithms have to be parameterised to perform effectively. Adaptive parameter control (APC) is an effective method used for this purpose. APC repeatedly adjusts parameter values during the optimisation process for optimal algorithm performance. The assignment of parameter values for a given iteration is based on previously measured performance. In recent research, time series prediction has been proposed as a method of projecting the probabilities to use for parameter value selection. In this work, we examine the suitability of a variety of prediction methods for the projection of future parameter performance based on previous data. All considered prediction methods have assumptions the time series data has to conform to for the prediction method to provide accurate projections. Looking specifically at parameters of evolutionary algorithms (EAs), we find that all standard EA parameters with the exception of population size conform largely to the assumptions made by the considered prediction methods. Evaluating the performance of these prediction methods, we find that linear regression provides the best results by a very small and statistically insignificant margin. Regardless of the prediction method, predictive parameter control outperforms state of the art parameter control methods when the performance data adheres to the assumptions made by the prediction method. When a parameter's performance data does not adhere to the assumptions made by the forecasting method, the use of prediction does not have a notable adverse impact on the algorithm's performance.

Evaluating the predictive accuracy and the clinical benefit of a nomogram aimed to predict survival in node-positive prostate cancer patients: External validation on a multi-institutional database.

PubMed

Bianchi, Lorenzo; Schiavina, Riccardo; Borghesi, Marco; Bianchi, Federico Mineo; Briganti, Alberto; Carini, Marco; Terrone, Carlo; Mottrie, Alex; Gacci, Mauro; Gontero, Paolo; Imbimbo, Ciro; Marchioro, Giansilvio; Milanese, Giulio; Mirone, Vincenzo; Montorsi, Francesco; Morgia, Giuseppe; Novara, Giacomo; Porreca, Angelo; Volpe, Alessandro; Brunocilla, Eugenio

2018-04-06

To assess the predictive accuracy and the clinical value of a recent nomogram predicting cancer-specific mortality-free survival after surgery in pN1 prostate cancer patients through an external validation. We evaluated 518 prostate cancer patients treated with radical prostatectomy and pelvic lymph node dissection with evidence of nodal metastases at final pathology, at 10 tertiary centers. External validation was carried out using regression coefficients of the previously published nomogram. The performance characteristics of the model were assessed by quantifying predictive accuracy, according to the area under the curve in the receiver operating characteristic curve and model calibration. Furthermore, we systematically analyzed the specificity, sensitivity, positive predictive value and negative predictive value for each nomogram-derived probability cut-off. Finally, we implemented decision curve analysis, in order to quantify the nomogram's clinical value in routine practice. External validation showed inferior predictive accuracy as referred to in the internal validation (65.8% vs 83.3%, respectively). The discrimination (area under the curve) of the multivariable model was 66.7% (95% CI 60.1-73.0%) by testing with receiver operating characteristic curve analysis. The calibration plot showed an overestimation throughout the range of predicted cancer-specific mortality-free survival rates probabilities. However, in decision curve analysis, the nomogram's use showed a net benefit when compared with the scenarios of treating all patients or none. In an external setting, the nomogram showed inferior predictive accuracy and suboptimal calibration characteristics as compared to that reported in the original population. However, decision curve analysis showed a clinical net benefit, suggesting a clinical implication to correctly manage pN1 prostate cancer patients after surgery. © 2018 The Japanese Urological Association.

The value of nodal information in predicting lung cancer relapse using 4DPET/4DCT

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

Li, Heyse, E-mail: heyse.li@mail.utoronto.ca; Becker, Nathan; Raman, Srinivas

2015-08-15

Purpose: There is evidence that computed tomography (CT) and positron emission tomography (PET) imaging metrics are prognostic and predictive in nonsmall cell lung cancer (NSCLC) treatment outcomes. However, few studies have explored the use of standardized uptake value (SUV)-based image features of nodal regions as predictive features. The authors investigated and compared the use of tumor and node image features extracted from the radiotherapy target volumes to predict relapse in a cohort of NSCLC patients undergoing chemoradiation treatment. Methods: A prospective cohort of 25 patients with locally advanced NSCLC underwent 4DPET/4DCT imaging for radiation planning. Thirty-seven image features were derivedmore » from the CT-defined volumes and SUVs of the PET image from both the tumor and nodal target regions. The machine learning methods of logistic regression and repeated stratified five-fold cross-validation (CV) were used to predict local and overall relapses in 2 yr. The authors used well-known feature selection methods (Spearman’s rank correlation, recursive feature elimination) within each fold of CV. Classifiers were ranked on their Matthew’s correlation coefficient (MCC) after CV. Area under the curve, sensitivity, and specificity values are also presented. Results: For predicting local relapse, the best classifier found had a mean MCC of 0.07 and was composed of eight tumor features. For predicting overall relapse, the best classifier found had a mean MCC of 0.29 and was composed of a single feature: the volume greater than 0.5 times the maximum SUV (N). Conclusions: The best classifier for predicting local relapse had only tumor features. In contrast, the best classifier for predicting overall relapse included a node feature. Overall, the methods showed that nodes add value in predicting overall relapse but not local relapse.« less

Will personal values predict the development of smoking and drinking behaviors? A prospective cohort study of children and adolescents in Taiwan.

PubMed

Nieh, Hsi-Ping; Wu, Wen-Chi; Luh, Dih-Ling; Yen, Lee-Lan; Hurng, Baai-Shyun; Chang, Hsing-Yi

2018-06-01

This study examined how personal values predict the development of smoking and drinking behaviors in adolescence. The longitudinal data of 1545 adolescents over a 6-year period were analyzed. The results showed that adolescents who valued health and academics had similarly lower odds of reporting cigarette and alcohol use and those who valued friends had significantly higher odds. While the odds increased over time, the trend on alcohol use lessened for adolescents who valued academics, while the trend accelerated for those who valued friends. The finding suggests the important role that personal values play in adolescent risk behavioral development.

Waist circumference shows the highest predictive value for metabolic syndrome, and waist-to-hip ratio for its components, in Spanish adolescents.

PubMed

Perona, Javier S; Schmidt-RioValle, Jacqueline; Rueda-Medina, Blanca; Correa-Rodríguez, María; González-Jiménez, Emilio

2017-09-01

Both waist circumference (WC) and waist-to-hip ratio (WHR) have been proposed as predictors of metabolic syndrome (MetS) in adolescents, but no consensus has been reached to date. This study hypothesizes that WC provides a greater predictive value for MetS in Spanish adolescents than WHR. A cross-sectional study was performed on 1001 adolescents (13.2 ± 1.2 years) randomly recruited from schools in southeast Spain. Anthropometric measures were correlated with the components of MetS (triglycerides, glucose, blood pressure, and high-density lipoprotein cholesterol) as well as inflammation markers (interleukin-6 and tumor necrosis factor-alpha , C-reactive protein, and ceruloplasmin). Receiver-operator curves were created to determine the predictive value of these variables for MetS. Boys had higher values of all anthropometric parameters compared with girls, but the prevalence of MetS was significantly higher in girls. WHR was the only parameter that correlated significantly with all biochemical and inflammatory variables in boys. In girls, WHR, body mass index, waist-to-height ratio, WC, and body fat percentage correlated only with plasma insulin levels, systolic and diastolic pressures, and ceruloplasmin. In both groups, all anthropometric measures were able to predict MetS (area under the curve > 0.94). In particular, WC was able to predict MetS with area under the curve = 1.00. However, WHR was able to predict a higher number of components of MetS. WHR was the anthropometric index that showed the highest predictive value for MetS components, whereas WC was the one that best predicted the MetS among the population of adolescents studied. These findings justify the need to incorporate WHR and WC determinations into daily clinical practice to predict the MetS. Copyright © 2017 Elsevier Inc. All rights reserved.

Evaluation of approaches for estimating the accuracy of genomic prediction in plant breeding

PubMed Central

2013-01-01

Background In genomic prediction, an important measure of accuracy is the correlation between the predicted and the true breeding values. Direct computation of this quantity for real datasets is not possible, because the true breeding value is unknown. Instead, the correlation between the predicted breeding values and the observed phenotypic values, called predictive ability, is often computed. In order to indirectly estimate predictive accuracy, this latter correlation is usually divided by an estimate of the square root of heritability. In this study we use simulation to evaluate estimates of predictive accuracy for seven methods, four (1 to 4) of which use an estimate of heritability to divide predictive ability computed by cross-validation. Between them the seven methods cover balanced and unbalanced datasets as well as correlated and uncorrelated genotypes. We propose one new indirect method (4) and two direct methods (5 and 6) for estimating predictive accuracy and compare their performances and those of four other existing approaches (three indirect (1 to 3) and one direct (7)) with simulated true predictive accuracy as the benchmark and with each other. Results The size of the estimated genetic variance and hence heritability exerted the strongest influence on the variation in the estimated predictive accuracy. Increasing the number of genotypes considerably increases the time required to compute predictive accuracy by all the seven methods, most notably for the five methods that require cross-validation (Methods 1, 2, 3, 4 and 6). A new method that we propose (Method 5) and an existing method (Method 7) used in animal breeding programs were the fastest and gave the least biased, most precise and stable estimates of predictive accuracy. Of the methods that use cross-validation Methods 4 and 6 were often the best. Conclusions The estimated genetic variance and the number of genotypes had the greatest influence on predictive accuracy. Methods 5 and 7 were the fastest and produced the least biased, the most precise, robust and stable estimates of predictive accuracy. These properties argue for routinely using Methods 5 and 7 to assess predictive accuracy in genomic selection studies. PMID:24314298

Evaluation of approaches for estimating the accuracy of genomic prediction in plant breeding.

PubMed

Ould Estaghvirou, Sidi Boubacar; Ogutu, Joseph O; Schulz-Streeck, Torben; Knaak, Carsten; Ouzunova, Milena; Gordillo, Andres; Piepho, Hans-Peter

2013-12-06

In genomic prediction, an important measure of accuracy is the correlation between the predicted and the true breeding values. Direct computation of this quantity for real datasets is not possible, because the true breeding value is unknown. Instead, the correlation between the predicted breeding values and the observed phenotypic values, called predictive ability, is often computed. In order to indirectly estimate predictive accuracy, this latter correlation is usually divided by an estimate of the square root of heritability. In this study we use simulation to evaluate estimates of predictive accuracy for seven methods, four (1 to 4) of which use an estimate of heritability to divide predictive ability computed by cross-validation. Between them the seven methods cover balanced and unbalanced datasets as well as correlated and uncorrelated genotypes. We propose one new indirect method (4) and two direct methods (5 and 6) for estimating predictive accuracy and compare their performances and those of four other existing approaches (three indirect (1 to 3) and one direct (7)) with simulated true predictive accuracy as the benchmark and with each other. The size of the estimated genetic variance and hence heritability exerted the strongest influence on the variation in the estimated predictive accuracy. Increasing the number of genotypes considerably increases the time required to compute predictive accuracy by all the seven methods, most notably for the five methods that require cross-validation (Methods 1, 2, 3, 4 and 6). A new method that we propose (Method 5) and an existing method (Method 7) used in animal breeding programs were the fastest and gave the least biased, most precise and stable estimates of predictive accuracy. Of the methods that use cross-validation Methods 4 and 6 were often the best. The estimated genetic variance and the number of genotypes had the greatest influence on predictive accuracy. Methods 5 and 7 were the fastest and produced the least biased, the most precise, robust and stable estimates of predictive accuracy. These properties argue for routinely using Methods 5 and 7 to assess predictive accuracy in genomic selection studies.

[Rapid determination of fatty acids in soybean oils by transmission reflection-near infrared spectroscopy].

PubMed

Song, Tao; Zhang, Feng-ping; Liu, Yao-min; Wu, Zong-wen; Suo, You-rui

2012-08-01

In the present research, a novel method was established for determination of five fatty acids in soybean oil by transmission reflection-near infrared spectroscopy. The optimum conditions of mathematics model of five components (C16:0, C18:0, C18:1, C18:2 and C18:3) were studied, including the sample set selection, chemical value analysis, the detection methods and condition. Chemical value was analyzed by gas chromatography. One hundred fifty eight samples were selected, 138 for modeling set, 10 for testing set and 10 for unknown sample set. All samples were placed in sample pools and scanned by transmission reflection-near infrared spectrum after sonicleaning for 10 minute. The 1100-2500 nm spectral region was analyzed. The acquisition interval was 2 nm. Modified partial least square method was chosen for calibration mode creating. Result demonstrated that the 1-VR of five fatty acids between the reference value of the modeling sample set and the near infrared spectrum predictive value were 0.8839, 0.5830, 0.9001, 0.9776 and 0.9596, respectively. And the SECV of five fatty acids between the reference value of the modeling sample set and the near infrared spectrum predictive value were 0.42, 0.29, 0.83, 0.46 and 0.21, respectively. The standard error of the calibration (SECV) of five fatty acids between the reference value of testing sample set and the near infrared spectrum predictive value were 0.891, 0.790, 0.900, 0.976 and 0.942, respectively. It was proved that the near infrared spectrum predictive value was linear with chemical value and the mathematical model established for fatty acids of soybean oil was feasible. For validation, 10 unknown samples were selected for analysis by near infrared spectrum. The result demonstrated that the relative standard deviation between predict value and chemical value was less than 5.50%. That was to say that transmission reflection-near infrared spectroscopy had a good veracity in analysis of fatty acids of soybean oil.

Predictive Value of Glasgow Coma Score and Full Outline of Unresponsiveness Score on the Outcome of Multiple Trauma Patients.

