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Sample records for multivariate stepwise regression

Retro-regression--another important multivariate regression improvement.

PubMed

Randić, M

2001-01-01

We review the serious problem associated with instabilities of the coefficients of regression equations, referred to as the MRA (multivariate regression analysis) "nightmare of the first kind". This is manifested when in a stepwise regression a descriptor is included or excluded from a regression. The consequence is an unpredictable change of the coefficients of the descriptors that remain in the regression equation. We follow with consideration of an even more serious problem, referred to as the MRA "nightmare of the second kind", arising when optimal descriptors are selected from a large pool of descriptors. This process typically causes at different steps of the stepwise regression a replacement of several previously used descriptors by new ones. We describe a procedure that resolves these difficulties. The approach is illustrated on boiling points of nonanes which are considered (1) by using an ordered connectivity basis; (2) by using an ordering resulting from application of greedy algorithm; and (3) by using an ordering derived from an exhaustive search for optimal descriptors. A novel variant of multiple regression analysis, called retro-regression (RR), is outlined showing how it resolves the ambiguities associated with both "nightmares" of the first and the second kind of MRA.
Applications of modern statistical methods to analysis of data in physical science

NASA Astrophysics Data System (ADS)

Wicker, James Eric

Modern methods of statistical and computational analysis offer solutions to dilemmas confronting researchers in physical science. Although the ideas behind modern statistical and computational analysis methods were originally introduced in the 1970's, most scientists still rely on methods written during the early era of computing. These researchers, who analyze increasingly voluminous and multivariate data sets, need modern analysis methods to extract the best results from their studies. The first section of this work showcases applications of modern linear regression. Since the 1960's, many researchers in spectroscopy have used classical stepwise regression techniques to derive molecular constants. However, problems with thresholds of entry and exit for model variables plagues this analysis method. Other criticisms of this kind of stepwise procedure include its inefficient searching method, the order in which variables enter or leave the model and problems with overfitting data. We implement an information scoring technique that overcomes the assumptions inherent in the stepwise regression process to calculate molecular model parameters. We believe that this kind of information based model evaluation can be applied to more general analysis situations in physical science. The second section proposes new methods of multivariate cluster analysis. The K-means algorithm and the EM algorithm, introduced in the 1960's and 1970's respectively, formed the basis of multivariate cluster analysis methodology for many years. However, several shortcomings of these methods include strong dependence on initial seed values and inaccurate results when the data seriously depart from hypersphericity. We propose new cluster analysis methods based on genetic algorithms that overcomes the strong dependence on initial seed values. In addition, we propose a generalization of the Genetic K-means algorithm which can accurately identify clusters with complex hyperellipsoidal covariance structures. We then use this new algorithm in a genetic algorithm based Expectation-Maximization process that can accurately calculate parameters describing complex clusters in a mixture model routine. Using the accuracy of this GEM algorithm, we assign information scores to cluster calculations in order to best identify the number of mixture components in a multivariate data set. We will showcase how these algorithms can be used to process multivariate data from astronomical observations.
Order Selection for General Expression of Nonlinear Autoregressive Model Based on Multivariate Stepwise Regression

NASA Astrophysics Data System (ADS)

Shi, Jinfei; Zhu, Songqing; Chen, Ruwen

2017-12-01

An order selection method based on multiple stepwise regressions is proposed for General Expression of Nonlinear Autoregressive model which converts the model order problem into the variable selection of multiple linear regression equation. The partial autocorrelation function is adopted to define the linear term in GNAR model. The result is set as the initial model, and then the nonlinear terms are introduced gradually. Statistics are chosen to study the improvements of both the new introduced and originally existed variables for the model characteristics, which are adopted to determine the model variables to retain or eliminate. So the optimal model is obtained through data fitting effect measurement or significance test. The simulation and classic time-series data experiment results show that the method proposed is simple, reliable and can be applied to practical engineering.
A survey of variable selection methods in two Chinese epidemiology journals

PubMed Central

2010-01-01

Background Although much has been written on developing better procedures for variable selection, there is little research on how it is practiced in actual studies. This review surveys the variable selection methods reported in two high-ranking Chinese epidemiology journals. Methods Articles published in 2004, 2006, and 2008 in the Chinese Journal of Epidemiology and the Chinese Journal of Preventive Medicine were reviewed. Five categories of methods were identified whereby variables were selected using: A - bivariate analyses; B - multivariable analysis; e.g. stepwise or individual significance testing of model coefficients; C - first bivariate analyses, followed by multivariable analysis; D - bivariate analyses or multivariable analysis; and E - other criteria like prior knowledge or personal judgment. Results Among the 287 articles that reported using variable selection methods, 6%, 26%, 30%, 21%, and 17% were in categories A through E, respectively. One hundred sixty-three studies selected variables using bivariate analyses, 80% (130/163) via multiple significance testing at the 5% alpha-level. Of the 219 multivariable analyses, 97 (44%) used stepwise procedures, 89 (41%) tested individual regression coefficients, but 33 (15%) did not mention how variables were selected. Sixty percent (58/97) of the stepwise routines also did not specify the algorithm and/or significance levels. Conclusions The variable selection methods reported in the two journals were limited in variety, and details were often missing. Many studies still relied on problematic techniques like stepwise procedures and/or multiple testing of bivariate associations at the 0.05 alpha-level. These deficiencies should be rectified to safeguard the scientific validity of articles published in Chinese epidemiology journals. PMID:20920252
Utility of an Abbreviated Dizziness Questionnaire to Differentiate between Causes of Vertigo and Guide Appropriate Referral: A Multicenter Prospective Blinded Study

PubMed Central

Roland, Lauren T.; Kallogjeri, Dorina; Sinks, Belinda C.; Rauch, Steven D.; Shepard, Neil T.; White, Judith A.; Goebel, Joel A.

2015-01-01

Objective Test performance of a focused dizziness questionnaire’s ability to discriminate between peripheral and non-peripheral causes of vertigo. Study Design Prospective multi-center Setting Four academic centers with experienced balance specialists Patients New dizzy patients Interventions A 32-question survey was given to participants. Balance specialists were blinded and a diagnosis was established for all participating patients within 6 months. Main outcomes Multinomial logistic regression was used to evaluate questionnaire performance in predicting final diagnosis and differentiating between peripheral and non-peripheral vertigo. Univariate and multivariable stepwise logistic regression were used to identify questions as significant predictors of the ultimate diagnosis. C-index was used to evaluate performance and discriminative power of the multivariable models. Results 437 patients participated in the study. Eight participants without confirmed diagnoses were excluded and 429 were included in the analysis. Multinomial regression revealed that the model had good overall predictive accuracy of 78.5% for the final diagnosis and 75.5% for differentiating between peripheral and non-peripheral vertigo. Univariate logistic regression identified significant predictors of three main categories of vertigo: peripheral, central and other. Predictors were entered into forward stepwise multivariable logistic regression. The discriminative power of the final models for peripheral, central and other causes were considered good as measured by c-indices of 0.75, 0.7 and 0.78, respectively. Conclusions This multicenter study demonstrates a focused dizziness questionnaire can accurately predict diagnosis for patients with chronic/relapsing dizziness referred to outpatient clinics. Additionally, this survey has significant capability to differentiate peripheral from non-peripheral causes of vertigo and may, in the future, serve as a screening tool for specialty referral. Clinical utility of this questionnaire to guide specialty referral is discussed. PMID:26485598
Utility of an Abbreviated Dizziness Questionnaire to Differentiate Between Causes of Vertigo and Guide Appropriate Referral: A Multicenter Prospective Blinded Study.

PubMed

Roland, Lauren T; Kallogjeri, Dorina; Sinks, Belinda C; Rauch, Steven D; Shepard, Neil T; White, Judith A; Goebel, Joel A

2015-12-01

Test performance of a focused dizziness questionnaire's ability to discriminate between peripheral and nonperipheral causes of vertigo. Prospective multicenter. Four academic centers with experienced balance specialists. New dizzy patients. A 32-question survey was given to participants. Balance specialists were blinded and a diagnosis was established for all participating patients within 6 months. Multinomial logistic regression was used to evaluate questionnaire performance in predicting final diagnosis and differentiating between peripheral and nonperipheral vertigo. Univariate and multivariable stepwise logistic regression were used to identify questions as significant predictors of the ultimate diagnosis. C-index was used to evaluate performance and discriminative power of the multivariable models. In total, 437 patients participated in the study. Eight participants without confirmed diagnoses were excluded and 429 were included in the analysis. Multinomial regression revealed that the model had good overall predictive accuracy of 78.5% for the final diagnosis and 75.5% for differentiating between peripheral and nonperipheral vertigo. Univariate logistic regression identified significant predictors of three main categories of vertigo: peripheral, central, and other. Predictors were entered into forward stepwise multivariable logistic regression. The discriminative power of the final models for peripheral, central, and other causes was considered good as measured by c-indices of 0.75, 0.7, and 0.78, respectively. This multicenter study demonstrates a focused dizziness questionnaire can accurately predict diagnosis for patients with chronic/relapsing dizziness referred to outpatient clinics. Additionally, this survey has significant capability to differentiate peripheral from nonperipheral causes of vertigo and may, in the future, serve as a screening tool for specialty referral. Clinical utility of this questionnaire to guide specialty referral is discussed.
Identifying Pedophiles "Eligible" for Community Notification under Megan's Law: A Multivariate Model for Actuarially Anchored Decisions.

ERIC Educational Resources Information Center

Pallone, Nathaniel J.; Hennessy, James J.; Voelbel, Gerald T.

1998-01-01

A scientifically sound methodology for identifying offenders about whose presence the community should be notified is demonstrated. A stepwise multiple regression was calculated among incarcerated pedophiles (N=52) including both psychological and legal data; a precision-weighted equation produced 90.4% "true positives." This methodology can be…
Proton radius from electron scattering data

NASA Astrophysics Data System (ADS)

Higinbotham, Douglas W.; Kabir, Al Amin; Lin, Vincent; Meekins, David; Norum, Blaine; Sawatzky, Brad

2016-05-01

Background: The proton charge radius extracted from recent muonic hydrogen Lamb shift measurements is significantly smaller than that extracted from atomic hydrogen and electron scattering measurements. The discrepancy has become known as the proton radius puzzle. Purpose: In an attempt to understand the discrepancy, we review high-precision electron scattering results from Mainz, Jefferson Lab, Saskatoon, and Stanford. Methods: We make use of stepwise regression techniques using the F test as well as the Akaike information criterion to systematically determine the predictive variables to use for a given set and range of electron scattering data as well as to provide multivariate error estimates. Results: Starting with the precision, low four-momentum transfer (Q2) data from Mainz (1980) and Saskatoon (1974), we find that a stepwise regression of the Maclaurin series using the F test as well as the Akaike information criterion justify using a linear extrapolation which yields a value for the proton radius that is consistent with the result obtained from muonic hydrogen measurements. Applying the same Maclaurin series and statistical criteria to the 2014 Rosenbluth results on GE from Mainz, we again find that the stepwise regression tends to favor a radius consistent with the muonic hydrogen radius but produces results that are extremely sensitive to the range of data included in the fit. Making use of the high-Q2 data on GE to select functions which extrapolate to high Q2, we find that a Padé (N =M =1 ) statistical model works remarkably well, as does a dipole function with a 0.84 fm radius, GE(Q2) =(1+Q2/0.66 GeV2) -2 . Conclusions: Rigorous applications of stepwise regression techniques and multivariate error estimates result in the extraction of a proton charge radius that is consistent with the muonic hydrogen result of 0.84 fm; either from linear extrapolation of the extremely-low-Q2 data or by use of the Padé approximant for extrapolation using a larger range of data. Thus, based on a purely statistical analysis of electron scattering data, we conclude that the electron scattering results and the muonic hydrogen results are consistent. It is the atomic hydrogen results that are the outliers.
Quantitative laser-induced breakdown spectroscopy data using peak area step-wise regression analysis: an alternative method for interpretation of Mars science laboratory results

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

Clegg, Samuel M; Barefield, James E; Wiens, Roger C

2008-01-01

The ChemCam instrument on the Mars Science Laboratory (MSL) will include a laser-induced breakdown spectrometer (LIBS) to quantify major and minor elemental compositions. The traditional analytical chemistry approach to calibration curves for these data regresses a single diagnostic peak area against concentration for each element. This approach contrasts with a new multivariate method in which elemental concentrations are predicted by step-wise multiple regression analysis based on areas of a specific set of diagnostic peaks for each element. The method is tested on LIBS data from igneous and metamorphosed rocks. Between 4 and 13 partial regression coefficients are needed to describemore » each elemental abundance accurately (i.e., with a regression line of R{sup 2} > 0.9995 for the relationship between predicted and measured elemental concentration) for all major and minor elements studied. Validation plots suggest that the method is limited at present by the small data set, and will work best for prediction of concentration when a wide variety of compositions and rock types has been analyzed.« less
Causal correlation of foliar biochemical concentrations with AVIRIS spectra using forced entry linear regression

NASA Technical Reports Server (NTRS)

Dawson, Terence P.; Curran, Paul J.; Kupiec, John A.

1995-01-01

A major goal of airborne imaging spectrometry is to estimate the biochemical composition of vegetation canopies from reflectance spectra. Remotely-sensed estimates of foliar biochemical concentrations of forests would provide valuable indicators of ecosystem function at regional and eventually global scales. Empirical research has shown a relationship exists between the amount of radiation reflected from absorption features and the concentration of given biochemicals in leaves and canopies (Matson et al., 1994, Johnson et al., 1994). A technique commonly used to determine which wavelengths have the strongest correlation with the biochemical of interest is unguided (stepwise) multiple regression. Wavelengths are entered into a multivariate regression equation, in their order of importance, each contributing to the reduction of the variance in the measured biochemical concentration. A significant problem with the use of stepwise regression for determining the correlation between biochemical concentration and spectra is that of 'overfitting' as there are significantly more wavebands than biochemical measurements. This could result in the selection of wavebands which may be more accurately attributable to noise or canopy effects. In addition, there is a real problem of collinearity in that the individual biochemical concentrations may covary. A strong correlation between the reflectance at a given wavelength and the concentration of a biochemical of interest, therefore, may be due to the effect of another biochemical which is closely related. Furthermore, it is not always possible to account for potentially suitable waveband omissions in the stepwise selection procedure. This concern about the suitability of stepwise regression has been identified and acknowledged in a number of recent studies (Wessman et al., 1988, Curran, 1989, Curran et al., 1992, Peterson and Hubbard, 1992, Martine and Aber, 1994, Kupiec, 1994). These studies have pointed to the lack of a physical link between wavelengths chosen by stepwise regression and the biochemical of interest, and this in turn has cast doubts on the use of imaging spectrometry for the estimation of foliar biochemical concentrations at sites distant from the training sites. To investigate this problem, an analysis was conducted on the variation in canopy biochemical concentrations and reflectance spectra using forced entry linear regression.
Proton radius from electron scattering data

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

Higinbotham, Douglas W.; Kabir, Al Amin; Lin, Vincent

Background: The proton charge radius extracted from recent muonic hydrogen Lamb shift measurements is significantly smaller than that extracted from atomic hydrogen and electron scattering measurements. The discrepancy has become known as the proton radius puzzle. Purpose: In an attempt to understand the discrepancy, we review high-precision electron scattering results from Mainz, Jefferson Lab, Saskatoon and Stanford. Methods: We make use of stepwise regression techniques using the F-test as well as the Akaike information criterion to systematically determine the predictive variables to use for a given set and range of electron scattering data as well as to provide multivariate errormore » estimates. Results: Starting with the precision, low four-momentum transfer (Q 2) data from Mainz (1980) and Saskatoon (1974), we find that a stepwise regression of the Maclaurin series using the F-test as well as the Akaike information criterion justify using a linear extrapolation which yields a value for the proton radius that is consistent with the result obtained from muonic hydrogen measurements. Applying the same Maclaurin series and statistical criteria to the 2014 Rosenbluth results on GE from Mainz, we again find that the stepwise regression tends to favor a radius consistent with the muonic hydrogen radius but produces results that are extremely sensitive to the range of data included in the fit. Making use of the high-Q 2 data on G E to select functions which extrapolate to high Q 2, we find that a Pad´e (N = M = 1) statistical model works remarkably well, as does a dipole function with a 0.84 fm radius, G E(Q 2) = (1 + Q 2/0.66 GeV 2) -2. Conclusions: Rigorous applications of stepwise regression techniques and multivariate error estimates result in the extraction of a proton charge radius that is consistent with the muonic hydrogen result of 0.84 fm; either from linear extrapolation of the extreme low-Q 2 data or by use of the Pad´e approximant for extrapolation using a larger range of data. Thus, based on a purely statistical analysis of electron scattering data, we conclude that the electron scattering result and the muonic hydrogen result are consistent. Lastly, it is the atomic hydrogen results that are the outliers.« less
Proton radius from electron scattering data

DOE PAGES

Higinbotham, Douglas W.; Kabir, Al Amin; Lin, Vincent; ...