PubMed

Baratloo, Alireza; Shokravi, Masumeh; Safari, Saeed; Aziz, Awat Kamal

2016-03-01

The Full Outline of Unresponsiveness (FOUR) score was developed to compensate for the limitations of Glasgow coma score (GCS) in recent years. This study aimed to assess the predictive value of GCS and FOUR score on the outcome of multiple trauma patients admitted to the emergency department. The present prospective cross-sectional study was conducted on multiple trauma patients admitted to the emergency department. GCS and FOUR scores were evaluated at the time of admission and at the sixth and twelfth hours after admission. Then the receiver operating characteristic (ROC) curve, sensitivity, specificity, as well as positive and negative predictive value of GCS and FOUR score were evaluated to predict patients' outcome. Patients' outcome was divided into discharge with and without a medical injury (motor deficit, coma or death). Finally, 89 patients were studied. Sensitivity and specificity of GCS in predicting adverse outcome (motor deficit, coma or death) were 84.2% and 88.6% at the time of admission, 89.5% and 95.4% at the sixth hour and 89.5% and 91.5% at the twelfth hour, respectively. These values for the FOUR score were 86.9% and 88.4% at the time of admission, 89.5% and 100% at the sixth hour and 89.5% and 94.4% at the twelfth hour, respectively. Findings of this study indicate that the predictive value of FOUR score and GCS on the outcome of multiple trauma patients admitted to the emergency department is similar.

Model for forecasting Olea europaea L. airborne pollen in South-West Andalusia, Spain

NASA Astrophysics Data System (ADS)

Galán, C.; Cariñanos, Paloma; García-Mozo, Herminia; Alcázar, Purificación; Domínguez-Vilches, Eugenio

Data on predicted average and maximum airborne pollen concentrations and the dates on which these maximum values are expected are of undoubted value to allergists and allergy sufferers, as well as to agronomists. This paper reports on the development of predictive models for calculating total annual pollen output, on the basis of pollen and weather data compiled over the last 19 years (1982-2000) for Córdoba (Spain). Models were tested in order to predict the 2000 pollen season; in addition, and in view of the heavy rainfall recorded in spring 2000, the 1982-1998 data set was used to test the model for 1999. The results of the multiple regression analysis show that the variables exerting the greatest influence on the pollen index were rainfall in March and temperatures over the months prior to the flowering period. For prediction of maximum values and dates on which these values might be expected, the start of the pollen season was used as an additional independent variable. Temperature proved the best variable for this prediction. Results improved when the 5-day moving average was taken into account. Testing of the predictive model for 1999 and 2000 yielded fairly similar results. In both cases, the difference between expected and observed pollen data was no greater than 10%. However, significant differences were recorded between forecast and expected maximum and minimum values, owing to the influence of rainfall during the flowering period.

Genomic selection in plant breeding

USDA-ARS?s Scientific Manuscript database

Genomic selection (GS) is a method to predict the genetic value of selection candidates based on the genomic estimated breeding value (GEBV) predicted from high-density markers positioned throughout the genome. Unlike marker-assisted selection, the GEBV is based on all markers including both minor ...

Enhancing the 'real world' prediction of cardiovascular events and major bleeding with the CHA2DS2-VASc and HAS-BLED scores using multiple biomarkers.

PubMed

Roldán, Vanessa; Rivera-Caravaca, José Miguel; Shantsila, Alena; García-Fernández, Amaya; Esteve-Pastor, María Asunción; Vilchez, Juan Antonio; Romera, Marta; Valdés, Mariano; Vicente, Vicente; Marín, Francisco; Lip, Gregory Y H

2018-02-01

Atrial fibrillation (AF)-European guidelines suggest the use of biomarkers to stratify patients for stroke and bleeding risks. We investigated if a multibiomarker strategy improved the predictive performance of CHA 2 DS 2 -VASc and HAS-BLED in anticoagulated AF patients. We included consecutive patients stabilized for six months on vitamin K antagonists (INRs 2.0-3.0). High sensitivity troponin T, NT-proBNP, interleukin-6, von Willebrand factor concentrations and glomerular filtration rate (eGFR; using MDRD-4 formula) were quantified at baseline. Time in therapeutic range (TTR) was recorded at six months after inclusion. Patients were follow-up during a median of 2375 (IQR 1564-2887) days and all adverse events were recorded. In 1361 patients, adding four blood biomarkers, TTR and MDRD-eGFR, the predictive value of CHA 2 DS 2 -VASc increased significantly by c-index (0.63 vs. 0.65; p = .030) and IDI (0.85%; p < .001), but not by NRI (-2.82%; p < .001). The predictive value of HAS-BLED increased up to 1.34% by IDI (p < .001). Nevertheless, the overall predictive value remains modest (c-indexes approximately 0.65) and decision curve analyses found lower net benefit compared with the originals scores. Addition of biomarkers enhanced the predictive value of CHA 2 DS 2 -VASc and HAS-BLED, although the overall improvement was modest and the added predictive advantage over original scores was marginal. Key Messages Recent atrial fibrillation (AF)-European guidelines for the first time suggest the use of biomarkers to stratify patients for stroke and bleeding risks, but their usefulness in real world for risk stratification is still questionable. In this cohort study involving 1361 AF patients optimally anticoagulated with vitamin K antagonists, adding high sensitivity troponin T, N-terminal pro-B-type natriuretic peptide, interleukin 6, von Willebrand factor, glomerular filtration rate (by the MDRD-4 formula) and time in therapeutic range, increased the predictive value of CHA 2 DS 2 -VASc for cardiovascular events, but not the predictive value of HAS-BLED for major bleeding. Reclassification analyses did not show improvement adding multiple biomarkers. Despite the improvement observed, the added predictive advantage is marginal and the clinical usefulness and net benefit over current clinical scores is lower.

Comparison of manual scaled and predicted foE and foF1 critical frequencies. Technical report

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

Gamache, R.R.; Kersey, W.T.

1990-07-01

The CCIR and Titheridge foE critical frequency prediction routines were tested by comparison with 1875 manually scaled values. The foF1 critical frequency prediction routine of Millman et al was tested by comparison with 1005 manually scaled values. Plots and statistics of the comparisons are presented and discussed. From the results recommendations are made to help improve autoscaling.

Prediction of Breeding Values for Dairy Cattle Using Artificial Neural Networks and Neuro-Fuzzy Systems

PubMed Central

Shahinfar, Saleh; Mehrabani-Yeganeh, Hassan; Lucas, Caro; Kalhor, Ahmad; Kazemian, Majid; Weigel, Kent A.

2012-01-01

Developing machine learning and soft computing techniques has provided many opportunities for researchers to establish new analytical methods in different areas of science. The objective of this study is to investigate the potential of two types of intelligent learning methods, artificial neural networks and neuro-fuzzy systems, in order to estimate breeding values (EBV) of Iranian dairy cattle. Initially, the breeding values of lactating Holstein cows for milk and fat yield were estimated using conventional best linear unbiased prediction (BLUP) with an animal model. Once that was established, a multilayer perceptron was used to build ANN to predict breeding values from the performance data of selection candidates. Subsequently, fuzzy logic was used to form an NFS, a hybrid intelligent system that was implemented via a local linear model tree algorithm. For milk yield the correlations between EBV and EBV predicted by the ANN and NFS were 0.92 and 0.93, respectively. Corresponding correlations for fat yield were 0.93 and 0.93, respectively. Correlations between multitrait predictions of EBVs for milk and fat yield when predicted simultaneously by ANN were 0.93 and 0.93, respectively, whereas corresponding correlations with reference EBV for multitrait NFS were 0.94 and 0.95, respectively, for milk and fat production. PMID:22991575

Systematic bias of correlation coefficient may explain negative accuracy of genomic prediction.

PubMed

Zhou, Yao; Vales, M Isabel; Wang, Aoxue; Zhang, Zhiwu

2017-09-01

Accuracy of genomic prediction is commonly calculated as the Pearson correlation coefficient between the predicted and observed phenotypes in the inference population by using cross-validation analysis. More frequently than expected, significant negative accuracies of genomic prediction have been reported in genomic selection studies. These negative values are surprising, given that the minimum value for prediction accuracy should hover around zero when randomly permuted data sets are analyzed. We reviewed the two common approaches for calculating the Pearson correlation and hypothesized that these negative accuracy values reflect potential bias owing to artifacts caused by the mathematical formulas used to calculate prediction accuracy. The first approach, Instant accuracy, calculates correlations for each fold and reports prediction accuracy as the mean of correlations across fold. The other approach, Hold accuracy, predicts all phenotypes in all fold and calculates correlation between the observed and predicted phenotypes at the end of the cross-validation process. Using simulated and real data, we demonstrated that our hypothesis is true. Both approaches are biased downward under certain conditions. The biases become larger when more fold are employed and when the expected accuracy is low. The bias of Instant accuracy can be corrected using a modified formula. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Development and Validation of an Algorithm to Identify Planned Readmissions From Claims Data.

PubMed

Horwitz, Leora I; Grady, Jacqueline N; Cohen, Dorothy B; Lin, Zhenqiu; Volpe, Mark; Ngo, Chi K; Masica, Andrew L; Long, Theodore; Wang, Jessica; Keenan, Megan; Montague, Julia; Suter, Lisa G; Ross, Joseph S; Drye, Elizabeth E; Krumholz, Harlan M; Bernheim, Susannah M

2015-10-01

It is desirable not to include planned readmissions in readmission measures because they represent deliberate, scheduled care. To develop an algorithm to identify planned readmissions, describe its performance characteristics, and identify improvements. Consensus-driven algorithm development and chart review validation study at 7 acute-care hospitals in 2 health systems. For development, all discharges qualifying for the publicly reported hospital-wide readmission measure. For validation, all qualifying same-hospital readmissions that were characterized by the algorithm as planned, and a random sampling of same-hospital readmissions that were characterized as unplanned. We calculated weighted sensitivity and specificity, and positive and negative predictive values of the algorithm (version 2.1), compared to gold standard chart review. In consultation with 27 experts, we developed an algorithm that characterizes 7.8% of readmissions as planned. For validation we reviewed 634 readmissions. The weighted sensitivity of the algorithm was 45.1% overall, 50.9% in large teaching centers and 40.2% in smaller community hospitals. The weighted specificity was 95.9%, positive predictive value was 51.6%, and negative predictive value was 94.7%. We identified 4 minor changes to improve algorithm performance. The revised algorithm had a weighted sensitivity 49.8% (57.1% at large hospitals), weighted specificity 96.5%, positive predictive value 58.7%, and negative predictive value 94.5%. Positive predictive value was poor for the 2 most common potentially planned procedures: diagnostic cardiac catheterization (25%) and procedures involving cardiac devices (33%). An administrative claims-based algorithm to identify planned readmissions is feasible and can facilitate public reporting of primarily unplanned readmissions. © 2015 Society of Hospital Medicine.

A prospective analysis of physical examination findings in the diagnosis of facial fractures: Determining predictive value.

PubMed

Timashpolsky, Alisa; Dagum, Alexander B; Sayeed, Syed M; Romeiser, Jamie L; Rosenfeld, Elisheva A; Conkling, Nicole

2016-01-01

There are >150,000 patient visits per year to emergency rooms for facial trauma. The reliability of a computed tomography (CT) scan has made it the primary modality for diagnosing facial skeletal injury, with the physical examination playing more a cursory role. Knowing the predictive value of physical findings in facial skeletal injuries may enable more appropriate use of imaging and health care resources. A blinded prospective study was undertaken to assess the predictive value of physical examination findings in detecting maxillofacial fracture in trauma patients, and in determining whether a patient will require surgical intervention. Over a four-month period, the authors' team examined patients admitted with facial trauma to the emergency department of their hospital. The evaluating physician completed a standardized physical examination evaluation form indicating the physical findings. Corresponding CT scans and surgical records were then reviewed, and the results recorded by a plastic surgeon who was blinded to the results of the physical examination. A total of 57 patients met the inclusion criteria; there were 44 male and 13 female patients. The sensitivity, specificity, positive predictive value and negative predictive value of grouped physical examination findings were determined in major areas. In further analysis, specific examination findings with n≥9 (15%) were also reported. The data demonstrated a high negative predictive value of at least 90% for orbital floor, zygomatic, mandibular and nasal bone fractures compared with CT scan. Furthermore, none of the patients who did not have a physical examination finding for a particular facial fracture required surgery for that fracture. Thus, the instrument performed well at ruling out fractures in these areas when there were none. Ultimately, these results may help reduce unnecessary radiation and costly imaging in patients with facial trauma without facial fractures.

Deciphering the use and predictive value of "emergency medical services provider judgment" in out-of-hospital trauma triage: a multisite, mixed methods assessment.

PubMed

Newgard, Craig D; Kampp, Michael; Nelson, Maria; Holmes, James F; Zive, Dana; Rea, Thomas; Bulger, Eileen M; Liao, Michael; Sherck, John; Hsia, Renee Y; Wang, N Ewen; Fleischman, Ross J; Barton, Erik D; Daya, Mohamud; Heineman, John; Kuppermann, Nathan

2012-05-01

"Emergency medical services (EMS) provider judgment" was recently added as a field triage criterion to the national guidelines, yet its predictive value and real world application remain unclear. We examine the use and independent predictive value of EMS provider judgment in identifying seriously injured persons. We analyzed a population-based retrospective cohort, supplemented by qualitative analysis, of injured children and adults evaluated and transported by 47 EMS agencies to 94 hospitals in five regions across the Western United States from 2006 to 2008. We used logistic regression models to evaluate the independent predictive value of EMS provider judgment for Injury Severity Score ≥ 16. EMS narratives were analyzed using qualitative methods to assess and compare common themes for each step in the triage algorithm, plus EMS provider judgment. 213,869 injured patients were evaluated and transported by EMS over the 3-year period, of whom 41,191 (19.3%) met at least one of the field triage criteria. EMS provider judgment was the most commonly used triage criterion (40.0% of all triage-positive patients; sole criterion in 21.4%). After accounting for other triage criteria and confounders, the adjusted odds ratio of Injury Severity Score ≥ 16 for EMS provider judgment was 1.23 (95% confidence interval, 1.03-1.47), although there was variability in predictive value across sites. Patients meeting EMS provider judgment had concerning clinical presentations qualitatively similar to those meeting mechanistic and other special considerations criteria. Among this multisite cohort of trauma patients, EMS provider judgment was the most commonly used field trauma triage criterion, independently associated with serious injury, and useful in identifying high-risk patients missed by other criteria. However, there was variability in predictive value between sites.

Use of the Abbott Architect HIV antigen/antibody assay in a low incidence population.

PubMed

Dubravac, Terry; Gahan, Thomas F; Pentella, Michael A

2013-12-01

With the availability of 4th generation HIV diagnostic tests which are capable of detecting acute infection, Iowa evaluated the 3rd and 4th generation HIV test and compared the performance of these products in a low incidence population. This study was conducted to evaluate the performance of an HIV antigen/antibody combination (4th generation) assay compared to an EIA 3rd generation assay. Over a 4 month period, 2037 specimens submitted for HIV screening were tested by Bio-Rad GS HIV-1/HIV-2 Plus O EIA and the Abbott Architect i1000SR HIV Ag/Ab Combo. The performance characteristics of sensitivity, specificity, positive predictive value and negative predictive value were determined. Of the 2037 specimens tested, there were 13 (0.64%) true positives detected. None of the positive specimens were from patients in the acute phase of infection. The Abbott antigen/antibody combo assay had a sensitivity, specificity, positive-predictive value and negative predictive value of 100%, 99.85%, 81.25%, and 100% respectively. The Bio-Rad EIA assay had a sensitivity, specificity, positive-predictive value and negative predictive value of 100%, 99.80%, 76.47% and 100%, respectively. The EIA had four false positive results which tested negative by the antigen/antibody assay and western blot. In a low-incidence state where early infections are less commonly encountered, the EIA assay and the antigen/antibody assay performed with near equivalency. The antigen/antibody assay had one less false positive result. While no patients were detected in the acute stage of infection, the use of the antigen/antibody assay presents the opportunity to detect an infected patient sooner and prevent transmission to others. Copyright © 2013 Elsevier B.V. All rights reserved.

The diagnostic value of troponin T testing in the community setting.

PubMed

Planer, David; Leibowitz, David; Paltiel, Ora; Boukhobza, Rina; Lotan, Chaim; Weiss, Teddy A

2006-03-08

Many patients presenting with chest pain to their family physician are referred to the emergency room, in part, due to lack of accurate objective diagnostic tools. This study aimed to assess the diagnostic value of bedside troponin T kit testing in patients presenting with chest pain to their family physician. Prospective, multi-center study. Consecutive subjects with chest pain were recruited from 44 community clinics in Jerusalem. Following clinical assessment by the family physician, qualitative troponin kit testing was performed. Patients with a negative clinical assessment and negative troponin kit were sent home and all others were referred to the emergency room. The final diagnosis at the time of hospital discharge was recorded and telephone follow up was performed after 60 days. Positive predictive value, negative predictive value, sensitivity and specificity of troponin kit for myocardial infarction diagnosis and of family physician for hospitalization, were assessed. Of 392 patients enrolled, 349 (89%) were included in the final analysis. The prevalence of myocardial infarction was 1.7%. The positive and negative predictive values of the troponin kit for myocardial infarction diagnosis were 100% and 99.7%, respectively. The positive and negative predictive values of the family physician's assessment to predict hospitalization were 41.4% and 94.1%, respectively. Troponin kit testing is an important tool to assist the family physician in the assessment of patients with chest pain in the community setting. Troponin kit testing may identify otherwise undiagnosed cases of myocardial infarctions, and reduce unnecessary referrals to the emergency room.

Optimising the utility of pleural fluid adenosine deaminase for the diagnosis of adult tuberculous pleural effusion in Hong Kong.

PubMed

Chang, K C; Chan, M C; Leung, W M; Kong, F Y; Mak, C M; Chen, S Pl; Yu, W C

2018-02-01

Pleural fluid adenosine deaminase level can be applied to rapidly detect tuberculous pleural effusion. We aimed to establish a local diagnostic cut-off value for pleural fluid adenosine deaminase to identify patients with tuberculous pleural effusion, and optimise its utility. We retrospectively reviewed the medical records of consecutive adults with pleural fluid adenosine deaminase level measured by the Diazyme commercial kit (Diazyme Laboratories, San Diego [CA], United States) during 1 January to 31 December 2011 in a cluster of public hospitals in Hong Kong. We considered its level alongside early (within 2 weeks) findings in pleural fluid and pleural biopsy, with and without applying Light's criteria in multiple scenarios. For each scenario, we used the receiver operating characteristic curve to identify a diagnostic cut-off value for pleural fluid adenosine deaminase, and estimated its positive and negative predictive values. A total of 860 medical records were reviewed. Pleural effusion was caused by congestive heart failure, chronic renal failure, or hypoalbuminaemia caused by liver or kidney diseases in 246 (28.6%) patients, malignancy in 198 (23.0%), non-tuberculous infection in 168 (19.5%), tuberculous pleural effusion in 157 (18.3%), and miscellaneous causes in 91 (10.6%). All those with tuberculous pleural effusion had a pleural fluid adenosine deaminase level of ≤100 U/L. When analysis was restricted to 689 patients with pleural fluid adenosine deaminase level of ≤100 U/L and early negative findings for malignancy and non-tuberculous infection in pleural fluid, the positive predictive value was significantly increased and the negative predictive value non-significantly reduced. Using this approach, neither additionally restricting analysis to exudates by Light's criteria nor adding closed pleural biopsy would further enhance predictive values. As such, the diagnostic cut-off value for pleural fluid adenosine deaminase is 26.5 U/L, with a sensitivity of 87.3%, specificity of 93.2%, positive predictive value of 79.2%, negative predictive value of 96.1%, and accuracy of 91.9%. Sex, age, and co-morbidity did not significantly affect prediction of tuberculous pleural effusion using the cut-off value. We have established a diagnostic cut-off level for pleural fluid adenosine deaminase in the diagnosis of tuberculous pleural effusion by restricting analysis to a level of ≤100 U/L, and considering early pleural fluid findings for malignancy and non-tuberculous infection, but not Light's criteria.

The Conforming Brain and Deontological Resolve

PubMed Central

Pincus, Melanie; LaViers, Lisa; Prietula, Michael J.; Berns, Gregory

2014-01-01

Our personal values are subject to forces of social influence. Deontological resolve captures how strongly one relies on absolute rules of right and wrong in the representation of one's personal values and may predict willingness to modify one's values in the presence of social influence. Using fMRI, we found that a neurobiological metric for deontological resolve based on relative activity in the ventrolateral prefrontal cortex (VLPFC) during the passive processing of sacred values predicted individual differences in conformity. Individuals with stronger deontological resolve, as measured by greater VLPFC activity, displayed lower levels of conformity. We also tested whether responsiveness to social reward, as measured by ventral striatal activity during social feedback, predicted variability in conformist behavior across individuals but found no significant relationship. From these results we conclude that unwillingness to conform to others' values is associated with a strong neurobiological representation of social rules. PMID:25170989

Goal-directed EEG activity evoked by discriminative stimuli in reinforcement learning.

PubMed

Luque, David; Morís, Joaquín; Rushby, Jacqueline A; Le Pelley, Mike E

2015-02-01

In reinforcement learning (RL), discriminative stimuli (S) allow agents to anticipate the value of a future outcome, and the response that will produce that outcome. We examined this processing by recording EEG locked to S during RL. Incentive value of outcomes and predictive value of S were manipulated, allowing us to discriminate between outcome-related and response-related activity. S predicting the correct response differed from nonpredictive S in the P2. S paired with high-value outcomes differed from those paired with low-value outcomes in a frontocentral positivity and in the P3b. A slow negativity then distinguished between predictive and nonpredictive S. These results suggest that, first, attention prioritizes detection of informative S. Activation of mental representations of these informative S then retrieves representations of outcomes, which in turn retrieve representations of responses that previously produced those outcomes. © 2014 Society for Psychophysiological Research.

Prediction of kinase-inhibitor binding affinity using energetic parameters

PubMed Central

Usha, Singaravelu; Selvaraj, Samuel

2016-01-01

The combination of physicochemical properties and energetic parameters derived from protein-ligand complexes play a vital role in determining the biological activity of a molecule. In the present work, protein-ligand interaction energy along with logP values was used to predict the experimental log (IC50) values of 25 different kinase-inhibitors using multiple regressions which gave a correlation coefficient of 0.93. The regression equation obtained was tested on 93 kinase-inhibitor complexes and an average deviation of 0.92 from the experimental log IC50 values was shown. The same set of descriptors was used to predict binding affinities for a test set of five individual kinase families, with correlation values > 0.9. We show that the protein-ligand interaction energies and partition coefficient values form the major deterministic factors for binding affinity of the ligand for its receptor. PMID:28149052

In silico Study of the Pharmacologic Properties and Cytotoxicity Pathways in Cancer Cells of Various Indolylquinone Analogues of Perezone.

PubMed

Escobedo-González, René; Vargas-Requena, Claudia Lucia; Moyers-Montoya, Edgar; Aceves-Hernández, Juan Manuel; Nicolás-Vázquez, María Inés; Miranda-Ruvalcaba, René

2017-06-25

Several indolylquinone analogues of perezone, a natural sesquiterpene quinone, were characterized in this work by theoretical methods. In addition, some physicochemical, toxicological and metabolic properties were predicted using bioinformatics software. The predicted physicochemical properties are in agreement with the solubility and cLogP values, the penetration across the cell membrane, and absorption values, as well as with a possible apoptosis-activated mechanism of cytotoxic action. The toxicological predictions suggest no mutagenic, tumorigenic or reproductive effects of the four target molecules. Complementarily, the results of a performed docking study show high scoring values and hydrogen bonding values in agreement with the cytotoxicity IC 50 value ranking, i.e: indolylmenadione > indolylperezone > indolylplumbagine > indolylisoperezone. Consequently, it is possible to suggest an appropriate apoptotic pathway for each compound. Finally, potential metabolic pathways of the molecules were proposed.

The habenula encodes negative motivational value associated with primary punishment in humans.

PubMed

Lawson, Rebecca P; Seymour, Ben; Loh, Eleanor; Lutti, Antoine; Dolan, Raymond J; Dayan, Peter; Weiskopf, Nikolaus; Roiser, Jonathan P

2014-08-12

Learning what to approach, and what to avoid, involves assigning value to environmental cues that predict positive and negative events. Studies in animals indicate that the lateral habenula encodes the previously learned negative motivational value of stimuli. However, involvement of the habenula in dynamic trial-by-trial aversive learning has not been assessed, and the functional role of this structure in humans remains poorly characterized, in part, due to its small size. Using high-resolution functional neuroimaging and computational modeling of reinforcement learning, we demonstrate positive habenula responses to the dynamically changing values of cues signaling painful electric shocks, which predict behavioral suppression of responses to those cues across individuals. By contrast, negative habenula responses to monetary reward cue values predict behavioral invigoration. Our findings show that the habenula plays a key role in an online aversive learning system and in generating associated motivated behavior in humans.

Method and system for monitoring and displaying engine performance parameters

NASA Technical Reports Server (NTRS)

Abbott, Terence S. (Inventor); Person, Jr., Lee H. (Inventor)

1991-01-01

The invention is a method and system for monitoring and directly displaying the actual thrust produced by a jet aircraft engine under determined operating conditions and the available thrust and predicted (commanded) thrust of a functional model of an ideal engine under the same determined operating conditions. A first set of actual value output signals representative of a plurality of actual performance parameters of the engine under the determined operating conditions is generated and compared with a second set of predicted value output signals representative of the predicted value of corresponding performance parameters of a functional model of the engine under the determined operating conditions to produce a third set of difference value output signals within a range of normal, caution, or warning limit values. A thrust indicator displays when any one of the actual value output signals is in the warning range while shaping function means shape each of the respective difference output signals as each approaches the limit of the respective normal, caution, and warning range limits.

Is the Factor-of-2 Rule Broadly Applicable for Evaluating the Prediction Accuracy of Metal-Toxicity Models?

PubMed

Meyer, Joseph S; Traudt, Elizabeth M; Ranville, James F

2018-01-01

In aquatic toxicology, a toxicity-prediction model is generally deemed acceptable if its predicted median lethal concentrations (LC50 values) or median effect concentrations (EC50 values) are within a factor of 2 of their paired, observed LC50 or EC50 values. However, that rule of thumb is based on results from only two studies: multiple LC50 values for the fathead minnow (Pimephales promelas) exposed to Cu in one type of exposure water, and multiple EC50 values for Daphnia magna exposed to Zn in another type of exposure water. We tested whether the factor-of-2 rule of thumb also is supported in a different dataset in which D. magna were exposed separately to Cd, Cu, Ni, or Zn. Overall, the factor-of-2 rule of thumb appeared to be a good guide to evaluating the acceptability of a toxicity model's underprediction or overprediction of observed LC50 or EC50 values in these acute toxicity tests.

Computational substrates of social value in interpersonal collaboration.

PubMed

Fareri, Dominic S; Chang, Luke J; Delgado, Mauricio R

2015-05-27

Decisions to engage in collaborative interactions require enduring considerable risk, yet provide the foundation for building and maintaining relationships. Here, we investigate the mechanisms underlying this process and test a computational model of social value to predict collaborative decision making. Twenty-six participants played an iterated trust game and chose to invest more frequently with their friends compared with a confederate or computer despite equal reinforcement rates. This behavior was predicted by our model, which posits that people receive a social value reward signal from reciprocation of collaborative decisions conditional on the closeness of the relationship. This social value signal was associated with increased activity in the ventral striatum and medial prefrontal cortex, which significantly predicted the reward parameters from the social value model. Therefore, we demonstrate that the computation of social value drives collaborative behavior in repeated interactions and provide a mechanistic account of reward circuit function instantiating this process. Copyright © 2015 the authors 0270-6474/15/358170-11$15.00/0.