2016-05-31

Background: The proton charge radius extracted from recent muonic hydrogen Lamb shift measurements is significantly smaller than that extracted from atomic hydrogen and electron scattering measurements. The discrepancy has become known as the proton radius puzzle. Purpose: In an attempt to understand the discrepancy, we review high-precision electron scattering results from Mainz, Jefferson Lab, Saskatoon and Stanford. Methods: We make use of stepwise regression techniques using the F-test as well as the Akaike information criterion to systematically determine the predictive variables to use for a given set and range of electron scattering data as well as to provide multivariate errormore » estimates. Results: Starting with the precision, low four-momentum transfer (Q 2) data from Mainz (1980) and Saskatoon (1974), we find that a stepwise regression of the Maclaurin series using the F-test as well as the Akaike information criterion justify using a linear extrapolation which yields a value for the proton radius that is consistent with the result obtained from muonic hydrogen measurements. Applying the same Maclaurin series and statistical criteria to the 2014 Rosenbluth results on GE from Mainz, we again find that the stepwise regression tends to favor a radius consistent with the muonic hydrogen radius but produces results that are extremely sensitive to the range of data included in the fit. Making use of the high-Q 2 data on G E to select functions which extrapolate to high Q 2, we find that a Pad´e (N = M = 1) statistical model works remarkably well, as does a dipole function with a 0.84 fm radius, G E(Q 2) = (1 + Q 2/0.66 GeV 2) -2. Conclusions: Rigorous applications of stepwise regression techniques and multivariate error estimates result in the extraction of a proton charge radius that is consistent with the muonic hydrogen result of 0.84 fm; either from linear extrapolation of the extreme low-Q 2 data or by use of the Pad´e approximant for extrapolation using a larger range of data. Thus, based on a purely statistical analysis of electron scattering data, we conclude that the electron scattering result and the muonic hydrogen result are consistent. Lastly, it is the atomic hydrogen results that are the outliers.« less
Visual Analysis of North Atlantic Hurricane Trends Using Parallel Coordinates and Statistical Techniques

DTIC Science & Technology

2008-07-07

analyzing multivariate data sets. The system was developed using the Java Development Kit (JDK) version 1.5; and it yields interactive performance on a... script and captures output from the MATLAB’s “regress” and “stepwisefit” utilities that perform simple and stepwise regression, respectively. The MATLAB...Statistical Association, vol. 85, no. 411, pp. 664–675, 1990. [9] H. Hauser, F. Ledermann, and H. Doleisch, “ Angular brushing of extended parallel coordinates
Multivariate calibration on NIR data: development of a model for the rapid evaluation of ethanol content in bakery products.

PubMed

Bello, Alessandra; Bianchi, Federica; Careri, Maria; Giannetto, Marco; Mori, Giovanni; Musci, Marilena

2007-11-05

A new NIR method based on multivariate calibration for determination of ethanol in industrially packed wholemeal bread was developed and validated. GC-FID was used as reference method for the determination of actual ethanol concentration of different samples of wholemeal bread with proper content of added ethanol, ranging from 0 to 3.5% (w/w). Stepwise discriminant analysis was carried out on the NIR dataset, in order to reduce the number of original variables by selecting those that were able to discriminate between the samples of different ethanol concentrations. With the so selected variables a multivariate calibration model was then obtained by multiple linear regression. The prediction power of the linear model was optimized by a new "leave one out" method, so that the number of original variables resulted further reduced.
Factors that influence the efficacy of acarbose and metformin as initial therapy in Chinese patients with newly diagnosed type 2 diabetes: a subanalysis of the MARCH trial.

PubMed

Zhang, Jinping; Wang, Na; Xing, Xiaoyan; Yang, Zhaojun; Wang, Xin; Yang, Wenying

2016-01-01

To conduct a subanalysis of the randomized MARCH (Metformin and AcaRbose in Chinese as the initial Hypoglycemic treatment) trial to investigate whether specific characteristics are associated with the efficacy of either acarbose or metformin as initial therapy. A total of 657 type 2 diabetes patients who were randomly assigned to 48 weeks of therapy with either acarbose or metformin in the MARCH trial were divided into two groups based upon their hemoglobin A1c (HbA1c) levels at the end of follow-up: HbA1c <7% (<53 mmol/mol) and ≥7% (≥53 mmol/mol). Univariate, multivariate, and stepwise linear regression analyses were applied to identify the factors associated with treatment efficacy. Because this was a subanalysis, no measurement was performed. Univariate analysis showed that the efficacy of acarbose and metformin was influenced by HbA1c, fasting blood glucose (FBG), and 2 hour postprandial venous blood glucose (2hPPG) levels, as well as by changes in body mass index (BMI) (p ≤ 0.006). Multivariate analysis and stepwise linear regression analyses indicated that lower baseline 2hPPG values and greater changes in BMI were factors that positively influenced efficacy in both treatment groups (p ≤ 0.05). Stepwise regression model analysis also revealed that a lower baseline homeostasis model assessment-estimated insulin resistance (HOMA-IR) and higher serum insulin area under the curve (AUC) were factors positively influencing HbA1c normalization in all patients (p ≤ 0.032). Newly diagnosed type 2 diabetes patients with lower baseline 2hPPG and HOMA-IR values are more likely to achieve glucose control with acarbose or metformin treatment. Furthermore, the change in BMI after acarbose or metformin treatment is also a factor influencing HbA1c normalization. A prospective study with a larger sample size is necessary to confirm our results as well as measure β cell function and examine the influence of the patients' dietary habits.
Seminal Plasma HIV-1 RNA Concentration Is Strongly Associated with Altered Levels of Seminal Plasma Interferon-γ, Interleukin-17, and Interleukin-5

PubMed Central

Hoffman, Jennifer C.; Anton, Peter A.; Baldwin, Gayle Cocita; Elliott, Julie; Anisman-Posner, Deborah; Tanner, Karen; Grogan, Tristan; Elashoff, David; Sugar, Catherine; Yang, Otto O.

2014-01-01

Abstract Seminal plasma HIV-1 RNA level is an important determinant of the risk of HIV-1 sexual transmission. We investigated potential associations between seminal plasma cytokine levels and viral concentration in the seminal plasma of HIV-1-infected men. This was a prospective, observational study of paired blood and semen samples from 18 HIV-1 chronically infected men off antiretroviral therapy. HIV-1 RNA levels and cytokine levels in seminal plasma and blood plasma were measured and analyzed using simple linear regressions to screen for associations between cytokines and seminal plasma HIV-1 levels. Forward stepwise regression was performed to construct the final multivariate model. The median HIV-1 RNA concentrations were 4.42 log10 copies/ml (IQR 2.98, 4.70) and 2.96 log10 copies/ml (IQR 2, 4.18) in blood and seminal plasma, respectively. In stepwise multivariate linear regression analysis, blood HIV-1 RNA level (p<0.0001) was most strongly associated with seminal plasma HIV-1 RNA level. After controlling for blood HIV-1 RNA level, seminal plasma HIV-1 RNA level was positively associated with interferon (IFN)-γ (p=0.03) and interleukin (IL)-17 (p=0.03) and negatively associated with IL-5 (p=0.0007) in seminal plasma. In addition to blood HIV-1 RNA level, cytokine profiles in the male genital tract are associated with HIV-1 RNA levels in semen. The Th1 and Th17 cytokines IFN-γ and IL-17 are associated with increased seminal plasma HIV-1 RNA, while the Th2 cytokine IL-5 is associated with decreased seminal plasma HIV-1 RNA. These results support the importance of genital tract immunomodulation in HIV-1 transmission. PMID:25209674
Correlation between increased urinary sodium excretion and decreased left ventricular diastolic function in patients with type 2 diabetes mellitus.

PubMed

Kagiyama, Shuntaro; Koga, Tokushi; Kaseda, Shigeru; Ishihara, Shiro; Kawazoe, Nobuyuki; Sadoshima, Seizo; Matsumura, Kiyoshi; Takata, Yutaka; Tsuchihashi, Takuya; Iida, Mitsuo

2009-10-01

Increased salt intake may induce hypertension, lead to cardiac hypertrophy, and exacerbate heart failure. When elderly patients develop heart failure, diastolic dysfunction is often observed, although the ejection fraction has decreased. Diabetes mellitus (DM) is an established risk factor for heart failure. However, little is known about the relationship between cardiac function and urinary sodium excretion (U-Na) in patients with DM. We measured 24-hour U-Na; cardiac function was evaluated directly during coronary catheterization in type 2 DM (n = 46) or non-DM (n = 55) patients with preserved cardiac systolic function (ejection fraction > or = 60%). Cardiac diastolic and systolic function was evaluated as - dp/dt and + dp/dt, respectively. The average of U-Na was 166.6 +/- 61.2 mEq/24 hour (mean +/- SD). In all patients, stepwise multivariate regression analysis revealed that - dp/dt had a negative correlation with serum B-type natriuretic peptide (BNP; beta = - 0.23, P = .021) and U-Na (beta = - 0.24, P = .013). On the other hand, + dp/dt negatively correlated with BNP (beta = - 0.30, P < .001), but did not relate to U-Na. In the DM-patients, stepwise multivariate regression analysis showed that - dp/dt still had a negative correlation with U-Na (beta = - 0.33, P = .025). The results indicated that increased urinary sodium excretion is associated with an impairment of cardiac diastolic function, especially in patients with DM, suggesting that a reduction of salt intake may improve cardiac diastolic function.
Impact of “Sick” and “Recovery” Roles on Brain Injury Rehabilitation Outcomes

PubMed Central

Barclay, David A.

2012-01-01

This study utilizes a multivariate, correlational, expost facto research design to examine Parsons' “sick role” as a dynamic, time-sensitive process of “sick role” and “recovery role” and the impact of this process on goal attainment (H1) and psychosocial distress (H2) of adult survivors of acquired brain injury. Measures used include the Brief Symptom Inventory-18, a Goal Attainment Scale, and an original instrument to measure sick role process. 60 survivors of ABI enrolled in community reentry rehabilitation participated. Stepwise regression analyses did not fully support the multivariate hypotheses. Two models emerged from the stepwise analyses. Goal attainment, gender, and postrehab responsibilities accounted for 40% of the shared variance of psychosocial distress. Anxiety and depression accounted for 22% of the shared variance of goal attainment with anxiety contributing to the majority of the explained variance. Bivariate analysis found sick role variables, anxiety, somatization, depression, gender, and goal attainment as significant. The study has implications for ABI rehabilitation in placing greater emphasis on sick role processes, anxiety, gender, and goal attainment in guiding program planning and future research with survivors of ABI. PMID:23119164
The relationship between hemoglobin level and the type 1 diabetic nephropathy in Anhui Han's patients.

PubMed

Jiang, Jun; Lei, Lan; Zhou, Xiaowan; Li, Peng; Wei, Ren

2018-02-20

Recent studies have shown that low hemoglobin (Hb) level promote the progression of chronic kidney disease. This study assessed the relationship between Hb level and type 1 diabetic nephropathy (DN) in Anhui Han's patients. There were a total of 236 patients diagnosed with type 1 diabetes mellitus and (T1DM) seen between January 2014 and December 2016 in our centre. Hemoglobin levels in patients with DN were compared with those without DN. The relationship between Hb level and the urinary albumin-creatinine ratio (ACR) was examined by Spearman's correlational analysis and multiple stepwise regression analysis. The binary logistic multivariate regression analysis was performed to analyze the correlated factors for type 1 DN, calculate the Odds Ratio (OR) and 95%confidence interval (CI). The predicting value of Hb level for DN was evaluated by area under receiver operation characteristic curve (AUROC) for discrimination and Hosmer-Lemeshow goodness-of-fit test for calibration. The average Hb levels in the DN group (116.1 ± 20.8 g/L) were significantly lower than the non-DN group (131.9 ± 14.4 g/L) , P < 0.001. Hb levels were independently correlated with the urinary ACR in multiple stepwise regression analysis. The logistic multivariate regression analysis showed that the Hb level (OR: 0.936, 95% CI: 0.910 to 0.963, P < 0.001) was inversely correlated with DN in patients with T1DM. In sub-analysis, low Hb level (Hb < 120g/L in female, Hb < 130g/L in male) was still negatively associated with DN in patients with T1DM. The AUROC was 0.721 (95% CI: 0.655 to 0.787) in assessing the discrimination of the Hb level for DN. The value of P was 0.593 in Hosmer-Lemeshow goodness-of-fit test. In Anhui Han's patients with T1DM, the Hb level is inversely correlated with urinary ACR and DN. This article is protected by copyright. All rights reserved.
The microbiological profile and presence of bloodstream infection influence mortality rates in necrotizing fasciitis

PubMed Central

2011-01-01

Introduction Necrotizing fasciitis (NF) is a life threatening infectious disease with a high mortality rate. We carried out a microbiological characterization of the causative pathogens. We investigated the correlation of mortality in NF with bloodstream infection and with the presence of co-morbidities. Methods In this retrospective study, we analyzed 323 patients who presented with necrotizing fasciitis at two different institutions. Bloodstream infection (BSI) was defined as a positive blood culture result. The patients were categorized as survivors and non-survivors. Eleven clinically important variables which were statistically significant by univariate analysis were selected for multivariate regression analysis and a stepwise logistic regression model was developed to determine the association between BSI and mortality. Results Univariate logistic regression analysis showed that patients with hypotension, heart disease, liver disease, presence of Vibrio spp. in wound cultures, presence of fungus in wound cultures, and presence of Streptococcus group A, Aeromonas spp. or Vibrio spp. in blood cultures, had a significantly higher risk of in-hospital mortality. Our multivariate logistic regression analysis showed a higher risk of mortality in patients with pre-existing conditions like hypotension, heart disease, and liver disease. Multivariate logistic regression analysis also showed that presence of Vibrio spp in wound cultures, and presence of Streptococcus Group A in blood cultures were associated with a high risk of mortality while debridement > = 3 was associated with improved survival. Conclusions Mortality in patients with necrotizing fasciitis was significantly associated with the presence of Vibrio in wound cultures and Streptococcus group A in blood cultures. PMID:21693053

Application of multivariate chemometric techniques for simultaneous determination of five parameters of cottonseed oil by single bounce attenuated total reflectance Fourier transform infrared spectroscopy.

PubMed

Talpur, M Younis; Kara, Huseyin; Sherazi, S T H; Ayyildiz, H Filiz; Topkafa, Mustafa; Arslan, Fatma Nur; Naz, Saba; Durmaz, Fatih; Sirajuddin

2014-11-01

Single bounce attenuated total reflectance (SB-ATR) Fourier transform infrared (FTIR) spectroscopy in conjunction with chemometrics was used for accurate determination of free fatty acid (FFA), peroxide value (PV), iodine value (IV), conjugated diene (CD) and conjugated triene (CT) of cottonseed oil (CSO) during potato chips frying. Partial least square (PLS), stepwise multiple linear regression (SMLR), principal component regression (PCR) and simple Beer׳s law (SBL) were applied to develop the calibrations for simultaneous evaluation of five stated parameters of cottonseed oil (CSO) during frying of French frozen potato chips at 170°C. Good regression coefficients (R(2)) were achieved for FFA, PV, IV, CD and CT with value of >0.992 by PLS, SMLR, PCR, and SBL. Root mean square error of prediction (RMSEP) was found to be less than 1.95% for all determinations. Result of the study indicated that SB-ATR FTIR in combination with multivariate chemometrics could be used for accurate and simultaneous determination of different parameters during the frying process without using any toxic organic solvent. Copyright © 2014 Elsevier B.V. All rights reserved.
Lithium might be associated with better decision-making performance in euthymic bipolar patients.

PubMed

Adida, Marc; Jollant, Fabrice; Clark, Luke; Guillaume, Sebastien; Goodwin, Guy M; Azorin, Jean-Michel; Courtet, Philippe

2015-06-01

Bipolar disorder is associated with impaired decision-making. Little is known about how treatment, especially lithium, influences decision-making abilities in bipolar patients when euthymic. We aimed at testing for an association between lithium medication and decision-making performance in remitted bipolar patients. Decision-making was measured using the Iowa Gambling Task in 3 groups of subjects: 34 and 56 euthymic outpatients with bipolar disorder, treated with lithium (monotherapy and lithium combined with anticonvulsant or antipsychotic) and without lithium (anticonvulsant, antipsychotic and combination treatment), respectively, and 152 matched healthy controls. Performance was compared between the 3 groups. In the 90 euthymic patients, the relationship between different sociodemographic and clinical variables and decision-making was assessed by stepwise multivariate regression analysis. Euthymic patients with lithium (p=0.007) and healthy controls (p=0.001) selected significantly more cards from the safe decks than euthymic patients without lithium, with no significant difference between euthymic patients with lithium and healthy controls (p=0.9). In the 90 euthymic patients, the stepwise linear multivariate regression revealed that decision-making was significantly predicted (p<0.001) by lithium dose, level of education and no family history of bipolar disorder (all p≤0.01). Because medication was not randomized, it was not possible to discriminate the effect of different medications. Lithium medication might be associated with better decision-making in remitted bipolar patients. A randomized trial is required to test for the hypothesis that lithium, but not other mood stabilizers, may specifically improve decision-making abilities in bipolar disorder. Copyright © 2015 Elsevier B.V. and ECNP. All rights reserved.
Testing Different Model Building Procedures Using Multiple Regression.

ERIC Educational Resources Information Center

Thayer, Jerome D.

The stepwise regression method of selecting predictors for computer assisted multiple regression analysis was compared with forward, backward, and best subsets regression, using 16 data sets. The results indicated the stepwise method was preferred because of its practical nature, when the models chosen by different selection methods were similar…
Episiotomy increases perineal laceration length in primiparous women.

PubMed

Nager, C W; Helliwell, J P

2001-08-01

The aim of this study was to determine the clinical factors that contribute to posterior perineal laceration length. A prospective observational study was performed in 80 consenting, mostly primiparous women with term pregnancies. Posterior perineal lacerations were measured immediately after delivery. Numerous maternal, fetal, and operator variables were evaluated against laceration length and degree of tear. Univariate and multivariate regression analyses were performed to evaluate laceration length and parametric clinical variables. Nonparametric clinical variables were evaluated against laceration length by the Mann-Whitney U test. A multivariate stepwise linear regression equation revealed that episiotomy adds nearly 3 cm to perineal lacerations. Tear length was highly associated with the degree of tear (R = 0.86, R(2) = 0.73) and the risk of recognized anal sphincter disruption. None of 35 patients without an episiotomy had a recognized anal sphincter disruption, but 6 of 27 patients with an episiotomy did (P <.001). Body mass index was the only maternal or fetal variable that showed even a slight correlation with laceration length (R = 0.30, P =.04). Episiotomy is the overriding determinant of perineal laceration length and recognized anal sphincter disruption.
Application of stepwise multiple regression techniques to inversion of Nimbus 'IRIS' observations.

NASA Technical Reports Server (NTRS)

Ohring, G.

1972-01-01

Exploratory studies with Nimbus-3 infrared interferometer-spectrometer (IRIS) data indicate that, in addition to temperature, such meteorological parameters as geopotential heights of pressure surfaces, tropopause pressure, and tropopause temperature can be inferred from the observed spectra with the use of simple regression equations. The technique of screening the IRIS spectral data by means of stepwise regression to obtain the best radiation predictors of meteorological parameters is validated. The simplicity of application of the technique and the simplicity of the derived linear regression equations - which contain only a few terms - suggest usefulness for this approach. Based upon the results obtained, suggestions are made for further development and exploitation of the stepwise regression analysis technique.
Emergency department blood transfusion: the first two units are free.

PubMed

Ley, Eric J; Liou, Douglas Z; Singer, Matthew B; Mirocha, James; Melo, Nicolas; Chung, Rex; Bukur, Marko; Salim, Ali

2013-09-01

Studies on blood product transfusions after trauma recommend targeting specific ratios to reduce mortality. Although crystalloid volumes as little as 1.5 L predict increased mortality after trauma, little data is available regarding the threshold of red blood cell (RBC) transfusion volume that predicts increased mortality. Data from a level I trauma center between January 2000 and December 2008 were reviewed. Trauma patients who received at least 100 mL RBC in the emergency department (ED) were included. Each unit of RBC was defined as 300 mL. Demographics, RBC transfusion volume, and mortality were analyzed in the nonelderly (<70 y) and elderly (≥70 y). Multivariate logistic regression was performed at various volume cutoffs to determine whether there was a threshold transfusion volume that independently predicted mortality. A total of 560 patients received ≥100 mL RBC in the ED. Overall mortality was 24.3%, with 22.5% (104 deaths) in the nonelderly and 32.7% (32 deaths) in the elderly. Multivariate logistic regression demonstrated that RBC transfusion of ≥900 mL was associated with increased mortality in both the nonelderly (adjusted odds ratio 2.06, P = 0.008) and elderly (adjusted odds ratio 5.08, P = 0.006). Although transfusion of greater than 2 units in the ED was an independent predictor of mortality, transfusion of 2 units or less was not. Interestingly, unlike crystalloid volume, stepwise increases in blood volume were not associated with stepwise increases in mortality. The underlying etiology for mortality discrepancies, such as transfusion ratios, hypothermia, or immunosuppression, needs to be better delineated. Copyright © 2013 Elsevier Inc. All rights reserved.
Determinants of brain-derived neurotrophic factor (BDNF) in umbilical cord and maternal serum.

PubMed

Flöck, A; Weber, S K; Ferrari, N; Fietz, C; Graf, C; Fimmers, R; Gembruch, U; Merz, W M

2016-01-01

Brain-derived neurotrophic factor (BDNF) plays a fundamental role in brain development; additionally, it is involved in various aspects of cerebral function, including neurodegenerative and psychiatric diseases. Involvement of BDNF in parturition has not been investigated. The aim of our study was to analyze determinants of umbilical cord BDNF (UC-BDNF) concentrations of healthy, term newborns and their respective mothers. This cross-sectional prospective study was performed at a tertiary referral center. Maternal venous blood samples were taken on admission to labor ward; newborn venous blood samples were drawn from the umbilical cord (UC), before delivery of the placenta. Analysis was performed with a commercially available immunoassay. Univariate analyses and stepwise multivariate regression models were applied. 120 patients were recruited. UC-BDNF levels were lower than maternal serum concentrations (median 641 ng/mL, IQR 506 vs. median 780 ng/mL, IQR 602). Correlation between UC- and maternal BDNF was low (R=0.251, p=0.01). In univariate analysis, mode of delivery (MoD), gestational age (GA), body mass index at delivery, and gestational diabetes were determinants of UC-BDNF (MoD and smoking for maternal BDNF, respectively). Stepwise multivariate regression analysis revealed a model with MoD and GA as determinants for UC-BDNF (MoD for maternal BDNF). MoD and GA at delivery are determinants of circulating BDNF in the mother and newborn. We hypothesize that BDNF, like other neuroendocrine factors, is involved in the neuroendocrine cascade of delivery. Timing and mode of delivery may exert BDNF-induced effects on the cerebral function of newborns and their mothers. Copyright © 2015 Elsevier Ltd. All rights reserved.
Developing screening services for colorectal cancer on Android smartphones.

PubMed

Wu, Hui-Ching; Chang, Chiao-Jung; Lin, Chun-Che; Tsai, Ming-Chang; Chang, Che-Chia; Tseng, Ming-Hseng

2014-08-01

Colorectal cancer (CRC) is an important health problem in Western countries and also in Asia. It is the third leading cause of cancer deaths in both men and women in Taiwan. According to the well-known adenoma-to-carcinoma sequence, the majority of CRC develops from colorectal adenomatous polyps. This concept provides the rationale for screening and prevention of CRC. Removal of colorectal adenoma could reduce the mortality and incidence of CRC. Mobile phones are now playing an ever more crucial role in people's daily lives. The latest generation of smartphones is increasingly viewed as hand-held computers rather than as phones, because of their powerful on-board computing capability, capacious memories, large screens, and open operating systems that encourage development of applications (apps). If we can detect the potential CRC patients early and offer them appropriate treatments and services, this would not only promote the quality of life, but also reduce the possible serious complications and medical costs. In this study, an intelligent CRC screening app on Android™ (Google™, Mountain View, CA) smartphones has been developed based on a data mining approach using decision tree algorithms. For comparison, the stepwise backward multivariate logistic regression model and the fecal occult blood test were also used. Compared with the stepwise backward multivariate logistic regression model and the fecal occult blood test, the proposed app system not only provides an easy and efficient way to quickly detect high-risk groups of potential CRC patients, but also brings more information about CRC to customer-oriented services. We developed and implemented an app system on Android platforms for ubiquitous healthcare services for CRC screening. It can assist people in achieving early screening, diagnosis, and treatment purposes, prevent the occurrence of complications, and thus reach the goal of preventive medicine.
Molecular Classification Substitutes for the Prognostic Variables Stage, Age, and MYCN Status in Neuroblastoma Risk Assessment.

PubMed

Rosswog, Carolina; Schmidt, Rene; Oberthuer, André; Juraeva, Dilafruz; Brors, Benedikt; Engesser, Anne; Kahlert, Yvonne; Volland, Ruth; Bartenhagen, Christoph; Simon, Thorsten; Berthold, Frank; Hero, Barbara; Faldum, Andreas; Fischer, Matthias

2017-12-01

Current risk stratification systems for neuroblastoma patients consider clinical, histopathological, and genetic variables, and additional prognostic markers have been proposed in recent years. We here sought to select highly informative covariates in a multistep strategy based on consecutive Cox regression models, resulting in a risk score that integrates hazard ratios of prognostic variables. A cohort of 695 neuroblastoma patients was divided into a discovery set (n=75) for multigene predictor generation, a training set (n=411) for risk score development, and a validation set (n=209). Relevant prognostic variables were identified by stepwise multivariable L1-penalized least absolute shrinkage and selection operator (LASSO) Cox regression, followed by backward selection in multivariable Cox regression, and then integrated into a novel risk score. The variables stage, age, MYCN status, and two multigene predictors, NB-th24 and NB-th44, were selected as independent prognostic markers by LASSO Cox regression analysis. Following backward selection, only the multigene predictors were retained in the final model. Integration of these classifiers in a risk scoring system distinguished three patient subgroups that differed substantially in their outcome. The scoring system discriminated patients with diverging outcome in the validation cohort (5-year event-free survival, 84.9±3.4 vs 63.6±14.5 vs 31.0±5.4; P<.001), and its prognostic value was validated by multivariable analysis. We here propose a translational strategy for developing risk assessment systems based on hazard ratios of relevant prognostic variables. Our final neuroblastoma risk score comprised two multigene predictors only, supporting the notion that molecular properties of the tumor cells strongly impact clinical courses of neuroblastoma patients. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.
[Contents of vitreous humor of dead body with different postmortem intervals].

PubMed

Tao, Tao; Xu, Jing; Luo, Tong-Xing; Liao, Zhi-Gang; Pan, Hong-Fu

2006-11-01

To establish regression correlations between postmortem interval (PMI) and contents of human vitreous humor of dead bodies for forensic purposes. The human vitreous humor were taken from 126 dead bodies between 0.5 to 216 hours after death, and 11 chemical elements were detected by the OLYMPUS AU400 auto-biochemistry instrument. (1) The glucose, natrium and chlorine in human vitreous humor decreased, while the urea, creatinine, uric acid, potassium, calcium, magnesium, phosphorus, and micro-protein increased after death. The change of glucose, potassium and phosphorus were well correlated with the PMI (r = 0.824, 0.967, 0.880). But the uric acid and micro-protein did not have a good correlation with the PMI(r = 0.350, 0.153). (2) The stepwise regression analysis established the following equations for the PMI (Y): Y = -35. 15+6.05X, R2 = 0.957 (X = potassium); Y = -27.83+ 5.49X(1) - 1.35X(2), R2 = 0.960 (X(1) = potassium, X(2) = glucose); Y = -6.37+3.93X(1) -2.29X(2) + 5.36X(3), R2 = 0.966 (X(1) = potassium, X(2) = glucose, X(3) = phosphorus). (1) Eleven chemical components in human vitreous humor change after death, among which postassium has the best linear correlation with the PMI within 72 hours after death. (2) The accuracy of the estimation of PMI could be improved by establishing a multi-variable equation through stepwise regression.
Study relationship between inorganic and organic coal analysis with gross calorific value by multiple regression and ANFIS

USGS Publications Warehouse

Chelgani, S.C.; Hart, B.; Grady, W.C.; Hower, J.C.

2011-01-01

The relationship between maceral content plus mineral matter and gross calorific value (GCV) for a wide range of West Virginia coal samples (from 6518 to 15330 BTU/lb; 15.16 to 35.66MJ/kg) has been investigated by multivariable regression and adaptive neuro-fuzzy inference system (ANFIS). The stepwise least square mathematical method comparison between liptinite, vitrinite, plus mineral matter as input data sets with measured GCV reported a nonlinear correlation coefficient (R2) of 0.83. Using the same data set the correlation between the predicted GCV from the ANFIS model and the actual GCV reported a R2 value of 0.96. It was determined that the GCV-based prediction methods, as used in this article, can provide a reasonable estimation of GCV. Copyright ?? Taylor & Francis Group, LLC.
Associations with substance abuse treatment completion in drug court

PubMed Central

Brown, Randall T

2009-01-01

Subjects in the study included all participants (N = 573) in drug treatment court in a mid-sized U.S. city from 1996 through 2004. Administrative data from the drug court included measures of demographics and socioeconomics, substance use, and criminal justice history. Stepwise multivariate logistic regression yielded a final model of failure to complete drug treatment. Unemployment, lower educational attainment, and cocaine use disorders were associated with failure to complete treatment. The limitations of administrative data should be considered in the interpretation of results. Funding was provided by the National Institutes of Health, National Institute on Drug Abuse (1 K23 DA017283-01). PMID:20380560
Impact of statistical learning methods on the predictive power of multivariate normal tissue complication probability models.

PubMed

Xu, Cheng-Jian; van der Schaaf, Arjen; Schilstra, Cornelis; Langendijk, Johannes A; van't Veld, Aart A

2012-03-15

To study the impact of different statistical learning methods on the prediction performance of multivariate normal tissue complication probability (NTCP) models. In this study, three learning methods, stepwise selection, least absolute shrinkage and selection operator (LASSO), and Bayesian model averaging (BMA), were used to build NTCP models of xerostomia following radiotherapy treatment for head and neck cancer. Performance of each learning method was evaluated by a repeated cross-validation scheme in order to obtain a fair comparison among methods. It was found that the LASSO and BMA methods produced models with significantly better predictive power than that of the stepwise selection method. Furthermore, the LASSO method yields an easily interpretable model as the stepwise method does, in contrast to the less intuitive BMA method. The commonly used stepwise selection method, which is simple to execute, may be insufficient for NTCP modeling. The LASSO method is recommended. Copyright Â© 2012 Elsevier Inc. All rights reserved.
Predictive equations for the estimation of body size in seals and sea lions (Carnivora: Pinnipedia)

PubMed Central

Churchill, Morgan; Clementz, Mark T; Kohno, Naoki

2014-01-01

Body size plays an important role in pinniped ecology and life history. However, body size data is often absent for historical, archaeological, and fossil specimens. To estimate the body size of pinnipeds (seals, sea lions, and walruses) for today and the past, we used 14 commonly preserved cranial measurements to develop sets of single variable and multivariate predictive equations for pinniped body mass and total length. Principal components analysis (PCA) was used to test whether separate family specific regressions were more appropriate than single predictive equations for Pinnipedia. The influence of phylogeny was tested with phylogenetic independent contrasts (PIC). The accuracy of these regressions was then assessed using a combination of coefficient of determination, percent prediction error, and standard error of estimation. Three different methods of multivariate analysis were examined: bidirectional stepwise model selection using Akaike information criteria; all-subsets model selection using Bayesian information criteria (BIC); and partial least squares regression. The PCA showed clear discrimination between Otariidae (fur seals and sea lions) and Phocidae (earless seals) for the 14 measurements, indicating the need for family-specific regression equations. The PIC analysis found that phylogeny had a minor influence on relationship between morphological variables and body size. The regressions for total length were more accurate than those for body mass, and equations specific to Otariidae were more accurate than those for Phocidae. Of the three multivariate methods, the all-subsets approach required the fewest number of variables to estimate body size accurately. We then used the single variable predictive equations and the all-subsets approach to estimate the body size of two recently extinct pinniped taxa, the Caribbean monk seal (Monachus tropicalis) and the Japanese sea lion (Zalophus japonicus). Body size estimates using single variable regressions generally under or over-estimated body size; however, the all-subset regression produced body size estimates that were close to historically recorded body length for these two species. This indicates that the all-subset regression equations developed in this study can estimate body size accurately. PMID:24916814
Searching for New Biomarkers and the Use of Multivariate Analysis in Gastric Cancer Diagnostics.

PubMed

Kucera, Radek; Smid, David; Topolcan, Ondrej; Karlikova, Marie; Fiala, Ondrej; Slouka, David; Skalicky, Tomas; Treska, Vladislav; Kulda, Vlastimil; Simanek, Vaclav; Safanda, Martin; Pesta, Martin

2016-04-01

The first aim of this study was to search for new biomarkers to be used in gastric cancer diagnostics. The second aim was to verify the findings presented in literature on a sample of the local population and investigate the risk of gastric cancer in that population using a multivariant statistical analysis. We assessed a group of 36 patients with gastric cancer and 69 healthy individuals. We determined carcinoembryonic antigen, cancer antigen 19-9, cancer antigen 72-4, matrix metalloproteinases (-1, -2, -7, -8 and -9), osteoprotegerin, osteopontin, prothrombin induced by vitamin K absence-II, pepsinogen I, pepsinogen II, gastrin and Helicobacter pylori for each sample. The multivariate stepwise logistic regression identified the following biomarkers as the best gastric cancer predictors: CEA, CA72-4, pepsinogen I, Helicobacter pylori presence and MMP7. CEA and CA72-4 remain the best markers for gastric cancer diagnostics. We suggest a mathematical model for the assessment of risk of gastric cancer. Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.
Methods for presentation and display of multivariate data

NASA Technical Reports Server (NTRS)

Myers, R. H.

1981-01-01

Methods for the presentation and display of multivariate data are discussed with emphasis placed on the multivariate analysis of variance problems and the Hotelling T(2) solution in the two-sample case. The methods utilize the concepts of stepwise discrimination analysis and the computation of partial correlation coefficients.
Generating linear regression model to predict motor functions by use of laser range finder during TUG.

PubMed

Adachi, Daiki; Nishiguchi, Shu; Fukutani, Naoto; Hotta, Takayuki; Tashiro, Yuto; Morino, Saori; Shirooka, Hidehiko; Nozaki, Yuma; Hirata, Hinako; Yamaguchi, Moe; Yorozu, Ayanori; Takahashi, Masaki; Aoyama, Tomoki

2017-05-01

The purpose of this study was to investigate which spatial and temporal parameters of the Timed Up and Go (TUG) test are associated with motor function in elderly individuals. This study included 99 community-dwelling women aged 72.9 ± 6.3 years. Step length, step width, single support time, variability of the aforementioned parameters, gait velocity, cadence, reaction time from starting signal to first step, and minimum distance between the foot and a marker placed to 3 in front of the chair were measured using our analysis system. The 10-m walk test, five times sit-to-stand (FTSTS) test, and one-leg standing (OLS) test were used to assess motor function. Stepwise multivariate linear regression analysis was used to determine which TUG test parameters were associated with each motor function test. Finally, we calculated a predictive model for each motor function test using each regression coefficient. In stepwise linear regression analysis, step length and cadence were significantly associated with the 10-m walk test, FTSTS and OLS test. Reaction time was associated with the FTSTS test, and step width was associated with the OLS test. Each predictive model showed a strong correlation with the 10-m walk test and OLS test (P < 0.01), which was not significant higher correlation than TUG test time. We showed which TUG test parameters were associated with each motor function test. Moreover, the TUG test time regarded as the lower extremity function and mobility has strong predictive ability in each motor function test. Copyright © 2017 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.
MULGRES: a computer program for stepwise multiple regression analysis

Treesearch

A. Jeff Martin

1971-01-01

MULGRES is a computer program source deck that is designed for multiple regression analysis employing the technique of stepwise deletion in the search for most significant variables. The features of the program, along with inputs and outputs, are briefly described, with a note on machine compatibility.
Comparison of Xenon-Enhanced Area-Detector CT and Krypton Ventilation SPECT/CT for Assessment of Pulmonary Functional Loss and Disease Severity in Smokers.