Bioclinical Test to Predict Nephropathia Epidemica Severity at Hospital Admission.

PubMed

Hentzien, Maxime; Mestrallet, Stéphanie; Halin, Pascale; Pannet, Laure-Anne; Lebrun, Delphine; Dramé, Moustapha; Bani-Sadr, Firouzé; Galempoix, Jean-Marc; Strady, Christophe; Reynes, Jean-Marc; Penalba, Christian; Servettaz, Amélie

2018-06-01

We conducted a multicenter, retrospective cohort study of hospitalized patients with serologically proven nephropathia epidemica (NE) living in Ardennes Department, France, during 2000-2014 to develop a bioclinical test predictive of severe disease. Among 205 patients, 45 (22.0%) had severe NE. We found the following factors predictive of severe NE: nephrotoxic drug exposure (p = 0.005, point value 10); visual disorders (p = 0.02, point value 8); microscopic or macroscopic hematuria (p = 0.04, point value 7); leukocyte count >10 × 10 9 cells/L (p = 0.01, point value 9); and thrombocytopenia <90 × 10 9 /L (p = 0.003, point value 11). When point values for each factor were summed, we found a score of <10 identified low-risk patients (3.3% had severe disease), and a score >20 identified high-risk patients (45.3% had severe disease). If validated in future studies, this test could be used to stratify patients by severity in research studies and in clinical practice.

MetCCS predictor: a web server for predicting collision cross-section values of metabolites in ion mobility-mass spectrometry based metabolomics.

PubMed

Zhou, Zhiwei; Xiong, Xin; Zhu, Zheng-Jiang

2017-07-15

In metabolomics, rigorous structural identification of metabolites presents a challenge for bioinformatics. The use of collision cross-section (CCS) values of metabolites derived from ion mobility-mass spectrometry effectively increases the confidence of metabolite identification, but this technique suffers from the limit number of available CCS values. Currently, there is no software available for rapidly generating the metabolites' CCS values. Here, we developed the first web server, namely, MetCCS Predictor, for predicting CCS values. It can predict the CCS values of metabolites using molecular descriptors within a few seconds. Common users with limited background on bioinformatics can benefit from this software and effectively improve the metabolite identification in metabolomics. The web server is freely available at: http://www.metabolomics-shanghai.org/MetCCS/ . jiangzhu@sioc.ac.cn. Supplementary data are available at Bioinformatics online. © The Author (2017). Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Conceptual beliefs about human values and their implications: human nature beliefs predict value importance, value trade-offs, and responses to value-laden rhetoric.

PubMed

Bain, Paul G; Kashima, Yoshihisa; Haslam, Nick

2006-08-01

Beliefs that may underlie the importance of human values were investigated in 4 studies, drawing on research that distinguishes natural-kind (natural), nominal-kind (conventional), and artifact (functional) beliefs. Values were best characterized by artifact and nominal-kind beliefs, as well as a natural-kind belief specific to the social domain, "human nature" (Studies 1 and 2). The extent to which values were considered central to human nature was associated with value importance in both Australia and Japan (Study 2), and experimentally manipulating human nature beliefs influenced value importance (Study 3). Beyond their association with importance, human nature beliefs predicted participants' reactions to value trade-offs (Study 1) and to value-laden rhetorical statements (Study 4). Human nature beliefs therefore play a central role in the psychology of values.

A model for prediction of color change after tooth bleaching based on CIELAB color space

NASA Astrophysics Data System (ADS)

Herrera, Luis J.; Santana, Janiley; Yebra, Ana; Rivas, María. José; Pulgar, Rosa; Pérez, María. M.

2017-08-01

An experimental study aiming to develop a model based on CIELAB color space for prediction of color change after a tooth bleaching procedure is presented. Multivariate linear regression models were obtained to predict the L*, a*, b* and W* post-bleaching values using the pre-bleaching L*, a*and b*values. Moreover, univariate linear regression models were obtained to predict the variation in chroma (C*), hue angle (h°) and W*. The results demonstrated that is possible to estimate color change when using a carbamide peroxide tooth-bleaching system. The models obtained can be applied in clinic to predict the colour change after bleaching.

Clinical value of preoperative serum CA 19-9 and CA 125 levels in predicting the resectability of hilar cholangiocarcinoma.

PubMed

Hu, Hai-Jie; Mao, Hui; Tan, Yong-Qiong; Shrestha, Anuj; Ma, Wen-Jie; Yang, Qin; Wang, Jun-Ke; Cheng, Nan-Sheng; Li, Fu-Yu

2016-01-01

To examine the predictive value of tumor markers for evaluating tumor resectability in patients with hilar cholangiocarcinoma and to explore the prognostic effect of various preoperative factors on resectability in patients with potentially resectable tumors. Patients with potentially resectable tumors judged by radiologic examination were included. The receiver operating characteristic (ROC) analysis was conducted to evaluate serum carbohydrate antigenic determinant 19-9 (CA 19-9), carbohydrate antigen 125 (CA 125) and carcino embryonie antigen levels on tumor resectability. Univariate and multivariate logistic regression models were also conducted to analysis the correlation of preoperative factors with resectability. In patients with normal bilirubin levels, ROC curve analysis calculated the ideal CA 19-9 cut-off value of 203.96 U/ml in prediction of resectability, with a sensitivity of 83.7 %, specificity of 80 %, positive predictive value of 91.1 % and negative predictive value of 66.7 %. Meanwhile, the optimal cut-off value for CA 125 to predict resectability was 25.905 U/ml (sensitivity, 78.6 %; specificity, 67.5 %). In a multivariate logistic regression model, tumor size ≤3 cm (OR 4.149, 95 % CI 1.326-12.981, P = 0.015), preoperative CA 19-9 level ≤200 U/ml (OR 20.324, 95 % CI 6.509-63.467, P < 0.001), preoperative CA 125 levels ≤26 U/ml (OR 8.209, 95 % CI 2.624-25.677, P < 0.001) were independent determinants of resectability in patients diagnosed as hilar cholangiocarcinoma. Preoperative CA 19-9 and CA 125 levels predict resectability in patients with radiological resectable hilar cholangiocarcinoma. Increased preoperative CA 19-9 levels and CA 125 levels are associated with poor resectability rate.

Gram staining of protected pulmonary specimens in the early diagnosis of ventilator-associated pneumonia.

PubMed

Mimoz, O; Karim, A; Mazoit, J X; Edouard, A; Leprince, S; Nordmann, P

2000-11-01

We evaluated prospectively the use of Gram staining of protected pulmonary specimens to allow the early diagnosis of ventilator-associated pneumonia (VAP), compared with the use of 60 bronchoscopic protected specimen brushes (PSB) and 126 blinded plugged telescopic catheters (PTC) obtained from 134 patients. Gram stains were from Cytospin slides; they were studied for the presence of microorganisms in 10 and 50 fields by two independent observers and classified according to their Gram stain morphology. Quantitative cultures were performed after serial dilution and plating on appropriate culture medium. A final diagnosis of VAP, based on a culture of > or = 10(3) c.f.u. ml-1, was established after 81 (44%) samplings. When 10 fields were analysed, a strong relationship was found between the presence of bacteria on Gram staining and the final diagnosis of VAP (for PSB and PTC respectively: sensitivity 74 and 81%, specificity 94 and 100%, positive predictive value 91 and 100%, negative predictive value 82 and 88%). The correlation was less when we compared the morphology of microorganisms observed on Gram staining with those of bacteria obtained from quantitative cultures (for PSB and PTC respectively: sensitivity 54 and 69%, specificity 86 and 89%, positive predictive value 72 and 78%, negative predictive value 74 and 84%). Increasing the number of fields read to 50 was associated with a slight decrease in specificity and positive predictive value of Gram staining, but with a small increase in its sensitivity and negative predictive value. The results obtained by the two observers were similar to each other for both numbers of fields analysed. Gram staining of protected pulmonary specimens performed on 10 fields predicted the presence of VAP and partially identified (using Gram stain morphology) the microorganisms growing at significant concentrations, and could help in the early choice of the treatment of VAP. Increasing the number of fields read or having the Gram stain analysed by two independent individuals did not improve the results.

The predictive value of external continuous lumbar drainage, with cerebrospinal fluid outflow controlled by medium pressure valve, in normal pressure hydrocephalus.

PubMed

Panagiotopoulos, V; Konstantinou, D; Kalogeropoulos, A; Maraziotis, T

2005-09-01

Although sporadic studies have described temporary external cerebrospinal fluid (CSF) lumbar drainage as a highly accurate test for predicting the outcome after ventricular shunting in normal pressure hydrocephalus (NPH) patients, a more recent study reports that the positive predictive value of external lumbar drainage (ELD) is high but the negative predictive value is deceptively low. Therefore, we conducted a prospective study in order to evaluate the predictive value of a continuous ELD, with CSF outflow controlled by medium pressure valve, in NPH patients. Twenty-seven patients with presumed NPH were admitted to our department and CSF drainage was carried out by a temporary (ELD) with CSF outflow controlled by a medium pressure valve for five days. All patients received a ventriculoperitoneal shunt using a medium pressure valve based upon preoperative clinical and radiographic criteria of NPH, regardless of ELD outcome. Clinical evaluation of gait disturbances, urinary incontinence and mental status, and radiological evaluation with brain CT was performed prior to and after ELD test, as well as three months after shunting. Twenty-two patients were finally shunted and included in this study. In a three-month follow-up, using a previously validated score system, overall improvement after permanent shunting correlated well to improvement after ELD test (Spearman's rho = 0.462, p = 0.03). When considering any degree of improvement as a positive response, ELD test yielded high positive predictive values for all individual parameters (gait disturbances 94%, 95% CI 71%-100%, urinary incontinence 100%, 95% CI 66%-100%, and mental status 100%, 95% CI 66%-100%) but negative predictive values were low (< 50%) except for cognitive impairment (85%, 95% CI 55%-98%). This study suggests that a positive ELD-valve system test should be considered a reliable criterion for preoperative selection of shunt-responsive NPH patients. In case of a negative ELD-valve system test, further investigation of the presumed NPH patients with additional tests should be performed.

Prediction of main factors’ values of air transportation system safety based on system dynamics

NASA Astrophysics Data System (ADS)

Spiridonov, A. Yu; Rezchikov, A. F.; Kushnikov, V. A.; Ivashchenko, V. A.; Bogomolov, A. S.; Filimonyuk, L. Yu; Dolinina, O. N.; Kushnikova, E. V.; Shulga, T. E.; Tverdokhlebov, V. A.; Kushnikov, O. V.; Fominykh, D. S.

2018-05-01

On the basis of the system-dynamic approach [1-8], a set of models has been developed that makes it possible to analyse and predict the values of the main safety indicators for the operation of aviation transport systems.

Multivariate linear regression analysis to identify general factors for quantitative predictions of implant stability quotient values

PubMed Central

Huang, Hairong; Xu, Zanzan; Shao, Xianhong; Wismeijer, Daniel; Sun, Ping; Wang, Jingxiao

2017-01-01

Objectives This study identified potential general influencing factors for a mathematical prediction of implant stability quotient (ISQ) values in clinical practice. Methods We collected the ISQ values of 557 implants from 2 different brands (SICace and Osstem) placed by 2 surgeons in 336 patients. Surgeon 1 placed 329 SICace implants, and surgeon 2 placed 113 SICace implants and 115 Osstem implants. ISQ measurements were taken at T1 (immediately after implant placement) and T2 (before dental restoration). A multivariate linear regression model was used to analyze the influence of the following 11 candidate factors for stability prediction: sex, age, maxillary/mandibular location, bone type, immediate/delayed implantation, bone grafting, insertion torque, I-stage or II-stage healing pattern, implant diameter, implant length and T1-T2 time interval. Results The need for bone grafting as a predictor significantly influenced ISQ values in all three groups at T1 (weight coefficients ranging from -4 to -5). In contrast, implant diameter consistently influenced the ISQ values in all three groups at T2 (weight coefficients ranging from 3.4 to 4.2). Other factors, such as sex, age, I/II-stage implantation and bone type, did not significantly influence ISQ values at T2, and implant length did not significantly influence ISQ values at T1 or T2. Conclusions These findings provide a rational basis for mathematical models to quantitatively predict the ISQ values of implants in clinical practice. PMID:29084260

Prediction possibilities of Arosa total ozone

NASA Astrophysics Data System (ADS)

Kane, R. P.

1987-01-01

Using the periodicities obtained by a Maximum Entropy Spectral Analysis (MESA) of the Arosa total ozone data ( CC') series for 1932 1971, the values predicted for 1972 onwards were compared with the observed values of the ( AD) series. A change of level was noticed, with the observed ( AD) values lower by about 7 D.U. Also, the matching was poor in 1980, 1981, 1982. In the monthly values, the most prominent periodicity was the annual wave, comprising some 80% variance. In the 12 month running averages, the annual wave was eliminated and the most prominent periodicity was T=3.7 years, encompassing roundly 20% variance. This and other periodicities at T=4.7, 5.4, 6.2, 10 and 16 years were all statistically significant at a 3.5δ a priori i.e., 2δ a posteriori level. However, the predictions from these were unsatisfactory, probably because some of these periodicities may be transient i.e., changing amplitudes and/or phases with time. Thus, no meaningful prediction seem possible for Arosa total ozone.

The Predicted Cross Value for Genetic Introgression of Multiple Alleles

PubMed Central

Han, Ye; Cameron, John N.; Wang, Lizhi; Beavis, William D.