PubMed

Ohno, Yoshiharu; Fujisawa, Yasuko; Takenaka, Daisuke; Kaminaga, Shigeo; Seki, Shinichiro; Sugihara, Naoki; Yoshikawa, Takeshi

2018-02-01

The objective of this study was to compare the capability of xenon-enhanced area-detector CT (ADCT) performed with a subtraction technique and coregistered 81m Kr-ventilation SPECT/CT for the assessment of pulmonary functional loss and disease severity in smokers. Forty-six consecutive smokers (32 men and 14 women; mean age, 67.0 years) underwent prospective unenhanced and xenon-enhanced ADCT, 81m Kr-ventilation SPECT/CT, and pulmonary function tests. Disease severity was evaluated according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) classification. CT-based functional lung volume (FLV), the percentage of wall area to total airway area (WA%), and ventilated FLV on xenon-enhanced ADCT and SPECT/CT were calculated for each smoker. All indexes were correlated with percentage of forced expiratory volume in 1 second (%FEV 1 ) using step-wise regression analyses, and univariate and multivariate logistic regression analyses were performed. In addition, the diagnostic accuracy of the proposed model was compared with that of each radiologic index by means of McNemar analysis. Multivariate logistic regression showed that %FEV 1 was significantly affected (r = 0.77, r 2 = 0.59) by two factors: the first factor, ventilated FLV on xenon-enhanced ADCT (p < 0.0001); and the second factor, WA% (p = 0.004). Univariate logistic regression analyses indicated that all indexes significantly affected GOLD classification (p < 0.05). Multivariate logistic regression analyses revealed that ventilated FLV on xenon-enhanced ADCT and CT-based FLV significantly influenced GOLD classification (p < 0.0001). The diagnostic accuracy of the proposed model was significantly higher than that of ventilated FLV on SPECT/CT (p = 0.03) and WA% (p = 0.008). Xenon-enhanced ADCT is more effective than 81m Kr-ventilation SPECT/CT for the assessment of pulmonary functional loss and disease severity.
Application of near-infrared spectroscopy for the rapid quality assessment of Radix Paeoniae Rubra

NASA Astrophysics Data System (ADS)

Zhan, Hao; Fang, Jing; Tang, Liying; Yang, Hongjun; Li, Hua; Wang, Zhuju; Yang, Bin; Wu, Hongwei; Fu, Meihong

2017-08-01

Near-infrared (NIR) spectroscopy with multivariate analysis was used to quantify gallic acid, catechin, albiflorin, and paeoniflorin in Radix Paeoniae Rubra, and the feasibility to classify the samples originating from different areas was investigated. A new high-performance liquid chromatography method was developed and validated to analyze gallic acid, catechin, albiflorin, and paeoniflorin in Radix Paeoniae Rubra as the reference. Partial least squares (PLS), principal component regression (PCR), and stepwise multivariate linear regression (SMLR) were performed to calibrate the regression model. Different data pretreatments such as derivatives (1st and 2nd), multiplicative scatter correction, standard normal variate, Savitzky-Golay filter, and Norris derivative filter were applied to remove the systematic errors. The performance of the model was evaluated according to the root mean square of calibration (RMSEC), root mean square error of prediction (RMSEP), root mean square error of cross-validation (RMSECV), and correlation coefficient (r). The results show that compared to PCR and SMLR, PLS had a lower RMSEC, RMSECV, and RMSEP and higher r for all the four analytes. PLS coupled with proper pretreatments showed good performance in both the fitting and predicting results. Furthermore, the original areas of Radix Paeoniae Rubra samples were partly distinguished by principal component analysis. This study shows that NIR with PLS is a reliable, inexpensive, and rapid tool for the quality assessment of Radix Paeoniae Rubra.

A Latent-Variable Causal Model of Faculty Reputational Ratings.

ERIC Educational Resources Information Center

King, Suzanne; Wolfle, Lee M.

A reanalysis was conducted of Saunier's research (1985) on sources of variation in the National Research Council (NRC) reputational ratings of university faculty. Saunier conducted a stepwise regression analysis using 12 predictor variables. Due to problems with multicollinearity and because of the atheoretical nature of stepwise regression,…
A stepwise regression tree for nonlinear approximation: applications to estimating subpixel land cover

USGS Publications Warehouse

Huang, C.; Townshend, J.R.G.

2003-01-01

A stepwise regression tree (SRT) algorithm was developed for approximating complex nonlinear relationships. Based on the regression tree of Breiman et al . (BRT) and a stepwise linear regression (SLR) method, this algorithm represents an improvement over SLR in that it can approximate nonlinear relationships and over BRT in that it gives more realistic predictions. The applicability of this method to estimating subpixel forest was demonstrated using three test data sets, on all of which it gave more accurate predictions than SLR and BRT. SRT also generated more compact trees and performed better than or at least as well as BRT at all 10 equal forest proportion interval ranging from 0 to 100%. This method is appealing to estimating subpixel land cover over large areas.
Perception of self and significant others by alcoholics and nonalcoholics.

PubMed

Quereshi, M Y; Soat, D M

1976-01-01

Ratings of self and 15 significant others on four personality factors by 47 alcoholic and 90 nonalcoholic males were analyzed by means of step-wise regression analysis and multivariate analysis of covariance. Alcoholics rated themselves less positively on extraversion and self-assertiveness (lower mean on extraversion and higher on self-assertiveness) and also judged intimate others (father, mother, and spouse) less positively on unhappiness, extraversion, and productive persistence (higher mean on unhappiness and lower means on extraversion and productive persistence). There were no significant differences between the two groups in judging persons as a whole or in the degree of differentiation that was exhibited in rating all 16 persons including self.
Stone volume is best predictor of operative time required in retrograde intrarenal surgery for renal calculi: implications for surgical planning and quality improvement.

PubMed

Sorokin, Igor; Cardona-Grau, Diana K; Rehfuss, Alexandra; Birney, Alan; Stavrakis, Costas; Leinwand, Gabriel; Herr, Allen; Feustel, Paul J; White, Mark D

2016-11-01

Retrograde intrarenal surgery (RIRS) is highly successful at eliminating renal stones of various sizes and compositions. As urologists are taking on more complex procedures using RIRS, this has led to an increase in operative (OR) times. Our objective was to determine the best predictor of OR time in patients undergoing RIRS. We retrospectively reviewed the records of patients undergoing unilateral RIRS for solitary stones over a 10 year time span. Stones were fragmented and actively extracted using a basket. Variables potentially affecting OR time such as patient age, sex, BMI, lower pole stone location, volume, Hounsfield units (HU), composition, ureteral access sheath (UAS) use, and pre-operative stenting were collected. Multivariable linear and stepwise regression was used to evaluate the predictors of OR time. There were 118 patients that met inclusion criteria. The median stone volume was 282.6 mm 3 (IQR 150.7-644.7) and the mean OR time was 50 min (±25.9 SD). On univariate linear regression, stone volume had a moderate correlation with OR time (y = 0.022x + 38.2, r 2 = 0.363, p < 0.01). On multivariable stepwise regression, stone volume had the strongest impact on OR time, increasing time by 2.0 min for each 100 mm 3 increase in stone volume (p < 0.001). UAS added 13.5 (SE 3.9, p = 0.001) minutes and renal lower pole location added 9 min (SE 4.3, p = 0.03) in each case they were used. Pre-operative stenting, HU, calcium oxalate stone composition, sex, and age had no significant effect on OR time. Amongst the main stone factors in RIRS, stone volume has the strongest impact on operative time. This can be used to predict the length of the procedure by roughly adding 2 min per 100 mm 3 increase in stone volume.
A simple prognostic model for overall survival in metastatic renal cell carcinoma.

PubMed

Assi, Hazem I; Patenaude, Francois; Toumishey, Ethan; Ross, Laura; Abdelsalam, Mahmoud; Reiman, Tony

2016-01-01

The primary purpose of this study was to develop a simpler prognostic model to predict overall survival for patients treated for metastatic renal cell carcinoma (mRCC) by examining variables shown in the literature to be associated with survival. We conducted a retrospective analysis of patients treated for mRCC at two Canadian centres. All patients who started first-line treatment were included in the analysis. A multivariate Cox proportional hazards regression model was constructed using a stepwise procedure. Patients were assigned to risk groups depending on how many of the three risk factors from the final multivariate model they had. There were three risk factors in the final multivariate model: hemoglobin, prior nephrectomy, and time from diagnosis to treatment. Patients in the high-risk group (two or three risk factors) had a median survival of 5.9 months, while those in the intermediate-risk group (one risk factor) had a median survival of 16.2 months, and those in the low-risk group (no risk factors) had a median survival of 50.6 months. In multivariate analysis, shorter survival times were associated with hemoglobin below the lower limit of normal, absence of prior nephrectomy, and initiation of treatment within one year of diagnosis.
A simple prognostic model for overall survival in metastatic renal cell carcinoma

PubMed Central

Assi, Hazem I.; Patenaude, Francois; Toumishey, Ethan; Ross, Laura; Abdelsalam, Mahmoud; Reiman, Tony

2016-01-01

Introduction: The primary purpose of this study was to develop a simpler prognostic model to predict overall survival for patients treated for metastatic renal cell carcinoma (mRCC) by examining variables shown in the literature to be associated with survival. Methods: We conducted a retrospective analysis of patients treated for mRCC at two Canadian centres. All patients who started first-line treatment were included in the analysis. A multivariate Cox proportional hazards regression model was constructed using a stepwise procedure. Patients were assigned to risk groups depending on how many of the three risk factors from the final multivariate model they had. Results: There were three risk factors in the final multivariate model: hemoglobin, prior nephrectomy, and time from diagnosis to treatment. Patients in the high-risk group (two or three risk factors) had a median survival of 5.9 months, while those in the intermediate-risk group (one risk factor) had a median survival of 16.2 months, and those in the low-risk group (no risk factors) had a median survival of 50.6 months. Conclusions: In multivariate analysis, shorter survival times were associated with hemoglobin below the lower limit of normal, absence of prior nephrectomy, and initiation of treatment within one year of diagnosis. PMID:27217858
Developing Screening Services for Colorectal Cancer on Android Smartphones

PubMed Central

Wu, Hui-Ching; Chang, Chiao-Jung; Lin, Chun-Che; Tsai, Ming-Chang; Chang, Che-Chia

2014-01-01

Abstract Introduction: Colorectal cancer (CRC) is an important health problem in Western countries and also in Asia. It is the third leading cause of cancer deaths in both men and women in Taiwan. According to the well-known adenoma-to-carcinoma sequence, the majority of CRC develops from colorectal adenomatous polyps. This concept provides the rationale for screening and prevention of CRC. Removal of colorectal adenoma could reduce the mortality and incidence of CRC. Mobile phones are now playing an ever more crucial role in people's daily lives. The latest generation of smartphones is increasingly viewed as hand-held computers rather than as phones, because of their powerful on-board computing capability, capacious memories, large screens, and open operating systems that encourage development of applications (apps). Subjects and Methods: If we can detect the potential CRC patients early and offer them appropriate treatments and services, this would not only promote the quality of life, but also reduce the possible serious complications and medical costs. In this study, an intelligent CRC screening app on Android™ (Google™, Mountain View, CA) smartphones has been developed based on a data mining approach using decision tree algorithms. For comparison, the stepwise backward multivariate logistic regression model and the fecal occult blood test were also used. Results: Compared with the stepwise backward multivariate logistic regression model and the fecal occult blood test, the proposed app system not only provides an easy and efficient way to quickly detect high-risk groups of potential CRC patients, but also brings more information about CRC to customer-oriented services. Conclusions: We developed and implemented an app system on Android platforms for ubiquitous healthcare services for CRC screening. It can assist people in achieving early screening, diagnosis, and treatment purposes, prevent the occurrence of complications, and thus reach the goal of preventive medicine. PMID:24848873
Psychoactive substances use and associated factors among middle and high school students in the North Center of Morocco: a cross-sectional questionnaire survey.

PubMed

Zarrouq, B; Bendaou, B; El Asri, A; Achour, S; Rammouz, I; Aalouane, R; Lyoussi, B; Khelafa, S; Bout, A; Berhili, N; Hlal, H; Najdi, A; Nejjari, C; El Rhazi, K

2016-06-04

Data on psychoactive substance (PAS) consumption among adolescents in the North Center of Morocco are not at all available. Therefore, the current study aimed at investigating the prevalence and the determinants of psychoactive substances use among middle and high school students in this region. A cross-sectional study was conducted from April 2012 to November 2013 in public middle and high schools in the North Central Region of Morocco. An anonymous self-administered questionnaire was used to assess psychoactive substances use among a representative sample of school students from the 7th to the 12th grade, aged 11-23 years, selected by stratified cluster random sampling. Factors associated with psychoactive substance use were identified using multivariate stepwise logistic regression analyses. A total of 3020 school students completed the questionnaires, 53.0 % of which were males. The overall lifetime smoking prevalence was 16.1 %. The lifetime, annual and past month rates of any psychoactive substance use among the study subjects were 9.3, 7.5, and 6.3 % respectively. Cannabis recorded the highest lifetime prevalence of 8.1 %, followed by alcohol 4.3 %, inhalants 1.7 %, psychotropic substances without medical prescription 1.0, cocaine 0.7, heroine 0.3, and amphetamine with only 0.2 %. Psychoactive substance use was associated with males more than females. The risk factors identified by multivariate stepwise logistic regression analyses were being male, studying in secondary school level, smoking tobacco, living with a family member who uses tobacco, and feeling insecure within the family. The prevalence among all school students reported by the current study was comparable to the national prevalence. Efforts to initiate psychoactive substance prevention programs among school students should be made by designing such programs based on the significant factors associated with psychoactive substance use identified in this study.
Work disability in Argentinian patients with systemic lupus erythematosus is prevalent and it is due to ethnic, socioeconomic and disease-related factors.

PubMed

Pisoni, Cecilia N; Muñoz, Sebastián A; Tamborenea, María N; García, Mercedes; Curti, Ana; Cappuccio, Ana; Rillo, Oscar; Imamura, Patricia M; Schneeberger, Emilce; Ballent, Marcela; Cousseau, Mario L; Velasco Zamora, Jorge; Saurit, Verónica; Toloza, Sergio; Danielsen, María C; Bellomio, Verónica I; Graf, Cesar; Paira, Sergio; Cavallasca, Javier; Pons Estel, Bernardo; Moreno, José L C; Díaz, Mónica; Alba, Paula; Verando, Marcela; Tate, Guillermo; Mysler, Eduardo; Sarano, Judith; Civit, Emma E; Risueño, Fabián; Álvarez Sepúlveda, Pablo; Larroude, María S; Méndez, Marcos F; Conforti, Andrea; Sohn, Débora

2018-04-02

To study the prevalence and the associated factors of work disability (WD) in systemic lupus erythematosus (SLE) patients. A sample of 419 SLE patients from an observational cross-sectional multicenter study was included. Sociodemographic features, disease characteristics, comorbidities, quality of life, unhealthy behaviors, and work-related factors were measured in a standardized interview. Work disability was defined by patient self-report of not being able to work because of SLE. To identify variables associated with work disability, two different multivariate regression models using a stepwise backward method were performed. Prevalence of WD due to SLE was 24.3%. Eighty-nine percent were female and 51% were Caucasians. Mean disease duration was 8.9 ± 7.2 years, and median System Lupus International Collaborating Clinics/American College of Rheumatology damage index SLICC-SDI was 1.5 (range 0-17). In stepwise multivariate logistic regression, living below the poverty line (odds ratio [OR] = 4.65), less than 12 years of education (OR = 2.84), Mestizo ethnicity (OR = 1.94) and SLICC-SDI (OR = 1.25) were predictors of WD. A second model was performed including patient-derived measures; in this model sedentary lifestyle (OR = 2.69) and lower emotional health domain score of the Lupus Quality of Life (LupusQoL) questionnaire (OR = 1.03) were found to be associated to WD and a higher score in LupusQoL physical health domain (OR = 0.93) was protective. The prevalence of WD in Argentinian SLE patients was 24.3%. WD was associated with ethnic (Mestizo), socioeconomic (poverty) and disease-related factors. Patient-related outcomes such us sedentary lifestyle and poor emotional quality of life were also associated with WD. © 2018 Asia Pacific League of Associations for Rheumatology and John Wiley & Sons Australia, Ltd.
Variable selection with stepwise and best subset approaches

PubMed Central

2016-01-01

While purposeful selection is performed partly by software and partly by hand, the stepwise and best subset approaches are automatically performed by software. Two R functions stepAIC() and bestglm() are well designed for stepwise and best subset regression, respectively. The stepAIC() function begins with a full or null model, and methods for stepwise regression can be specified in the direction argument with character values “forward”, “backward” and “both”. The bestglm() function begins with a data frame containing explanatory variables and response variables. The response variable should be in the last column. Varieties of goodness-of-fit criteria can be specified in the IC argument. The Bayesian information criterion (BIC) usually results in more parsimonious model than the Akaike information criterion. PMID:27162786
Soil sail content estimation in the yellow river delta with satellite hyperspectral data

USGS Publications Warehouse

Weng, Yongling; Gong, Peng; Zhu, Zhi-Liang

2008-01-01

Soil salinization is one of the most common land degradation processes and is a severe environmental hazard. The primary objective of this study is to investigate the potential of predicting salt content in soils with hyperspectral data acquired with EO-1 Hyperion. Both partial least-squares regression (PLSR) and conventional multiple linear regression (MLR), such as stepwise regression (SWR), were tested as the prediction model. PLSR is commonly used to overcome the problem caused by high-dimensional and correlated predictors. Chemical analysis of 95 samples collected from the top layer of soils in the Yellow River delta area shows that salt content was high on average, and the dominant chemicals in the saline soil were NaCl and MgCl2. Multivariate models were established between soil contents and hyperspectral data. Our results indicate that the PLSR technique with laboratory spectral data has a strong prediction capacity. Spectral bands at 1487-1527, 1971-1991, 2032-2092, and 2163-2355 nm possessed large absolute values of regression coefficients, with the largest coefficient at 2203 nm. We obtained a root mean squared error (RMSE) for calibration (with 61 samples) of RMSEC = 0.753 (R2 = 0.893) and a root mean squared error for validation (with 30 samples) of RMSEV = 0.574. The prediction model was applied on a pixel-by-pixel basis to a Hyperion reflectance image to yield a quantitative surface distribution map of soil salt content. The result was validated successfully from 38 sampling points. We obtained an RMSE estimate of 1.037 (R2 = 0.784) for the soil salt content map derived by the PLSR model. The salinity map derived from the SWR model shows that the predicted value is higher than the true value. These results demonstrate that the PLSR method is a more suitable technique than stepwise regression for quantitative estimation of soil salt content in a large area. ?? 2008 CASI.
Improved model of the retardance in citric acid coated ferrofluids using stepwise regression

NASA Astrophysics Data System (ADS)

Lin, J. F.; Qiu, X. R.

2017-06-01

Citric acid (CA) coated Fe3O4 ferrofluids (FFs) have been conducted for biomedical application. The magneto-optical retardance of CA coated FFs was measured by a Stokes polarimeter. Optimization and multiple regression of retardance in FFs were executed by Taguchi method and Microsoft Excel previously, and the F value of regression model was large enough. However, the model executed by Excel was not systematic. Instead we adopted the stepwise regression to model the retardance of CA coated FFs. From the results of stepwise regression by MATLAB, the developed model had highly predictable ability owing to F of 2.55897e+7 and correlation coefficient of one. The average absolute error of predicted retardances to measured retardances was just 0.0044%. Using the genetic algorithm (GA) in MATLAB, the optimized parametric combination was determined as [4.709 0.12 39.998 70.006] corresponding to the pH of suspension, molar ratio of CA to Fe3O4, CA volume, and coating temperature. The maximum retardance was found as 31.712°, close to that obtained by evolutionary solver in Excel and a relative error of -0.013%. Above all, the stepwise regression method was successfully used to model the retardance of CA coated FFs, and the maximum global retardance was determined by the use of GA.
Predictors of Parent-Adolescent Communication in Post-apartheid South Africa: A Protective Factor in Adolescent Sexual and Reproductive Health

PubMed Central

Coetzee, Jenny; Dietrich, Janan; Otwombe, Kennedy; Nkala, Busi; Khunwane, Mamakiri; van der Watt, Martin; Sikkema, Kathleen J; Gray, Glenda E

2014-01-01

In the HIV context, risky sexual behaviours can be reduced through effective parent-adolescent communication. This study used the Parent Adolescent Communication Scale to determine parent-adolescent communication by ethnicity and identify predictors of high parent-adolescent communication amongst South African adolescents post-apartheid. A cross-sectional interviewer-administered survey was administered to 822 adolescents from Johannesburg, South Africa. Backward stepwise multivariate regressions were performed. The sample was predominantly Black African (62%, n=506) and female (57%, n=469). Of the participants, 57% (n=471) reported high parent-adolescent communication. Multivariate regression showed that gender was a significant predictor of high parent-adolescent communication (Black African OR:1.47,CI:1.0-2.17, Indian OR:2.67,CI:1.05-6.77, White OR:2.96,CI:1.21-7.18). Female-headed households were predictors of high parent-adolescent communication amongst Black Africans (OR:1.49,CI:1.01-2.20), but of low parent-adolescent communication amongst Whites (OR:0.36,CI: 0.15-0.89). Overall levels of parent-adolescent communication in South Africa are low. HIV prevention programmes for South African adolescents should include information and skills regarding effective parent-adolescent communication. PMID:24636691
Personal Well-being and Stress Symptoms in Wives of Iranian Martyrs, Prisoners of wars and Disabled Veterans

PubMed Central

Sharif, Nasim

2010-01-01

Objective This study was conducted to compare the personal well-being among the wives of Iranian veterans living in the city of Qom. Method A sample of 300 was randomly selected from a database containing the addresses of veteran's families at Iran's Veterans Foundation in Qom (Bonyad-e-Shahid va Omoore Isargaran). The veterans' wives were divided into three groups: wives of martyrs (killed veterans), wives of prisoners of war, and wives of disabled veterans. The Persian translation of Personal Well-being Index and Stress Symptoms Checklist (SSC) were administered for data collection. Four women chose not to respond to Personal Well-being Index. Data were then analyzed using linear multivariate regression (stepwise method), analysis of variance, and by computing the correlation between variables. Results Results showed a negative correlation between well-being and stress symptoms. However, each group demonstrated different levels of stress symptoms. Furthermore, multivariate linear regression in the 3 groups showed that overall satisfaction of life and personal well-being (total score and its domains) could be predicted by different symptoms. Conclusion Each group experienced different challenges and thus different stress symptoms. Therefore, although they all need help, each group needs to be helped in a different way. PMID:22952487
[Risk factors for anorexia in children].

PubMed

Liu, Wei-Xiao; Lang, Jun-Feng; Zhang, Qin-Feng

2016-11-01

To investigate the risk factors for anorexia in children, and to reduce the prevalence of anorexia in children. A questionnaire survey and a case-control study were used to collect the general information of 150 children with anorexia (case group) and 150 normal children (control group). Univariate analysis and multivariate logistic stepwise regression analysis were performed to identify the risk factors for anorexia in children. The results of the univariate analysis showed significant differences between the case and control groups in the age in months when supplementary food were added, feeding pattern, whether they liked meat, vegetables and salty food, whether they often took snacks and beverages, whether they liked to play while eating, and whether their parents asked them to eat food on time (P<0.05). The results of the multivariate logistic regression analysis showed that late addition of supplementary food (OR=5.408), high frequency of taking snacks and/or drinks (OR=11.813), and eating while playing (OR=6.654) were major risk factors for anorexia in children. Liking of meat (OR=0.093) and vegetables (OR=0.272) and eating on time required by parents (OR=0.079) were protective factors against anorexia in children. Timely addition of supplementary food, a proper diet, and development of children's proper eating and living habits can reduce the incidence of anorexia in children.
H. Pylori as a predictor of marginal ulceration: A nationwide analysis.

PubMed

Schulman, Allison R; Abougergi, Marwan S; Thompson, Christopher C

2017-03-01

Helicobacter pylori has been implicated as a risk factor for development of marginal ulceration following gastric bypass, although studies have been small and yielded conflicting results. This study sought to determine the relationship between H. pylori infection and development of marginal ulceration following bariatric surgery in a nationwide analysis. This was a retrospective cohort study using the 2012 Nationwide Inpatient Sample (NIS) database. Discharges with ICD-9-CM code indicating marginal ulceration and a secondary ICD-9-CM code for bariatric surgery were included. Primary outcome was incidence of marginal ulceration. A stepwise forward selection model was used to build the multivariate logistic regression model based on known risk factors. A P value of 0.05 was considered significant. There were 253,765 patients who met inclusion criteria. Prevalence of marginal ulceration was 3.90%. Of those patients found to have marginal ulceration, 31.20% of patients were H. pylori-positive. Final multivariate regression analysis revealed that H. pylori was the strongest independent predictor of marginal ulceration. H. pylori is an independent predictor of marginal ulceration using a large national database. Preoperative testing for and eradication of H. pylori prior to bariatric surgery may be an important preventive measure to reduce the incidence of ulcer development. © 2017 The Obesity Society.
A method for the selection of a functional form for a thermodynamic equation of state using weighted linear least squares stepwise regression

NASA Technical Reports Server (NTRS)

Jacobsen, R. T.; Stewart, R. B.; Crain, R. W., Jr.; Rose, G. L.; Myers, A. F.

1976-01-01

A method was developed for establishing a rational choice of the terms to be included in an equation of state with a large number of adjustable coefficients. The methods presented were developed for use in the determination of an equation of state for oxygen and nitrogen. However, a general application of the methods is possible in studies involving the determination of an optimum polynomial equation for fitting a large number of data points. The data considered in the least squares problem are experimental thermodynamic pressure-density-temperature data. Attention is given to a description of stepwise multiple regression and the use of stepwise regression in the determination of an equation of state for oxygen and nitrogen.
Factors Associated With Work Ability in Patients Undergoing Surgery for Cervical Radiculopathy.

PubMed

Ng, Eunice; Johnston, Venerina; Wibault, Johanna; Löfgren, Håkan; Dedering, Åsa; Öberg, Birgitta; Zsigmond, Peter; Peolsson, Anneli

2015-08-15

Cross-sectional study. To investigate the factors associated with work ability in patients undergoing surgery for cervical radiculopathy. Surgery is a common treatment of cervical radiculopathy in people of working age. However, few studies have investigated the impact on the work ability of these patients. Patients undergoing surgery for cervical radiculopathy (n = 201) were recruited from spine centers in Sweden to complete a battery of questionnaires and physical measures the day before surgery. The associations between various individual, psychological, and work-related factors and self-reported work ability were investigated by Spearman rank correlation coefficient, multivariate linear regression, and forward stepwise regression analyses. Factors that were significant (P < 0.05) in each statistical analysis were entered into the successive analysis to reveal the factors most related to work ability. Work ability was assessed using the Work Ability Index. The mean Work Ability Index score was 28 (SD, 9.0). The forward stepwise regression analysis revealed 6 factors significantly associated with work ability, which explained 62% of the variance in the Work Ability Index. Factors highly correlated with greater work ability included greater self-efficacy in performing self-cares, lower physical load on the neck at work, greater self-reported chance of being able to work in 6 months' time, greater use of active coping strategies, lower frequency of hand weakness, and higher health-related quality of life. Psychological, work-related and individual factors were significantly associated with work ability in patients undergoing surgery for cervical radiculopathy. High self-efficacy was most associated with greater work ability. Consideration of these factors by surgeons preoperatively may provide optimal return to work outcomes after surgery. 3.
The rate of adherence to urate-lowering therapy and associated factors in Chinese gout patients: a cross-sectional study.

PubMed

Yin, Rulan; Cao, Haixia; Fu, Ting; Zhang, Qiuxiang; Zhang, Lijuan; Li, Liren; Gu, Zhifeng

2017-07-01

The aim of this study was to assess adherence rate and predictors of non-adherence with urate-lowering therapy (ULT) in Chinese gout patients. A cross-sectional study was administered to 125 gout patients using the Compliance Questionnaire on Rheumatology (CQR) for adherence to ULT. Patients were asked to complete the Treatment Satisfaction Questionnaire for Medication version II, Health Assessment Questionnaire, Confidence in Gout Treatment Questionnaire, Gout Knowledge Questionnaire, Patient Health Questionnaire-9, Generalized Anxiety Disorder-7, and 36-Item Short Form Health Survey. Data were analyzed by independent sample t test, rank sum test, Chi-square analysis as well as binary stepwise logistic regression modeling. The data showed that the rate of adherence (CQR ≥80%) to ULT was 9.6% in our investigated gout patients. Adherence was associated with functional capacity, gout-related knowledge, satisfaction with medication, confidence in gout treatment and mental components summary. Multivariable analysis of binary stepwise logistic regression identified gout-related knowledge and satisfaction of effectiveness with medication was the independent risk factors of medication non-adherence. Patients unaware of gout-related knowledge, or with low satisfaction of effectiveness with medication, were more likely not to adhere to ULT. Non-adherence to ULT among gout patients is exceedingly common, particularly in patients unaware of gout-related knowledge, or with low satisfaction of effectiveness with medication. These findings could help medical personnel develop useful interventions to improve gout patients' medication adherence.
Relationships between temperaments, occupational stress, and insomnia among Japanese workers.

PubMed

Deguchi, Yasuhiko; Iwasaki, Shinichi; Ishimoto, Hideyuki; Ogawa, Koichiro; Fukuda, Yuichi; Nitta, Tomoko; Mitake, Tomoe; Nogi, Yukako; Inoue, Koki

2017-01-01

Insomnia among workers reduces the quality of life, contributes toward the economic burden of healthcare costs and losses in work performance. The relationship between occupational stress and insomnia has been reported in previous studies, but there has been little attention to temperament in occupational safety and health research. The aim of this study was to clarify the relationships between temperament, occupational stress, and insomnia. The subjects were 133 Japanese daytime local government employees. Temperament was assessed using the Temperament Evaluation of Memphis, Pisa, Paris, and San Diego-Auto questionnaire (TEMPS-A). Occupational stress was assessed using the Generic Job Stress Questionnaire (GJSQ). Insomnia was assessed using the Athens Insomnia Scale (AIS). Stepwise multiple logistic regression analyses were conducted. In a stepwise multivariate logistic regression analysis, it was found that the higher subdivided stress group by "role conflict" (OR = 5.29, 95% CI, 1.61-17.32) and anxious temperament score (OR = 1.33; 95% CI, 1.19-1.49) was associated with the presence of insomnia using an adjusted model, whereas other factors were excluded from the model. The study limitations were the sample size and the fact that only Japanese local government employees were surveyed. This study demonstrated the relationships between workers' anxious temperament, role conflict, and insomnia. Recognizing one's own anxious temperament would lead to self-insight, and the recognition of anxious temperament and reduction of role conflict by their supervisors or coworkers would reduce the prevalence of insomnia among workers in the workplace.

Behavioral activation: Is it the expectation or achievement, of mastery or pleasure that contributes to improvement in depression?

PubMed

Furukawa, Toshi A; Imai, Hissei; Horikoshi, Masaru; Shimodera, Shinji; Hiroe, Takahiro; Funayama, Tadashi; Akechi, Tatsuo

2018-06-06

Behavioral activation (BA) is receiving renewed interest as a stand-alone or as a component of cognitive-behavior therapy (CBT) for depression. However, few studies have examined which aspects of BA are most contributory to its efficacy. This is a secondary analysis of a 9-week randomized controlled trial of smartphone CBT for patients with major depression. Depression severity was measured at baseline and at end of treatment by the Patient Health Questionnaire-9. All aspects of behavioral activation tasks that the participants had engaged in, including their expected mastery and pleasure and obtained mastery and pleasure, were recorded in the web server. We examined their contribution to improvement in depression as simple correlations and in stepwise multivariable linear regression. Among the 78 patients who completed at least one behavioral experiment, all aspects of expected or achieved mastery or pleasure correlated with change in depression severity. Discrepancy between the expectation and achievement, representing unexpected gain in mastery or pleasure, was not correlated. In stepwise regression, expected mastery and pleasure, especially the maximum level of the latter, emerged as the strongest contributing factors. The study is observational and cannot deduce cause-effect relationships. It may be the expected and continued sense of pleasure in planning activities that are most meaningful and rewarding to individuals, and not the simple level or amount of obtained pleasure, that contributes to the efficacy of BA. Copyright © 2018. Published by Elsevier B.V.
Relationships between temperaments, occupational stress, and insomnia among Japanese workers

PubMed Central

Ishimoto, Hideyuki; Ogawa, Koichiro; Fukuda, Yuichi; Nitta, Tomoko; Mitake, Tomoe; Nogi, Yukako; Inoue, Koki

2017-01-01

Insomnia among workers reduces the quality of life, contributes toward the economic burden of healthcare costs and losses in work performance. The relationship between occupational stress and insomnia has been reported in previous studies, but there has been little attention to temperament in occupational safety and health research. The aim of this study was to clarify the relationships between temperament, occupational stress, and insomnia. The subjects were 133 Japanese daytime local government employees. Temperament was assessed using the Temperament Evaluation of Memphis, Pisa, Paris, and San Diego-Auto questionnaire (TEMPS-A). Occupational stress was assessed using the Generic Job Stress Questionnaire (GJSQ). Insomnia was assessed using the Athens Insomnia Scale (AIS). Stepwise multiple logistic regression analyses were conducted. In a stepwise multivariate logistic regression analysis, it was found that the higher subdivided stress group by “role conflict” (OR = 5.29, 95% CI, 1.61–17.32) and anxious temperament score (OR = 1.33; 95% CI, 1.19–1.49) was associated with the presence of insomnia using an adjusted model, whereas other factors were excluded from the model. The study limitations were the sample size and the fact that only Japanese local government employees were surveyed. This study demonstrated the relationships between workers’ anxious temperament, role conflict, and insomnia. Recognizing one’s own anxious temperament would lead to self-insight, and the recognition of anxious temperament and reduction of role conflict by their supervisors or coworkers would reduce the prevalence of insomnia among workers in the workplace. PMID:28407025
Is patriarchy the source of men's higher mortality?

PubMed Central

Stanistreet, D; Bambra, C; Scott-Samuel, A

2005-01-01

Objective: To examine the relation between levels of patriarchy and male health by comparing female homicide rates with male mortality within countries. Hypothesis: High levels of patriarchy in a society are associated with increased mortality among men. Design: Cross sectional ecological study design. Setting: 51 countries from four continents were represented in the data—America, Europe, Australasia, and Asia. No data were available for Africa. Results: A multivariate stepwise linear regression model was used. Main outcome measure was age standardised male mortality rates for 51 countries for the year 1995. Age standardised female homicide rates and GDP per capita ranking were the explanatory variables in the model. Results were also adjusted for the effects of general rates of homicide. Age standardised female homicide rates and ranking of GDP were strongly correlated with age standardised male mortality rates (Pearson's r = 0.699 and Spearman's 0.744 respectively) and both correlations achieved significance (p<0.005). Both factors were subsequently included in the stepwise regression model. Female homicide rates explained 48.8% of the variance in male mortality, and GDP a further 13.6% showing that the higher the rate of female homicide, and hence the greater the indicator of patriarchy, the higher is the rate of mortality among men. Conclusion: These data suggest that oppression and exploitation harm the oppressors as well as those they oppress, and that men's higher mortality is a preventable social condition, which could be tackled through global social policy measures. PMID:16166362
Sexual dimorphism of the mandible in a contemporary Chinese Han population.