2017-01-01

We consider the plant genetic improvement challenge of introgressing multiple alleles from a homozygous donor to a recipient. First, we frame the project as an algorithmic process that can be mathematically formulated. We then introduce a novel metric for selecting breeding parents that we refer to as the predicted cross value (PCV). Unlike estimated breeding values, which represent predictions of general combining ability, the PCV predicts specific combining ability. The PCV takes estimates of recombination frequencies as an input vector and calculates the probability that a pair of parents will produce a gamete with desirable alleles at all specified loci. We compared the PCV approach with existing estimated-breeding-value approaches in two simulation experiments, in which 7 and 20 desirable alleles were to be introgressed from a donor line into a recipient line. Results suggest that the PCV is more efficient and effective for multi-allelic trait introgression. We also discuss how operations research can be used for other crop genetic improvement projects and suggest several future research directions. PMID:28122824

Ballistic projectile trajectory determining system

DOEpatents

Karr, Thomas J.

1997-01-01

A computer controlled system determines the three-dimensional trajectory of a ballistic projectile. To initialize the system, predictions of state parameters for a ballistic projectile are received at an estimator. The estimator uses the predictions of the state parameters to estimate first trajectory characteristics of the ballistic projectile. A single stationary monocular sensor then observes the actual first trajectory characteristics of the ballistic projectile. A comparator generates an error value related to the predicted state parameters by comparing the estimated first trajectory characteristics of the ballistic projectile with the observed first trajectory characteristics of the ballistic projectile. If the error value is equal to or greater than a selected limit, the predictions of the state parameters are adjusted. New estimates for the trajectory characteristics of the ballistic projectile are made and are then compared with actual observed trajectory characteristics. This process is repeated until the error value is less than the selected limit. Once the error value is less than the selected limit, a calculator calculates trajectory characteristics such a the origin and destination of the ballistic projectile.

[Validity and concordance of electronic health records in primary care (AP-Madrid) for surveillance of diabetes mellitus. PREDIMERC study].

PubMed

Gil Montalbán, Elisa; Ortiz Marrón, Honorato; López-Gay Lucio-Villegas, Dulce; Zorrilla Torrás, Belén; Arrieta Blanco, Francisco; Nogales Aguado, Pedro

2014-01-01

To assess the validity and concordance of diabetes data in the electronic health records of primary care (Madrid-PC) by comparing with those from the PREDIMERC study. The sensitivity, specificity, positive predictive value, negative predictive value and kappa index of diabetes cases recorded in the health records of Madrid-PC were calculated by using data from PREDIMERC as the gold standard. The prevalence of diabetes was also determined according to each data source. The sensitivity of diabetes recorded in Madrid-PC was 74%, the specificity was 98.8%, the positive predictive value was 87.9%, the negative predictive value was 97.3%, and the kappa index was 0.78. The prevalence of diabetes recorded in Madrid-PC was 6.7% versus 8.1% by PREDIMERC, where known diabetes was 6.3%. The electronic health records of primary care are a valid source for epidemiological surveillance of diabetes in Madrid. Copyright © 2013 SESPAS. Published by Elsevier Espana. All rights reserved.

Best of both worlds: combining pharma data and state of the art modeling technology to improve in Silico pKa prediction.

PubMed

Fraczkiewicz, Robert; Lobell, Mario; Göller, Andreas H; Krenz, Ursula; Schoenneis, Rolf; Clark, Robert D; Hillisch, Alexander

2015-02-23

In a unique collaboration between a software company and a pharmaceutical company, we were able to develop a new in silico pKa prediction tool with outstanding prediction quality. An existing pKa prediction method from Simulations Plus based on artificial neural network ensembles (ANNE), microstates analysis, and literature data was retrained with a large homogeneous data set of drug-like molecules from Bayer. The new model was thus built with curated sets of ∼14,000 literature pKa values (∼11,000 compounds, representing literature chemical space) and ∼19,500 pKa values experimentally determined at Bayer Pharma (∼16,000 compounds, representing industry chemical space). Model validation was performed with several test sets consisting of a total of ∼31,000 new pKa values measured at Bayer. For the largest and most difficult test set with >16,000 pKa values that were not used for training, the original model achieved a mean absolute error (MAE) of 0.72, root-mean-square error (RMSE) of 0.94, and squared correlation coefficient (R(2)) of 0.87. The new model achieves significantly improved prediction statistics, with MAE = 0.50, RMSE = 0.67, and R(2) = 0.93. It is commercially available as part of the Simulations Plus ADMET Predictor release 7.0. Good predictions are only of value when delivered effectively to those who can use them. The new pKa prediction model has been integrated into Pipeline Pilot and the PharmacophorInformatics (PIx) platform used by scientists at Bayer Pharma. Different output formats allow customized application by medicinal chemists, physical chemists, and computational chemists.

How reliably can computed tomography predict thyroid invasion prior to laryngectomy?

PubMed

Harris, Andrew S; Passant, Carl D; Ingrams, Duncan R

2018-05-01

There is little evidence to support the removal of thyroid tissue during total laryngectomy. Although oncological control of the tumor is the priority, thyroidectomy can lead to hypothyroidism and hypoparathyroidism. This study aimed to test the usefulness of preoperative computed tomography in predicting histological invasion of the thyroid. Ambispective cohort study. All patients undergoing total laryngectomy for squamous cell carcinoma at one center from 2006 to 2016 were included. Data were recorded prospectively as part of the patients' standard care, but were collated retrospectively, giving this study an ambispective design. The histology report for thyroid invasion was taken as the gold standard. The computed tomography report was categorized by invasion of tumor into intralaryngeal, laryngeal cartilage involvement, and extralaryngeal tissues. Seventy-nine patients were included. Nine patients had thyroid involvement on histology, translating to an incidence of 11.29% in this population. The positive predictive value for cartilage involvement on computed tomography for thyroid invasion was 52.9% (95% confidence interval [CI]: 28.5%-76.1%) and the negative predictive value was 100% (95% CI: 92.7%-100%).The positive predictive value for extralaryngeal spread on computed tomography for thyroid involvement was 100% (95% CI: 62.9%-100%), and the negative predictive value was also 100% (95% CI: 93.5%-100%). This study has shown that preoperative computed tomography is an effective method of ruling out thyroid gland invasion. The absence of extralaryngeal spread on computed tomography has been shown to be the most useful finding, with a high negative predictive value and a narrow 95% CI. 4. Laryngoscope, 128:1099-1102, 2018. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

Results of the two incidence screenings in the National Lung Screening Trial.

PubMed

Aberle, Denise R; DeMello, Sarah; Berg, Christine D; Black, William C; Brewer, Brenda; Church, Timothy R; Clingan, Kathy L; Duan, Fenghai; Fagerstrom, Richard M; Gareen, Ilana F; Gatsonis, Constantine A; Gierada, David S; Jain, Amanda; Jones, Gordon C; Mahon, Irene; Marcus, Pamela M; Rathmell, Joshua M; Sicks, JoRean

2013-09-05

The National Lung Screening Trial was conducted to determine whether three annual screenings (rounds T0, T1, and T2) with low-dose helical computed tomography (CT), as compared with chest radiography, could reduce mortality from lung cancer. We present detailed findings from the first two incidence screenings (rounds T1 and T2). We evaluated the rate of adherence of the participants to the screening protocol, the results of screening and downstream diagnostic tests, features of the lung-cancer cases, and first-line treatments, and we estimated the performance characteristics of both screening methods. At the T1 and T2 rounds, positive screening results were observed in 27.9% and 16.8% of participants in the low-dose CT group and in 6.2% and 5.0% of participants in the radiography group, respectively. In the low-dose CT group, the sensitivity was 94.4%, the specificity was 72.6%, the positive predictive value was 2.4%, and the negative predictive value was 99.9% at T1; at T2, the positive predictive value increased to 5.2%. In the radiography group, the sensitivity was 59.6%, the specificity was 94.1%, the positive predictive value was 4.4%, and the negative predictive value was 99.8% at T1; both the sensitivity and the positive predictive value increased at T2. Among lung cancers of known stage, 87 (47.5%) were stage IA and 57 (31.1%) were stage III or IV in the low-dose CT group at T1; in the radiography group, 31 (23.5%) were stage IA and 78 (59.1%) were stage III or IV at T1. These differences in stage distribution between groups persisted at T2. Low-dose CT was more sensitive in detecting early-stage lung cancers, but its measured positive predictive value was lower than that of radiography. As compared with radiography, the two annual incidence screenings with low-dose CT resulted in a decrease in the number of advanced-stage cancers diagnosed and an increase in the number of early-stage lung cancers diagnosed. (Funded by the National Cancer Institute; NLST ClinicalTrials.gov number, NCT00047385.).

Multi-allelic haplotype model based on genetic partition for genomic prediction and variance component estimation using SNP markers.

PubMed

Da, Yang

2015-12-18

The amount of functional genomic information has been growing rapidly but remains largely unused in genomic selection. Genomic prediction and estimation using haplotypes in genome regions with functional elements such as all genes of the genome can be an approach to integrate functional and structural genomic information for genomic selection. Towards this goal, this article develops a new haplotype approach for genomic prediction and estimation. A multi-allelic haplotype model treating each haplotype as an 'allele' was developed for genomic prediction and estimation based on the partition of a multi-allelic genotypic value into additive and dominance values. Each additive value is expressed as a function of h - 1 additive effects, where h = number of alleles or haplotypes, and each dominance value is expressed as a function of h(h - 1)/2 dominance effects. For a sample of q individuals, the limit number of effects is 2q - 1 for additive effects and is the number of heterozygous genotypes for dominance effects. Additive values are factorized as a product between the additive model matrix and the h - 1 additive effects, and dominance values are factorized as a product between the dominance model matrix and the h(h - 1)/2 dominance effects. Genomic additive relationship matrix is defined as a function of the haplotype model matrix for additive effects, and genomic dominance relationship matrix is defined as a function of the haplotype model matrix for dominance effects. Based on these results, a mixed model implementation for genomic prediction and variance component estimation that jointly use haplotypes and single markers is established, including two computing strategies for genomic prediction and variance component estimation with identical results. The multi-allelic genetic partition fills a theoretical gap in genetic partition by providing general formulations for partitioning multi-allelic genotypic values and provides a haplotype method based on the quantitative genetics model towards the utilization of functional and structural genomic information for genomic prediction and estimation.

GEMAS: prediction of solid-solution phase partitioning coefficients (Kd) for oxoanions and boric acid in soils using mid-infrared diffuse reflectance spectroscopy.

PubMed

Janik, Leslie J; Forrester, Sean T; Soriano-Disla, José M; Kirby, Jason K; McLaughlin, Michael J; Reimann, Clemens

2015-02-01

The authors' aim was to develop rapid and inexpensive regression models for the prediction of partitioning coefficients (Kd), defined as the ratio of the total or surface-bound metal/metalloid concentration of the solid phase to the total concentration in the solution phase. Values of Kd were measured for boric acid (B[OH]3(0)) and selected added soluble oxoanions: molybdate (MoO4(2-)), antimonate (Sb[OH](6-)), selenate (SeO4(2-)), tellurate (TeO4(2-)) and vanadate (VO4(3-)). Models were developed using approximately 500 spectrally representative soils of the Geochemical Mapping of Agricultural Soils of Europe (GEMAS) program. These calibration soils represented the major properties of the entire 4813 soils of the GEMAS project. Multiple linear regression (MLR) from soil properties, partial least-squares regression (PLSR) using mid-infrared diffuse reflectance Fourier-transformed (DRIFT) spectra, and models using DRIFT spectra plus analytical pH values (DRIFT + pH), were compared with predicted log K(d + 1) values. Apart from selenate (R(2)  = 0.43), the DRIFT + pH calibrations resulted in marginally better models to predict log K(d + 1) values (R(2)  = 0.62-0.79), compared with those from PSLR-DRIFT (R(2)  = 0.61-0.72) and MLR (R(2)  = 0.54-0.79). The DRIFT + pH calibrations were applied to the prediction of log K(d + 1) values in the remaining 4313 soils. An example map of predicted log K(d + 1) values for added soluble MoO4(2-) in soils across Europe is presented. The DRIFT + pH PLSR models provided a rapid and inexpensive tool to assess the risk of mobility and potential availability of boric acid and selected oxoanions in European soils. For these models to be used in the prediction of log K(d + 1) values in soils globally, additional research will be needed to determine if soil variability is accounted on the calibration. © 2014 SETAC.

[Geographical distribution of the Serum creatinine reference values of healthy adults].

PubMed

Wei, De-Zhi; Ge, Miao; Wang, Cong-Xia; Lin, Qian-Yi; Li, Meng-Jiao; Li, Peng

2016-11-20

To explore the relationship between serum creatinine (Scr) reference values in healthy adults and geographic factors and provide evidence for establishing Scr reference values in different regions. We collected 29 697 Scr reference values from healthy adults measured by 347 medical facilities from 23 provinces, 4 municipalities and 5 autonomous regions. We chose 23 geographical factors and analyzed their correlation with Scr reference values to identify the factors correlated significantly with Scr reference values. According to the Principal component analysis and Ridge regression analysis, two predictive models were constructed and the optimal model was chosen after comparison of the two model's fitting degree of predicted results and measured results. The distribution map of Scr reference values was drawn using the Kriging interpolation method. Seven geographic factors, including latitude, annual sunshine duration, annual average temperature, annual average relative humidity, annual precipitation, annual temperature range and topsoil (silt) cation exchange capacity were found to correlate significantly with Scr reference values. The overall distribution of Scr reference values featured a pattern that the values were high in the south and low in the north, varying consistently with the latitude change. The data of the geographic factors in a given region allows the prediction of the Scr values in healthy adults. Analysis of these geographical factors can facilitate the determination of the reference values specific to a region to improve the accuracy for clinical diagnoses.

[Determination and prediction for vapor pressures of organophosphate flame retardants by gas chromatography].

PubMed

Wang, Qingzhi; Zhao, Hongxia; Wang, Yan; Xie, Qing; Chen, Jingwen; Quan, Xie

2017-09-08

Organophosphate flame retardants (OPFRs) are ubiquitous in the environment. To better understand and predict their environmental transport and fate, well-defined physicochemical properties are required. Vapor pressures ( P ) of 14 OPFRs were estimated as a function of temperature ( T ) by gas chromatography (GC), while 1,1,1-trichioro-2,2-bis (4-chlorophenyl) ethane ( p,p '-DDT) was acted as a reference substance. Their log P GC values and internal energies of phase transfer (△ vap H ) ranged from -6.17 to -1.25 and 74.1 kJ/mol to 122 kJ/mol, respectively. Substitution pattern and molar volume ( V M ) were found to be capable of influencing log P GC values of the OPFRs. The halogenated alkyl-OPFRs had lower log P GC values than aryl-or alkyl-OPFRs. The bigger the molar volume was, the smaller the log P GC value was. In addition, a quantitative structure-property relationship (QSPR) model of log P GC versus different relative retention times (RRTs) was developed with a high cross-validated value ( Q 2 cum ) of 0.946, indicating a good predictive ability and stability. Therefore, the log P GC values of the OPFRs without standard substance can be predicted by using their RRTs on different GC columns.

Determination and prediction of octanol-air partition coefficients for organophosphate flame retardants.

PubMed

Wang, Qingzhi; Zhao, Hongxia; Wang, Yan; Xie, Qing; Chen, Jingwen; Quan, Xie

2017-11-01

Organophosphate flame retardants (OPFRs) have attracted wide concerns due to their toxicities and ubiquitous occurrence in the environment. In this work, Octanol-air partition coefficient (K OA ) for 14 OPFRs including 4 halogenated alkyl-, 5 aryl- and 5 alkyl-OPFRs, were estimated as a function of temperature using a gas chromatographic retention time (GC-RT) method. Their log K OA-GC values and internal energies of phase transfer (Δ OA U/kJmol -1 ) ranged from 8.03 to 13.0 and from 69.7 to 149, respectively. Substitution pattern and molar volume (V M ) were found to be capable of influencing log K OA-GC values of OPFRs. The halogenated alkyl-OPFRs had higher log K OA-GC values than aryl- or alkyl-OPFRs. The bigger the molar volume was, the greater the log K OA-GC values increased. In addition, a predicted model of log K OA-GC versus different relative retention times (RRTs) was developed with a high cross-validated value (Q 2 (cum) ) of 0.951, indicating a good predictive ability and stability. Therefore, the log K OA-GC values of the remaining OPFRs can be predicted by using their RRTs on different GC columns. Copyright © 2017 Elsevier Inc. All rights reserved.

Comparison of Taxi Time Prediction Performance Using Different Taxi Speed Decision Trees

NASA Technical Reports Server (NTRS)

Lee, Hanbong

2017-01-01

In the STBO modeler and tactical surface scheduler for ATD-2 project, taxi speed decision trees are used to calculate the unimpeded taxi times of flights taxiing on the airport surface. The initial taxi speed values in these decision trees did not show good prediction accuracy of taxi times. Using the more recent, reliable surveillance data, new taxi speed values in ramp area and movement area were computed. Before integrating these values into the STBO system, we performed test runs using live data from Charlotte airport, with different taxi speed settings: 1) initial taxi speed values and 2) new ones. Taxi time prediction performance was evaluated by comparing various metrics. The results show that the new taxi speed decision trees can calculate the unimpeded taxi-out times more accurately.

Relationship among performance, carcass, and feed efficiency characteristics, and their ability to predict economic value in the feedlot.

PubMed

Retallick, K M; Faulkner, D B; Rodriguez-Zas, S L; Nkrumah, J D; Shike, D W

2013-12-01

A 4-yr study was conducted using 736 steers of known Angus, Simmental, or Simmental × Angus genetics to determine performance, carcass, and feed efficiency factors that explained variation in economic performance. Steers were pen fed and individual DMI was recorded using a GrowSafe automated feeding system (GrowSafe Systems Ltd., Airdrie, Alberta, Canada). Steers consumed a similar diet and received similar management each year. The objectives of this study were to: 1) determine current economic value of feed efficiency and 2) identify performance, carcass, and feed efficiency characteristics that predict: carcass value, profit, cost of gain, and feed costs. Economic data used were from 2011 values. Feed efficiency values investigated were: feed conversion ratio (FCR; feed to gain), residual feed intake (RFI), residual BW gain (RG), and residual intake and BW gain (RIG). Dependent variables were carcass value ($/steer), profit ($/steer), feed costs ($/steer • d(-1)), and cost of gain ($/kg). Independent variables were year, DMI, ADG, HCW, LM area, marbling, yield grade, dam breed, and sire breed. A 10% improvement in RG (P < 0.05) yielded the lowest cost of gain at $0.09/kg and highest carcass value at $17.92/steer. Carcass value increased (P < 0.05) as feed efficiency improved for FCR, RG, and RIG. Profit increased with a 10% improvement in feed efficiency (P < 0.05) with FCR at $34.65/steer, RG at $31.21/steer, RIG at $21.66/steer, and RFI at $11.47/steer. The carcass value prediction model explained 96% of the variation among carcasses and included HCW, marbling score, and yield grade. Average daily gain, marbling score, yield grade, DMI, HCW, and year born constituted 81% of the variation for prediction of profit. Eighty-five percent of the variation in cost of gain was explained by ADG, DMI, HCW, and year. Prediction equations were developed that excluded ADG and DMI, and included feed efficiency values. Using these equations, cost of gain was explained primarily by FCR (R(2) = 0.71). Seventy-three percent of profitability was explained, with 55% being accounted for by RG and marbling. These prediction equations represent the relative importance of factors contributing to economic success in feedlot cattle based on current prices.

The value of the injury severity score in pediatric trauma: Time for a new definition of severe injury?

PubMed

Brown, Joshua B; Gestring, Mark L; Leeper, Christine M; Sperry, Jason L; Peitzman, Andrew B; Billiar, Timothy R; Gaines, Barbara A

2017-06-01

The Injury Severity Score (ISS) is the most commonly used injury scoring system in trauma research and benchmarking. An ISS greater than 15 conventionally defines severe injury; however, no studies evaluate whether ISS performs similarly between adults and children. Our objective was to evaluate ISS and Abbreviated Injury Scale (AIS) to predict mortality and define optimal thresholds of severe injury in pediatric trauma. Patients from the Pennsylvania trauma registry 2000-2013 were included. Children were defined as younger than 16 years. Logistic regression predicted mortality from ISS for children and adults. The optimal ISS cutoff for mortality that maximized diagnostic characteristics was determined in children. Regression also evaluated the association between mortality and maximum AIS in each body region, controlling for age, mechanism, and nonaccidental trauma. Analysis was performed in single and multisystem injuries. Sensitivity analyses with alternative outcomes were performed. Included were 352,127 adults and 50,579 children. Children had similar predicted mortality at ISS of 25 as adults at ISS of 15 (5%). The optimal ISS cutoff in children was ISS greater than 25 and had a positive predictive value of 19% and negative predictive value of 99% compared to a positive predictive value of 7% and negative predictive value of 99% for ISS greater than 15 to predict mortality. In single-system-injured children, mortality was associated with head (odds ratio, 4.80; 95% confidence interval, 2.61-8.84; p < 0.01) and chest AIS (odds ratio, 3.55; 95% confidence interval, 1.81-6.97; p < 0.01), but not abdomen, face, neck, spine, or extremity AIS (p > 0.05). For multisystem injury, all body region AIS scores were associated with mortality except extremities. Sensitivity analysis demonstrated ISS greater than 23 to predict need for full trauma activation, and ISS greater than 26 to predict impaired functional independence were optimal thresholds. An ISS greater than 25 may be a more appropriate definition of severe injury in children. Pattern of injury is important, as only head and chest injury drive mortality in single-system-injured children. These findings should be considered in benchmarking and performance improvement efforts. Epidemiologic study, level III.

An Intercomparison of Lidar Ozone and Temperature Measurements From the SOLVE Mission With Predicted Model Values

NASA Technical Reports Server (NTRS)

Burris, John; McGee, Thomas J.; Hoegy, Walt; Lait, Leslie; Sumnicht, Grant; Twigg, Larry; Heaps, William

2000-01-01

Temperature profiles acquired by Goddard Space Flight Center's AROTEL lidar during the SOLVE mission onboard NASA's DC-8 are compared with predicted values from several atmospheric models (DAO, NCEP and UKMO). The variability in the differences between measured and calculated temperature fields was approximately 5 K. Retrieved temperatures within the polar vortex showed large regions that were significantly colder than predicted by the atmospheric models.

Is it possible to detect malposition of the vertex at an early stage in labour? A case-control study.

PubMed

Mathisen, Marit; Olsen, Rudi Valde; Andreasen, Stine; Nielsen, Erik Waage

2014-12-01

The aim of this study was to investigate if there are clinical signs which allow detection of malposition of the vertex on admission to the delivery unit, or when crossing the action line on the partogram. Case-control study from 2007 to 2010 conducted on the delivery unit of Nordland Hospital, Bodø. Labours with malposition of the vertex (n = 171) were compared with a group with normal vertex presentation (n = 165). The positive predictive value was estimated for each sign using Bayes' rule. Magnitude of positive predictive value for each clinical sign. The positive predictive values for malposition were 9% if the foetus were in a right position, 11% if the labour was induced, 5% if the foetus was above the ischial spines, 4% if the reason for admission was contractions and 6% if cervix was <3 cm. The ability of clinical assessment to predict malposition, either on admission or when crossing the action line on the partogram, was poor. Diagnosing malposition of the vertex requires other methods with a higher predictive value. Copyright © 2014 Elsevier B.V. All rights reserved.

Prediction of Neonatal Hyperbilirubinemia Using 1st Day Serum Bilirubin Levels.

PubMed

Spoorthi, S M; Dandinavar, Siddappa F; Ratageri, Vinod H; Wari, Prakash K

2018-02-15

The study was conducted on Full term neonates with birth weight > 2.5 kg born in KIMS, Hubballi with an objective to determine the first day Total Serum Bilirubin (TSB) value so as to predict subsequent development of significant hyperbilirubinemia in term neonates. All enrolled neonates were sampled for TSB and blood group on Day 1 at 20 ± 4 h and then followed up clinically by Kramer's rule and when the clinical jaundice by Kramer's rule was >10 mg/dl, TSB levels were repeated. A total of 180 newborns were enrolled for the study and 165 babies completed the study. Out of these, 17(10.3%) babies had significant hyperbilirubinemia by day 5 of life. Using Receiver Operating Characteristic (ROC) Curve, a cut off TSB value of 6.15 mg/dl was determined with sensitivity of 82.4%, specificity of 81.8%, positive predictive value of 32.8%, negative predictive value 97.6%. In term neonates, the first day total bilirubin level at 20 ± 4 h of life <6.15 predicts the low risk of subsequent significant hyperbilirubinemia with high probability.

Assessing cutoff values for increased exercise blood pressure to predict incident hypertension in a general population.

PubMed

Lorbeer, Roberto; Ittermann, Till; Völzke, Henry; Gläser, Sven; Ewert, Ralf; Felix, Stephan B; Dörr, Marcus

2015-07-01

Cutoff values for increased exercise blood pressure (BP) are not established in hypertension guidelines. The aim of the study was to assess optimal cutoff values for increased exercise BP to predict incident hypertension. Data of 661 normotensive participants (386 women) aged 25-77 years from the Study of Health in Pomerania (SHIP-1) with a 5-year follow-up were used. Exercise BP was measured at a submaximal level of 100 W and at maximum level of a symptom-limited cycle ergometry test. Cutoff values for increased exercise BP were defined at the maximum sum of sensitivity and specificity for the prediction of incident hypertension. The area under the receiver-operating characteristic curve (AUC) and net reclassification index (NRI) were calculated to investigate whether increased exercise BP adds predictive value for incident hypertension beyond established cardiovascular risk factors. In men, values of 160  mmHg (100  W level; AUC = 0.7837; NRI = 0.534, P < 0.001) and 210  mmHg (maximum level; AUC = 0.7677; NRI = 0.340, P = 0.003) were detected as optimal cutoff values for the definition of increased exercise SBP. A value of 190  mmHg (AUC = 0.8347; NRI = 0.519, P < 0.001) showed relevance for the definition of increased exercise SBP in women at the maximum level. According to our analyses, 190 and 210  mmHg are clinically relevant cutoff values for increased exercise SBP at the maximum exercise level of cycle ergometry test for women and men, respectively. In addition, for men, our analyses provided a cutoff value of 160  mmHg for increased exercise SBP at the 100  W level.

The predictive value of the heart-rate-variability derived Analgesia Nociception Index in children anaesthetised with sevoflurane - an observational pilot-study.

PubMed

Weber, Frank; Geerts, Noortje J E; Roeleveld, Hilde G; Warmenhoven, Annejet T; Liebrand, Chantal A

2018-05-13

The heart rate variability (HRV) derived Analgesia Nociception Index (ANI ™ ) is a continuous non-invasive tool to assess the nociception/anti-nociception balance in unconscious patients. It has been shown to be superior to hemodynamic variables in detecting insufficient anti-nociception in children, while little is known about its predictive value. The primary objective of this prospective observational pilot study in paediatric surgical patients under sevoflurane anaesthesia, was to compare the predictive value of the ANI and heart rate to help decide to give additional opioids. The paediatric anaesthesiologist in charge was blinded to ANI values. In patients with an ANI value <50 (indicating insufficient anti-nociception) at the moment of decision, ANI values dropped from ±55 (indicating sufficient anti-nociception) to ±35, starting 60 sec. before decision. Within 120 sec. after administration of fentanyl (1 mcg/kg), ANI values returned to ±60. This phenomenon was only observed in the ANI values derived from HRV data averaged over 2 min. Heart rate remained unchanged. In patients with ANI values ≥50 at the time of decision, opioid administration had no effect on ANI or heart rate. The same accounts for morphine for postoperative analgesia and fentanyl in case of intraoperative movement. This study provides evidence of a better predictive value of the ANI in detecting insufficient anti-nociception in paediatric surgical patients than heart rate. The same accounts for depicting re-establishment of sufficient anti-nociception after opioid drug administration. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Flow Test to Predict Early Hypotony and Hypertensive Phase After Ahmed Glaucoma Valve (AGV) Surgical Implantation.