PubMed

Dong, Hongmei; Deng, Mohong; Wang, WenPeng; Zhang, Ji; Mu, Jiao; Zhu, Guanghui

2015-10-01

A present limitation of forensic anthropology practice in China is the lack of population-specific criteria on contemporary human skeletons. In this study, a sample of 203 maxillofacial Cone beam computed tomography (CBCT) images, including 96 male and 107 female cases (20-65 years old), was analyzed to explore mandible sexual dimorphism in a population of contemporary adult Han Chinese to investigate the potential use of the mandible as sex indicator. A three-dimensional image from mandible CBCT scans was reconstructed using the SimPlant Pro 11.40 software. Nine linear and two angular parameters were measured. Discriminant function analysis (DFA) and logistic regression analysis (LRA) were used to develop the mathematics models for sex determination. All of the linear measurements studied and one angular measurement were found to be sexually dimorphic, with the maximum mandibular length and bi-condylar breadth being the most dimorphic by univariate DFA and LRA respectively. The cross-validated sex allocation accuracies on multivariate were ranged from 84.2% (direct DFA), 83.5% (direct LRA), 83.3% (stepwise DFA) to 80.5% (stepwise LRA). In general, multivariate DFA yielded a higher accuracy and LRA obtained a lower sex bias, and therefore both DFA and LRA had their own advantages for sex determination by the mandible in this sample. These results suggest that the mandible expresses sexual dimorphism in the contemporary adult Han Chinese population, indicating an excellent sexual discriminatory ability. Cone beam computed tomography scanning can be used as alternative source for contemporary osteometric techniques. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
Dancing with the Muses: dissociation and flow.

PubMed

Thomson, Paula; Jaque, S Victoria

2012-01-01

This study investigated dissociative psychological processes and flow (dispositional and state) in a group of professional and pre-professional dancers (n=74). In this study, high scores for global (Mdn=4.14) and autotelic (Mdn=4.50) flow suggest that dancing was inherently integrating and rewarding, although 17.6% of the dancers were identified as possibly having clinical levels of dissociation (Dissociative Experiences Scale-Taxon cutoff score≥20). The results of the multivariate analysis of variance indicated that subjects with high levels of dissociation had significantly lower levels of global flow (p<.05). Stepwise linear regression analyses demonstrated that dispositional flow negatively predicted the dissociative constructs of depersonalization and taxon (p<.05) but did not significantly predict the variance in absorption/imagination (p>.05). As hypothesized, dissociation and flow seem to operate as different mental processes.
Predictors of parent-adolescent communication in post-apartheid South Africa: a protective factor in adolescent sexual and reproductive health.

PubMed

Coetzee, Jenny; Dietrich, Janan; Otwombe, Kennedy; Nkala, Busi; Khunwane, Mamakiri; van der Watt, Martin; Sikkema, Kathleen J; Gray, Glenda E

2014-04-01

In the HIV context, risky sexual behaviours can be reduced through effective parent-adolescent communication. This study used the Parent Adolescent Communication Scale to determine parent-adolescent communication by ethnicity and identify predictors of high parent-adolescent communication amongst South African adolescents post-apartheid. A cross-sectional interviewer-administered survey was administered to 822 adolescents from Johannesburg, South Africa. Backward stepwise multivariate regressions were performed. The sample was predominantly Black African (62%, n = 506) and female (57%, n = 469). Of the participants, 57% (n = 471) reported high parent-adolescent communication. Multivariate regression showed that gender was a significant predictor of high parent-adolescent communication (Black African OR:1.47, CI: 1.0-2.17, Indian OR: 2.67, CI: 1.05-6.77, White OR: 2.96, CI: 1.21-7.18). Female-headed households were predictors of high parent-adolescent communication amongst Black Africans (OR:1.49, CI: 1.01-2.20), but of low parent-adolescent communication amongst Whites (OR:0.36, CI: 0.15-0.89). Overall levels of parent-adolescent communication in South Africa are low. HIV prevention programmes for South African adolescents should include information and skills regarding effective parent-adolescent communication. Copyright © 2014 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.
The association of corporate work environment factors, health risks, and medical conditions with presenteeism among Australian employees.

PubMed

Musich, Shirley; Hook, Dan; Baaner, Stephanie; Spooner, Michelle; Edington, Dee W

2006-01-01

To investigate the impact of selected corporate environment factors, health risks, and medical conditions on job performance using a self-reported measure of presenteeism. A cross-sectional survey utilizing health risk appraisal (HRA) data merging presenteeism with corporate environment factors, health risks, and medical conditions. Approximately 8000 employees across ten diverse Australian corporations. Employees (N = 1523; participation rate, 19%) who completed an HRA questionnaire. Self-reported HRA data were used to test associations of defined adverse corporate environment factors with presenteeism. Stepwise multivariate logistic regression modeling assessed the relative associations of corporate environment factors, health risks, and medical conditions with increased odds of any presenteeism. Increased presenteeism was significantly associated with poor working conditions, ineffective management/leadership, and work/life imbalance (adjusting for age, gender, health risks, and medical conditions). In multivariate logistic regression models, work/life imbalance, poor working conditions, life dissatisfaction, high stress, back pain, allergies, and younger age were significantly associated with presenteeism. Although the study has some limitations, including a possible response bias caused by the relatively low participation rate across the corporations, the study does demonstrate significant associations between corporate environment factors, health risks, and medical conditions and self-reported presenteeism. The study provides initial evidence that health management programming may benefit on-the-job productivity outcomes if expanded to include interventions targeting work environments.
Timescale dependence of environmental controls on methane efflux from Poyang Hu, China

NASA Astrophysics Data System (ADS)

Liu, Lixiang; Xu, Ming; Li, Renqiang; Shao, Rui

2017-04-01

Lakes are an important natural source of CH4 to the atmosphere. However, the multi-seasonal CH4 efflux from lakes has been rarely studied. In this study, the CH4 efflux from Poyang Hu, the largest freshwater lake in China, was measured monthly over a 4-year period by using the floating-chamber technique. The mean annual CH4 efflux throughout the 4 years was 0.54 mmol m-2 day-1, ranging from 0.47 to 0.60 mmol m-2 day-1. The CH4 efflux had a high seasonal variation with an average summer (June to August) efflux of 1.34 mmol m-2 day-1 and winter (December to February) efflux of merely 0.18 mmol m-2 day-1. The efflux showed no apparent diel pattern, although most of the peak effluxes appeared in the late morning, from 10:00 to 12:00 CST (GMT + 8). Multivariate stepwise regression on a seasonal scale showed that environmental factors, such as sediment temperature, sediment total nitrogen content, dissolved oxygen, and total phosphorus content in the water, mainly regulated the CH4 efflux. However, the CH4 efflux only showed a strong positive linear correlation with wind speed within 1 day on a bihourly scale in the multivariate regression analyses but almost no correlation with wind speed on diurnal and seasonal scales.
Multivariate assessment of subjective and objective measures of social and family satisfaction in Veterans with history of traumatic brain injury.

PubMed

Orff, Henry J; Hays, Chelsea C; Twamley, Elizabeth W

2016-01-01

Approximately 20% of current-era Veterans have sustained a traumatic brain injury (TBI), which can result in persistent postconcussive symptoms. These symptoms may disrupt family and social functioning. We explored psychiatric, postconcussive, and cognitive factors as correlates of objective functioning and subjective satisfaction in family and social relationships. At entry into a supported employment study, 50 unemployed Veterans with a history of mild to moderate TBI and current cognitive impairment were administered baseline assessments. Multivariate stepwise regressions determined that higher levels of depressive symptomatology were strongly associated with less frequent social contact, as well as lower subjective satisfaction with family and social relationships. Worse verbal fluency predicted less frequent social contact, whereas worse processing speed and switching predicted higher levels of subjective satisfaction with family relationships. The pattern of results remained similar when examining those Veterans with only mild TBI. Depressive symptoms and cognitive functioning may impact Veterans' social contact and satisfaction with family and social relationships. Evidence-based interventions addressing depression and cognition may therefore aid in improving community reintegration and satisfaction with social and family relationships.
Risk factors for highly pathogenic avian influenza in commercial layer chicken farms in bangladesh during 2011.

PubMed

Osmani, M G; Thornton, R N; Dhand, N K; Hoque, M A; Milon, Sk M A; Kalam, M A; Hossain, M; Yamage, M

2014-12-01

A case-control study conducted during 2011 involved 90 randomly selected commercial layer farms infected with highly pathogenic avian influenza type A subtype H5N1 (HPAI) and 175 control farms randomly selected from within 5 km of infected farms. A questionnaire was designed to obtain information about potential risk factors for contracting HPAI and was administered to farm owners or managers. Logistic regression analyses were conducted to identify significant risk factors. A total of 20 of 43 risk factors for contracting HPAI were identified after univariable logistic regression analysis. A multivariable logistic regression model was derived by forward stepwise selection. Both unmatched and matched analyses were performed. The key risk factors identified were numbers of staff, frequency of veterinary visits, presence of village chickens roaming on the farm and staff trading birds. Aggregating these findings with those from other studies resulted in a list of 16 key risk factors identified in Bangladesh. Most of these related to biosecurity. It is considered feasible for Bangladesh to achieve a very low incidence of HPAI. Using the cumulative list of risk factors to enhance biosecurity pertaining to commercial farms would facilitate this objective. © 2013 Blackwell Verlag GmbH.
Monitoring heavy metal Cr in soil based on hyperspectral data using regression analysis

NASA Astrophysics Data System (ADS)

Zhang, Ningyu; Xu, Fuyun; Zhuang, Shidong; He, Changwei

2016-10-01

Heavy metal pollution in soils is one of the most critical problems in the global ecology and environment safety nowadays. Hyperspectral remote sensing and its application is capable of high speed, low cost, less risk and less damage, and provides a good method for detecting heavy metals in soil. This paper proposed a new idea of applying regression analysis of stepwise multiple regression between the spectral data and monitoring the amount of heavy metal Cr by sample points in soil for environmental protection. In the measurement, a FieldSpec HandHeld spectroradiometer is used to collect reflectance spectra of sample points over the wavelength range of 325-1075 nm. Then the spectral data measured by the spectroradiometer is preprocessed to reduced the influence of the external factors, and the preprocessed methods include first-order differential equation, second-order differential equation and continuum removal method. The algorithms of stepwise multiple regression are established accordingly, and the accuracy of each equation is tested. The results showed that the accuracy of first-order differential equation works best, which makes it feasible to predict the content of heavy metal Cr by using stepwise multiple regression.
Differentiation of infiltrative cholangiocarcinoma from benign common bile duct stricture using three-dimensional dynamic contrast-enhanced MRI with MRCP.

PubMed

Yu, X-R; Huang, W-Y; Zhang, B-Y; Li, H-Q; Geng, D-Y

2014-06-01

To retrospectively evaluate the criteria for discriminating infiltrative cholangiocarcinoma from benign common bile duct (CBD) stricture using three-dimensional dynamic contrast-enhanced (3D-DCE) magnetic resonance imaging (MRI) combined with magnetic resonance cholangiopancreatography (MRCP) imaging and to determine the predictors for cholangiocarcinoma versus benign CBD stricture. 3D-DCE MRI and MRCP images in 28 patients with infiltrative cholangiocarcinoma and 23 patients with benign causes of CBD stricture were reviewed retrospectively. The final diagnosis was based on surgical or biopsy records. Two radiologists analysed the MRI images for asymmetry, including the wall thickness, length, and enhancement pattern of the narrowed CBD segment, and upstream CBD dilatation. MRI findings that could be used as predictors were identified by univariate analysis and multivariable stepwise logistic regression analysis. Malignant strictures were significantly thicker (4.4 ± 1.2 mm) and longer (16.7 ± 7.7 mm) than the benign strictures (p < 0.05), and upstream CBD dilatation was larger in the infiltrative cholangiocarcinoma cases (20.7 ± 5.7 mm) than in the benign cases (16.5 ± 5.2 mm; p = 0.018). During both the portal venous and equilibrium phases, hyperenhancement was more frequently observed in malignant cases than in benign cases (p < 0.001). The results of the multivariable stepwise logistic regression analysis showed that both hyperenhancement of the involved CBD during the equilibrium phase and the ductal thickness were significant predictors for malignant strictures. When two diagnostic predictive values were used in combination, almost all patients with malignant strictures (n = 26, 92.9%) and benign strictures (n = 21, 91.3%) were correctly identified; the overall accuracy was 92.2% with correct classifications in 47 of the 51 patients. Infiltrative cholangiocarcinoma and benign CBD strictures could be effectively differentiated using DCE-MRI and MRCP based on hyperenhancement during the equilibrium phase and bile wall thickness of the involved segment. Copyright © 2014 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.
Association of serum orosomucoid with 30-min plasma glucose and glucose excursion during oral glucose tolerance tests in non-obese young Japanese women.

PubMed

Tsuboi, Ayaka; Minato, Satomi; Yano, Megumu; Takeuchi, Mika; Kitaoka, Kaori; Kurata, Miki; Yoshino, Gen; Wu, Bin; Kazumi, Tsutomu; Fukuo, Keisuke

2018-01-01

Inflammatory markers are elevated in insulin resistance (IR) and diabetes. We tested whether serum orosomucoid (ORM) is associated with postload glucose, β-cell dysfunction and IR inferred from plasma insulin kinetics during a 75 g oral glucose tolerance test (OGTT). 75 g OGTTs were performed with multiple postload glucose and insulin measurements over a 30-120 min period in 168 non-obese Japanese women (aged 18-24 years). OGTT responses, serum adiponectin and high-sensitivity C reactive protein (hsCRP) were cross-sectionally analyzed by analysis of variance and then Bonferroni's multiple comparison procedure. Stepwise multivariate linear regression analyses were used to identify most important determinants of ORM. Of 168 women, 161 had normal glucose tolerance. Postload glucose levels and the area under the glucose curve (AUCg) increased in a stepwise fashion from the first through the third ORM tertile. In contrast, there was no or modest, if any, association with fat mass index, trunk/leg fat ratio, adiponectin, hsCRP, postload insulinemia, the Matsuda index and homeostasis model assessment IR. In multivariable models, which incorporated the insulinogenic index, the Matsuda index and HOMA-IR, 30 min glucose (standardized β: 0.517) and AUCg (standardized β: 0.495) explained 92.8% of ORM variations. Elevated circulating orosomucoid was associated with elevated 30 min glucose and glucose excursion in non-obese young Japanese women independently of adiposity, IR, insulin secretion, adiponectin and other investigated markers of inflammation. Although further research is needed, these results may suggest a clue to identify novel pathways that may have utility in monitoring dysglycemia within normal glucose tolerance.
The relation of digital vascular function to cardiovascular risk factors in African-Americans using digital tonometry: the Jackson Heart Study.

PubMed

McClendon, Eric E; Musani, Solomon K; Samdarshi, Tandaw E; Khaire, Sushant; Stokes, Donny; Hamburg, Naomi M; Sheffy, Koby; Mitchell, Gary F; Taylor, Herman R; Benjamin, Emelia J; Fox, Ervin R

2017-06-01

Digital vascular tone and function, as measured by peripheral arterial tonometry (PAT), are associated with cardiovascular risk and events in non-Hispanic whites. There are limited data on relations between PAT and cardiovascular risk in African-Americans. PAT was performed on a subset of Jackson Heart Study participants using a fingertip tonometry device. Resting digital vascular tone was assessed as baseline pulse amplitude. Hyperemic vascular response to 5 minutes of ischemia was expressed as the PAT ratio (hyperemic/baseline amplitude ratio). Peripheral augmentation index (AI), a measure of relative wave reflection, also was estimated. The association of baseline pulse amplitude (PA), PAT ratio, and AI to risk factors was assessed using stepwise multivariable models. The study sample consisted of 837 participants from the Jackson Heart Study (mean age, 54 ± 11 years; 61% women). In stepwise multivariable regression models, baseline pulse amplitude was related to male sex, body mass index, and diastolic blood pressure (BP), accounting for 16% of the total variability of the baseline pulse amplitude. Age, male sex, systolic BP, diastolic BP, antihypertensive medication, and prevalent cardiovascular disease contributed to 11% of the total variability of the PAT ratio. Risk factors (primarily age, sex, and heart rate) explained 47% of the total variability of the AI. We confirmed in our cohort of African-Americans, a significant relation between digital vascular tone and function measured by PAT and multiple traditional cardiovascular risk factors. Further studies are warranted to investigate the utility of these measurements in predicting clinical outcomes in African-Americans. Copyright © 2017 American Society of Hypertension. Published by Elsevier Inc. All rights reserved.
Modeling Governance KB with CATPCA to Overcome Multicollinearity in the Logistic Regression

NASA Astrophysics Data System (ADS)

Khikmah, L.; Wijayanto, H.; Syafitri, U. D.

2017-04-01

The problem often encounters in logistic regression modeling are multicollinearity problems. Data that have multicollinearity between explanatory variables with the result in the estimation of parameters to be bias. Besides, the multicollinearity will result in error in the classification. In general, to overcome multicollinearity in regression used stepwise regression. They are also another method to overcome multicollinearity which involves all variable for prediction. That is Principal Component Analysis (PCA). However, classical PCA in only for numeric data. Its data are categorical, one method to solve the problems is Categorical Principal Component Analysis (CATPCA). Data were used in this research were a part of data Demographic and Population Survey Indonesia (IDHS) 2012. This research focuses on the characteristic of women of using the contraceptive methods. Classification results evaluated using Area Under Curve (AUC) values. The higher the AUC value, the better. Based on AUC values, the classification of the contraceptive method using stepwise method (58.66%) is better than the logistic regression model (57.39%) and CATPCA (57.39%). Evaluation of the results of logistic regression using sensitivity, shows the opposite where CATPCA method (99.79%) is better than logistic regression method (92.43%) and stepwise (92.05%). Therefore in this study focuses on major class classification (using a contraceptive method), then the selected model is CATPCA because it can raise the level of the major class model accuracy.
Predictive factors for rebleeding and death in alcoholic cirrhotic patients with acute variceal bleeding: a multivariate analysis.

PubMed

Krige, Jake E J; Kotze, Urda K; Distiller, Greg; Shaw, John M; Bornman, Philippus C

2009-10-01

Bleeding from esophageal varices is a leading cause of death in alcoholic cirrhotic patients. The aim of the present single-center study was to identify risk factors predictive of variceal rebleeding and death within 6 weeks of initial treatment. Univariate and multivariate analyses were performed on 310 prospectively documented alcoholic cirrhotic patients with acute variceal hemorrhage (AVH) who underwent 786 endoscopic variceal injection treatments between January 1984 and December 2006. All injections were administered during the first 6 weeks after the patients were treated for their first variceal bleed. Seventy-five (24.2%) patients experienced a rebleed, 38 within 5 days of the initial treatment and 37 within 6 weeks of their initial treatment. Of the 15 variables studied and included in a multivariate analysis using a logistic regression model, a bilirubin level >51 mmol/l and transfusion of >6 units of blood during the initial hospital admission were predictors of variceal rebleeding within the first 6 weeks. Seventy-seven (24.8%) patients died, 29 (9.3%) within 5 days and 48 (15.4%) between 6 and 42 days after the initial treatment. Stepwise multivariate logistic regression analysis showed that six variables were predictors of death within the first 6 weeks: encephalopathy, ascites, bilirubin level >51 mmol/l, international normalized ratio (INR) >2.3, albumin <25 g/l, and the need for balloon tube tamponade. Survival was influenced by the severity of liver failure, with most deaths occurring in Child-Pugh grade C patients. Patients with AVH and encephalopathy, ascites, bilirubin levels >51 mmol/l, INR >2.3, albumin <25 g/l and who require balloon tube tamponade are at increased risk of dying within the first 6 weeks. Bilirubin levels >51 mmol/l and transfusion of >6 units of blood were predictors of variceal rebleeding.
Correlates of consistent condom use among men who have sex with men recruited through the Internet in Huzhou city: a cross-sectional survey.

PubMed

Jin, Meihua; Yang, Zhongrong; Dong, Zhengquan; Han, Jiankang

2013-12-01

There is growing evidence that men who have sex with men (MSM) are currently a group at high risk of HIV infection in China. Our study aims to know the factors affecting consistent condom use among MSM recruited through the internet in Huzhou city. An anonymous cross-sectional study was conducted by recruiting 410 MSM living in Huzhou city via the Internet. The socio-demographic profiles (age, education level, employment status, etc.) and sexual risk behaviors of the respondents were investigated. Bivariate logistic regression analyses were performed to compare the differences between consistent condom users and inconsistent condom users. Variables with significant bivariate between groups' differences were used as candidate variables in a stepwise multivariate logistic regression model. All statistical analyses were performed using SPSS for Windows 17.0, and a p value < 0.05 was considered to be statistically significant. According to their condom use, sixty-eight respondents were classified into two groups. One is consistent condom users, and the other is inconsistent condom users. Multivariate logistic regression showed that respondents who had a comprehensive knowledge of HIV (OR = 4.08, 95% CI: 1.85-8.99), who had sex with male sex workers (OR = 15.30, 95% CI: 5.89-39.75) and who had not drunk alcohol before sex (OR = 3.10, 95% CI: 1.38-6.95) were more likely to be consistent condom users. Consistent condom use among MSM was associated with comprehensive knowledge of HIV and a lack of alcohol use before sexual contact. As a result, reducing alcohol consumption and enhancing education regarding the risks of HIV among sexually active MSM would be effective in preventing of HIV transmission.
Predictors of Depression in Youth With Crohn Disease

PubMed Central

Clark, Jeffrey G.; Srinath, Arvind I.; Youk, Ada O.; Kirshner, Margaret A.; McCarthy, F. Nicole; Keljo, David J.; Bousvaros, Athos; DeMaso, David R.; Szigethy, Eva M.

2014-01-01

Objective The aim of the study was to determine whether infliximab use and other potential predictors are associated with decreased prevalence and severity of depression in pediatric patients with Crohn disease (CD). Methods A total of 550 (n = 550) youth ages 9 to 17 years with biopsy-confirmed CD were consecutively recruited as part of a multicenter randomized controlled trial. Out of the 550, 499 patients met study criteria and were included in the analysis. At recruitment, each subject and a parent completed the Children’s Depression Inventory (CDI). A child or parent CDI score ≥ 12 was used to denote clinically significant depressive symptoms (CSDS). Child and parent CDI scores were summed to form total CDI (CDIT). Infliximab use, demographic information, steroid use, laboratory values, and Pediatric Crohn’s Disease Activity Index (PCDAI) were collected as the potential predictors of depression. Univariate regression models were constructed to determine the relations among predictors, CSDS, and CDIT. Stepwise multivariate regression models were constructed to predict the relation between infliximab use and depression while controlling for other predictors of depression. Results Infliximab use was not associated with a decreased proportion of CSDS and CDIT after adjusting for multiple comparisons. CSDS and CDIT were positively associated with PCDAI, erythrocyte sedimentation rate, and steroid dose (P<0.01) and negatively associated with socioeconomic status (SES) (P<0.001). In multivariate models, PCDAI and SES were the strongest predictors of depression. Conclusions Disease activity and SES are significant predictors of depression in youth with Crohn disease. PMID:24343281
Factors Impacting Growth in Infants with Single Ventricle Physiology: A Report from Pediatric Heart Network Infant Single Ventricle Trial

PubMed Central

Williams, Richard V.; Zak, Victor; Ravishankar, Chitra; Altmann, Karen; Anderson, Jeffrey; Atz, Andrew M.; Dunbar-Masterson, Carolyn; Ghanayem, Nancy; Lambert, Linda; Lurito, Karen; Medoff-Cooper, Barbara; Margossian, Renee; Pemberton, Victoria L.; Russell, Jennifer; Stylianou, Mario; Hsu, Daphne

2011-01-01

Objectives To describe growth patterns in infants with single ventricle physiology and determine factors influencing growth. Study design Data from 230 subjects enrolled in the Pediatric Heart Network Infant Single Ventricle Enalapril Trial were used to assess factors influencing change in weight-for-age z-score (Δz) from study enrollment (0.7 ± 0.4 months) to pre-superior cavopulmonary connection (SCPC) (5.1 ± 1.8 months, period 1), and pre-SCPC to final study visit (14.1 ± 0.9 months, period 2). Predictor variables included patient characteristics, feeding regimen, clinical center, and medical factors during neonatal (period 1) and SCPC hospitalizations (period 2). Univariate regression analysis was performed, followed by backward stepwise regression and bootstrapping reliability to inform a final multivariable model. Results Weights were available for 197/230 subjects for period 1 and 173/197 for period 2. For period 1, greater gestational age, younger age at study enrollment, tube feeding at neonatal discharge, and clinical center were associated with a greater negative Δz (poorer growth) in multivariable modeling (adjusted R2 = 0.39, p < 0.001). For period 2, younger age at SCPC and greater daily caloric intake were associated with greater positive Δz (better growth) (R2 = 0.10, p = 0.002). Conclusions Aggressive nutritional support and earlier SCPC are modifiable factors associated with a favorable change in weight-for-age z-score. PMID:21784436
PREOPERATIVE MRI IMPROVES PREDICTION OF EXTENSIVE OCCULT AXILLARY LYMPH NODE METASTASES IN BREAST CANCER PATIENTS WITH A POSITIVE SENTINEL LYMPH NODE BIOPSY

PubMed Central

Loiselle, Christopher; Eby, Peter R.; Kim, Janice N.; Calhoun, Kristine E.; Allison, Kimberly H.; Gadi, Vijayakrishna K.; Peacock, Sue; Storer, Barry; Mankoff, David A.; Partridge, Savannah C.; Lehman, Constance D.

2014-01-01

Rationale and Objectives To test the ability of quantitative measures from preoperative Dynamic Contrast Enhanced MRI (DCE-MRI) to predict, independently and/or with the Katz pathologic nomogram, which breast cancer patients with a positive sentinel lymph node biopsy will have ≥ 4 positive axillary lymph nodes upon completion axillary dissection. Methods and Materials A retrospective review was conducted to identify clinically node-negative invasive breast cancer patients who underwent preoperative DCE-MRI, followed by sentinel node biopsy with positive findings and complete axillary dissection (6/2005 – 1/2010). Clinical/pathologic factors, primary lesion size and quantitative DCE-MRI kinetics were collected from clinical records and prospective databases. DCE-MRI parameters with univariate significance (p < 0.05) to predict ≥ 4 positive axillary nodes were modeled with stepwise regression and compared to the Katz nomogram alone and to a combined MRI-Katz nomogram model. Results Ninety-eight patients with 99 positive sentinel biopsies met study criteria. Stepwise regression identified DCE-MRI total persistent enhancement and volume adjusted peak enhancement as significant predictors of ≥4 metastatic nodes. Receiver operating characteristic (ROC) curves demonstrated an area under the curve (AUC) of 0.78 for the Katz nomogram, 0.79 for the DCE-MRI multivariate model, and 0.87 for the combined MRI-Katz model. The combined model was significantly more predictive than the Katz nomogram alone (p = 0.003). Conclusion Integration of DCE-MRI primary lesion kinetics significantly improved the Katz pathologic nomogram accuracy to predict presence of metastases in ≥ 4 nodes. DCE-MRI may help identify sentinel node positive patients requiring further localregional therapy. PMID:24331270

Correlation of P-wave dispersion with insulin sensitivity in obese adolescents.

PubMed

Sert, Ahmet; Aslan, Eyup; Buyukınan, Muammer; Pirgon, Ozgur

2017-03-01

P-wave dispersion is a new and simple electrocardiographic marker that has been reported to be associated with inhomogeneous and discontinuous propagation of sinus impulses. In the present study, we evaluated P-wave dispersion in obese adolescents and investigated the relationship between P-wave dispersion, cardiovascular risk factors, and echocardiographic parameters. We carried out a case-control study comparing 150 obese adolescents and 50 healthy controls. Maximum and minimum P-wave durations were measured using a 12-lead surface electrocardiogram, and P-wave dispersion was calculated as the difference between these two measures. Echocardiographic examination was also performed for each subject. Multivariate linear regression analysis with stepwise variable selection was used to evaluate parameters associated with increased P-wave dispersion in obese subjects. Maximum P-wave duration and P-wave dispersion were significantly higher in obese adolescents than control subjects (143±19 ms versus 117±20 ms and 49±15 ms versus 29±9 ms, p<0.0001 for both). P-wave dispersion was positively correlated with body mass index, waist and hip circumferences, systolic and diastolic blood pressures, total cholesterol, serum levels of low-density lipoprotein cholesterol, triglycerides, glucose, and insulin, homoeostasis model assessment for insulin resistance score, left ventricular mass, and left atrial dimension. P-wave dispersion was negatively correlated with high-density lipoprotein cholesterol levels. By multiple stepwise regression analysis, left atrial dimension (β: 0.252, p=0.008) and homoeostasis model assessment for insulin resistance (β: 0.205; p=0.009) were independently associated with increased P-wave dispersion in obese adolescents. Insulin resistance is a significant, independent predictor of P-wave dispersion in obese adolescents.
Complex interaction between symptoms, social factors, and gender in social functioning in a community-dwelling sample of schizophrenia.

PubMed

Vila-Rodriguez, F; Ochoa, S; Autonell, J; Usall, J; Haro, J M

2011-12-01

Social functioning (SF) is the ultimate target aimed in treatment plans in schizophrenia, thus it is critical to know what are the factors that determine SF. Gender is a well-established variable influencing SF, yet it is not known how social variables and symptoms interact in schizophrenia patients. Furthermore, it remains unclear whether the interaction between social variables and symptoms is different in men compared to women. Our aim is to test whether social variables are better predictors of SF in community-dwelled individuals with schizophrenia, and whether men and women differ in how symptoms and social variables interact to impact SF. Community-dwelling individuals with schizophrenia (N = 231) were randomly selected from a register. Participants were assessed with symptom measures (PANSS), performance-based social scale (LSP), objective social and demographic variables. Stratification by gender and stepwise multivariate regression analyses by gender were used to find the best-fitting models that predict SF in both gender. Men had poorer SF than women in spite of showing similar symptom scores. On stepwise regression analyses, gender was the main variable explaining SF, with a significant contribution by disorganized and excitatory symptoms. Age of onset made a less marked, yet significant, contribution to explain SF. When the sample was stratified by gender, disorganized symptoms and 'Income' variable entered the model and accounted for a 30.8% of the SF variance in women. On the other hand, positive and disorganized symptoms entered the model and accounted for a 36.1% of the SF variance in men. Community-dwelling men and women with schizophrenia differ in the constellation of variables associated with SF. Symptom scores still account for most of the variance in SF in both genders.
Regression and multivariate models for predicting particulate matter concentration level.

PubMed

Nazif, Amina; Mohammed, Nurul Izma; Malakahmad, Amirhossein; Abualqumboz, Motasem S

2018-01-01

The devastating health effects of particulate matter (PM 10 ) exposure by susceptible populace has made it necessary to evaluate PM 10 pollution. Meteorological parameters and seasonal variation increases PM 10 concentration levels, especially in areas that have multiple anthropogenic activities. Hence, stepwise regression (SR), multiple linear regression (MLR) and principal component regression (PCR) analyses were used to analyse daily average PM 10 concentration levels. The analyses were carried out using daily average PM 10 concentration, temperature, humidity, wind speed and wind direction data from 2006 to 2010. The data was from an industrial air quality monitoring station in Malaysia. The SR analysis established that meteorological parameters had less influence on PM 10 concentration levels having coefficient of determination (R 2 ) result from 23 to 29% based on seasoned and unseasoned analysis. While, the result of the prediction analysis showed that PCR models had a better R 2 result than MLR methods. The results for the analyses based on both seasoned and unseasoned data established that MLR models had R 2 result from 0.50 to 0.60. While, PCR models had R 2 result from 0.66 to 0.89. In addition, the validation analysis using 2016 data also recognised that the PCR model outperformed the MLR model, with the PCR model for the seasoned analysis having the best result. These analyses will aid in achieving sustainable air quality management strategies.
Differences in temperament, character and psychopathology among subjects with different patterns of cannabis use.

PubMed

Spalletta, Gianfranco; Bria, Pietro; Caltagirone, Carlo

2007-01-01

Patients who use illicit drugs and suffer from comorbid psychiatric illnesses have worse outcomes than drug users without a dual diagnosis. For this reason we aimed at identifying predictors of cannabis use severity using a multivariate model in which different clinical and socio-demographic variables were included. We administered the Temperament and Character Inventory, SCID-P, SCID-II, the Beck Depression Inventory and the State-Trait Anxiety Inventory. Of the 84 subjects included, 25 were occasional users, 37 were abusers, and 22 were dependent on cannabis. A stepwise multiple regression analysis identified increased self-transcendence scores and state anxiety severity as the only predictors of a increased cannabis use severity (F = 6.635; d.f. = 2, 81; p = 0.0021). In particular, in a further multivariate analysis of variance, the transpersonal identification issue of self-transcendence was associated significantly (F = 4.267; d.f. = 2, 81; p = 0.017) with greater severity of cannabis use. Character dimension of self-transcendence and symptoms of state anxiety should be taken into consideration during the assessment procedure of patients with cannabis use as they may be helpful in the discrimination of cannabis use severity.
Pharmacy Student Attitudes and Willingness to Engage in Care with People Living with HIV/AIDS

PubMed Central

Furtek, Kari J.; Malladi, Ruthvik; Ng, Eric; Zhou, Maria

2016-01-01

Objective. To describe the extent to which pharmacy students hold negative attitudes toward people living with HIV/AIDS (PLWHA) and to determine whether background variables, student knowledge, and professional attitudes may affect willingness to care for PLWHA. Methods. An online survey tool was developed and administered to 150 pharmacy students in their third professional year. Descriptive and stepwise multivariate regressions were performed. Results. While descriptive results showed a majority of respondents had favorable professional attitudes towards caring for PLWHA, most pharmacy students expressed discomfort with specific attitudes about being in close physical contact and receiving selected services from PLWHA. Multivariate results revealed that: (1) being a minority predicted greater knowledge; (2) having received prior HIV instruction and greater HIV knowledge predicted more positive professional attitudes caring for PLWHA; (3) being more socially liberal, having more positive professional attitudes caring for PLWHA, and having greater empathy towards PLWHA predicted student willingness to provide services. Conclusion. Future educational interventions specifically targeted toward socially conservative whites may impact greater student willingness to care for PLWHA. Additional research should also explore the generalizability of the present findings and modeling to pharmacy students in other regions of the country. PMID:27170816
Exploring the facilitators and barriers to engagement in physical activity for people with multiple sclerosis.

PubMed

Kayes, Nicola M; McPherson, Kathryn M; Schluter, Philip; Taylor, Denise; Leete, Marta; Kolt, Gregory S

2011-01-01

To explore the relationship that cognitive behavioural and other previously identified variables have with physical activity engagement in people with multiple sclerosis (MS). This study adopted a cross-sectional questionnaire design. Participants were 282 individuals with MS. Outcome measures included the Physical Activity Disability Survey--Revised, Cognitive and Behavioural Responses to Symptoms Questionnaire, Barriers to Health Promoting Activities for Disabled Persons Scale, Multiple Sclerosis Self-efficacy Scale, Self-Efficacy for Chronic Diseases Scales and Chalder Fatigue Questionnaire. Multivariable stepwise regression analyses found that greater self-efficacy, greater reported mental fatigue and lower number of perceived barriers to physical activity accounted for a significant proportion of variance in physical activity behaviour, over that accounted for by illness-related variables. Although fear-avoidance beliefs accounted for a significant proportion of variance in the initial analyses, its effect was explained by other factors in the final multivariable analyses. Self-efficacy, mental fatigue and perceived barriers to physical activity are potentially modifiable variables which could be incorporated into interventions designed to improve physical activity engagement. Future research should explore whether a measurement tool tailored to capture beliefs about physical activity identified by people with MS would better predict participation in physical activity.
A regression-kriging model for estimation of rainfall in the Laohahe basin

NASA Astrophysics Data System (ADS)

Wang, Hong; Ren, Li L.; Liu, Gao H.