PubMed

Cheng, Jason; Beltran-Agullo, Laura; Buys, Yvonne M; Moss, Edward B; Gonzalez, Johanna; Trope, Graham E

2016-06-01

To assess the validity of a preimplantation flow test to predict early hypotony [intraocular pressure (IOP)≤5 mm Hg on 2 consecutive visits and hypertensive phase (HP) (IOP>21 mm Hg) after Ahmed Glaucoma Valve (AGV) implantation. Prospective interventional study on patients receiving an AGV. A preimplantation flow test using a gravity-driven reservoir and an open manometer was performed on all AGVs. Opening pressure (OP) and closing pressure (CP) were defined as the pressure at which fluid was seen to flow or stop flowing through the AGV, respectively. OP and CP were measured twice per AGV. Patients were followed for 12 weeks. In total, 20 eyes from 19 patients were enrolled. At 12 weeks the mean IOP decreased from 29.2±9.1 to 16.8±5.2 mm Hg (P<0.01). The mean AGV OP was 17.5±5.4 mm Hg and the mean CP was 6.7±2.3 mm Hg. Early (within 2 wk postoperative) HP occurred in 37% and hypotony in 16% of cases. An 18 mm Hg cutoff for the OP gave a sensitivity of 0.71, specificity of 0.83, positive predictive value of 0.71, and negative predictive value of 0.83 for predicting an early HP. A 7 mm Hg cutoff for the CP yielded a sensitivity of 1.0, specificity of 0.38, positive predictive value of 0.23, and negative predictive value of 1.0 for predicting hypotony. Preoperative OP and CP may predict early hypotony or HP and may be used as a guide as to which AGV valves to discard before implantation surgery.

Ability of preoperative 3.0-Tesla magnetic resonance imaging to predict the absence of side-specific extracapsular extension of prostate cancer.

PubMed

Hara, Tomohiko; Nakanishi, Hiroyuki; Nakagawa, Tohru; Komiyama, Motokiyo; Kawahara, Takashi; Manabe, Tomoko; Miyake, Mototaka; Arai, Eri; Kanai, Yae; Fujimoto, Hiroyuki

2013-10-01

Recent studies have shown an improvement in prostate cancer diagnosis with the use of 3.0-Tesla magnetic resonance imaging. We retrospectively assessed the ability of this imaging technique to predict side-specific extracapsular extension of prostate cancer. From October 2007 to August 2011, prostatectomy was carried out in 396 patients after preoperative 3.0-Tesla magnetic resonance imaging. Among these, 132 (primary sample) and 134 patients (validation sample) underwent 12-core prostate biopsy at the National Cancer Center Hospital of Tokyo, Japan, and at other institutions, respectively. In the primary dataset, univariate and multivariate analyses were carried out to predict side-specific extracapsular extension using variables determined preoperatively, including 3.0-Tesla magnetic resonance imaging findings (T2-weighted and diffusion-weighted imaging). A prediction model was then constructed and applied to the validation study sample. Multivariate analysis identified four significant independent predictors (P < 0.05), including a biopsy Gleason score of ≥8, positive 3.0-Tesla diffusion-weighted magnetic resonance imaging findings, ≥2 positive biopsy cores on each side and a maximum percentage of positive cores ≥31% on each side. The negative predictive value was 93.9% in the combination model with these four predictors, meanwhile the positive predictive value was 33.8%. Good reproducibility of these four significant predictors and the combination model was observed in the validation study sample. The side-specific extracapsular extension prediction by the biopsy Gleason score and factors associated with tumor location, including a positive 3.0-Tesla diffusion-weighted magnetic resonance imaging finding, have a high negative predictive value, but a low positive predictive value. © 2013 The Japanese Urological Association.

Prevalence and prediction of exercise-induced oxygen desaturation in patients with chronic obstructive pulmonary disease.

PubMed

van Gestel, A J R; Clarenbach, C F; Stöwhas, A C; Teschler, S; Russi, E W; Teschler, H; Kohler, M

2012-01-01

Previous studies with small sample sizes reported contradicting findings as to whether pulmonary function tests can predict exercise-induced oxygen desaturation (EID). To evaluate whether forced expiratory volume in one second (FEV(1)), resting oxygen saturation (SpO(2)) and diffusion capacity for carbon monoxide (DLCO) are predictors of EID in chronic obstructive pulmonary disease (COPD). We measured FEV(1), DLCO, SpO(2) at rest and during a 6-min walking test as well as physical activity by an accelerometer. A drop in SpO(2) of >4 to <90% was defined as EID. To evaluate associations between measures of lung function and EID univariate and multivariate analyses were used and positive/negative predictive values were calculated. Receiver operating characteristic curve analysis was performed to determine the most useful threshold in order to predict/exclude EID. We included 154 patients with COPD (87 females). The mean FEV(1) was 43.0% (19.2) predicted and the prevalence of EID was 61.7%. The only independent predictor of EID was FEV(1) and the optimal cutoff value of FEV(1) was at 50% predicted (area under ROC curve, 0.85; p < 0.001). The positive predictive value of a threshold of FEV(1) <50% was 0.83 with a likelihood ratio of 3.03 and the negative predicting value of a threshold of FEV(1) ≥80% was 1.0. The severity of EID was correlated with daily physical activity (r = -0.31, p = 0.008). EID is highly prevalent among patients with COPD and can be predicted by FEV(1). EID seems to be associated with impaired daily physical activity which supports its clinical importance. Copyright © 2012 S. Karger AG, Basel.

Added value of delayed computed tomography angiography in primary intracranial hemorrhage and hematoma size for predicting spot sign.

PubMed

Wu, Te Chang; Chen, Tai Yuan; Shiue, Yow Ling; Chen, Jeon Hor; Hsieh, Tsyh-Jyi; Ko, Ching Chung; Lin, Ching Po

2018-04-01

Background The computed tomography angiography (CTA) spot sign represents active contrast extravasation within acute primary intracerebral hemorrhage (ICH) and is an independent predictor of hematoma expansion (HE) and poor clinical outcomes. The spot sign could be detected on first-pass CTA (fpCTA) or delayed CTA (dCTA). Purpose To investigate the additional benefits of dCTA spot sign in primary ICH and hematoma size for predicting spot sign. Material and Methods This is a retrospective study of 100 patients who underwent non-contrast CT (NCCT) and CTA within 24 h of onset of primary ICH. The presence of spot sign on fpCTA or dCTA, and hematoma size on NCCT were recorded. The spot sign on fpCTA or dCTA for predicting significant HE, in-hospital mortality, and poor clinical outcomes (mRS ≥ 4) are calculated. The hematoma size for prediction of CTA spot sign was also analyzed. Results Only the spot sign on dCTA could predict high risk of significant HE and poor clinical outcomes as on fpCTA ( P < 0.05). With dCTA, there is increased sensitivity and negative predictive value (NPV) for predicting significant HE, in-hospital mortality, and poor clinical outcomes. The XY value (product of the two maximum perpendicular axial dimensions) is the best predictor (area under the curve [AUC] = 0.82) for predicting spot sign on fpCTA or dCTA in the absence of intraventricular and subarachnoid hemorrhage. Conclusion This study clarifies that dCTA imaging could improve predictive performance of CTA in primary ICH. Furthermore, the XY value is the best predictor for CTA spot sign.

The predictive accuracy of the black hole sign and the spot sign for hematoma expansion in patients with spontaneous intracerebral hemorrhage.

PubMed

Yu, Zhiyuan; Zheng, Jun; Ma, Lu; Guo, Rui; Li, Mou; Wang, Xiaoze; Lin, Sen; Li, Hao; You, Chao

2017-09-01

In patients with spontaneous intracerebral hemorrhage (sICH), hematoma expansion (HE) is associated with poor outcome. Spot sign and black hole sign are neuroimaging predictors for HE. This study was aimed to compare the predictive value of two signs for HE. Within 6 h after onset of sICH, patients were screened for the computed tomography angiography spot sign and the non-contrast computed tomography black hole sign. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of two signs for HE prediction were calculated. The accuracy of two signs in predicting HE was analyzed by receiver-operator analysis. A total of 129 patients were included in this study. Spot sign was identified in 30 (23.3%) patients and black hole sign in 29 (22.5%) patients, respectively. Of 32 patients with HE, spot sign was observed in 19 (59.4%) and black hole sign was found in 14 (43.8%). The occurrence of black hole sign was significantly associated with spot sign (P < 0.001). The sensitivity, specificity, PPV, and NPV of spot sign for predicting HE were 59.38, 88.66, 63.33, and 86.87% respectively. In contrast, the sensitivity, specificity, PPV, and NPV of black hole sign for predicting HE were 43.75, 84.54, 48.28, and 82.00%, respectively. The area under the curve was 0.740 for spot sign and 0.641 for black hole sign. (P = 0.228) Both spot sign and black hole sign appeared to have good predictive value for HE, and spot sign seemed to be a better predictor.

The roles of values, behavior, and value-behavior fit in the relation of agency and communion to well-being.

PubMed

Buchanan, Kathryn; Bardi, Anat

2015-06-01

Four studies examined whether agency and communion values, behaviors, or an interaction between values and behaviors (value-behavior fit) would predict well-being. In addition, Study 2 examined whether agency and communion goals, behaviors, or goal-behavior fit would predict well-being. In all four studies, participants completed online questionnaires containing measures of agency and communion values, behaviors, and well-being. In Studies 1 and 4, participants were recruited from the general population (respectively, N = 371, Mage  = 37.49, and N = 133, Mage  = 36.59). In Studies 2 and 3, participants were undergraduate students (respectively, N = 239, Mage  = 20.8, and N = 242, Mage  = 21.6). All four studies consistently found that agency and communion behaviors were significantly positively correlated with both subjective and psychological well-being. There was no strong indication that either values were directly associated with well-being. Neither was there any indication that well-being was predicted by value-behavior fit. The implications of these findings for theory and improving well-being are discussed. © 2014 Wiley Periodicals, Inc.

Prediction of area under the curve for a p-glycoprotein, a CYP3A4 and a CYP2C9 substrate using a single time point strategy: assessment using fexofenadine, itraconazole and losartan and metabolites.

PubMed

Srinivas, Nuggehally R

2016-01-01

In the present age of polypharmacy, limited sampling strategy becomes important to verify if drug levels are within the prescribed threshold limits from efficacy and safety considerations. The need to establish reliable single time concentration dependent models to predict exposure becomes important from cost and time perspectives. A simple unweighted linear regression model was developed to describe the relationship between Cmax versus AUC for fexofenadine, losartan, EXP3174, itraconazole and hydroxyitraconazole. The fold difference, defined as the quotient of the observed and predicted AUC values, were evaluated along with statistical comparison of the predicted versus observed values. The correlation between Cmax versus AUC was well established for all the five drugs with a correlation coefficient (r) ranging from 0.9130 to 0.9997. Majority of the predicted values for all the five drugs (77%) were contained within a narrow boundary of 0.75- to 1.5-fold difference. The r values for observed versus predicted AUC were 0.9653 (n = 145), 0.8342 (n = 76), 0.9524 (n = 88), 0.9339 (n = 89) and 0.9452 (n = 66) for fexofenadine, losartan, EXP3174, itraconazole and hydroxyitraconazole, respectively. Cmax versus AUC relationships were established for all drugs and were amenable for limited sampling strategy for AUC prediction. However, fexofenadine, EXP3174 and hydroxyitraconazole may be most relevant for AUC prediction by a single time concentration as judged by the various criteria applied in this study.

IL-10 combined with procalcitonin improves early prediction of complications of febrile neutropenia in hematological patients.

PubMed

Vänskä, Matti; Koivula, Irma; Jantunen, Esa; Hämäläinen, Sari; Purhonen, Anna-Kaisa; Pulkki, Kari; Juutilainen, Auni

2012-12-01

Early diagnosis of complicated course in febrile neutropenia is cumbersome due to the non-specificity of clinical and laboratory signs of severe infection. This prospective study included 100 adult hematological patients with febrile neutropenia after intensive chemotherapy at the onset of fever (d0) and for 3 days (d1-d3) thereafter. The study aim was to find early predictors for complicated course of febrile neutropenia, defined as bacteremia or septic shock. Interleukin 6 (IL-6), interleukin 10 (IL-10), procalcitonin (PCT) and C-reactive protein (CRP) all predicted complicated course of febrile neutropenia on d0, but only PCT was predictive throughout the study period. For IL-10 on d0-1 with cut-off 37 ng/L, sensitivity was 0.71, specificity 0.82, positive predictive value 0.52 and negative predictive value 0.92. For PCT on d0-1 with cut-off 0.13 μg/L, the respective measures were 0.95, 0.53, 0.36, and 0.98. For the combination of IL-10 and PCT on d0-1 with the same cut-offs, specificity improved to 0.85 and positive predictive value to 0.56. In conclusion, the present study confirms the high negative predictive value of PCT and provides new evidence for IL-10 as an early predictor for complicated course of febrile neutropenia in hematological patients. Combining IL-10 with PCT improves the early prediction for complicated course of febrile neutropenia. Copyright © 2012 Elsevier Ltd. All rights reserved.

Validity, accuracy, and predictive value of urinary tract infection signs and symptoms in individuals with spinal cord injury on intermittent catheterization.

PubMed

Massa, Luiz M; Hoffman, Jeanne M; Cardenas, Diana D

2009-01-01

To determine the validity, accuracy, and predictive value of the signs and symptoms of urinary tract infection (UTI) for individuals with spinal cord injury (SCI) using intermittent catheterization (IC) and the accuracy of individuals with SCI on IC at predicting their own UTI. Prospective cohort based on data from the first 3 months of a 1-year randomized controlled trial to evaluate UTI prevention effectiveness of hydrophilic and standard catheters. Fifty-six community-based individuals on IC. Presence of UTI as defined as bacteriuria with a colony count of at least 10(5) colony-forming units/mL and at least 1 sign or symptom of UTI. Analysis of monthly urine culture and urinalysis data combined with analysis of monthly data collected using a questionnaire that asked subjects to self-report on UTI signs and symptoms and whether or not they felt they had a UTI. Overall, "cloudy urine" had the highest accuracy (83.1%), and "leukocytes in the urine" had the highest sensitivity (82.8%). The highest specificity was for "fever" (99.0%); however, it had a very low sensitivity (6.9%). Subjects were able to predict their own UTI with an accuracy of 66.2%, and the negative predictive value (82.8%) was substantially higher than the positive predictive value (32.6%). The UTI signs and symptoms can predict a UTI more accurately than individual subjects can by using subjective impressions of their own signs and symptoms. Subjects were better at predicting when they did not have a UTI than when they did have a UTI.

An equation for the prediction of human skin permeability of neutral molecules, ions and ionic species.

PubMed

Zhang, Keda; Abraham, Michael H; Liu, Xiangli

2017-04-15

Experimental values of permeability coefficients, as log K p , of chemical compounds across human skin were collected by carefully screening the literature, and adjusted to 37°C for the effect of temperature. The values of log K p for partially ionized acids and bases were separated into those for their neutral and ionic species, forming a total data set of 247 compounds and species (including 35 ionic species). The obtained log K p values have been regressed against Abraham solute descriptors to yield a correlation equation with R 2 =0.866 and SD=0.432 log units. The equation can provide valid predictions for log K p of neutral molecules, ions and ionic species, with predictive R 2 =0.858 and predictive SD=0.445 log units calculated by the leave-one-out statistics. The predicted log K p values for Na + and Et 4 N + are in good agreement with the observed values. We calculated the values of log K p of ketoprofen as a function of the pH of the donor solution, and found that log K p markedly varies only when ketoprofen is largely ionized. This explains why models that neglect ionization of permeants still yield reasonable statistical results. The effect of skin thickness on log K p was investigated by inclusion of two indicator variables, one for intermediate thickness skin and one for full thickness skin, into the above equation. The newly obtained equations were found to be statistically very close to the above equation. Therefore, the thickness of human skin used makes little difference to the experimental values of log K p . Copyright © 2017 Elsevier B.V. All rights reserved.

Validity of Alcohol Use Disorder Identification Test-Korean Revised Version for Screening Alcohol Use Disorder according to Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition Criteria.

PubMed

Chang, Jung Wei; Kim, Jong Sung; Jung, Jin Gyu; Kim, Sung Soo; Yoon, Seok Joon; Jang, Hak Sun

2016-11-01

The Alcohol Use Disorder Identification Test (AUDIT) has been widely used to identify alcohol use disorder (AUD). This study evaluated the validity of the AUDIT-Korean revised version (AUDIT-KR) for screening AUD according to Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5) criteria. This research was conducted with 443 subjects who visited the Chungnam National University Hospital for a comprehensive medical examination. All subjects completed the demographic questionnaire and AUDIT-KR without assistance. Subjects were divided into two groups according to DSM-5 criteria: an AUD group, which included patients that fit the criteria for AUD (120 males and 21 females), and a non-AUD group, which included 146 males and 156 females that did not meet AUD criteria. The appropriate cut-off values, sensitivity, specificity, and positive and negative predictive values of the AUDIT-KR were evaluated. The mean±standard deviation AUDIT-KR scores were 10.32±7.48 points in males and 3.23±4.42 points in females. The area under the receiver operating characteristic curve (95% confidence interval, CI) of the AUDIT-KR for identifying AUD was 0.884 (0.840-0.920) in males and 0.962 (0.923-0.985) in females. The optimal cut-off value of the AUDIT-KR was 10 points for males (sensitivity, 81.90%; specificity, 81.33%; positive predictive value, 77.2%; negative predictive value, 85.3%) and 5 points for females (sensitivity, 100.00%; specificity, 88.54%; positive predictive value, 52.6%; negative predictive value, 100.0%). The AUDIT-KR has high reliability and validity for identifying AUD according to DSM-5 criteria.

Predicting residue-wise contact orders in proteins by support vector regression.

PubMed

Song, Jiangning; Burrage, Kevin

2006-10-03

The residue-wise contact order (RWCO) describes the sequence separations between the residues of interest and its contacting residues in a protein sequence. It is a new kind of one-dimensional protein structure that represents the extent of long-range contacts and is considered as a generalization of contact order. Together with secondary structure, accessible surface area, the B factor, and contact number, RWCO provides comprehensive and indispensable important information to reconstructing the protein three-dimensional structure from a set of one-dimensional structural properties. Accurately predicting RWCO values could have many important applications in protein three-dimensional structure prediction and protein folding rate prediction, and give deep insights into protein sequence-structure relationships. We developed a novel approach to predict residue-wise contact order values in proteins based on support vector regression (SVR), starting from primary amino acid sequences. We explored seven different sequence encoding schemes to examine their effects on the prediction performance, including local sequence in the form of PSI-BLAST profiles, local sequence plus amino acid composition, local sequence plus molecular weight, local sequence plus secondary structure predicted by PSIPRED, local sequence plus molecular weight and amino acid composition, local sequence plus molecular weight and predicted secondary structure, and local sequence plus molecular weight, amino acid composition and predicted secondary structure. When using local sequences with multiple sequence alignments in the form of PSI-BLAST profiles, we could predict the RWCO distribution with a Pearson correlation coefficient (CC) between the predicted and observed RWCO values of 0.55, and root mean square error (RMSE) of 0.82, based on a well-defined dataset with 680 protein sequences. Moreover, by incorporating global features such as molecular weight and amino acid composition we could further improve the prediction performance with the CC to 0.57 and an RMSE of 0.79. In addition, combining the predicted secondary structure by PSIPRED was found to significantly improve the prediction performance and could yield the best prediction accuracy with a CC of 0.60 and RMSE of 0.78, which provided at least comparable performance compared with the other existing methods. The SVR method shows a prediction performance competitive with or at least comparable to the previously developed linear regression-based methods for predicting RWCO values. In contrast to support vector classification (SVC), SVR is very good at estimating the raw value profiles of the samples. The successful application of the SVR approach in this study reinforces the fact that support vector regression is a powerful tool in extracting the protein sequence-structure relationship and in estimating the protein structural profiles from amino acid sequences.

Impact of the endoscopist's experience on the negative predictive value of capsule endoscopy.

PubMed

Velayos Jiménez, Benito; Alcaide Suárez, Noelia; González Redondo, Guillermo; Fernández Salazar, Luis; Aller de la Fuente, Rocío; Del Olmo Martínez, Lourdes; Ruiz Rebollo, Lourdes; González Hernández, José Manuel

2017-01-01

The impact of the accumulated experience of the capsule endoscopy (CE) reader on the accuracy of this test is discussed. To determine whether the negative predictive value of CE findings changes along the learning curve. We reviewed the first 900 CE read by 3 gastroenterologists experienced in endoscopy over 8 years. These 900 CE were divided into 3 groups (300 CE each): group 1 consisted of the sum of the first 100 CE read by each of the 3 endoscopists; group 2, the sum of the second 100 and groups 3, the sum of the third 100. Patients with normal CE were monitored for at least 28 months to estimate the negative predictive value. A total of 54 (18%) CE in group 1, 58 (19.3%) in group 2 and 47 (15.6%) in group 3 were normal, although only 34 patients in group 1, 38 in group 2 and 36 in group 3 with normal CE completed follow up and were eventually studied. The negative predictive value was 88.2% in group 1, 89.5% in group 2 and 97% in group 3 (P>.05). The negative predictive value tended to increase, but remained high and did not change significantly after the first 100 when readers are experienced in conventional endoscopy and have preliminary specific training. Copyright © 2016 Elsevier España, S.L.U., AEEH y AEG. All rights reserved.

Reassessment of the positive predictive value and specificity of Xpert MTB/RIF: a diagnostic accuracy study in the context of community-wide screening for tuberculosis.

PubMed

Ho, Jennifer; Nguyen, Phuong Thi Bich; Nguyen, Thu Anh; Tran, Khoa Hien; Van Nguyen, Son; Nguyen, Nhung Viet; Nguyen, Hoa Binh; Luu, Khanh Boi; Fox, Greg J; Marks, Guy B

2016-09-01

Community-wide screening for tuberculosis with Xpert MTB/RIF as a primary screening tool overcomes some of the limitations of conventional screening. However, concerns exist about the low positive predictive value of this test in screening settings. We did a cross-sectional assessment of this diagnostic test to directly estimate the actual positive predictive value of Xpert MTB/RIF when used in the setting of community-wide screening for tuberculosis, and to draw an inference about the specificity of the test for tuberculosis detection. Field staff visited households in 60 randomly selected villages in Ca Mau province, Vietnam. We included people aged 15 years or older who provided written informed consent and were able to produce 0·5 mL or more of sputum, irrespective of reported symptoms. Participants were tested with Xpert MTB/RIF, then those with positive results had two further sputum samples tested for smear microscopy and culture, and underwent chest radiography at the provincial TB Health Center. The positive predictive value of Xpert MTB/RIF was compared against two reference standards for tuberculosis diagnosis-a positive sputum culture for Mycobacterium tuberculosis, and a positive sputum culture or a chest radiograph consistent with active pulmonary tuberculosis. We then calculated the specificity of Xpert MTB/RIF for tuberculosis detection on the basis of these positive predictive values and disease prevalence in this setting. 43 435 adults consented to screening with Xpert MTB/RIF. Sputum samples of 0·5 mL or greater were collected from 23 202 participants, producing 22 673 valid results. 169 participants had positive Xpert MTB/RIF results (0·39% of those screened and 0·75% of those with valid sputum results). The positive predictive value of Xpert MTB/RIF was 61·0% (95% CI 52·8-68·7) when compared against a positive sputum culture and 83·9% (76·8-89·2) when compared against a positive sputum culture or chest radiograph consistent with active tuberculosis. On the basis of these positive predictive values, the specificity of Xpert MTB/RIF was determined to be between 99·78% (95% CI 99·71-99·84) and 99·93% (99·88-99·96). The positive predictive value and specificity of Xpert MTB/RIF in the context of community-wide screening for tuberculosis is substantially higher than that predicted in previous studies. Our findings support the potential role of Xpert MTB/RIF as a primary screening tool to detect prevalent cases of tuberculosis in the community. Australian National Health and Medical Research Council. Copyright © 2016 Elsevier Ltd. All rights reserved.

EVALUATING RISK-PREDICTION MODELS USING DATA FROM ELECTRONIC HEALTH RECORDS.

PubMed

Wang, L E; Shaw, Pamela A; Mathelier, Hansie M; Kimmel, Stephen E; French, Benjamin

2016-03-01

The availability of data from electronic health records facilitates the development and evaluation of risk-prediction models, but estimation of prediction accuracy could be limited by outcome misclassification, which can arise if events are not captured. We evaluate the robustness of prediction accuracy summaries, obtained from receiver operating characteristic curves and risk-reclassification methods, if events are not captured (i.e., "false negatives"). We derive estimators for sensitivity and specificity if misclassification is independent of marker values. In simulation studies, we quantify the potential for bias in prediction accuracy summaries if misclassification depends on marker values. We compare the accuracy of alternative prognostic models for 30-day all-cause hospital readmission among 4548 patients discharged from the University of Pennsylvania Health System with a primary diagnosis of heart failure. Simulation studies indicate that if misclassification depends on marker values, then the estimated accuracy improvement is also biased, but the direction of the bias depends on the direction of the association between markers and the probability of misclassification. In our application, 29% of the 1143 readmitted patients were readmitted to a hospital elsewhere in Pennsylvania, which reduced prediction accuracy. Outcome misclassification can result in erroneous conclusions regarding the accuracy of risk-prediction models.

Predictive utility of blood pressure, waist circumference and body mass index for metabolic syndrome in patients with schizophrenia in Singapore.

PubMed

Nurjono, Milawaty; Lee, Jimmy

2013-05-01

This study aims to examine and compare the predictive utility of blood pressure (BP), waist circumference (WC) and body mass index (BMI), and to determine optimal cut-off values in prediction of metabolic syndrome (MetS) in patients with chronic schizophrenia. About 100 patients with chronic schizophrenia were recruited. BMI and BP were measured and laboratory tests to evaluate patients' high-density lipoprotein cholesterol, triglycerides and glucose levels were performed. Presence of MetS was examined according to AHA/NHLBI guidelines. Predictive utility of BP, WC and BMI was examined using receiver operating curve and discriminant indices were determined accordingly. Forty-six (46%) patients were identified to have MetS. BMI of ≥23 kg m(-2) was most accurate (AUC = 0.83, P < 0.001), with sensitivity of 93.5%, specificity of 48.1%, positive predictive value of 60.6% and negative predictive value of 92.9% in identifying MetS. This finding has immediate and significant clinical implications in the local population with schizophrenia. © 2012 Wiley Publishing Asia Pty Ltd.