2009-10-01

This paper presents a multivariate geostatistical algorithm called regression-kriging (RK) for predicting the spatial distribution of rainfall by incorporating five topographic/geographic factors of latitude, longitude, altitude, slope and aspect. The technique is illustrated using rainfall data collected at 52 rain gauges from the Laohahe basis in northeast China during 1986-2005 . Rainfall data from 44 stations were selected for modeling and the remaining 8 stations were used for model validation. To eliminate multicollinearity, the five explanatory factors were first transformed using factor analysis with three Principal Components (PCs) extracted. The rainfall data were then fitted using step-wise regression and residuals interpolated using SK. The regression coefficients were estimated by generalized least squares (GLS), which takes the spatial heteroskedasticity between rainfall and PCs into account. Finally, the rainfall prediction based on RK was compared with that predicted from ordinary kriging (OK) and ordinary least squares (OLS) multiple regression (MR). For correlated topographic factors are taken into account, RK improves the efficiency of predictions. RK achieved a lower relative root mean square error (RMSE) (44.67%) than MR (49.23%) and OK (73.60%) and a lower bias than MR and OK (23.82 versus 30.89 and 32.15 mm) for annual rainfall. It is much more effective for the wet season than for the dry season. RK is suitable for estimation of rainfall in areas where there are no stations nearby and where topography has a major influence on rainfall.
Serum magnesium but not calcium was associated with hemorrhagic transformation in stroke overall and stroke subtypes: a case-control study in China.

PubMed

Tan, Ge; Yuan, Ruozhen; Wei, ChenChen; Xu, Mangmang; Liu, Ming

2018-05-26

Association between serum calcium and magnesium versus hemorrhagic transformation (HT) remains to be identified. A total of 1212 non-thrombolysis patients with serum calcium and magnesium collected within 24 h from stroke onset were enrolled. Backward stepwise multivariate logistic regression analysis was conducted to investigate association between calcium and magnesium versus HT. Calcium and magnesium were entered into logistic regression analysis in two models, separately: model 1, as continuous variable (per 1-mmol/L increase), and model 2, as four-categorized variable (being collapsed into quartiles). HT occurred in 140 patients (11.6%). Serum calcium was slightly lower in patients with HT than in patient without HT (P = 0.273). But serum magnesium was significantly lower in patients with HT than in patients without HT (P = 0.007). In logistic regression analysis, calcium displayed no association with HT. Magnesium, as either continuous or four-categorized variable, was independently and inversely associated with HT in stroke overall and stroke of large-artery atherosclerosis (LAA). The results demonstrated that serum calcium had no association with HT in patients without thrombolysis after acute ischemic stroke. Serum magnesium in low level was independently associated with increasing HT in stroke overall and particularly in stroke of LAA.
A Statistical Discrimination Experiment for Eurasian Events Using a Twenty-Seven-Station Network

DTIC Science & Technology

1980-07-08

to test the effectiveness of a multivariate method of analysis for distinguishing earthquakes from explosions. The data base for the experiment...to test the effectiveness of a multivariate method of analysis for distinguishing earthquakes from explosions. The data base for the experiment...the weight assigned to each variable whenever a new one is added. Jennrich, R. I. (1977). Stepwise discriminant analysis , in Statistical Methods for
Clinical and laboratory factors associated with mortality in dengue.

PubMed

Saroch, Atul; Arya, Vivek; Sinha, Nitin; Taneja, R S; Sahai, Pooja; Mahajan, R K

2017-04-01

Dengue is endemic in more than 100 countries, giving rise to an increased number of deaths in the last five years in the South-East Asian region. We report our findings from a retrospective study of adults admitted with confirmed dengue at our institution. We studied the clinical and laboratory parameters associated with mortality in these patients. Of the 172 hospitalised patients studied, 156 (90.69 %) recovered while 16 (9.3%) died. Univariate analysis showed altered sensorium on presentation, lower haemoglobin and haematocrit levels, higher serum creatinine, higher serum transaminase and lower serum albumin levels to be significantly associated with mortality in dengue. Further, using stepwise multivariate logistic regression, altered sensorium ( P = 0.006) and hypoalbuminemia ( P = 0.013) were identified as independent predictors of mortality in dengue. Identification of these parameters early in the course of disease should prompt intensification of treatment in dengue cases.
Stepwise versus Hierarchical Regression: Pros and Cons

ERIC Educational Resources Information Center

Lewis, Mitzi

2007-01-01

Multiple regression is commonly used in social and behavioral data analysis. In multiple regression contexts, researchers are very often interested in determining the "best" predictors in the analysis. This focus may stem from a need to identify those predictors that are supportive of theory. Alternatively, the researcher may simply be interested…
Predictive factors for postoperative visual function of primary chronic rhegmatogenous retinal detachment after scleral buckling.

PubMed

Fang, Wei; Li, Jiu-Ke; Jin, Xiao-Hong; Dai, Yuan-Min; Li, Yu-Min

2016-01-01

To evaluate predictive factors for postoperative visual function of primary chronic rhegmatgenous retinal detachment (RRD) after sclera buckling (SB). Totally 48 patients (51 eyes) with primary chronic RRD were included in this prospective interventional clinical cases study, which underwent SB alone from June 2008 to December 2014. Age, sex, symptoms duration, detached extension, retinal hole position, size, type, fovea on/off, proliferative vitreoretinopathy (PVR), posterior vitreous detachment (PVD), baseline best corrected visual acuity (BCVA), operative duration, follow up duration, final BCVA were measured. Pearson correlation analysis, Spearman correlation analysis and multivariate linear stepwise regression were used to confirm predictive factors for better final visual acuity. Student's t-test, Wilcoxon two-sample test, Chi-square test and logistic stepwise regression were used to confirm predictive factors for better vision improvement. Baseline BCVA was 0.8313±0.6911 logMAR and final BCVA was 0.4761±0.4956 logMAR. Primary surgical success rate was 92.16% (47/51). Correlation analyses revealed shorter symptoms duration (r=0.3850, P=0.0053), less detached area (r=0.5489, P<0.0001), fovea (r=0.4605, P=0.0007), no PVR (r=0.3138, P=0.0250), better baseline BCVA (r=0.7291, P<0.0001), shorter operative duration (r=0.3233, P=0.0207) and longer follow up (r=-0.3358, P=0.0160) were related with better final BCVA, while independent predictive factors were better baseline BCVA [partial R-square (PR(2))=0.5316, P<0.0001], shorter symptoms duration (PR(2)=0.0609, P=0.0101), longer follow up duration (PR(2)=0.0278, P=0.0477) and shorter operative duration (PR(2)=0.0338, P=0.0350). Patients with vision improvement took up 49.02% (25/51). Univariate and multivariate analyses both revealed predictive factors for better vision improvement were better baseline vision [odds ratio (OR) =50.369, P=0.0041] and longer follow up duration (OR=1.144, P=0.0067). Independent predictive factors for better visual outcome of primary chronic RRD after SB are better baseline BCVA, shorter symptoms duration, shorter operative duration and longer follow up duration, while independent predictive factors for better vision improvement after operation are better baseline vision and longer follow up duration.
Pre-Stroke Weight Loss is Associated with Post-Stroke Mortality among Men in the Honolulu-Asia Aging Study

PubMed Central

Bell, Christina L.; Rantanen, Taina; Chen, Randi; Davis, James; Petrovitch, Helen; Ross, G. Webster; Masaki, Kamal

2013-01-01

Objective To examine baseline pre-stroke weight loss and post-stroke mortality among men. Design Longitudinal study of late-life pre-stroke body mass index (BMI), weight loss and BMI change (midlife to late-life), with up to 8-year incident stroke and mortality follow-up. Setting Honolulu Heart Program/Honolulu-Asia Aging Study. Participants 3,581 Japanese-American men aged 71–93 years and stroke-free at baseline. Main Outcome Measure Post-stroke Mortality: 30-day post-stroke, analyzed with stepwise multivariable logistic regression and long-term post-stroke (up to 8-year), analyzed with stepwise multivariable Cox regression. Results Weight loss (10-pound decrements) was associated with increased 30-day post-stroke mortality (aOR=1.48, 95%CI 1.14–1.92), long-term mortality after incident stroke (all types n=225, aHR=1.25, 95%CI=1.09–1.44) and long-term mortality after incident thromboembolic stroke (n=153, aHR 1.19, 95%CI-1.01–1.40). Men with overweight/obese late-life BMI (≥25kg/m2, compared to normal/underweight BMI) had increased long-term mortality after incident hemorrhagic stroke (n=54, aHR=2.27, 95%CI=1.07–4.82). Neither desirable nor excessive BMI reductions (vs. no change/increased BMI) were associated with post-stroke mortality. In the overall sample (n=3,581), nutrition factors associated with increased long-term mortality included 1) weight loss (10-pound decrements, aHR=1.15, 1.09–1.21); 2) underweight BMI (vs. normal BMI, aHR=1.76, 1.40–2.20); and 3) both desirable and excessive BMI reductions (vs. no change or gain, separate model from weight loss and BMI, aHRs=1.36–1.97, p<0.001). Conclusions Although obesity is a risk factor for stroke incidence, pre-stroke weight loss was associated with increased post-stroke (all types and thromboembolic) mortality. Overweight/obese late-life BMI was associated with increased post-hemorrhagic stroke mortality. Desirable and excessive BMI reductions were not associated with post-stroke mortality. Weight loss, underweight late-life BMI and any BMI reduction were all associated with increased long-term mortality in the overall sample. PMID:24113337
A Hybrid Approach of Stepwise Regression, Logistic Regression, Support Vector Machine, and Decision Tree for Forecasting Fraudulent Financial Statements

PubMed Central

Goo, Yeong-Jia James; Shen, Zone-De

2014-01-01

As the fraudulent financial statement of an enterprise is increasingly serious with each passing day, establishing a valid forecasting fraudulent financial statement model of an enterprise has become an important question for academic research and financial practice. After screening the important variables using the stepwise regression, the study also matches the logistic regression, support vector machine, and decision tree to construct the classification models to make a comparison. The study adopts financial and nonfinancial variables to assist in establishment of the forecasting fraudulent financial statement model. Research objects are the companies to which the fraudulent and nonfraudulent financial statement happened between years 1998 to 2012. The findings are that financial and nonfinancial information are effectively used to distinguish the fraudulent financial statement, and decision tree C5.0 has the best classification effect 85.71%. PMID:25302338
A hybrid approach of stepwise regression, logistic regression, support vector machine, and decision tree for forecasting fraudulent financial statements.

PubMed

Chen, Suduan; Goo, Yeong-Jia James; Shen, Zone-De

2014-01-01

As the fraudulent financial statement of an enterprise is increasingly serious with each passing day, establishing a valid forecasting fraudulent financial statement model of an enterprise has become an important question for academic research and financial practice. After screening the important variables using the stepwise regression, the study also matches the logistic regression, support vector machine, and decision tree to construct the classification models to make a comparison. The study adopts financial and nonfinancial variables to assist in establishment of the forecasting fraudulent financial statement model. Research objects are the companies to which the fraudulent and nonfraudulent financial statement happened between years 1998 to 2012. The findings are that financial and nonfinancial information are effectively used to distinguish the fraudulent financial statement, and decision tree C5.0 has the best classification effect 85.71%.
Risk factors for displaced abomasum or ketosis in Swedish dairy herds.

PubMed

Stengärde, L; Hultgren, J; Tråvén, M; Holtenius, K; Emanuelson, U

2012-03-01

Risk factors associated with high or low long-term incidence of displaced abomasum (DA) or clinical ketosis were studied in 60 Swedish dairy herds, using multivariable logistic regression modelling. Forty high-incidence herds were included as cases and 20 low-incidence herds as controls. Incidence rates were calculated based on veterinary records of clinical diagnoses. During the 3-year period preceding the herd classification, herds with a high incidence had a disease incidence of DA or clinical ketosis above the 3rd quartile in a national database for disease recordings. Control herds had no cows with DA or clinical ketosis. All herds were visited during the housing period and herdsmen were interviewed about management routines, housing, feeding, milk yield, and herd health. Target groups were heifers in late gestation, dry cows, and cows in early lactation. Univariable logistic regression was used to screen for factors associated with being a high-incidence herd. A multivariable logistic regression model was built using stepwise regression. A higher maximum daily milk yield in multiparous cows and a large herd size (p=0.054 and p=0.066, respectively) tended to be associated with being a high-incidence herd. Not cleaning the heifer feeding platform daily increased the odds of having a high-incidence herd twelvefold (p<0.01). Keeping cows in only one group in the dry period increased the odds of having a high incidence herd eightfold (p=0.03). Herd size was confounded with housing system. Housing system was therefore added to the final logistic regression model. In conclusion, a large herd size, a high maximum daily milk yield, keeping dry cows in one group, and not cleaning the feeding platform daily appear to be important risk factors for a high incidence of DA or clinical ketosis in Swedish dairy herds. These results confirm the importance of housing, management and feeding in the prevention of metabolic disorders in dairy cows around parturition and in early lactation. Copyright © 2011 Elsevier B.V. All rights reserved.
Effect of injection augmentation on need for framework surgery in unilateral vocal fold paralysis.

PubMed

Francis, David O; Williamson, Kelly; Hovis, Kristen; Gelbard, Alexander; Merati, Albert L; Penson, David F; Netterville, James L; Garrett, C Gaelyn

2016-01-01

To determine whether injection augmentation reduces the likelihood of ultimately needing definitive framework surgery in unilateral vocal fold paralysis (UVFP) patients. Retrospective cohort study. All patients diagnosed with UVFP (2008-2012) at the academic center were identified. The time from symptom onset to presentation to either community otolaryngologist and/or academic center, as well as any directed treatment(s), were recorded. Stepwise, multivariate logistic regression analysis was used to determine whether injection augmentation independently affected odds of needing definitive, framework surgery among patients who were seen within 9 months of symptom onset and had not undergone any prior rehabilitative procedures. Cohort consisted of 633 patients (55% female, 80% Caucasian, median age 60 years) with UVFP. The majority of etiologies were either surgery (48%) or idiopathic (37%). Duration to presentation at community otolaryngologist was shorter than to the academic center (median 2 vs. 6 months). Overall, less than half of UVFP patients had any operation (46%). Multivariate logistic regression found that earlier injection augmentation did not affect odds of ultimately undergoing framework surgery (odds ratio 1.13; confidence interval, 0.92-1.40; P = 0.23). Nearly half of UVFP patients do not require any rehabilitative procedure. When indicated, early injection augmentation is effective at temporarily alleviating associated symptoms but does not reduce likelihood of needing a definitive framework operation in patients with UVFP. Understanding practice patterns and fostering early detection and treatment may improve quality of life in this patient population. © 2015 The American Laryngological, Rhinological and Otological Society, Inc.
Radiographic absence of the posterior communicating arteries and the prediction of cognitive dysfunction after carotid endarterectomy.

PubMed

Sussman, Eric S; Kellner, Christopher P; Mergeche, Joanna L; Bruce, Samuel S; McDowell, Michael M; Heyer, Eric J; Connolly, E Sander

2014-09-01

Approximately 25% of patients exhibit cognitive dysfunction 24 hours after carotid endarterectomy (CEA). One of the purported mechanisms of early cognitive dysfunction (eCD) is hypoperfusion due to inadequate collateral circulation during cross-clamping of the carotid artery. The authors assessed whether poor collateral circulation within the circle of Willis, as determined by preoperative CT angiography (CTA) or MR angiography (MRA), could predict eCD. Patients who underwent CEA after preoperative MRA or CTA imaging and full neuropsychometric evaluation were included in this study (n = 42); 4 patients were excluded due to intraoperative electroencephalographic changes and subsequent shunt placement. Thirty-eight patients were included in the statistical analyses. Patients were stratified according to posterior communicating artery (PCoA) status (radiographic visualization of at least 1 PCoA vs of no PCoAs). Variables with p < 0.20 in univariate analyses were included in a stepwise multivariate logistic regression model to identify predictors of eCD after CEA. Overall, 23.7% of patients exhibited eCD. In the final multivariate logistic regression model, radiographic absence of both PCoAs was the only independent predictor of eCD (OR 9.64, 95% CI 1.43-64.92, p = 0.02). The absence of both PCoAs on preoperative radiographic imaging is predictive of eCD after CEA. This finding supports the evidence for an underlying ischemic etiology of eCD. Larger studies are justified to verify the findings of this study. Clinical trial registration no.: NCT00597883 ( http://www.clinicaltrials.gov ).
Multivariate Analysis of Factors Affecting Presence and/or Agenesis of Third Molar Tooth

PubMed Central

Alam, Mohammad Khursheed; Hamza, Muhammad Asyraf; Khafiz, Muhammad Aizuddin; Rahman, Shaifulizan Abdul; Shaari, Ramizu; Hassan, Akram

2014-01-01

To investigate the presence and/or agenesis of third molar (M3) tooth germs in orthodontics patients in Malaysian Malay and Chinese population and evaluate the relationship between presence and/or agenesis of M3 with different skeletal malocclusion patterns and sagittal maxillomandibular jaw dimensions. Pretreatment records of 300 orthodontic patients (140 males and 160 females, 219 Malaysian Malay and 81 Chinese, average age was 16.27±4.59) were used. Third-molar agenesis was calculated with respect to race, genders, number of missing teeth, jaws, skeletal malocclusion patterns and sagittal maxillomandibular jaw dimensions. The Pearson chi-square test and ANOVA was performed to determine potential differences. Associations between various factors and M3 presence/agenesis groups were assessed using logistic regression analysis. The percentages of subjects with 1 or more M3 agenesis were 30%, 33% and 31% in the Malaysian Malay, Chinese and total population, respectively. Overall prevalence of M3 agenesis in male and female was equal (P>0.05). The frequency of the agenesis of M3s is greater in maxilla as well in the right side (P>0.05). The prevalence of M3 agenesis in those with a Class III and Class II malocclusion was relatively higher in Malaysian Malay and Malaysian Chinese population respectively. Using stepwise regression analyses, significant associations were found between Mx (P<0.05) and ANB (P<0.05) and M3 agenesis. This multivariate analysis suggested that Mx and ANB were significantly correlated with the M3 presence/agenesis. PMID:24967595
The association between temperature and mortality in tropical middle income Thailand from 1999 to 2008

NASA Astrophysics Data System (ADS)

Tawatsupa, Benjawan; Dear, Keith; Kjellstrom, Tord; Sleigh, Adrian

2014-03-01

We have investigated the association between tropical weather condition and age-sex adjusted death rates (ADR) in Thailand over a 10-year period from 1999 to 2008. Population, mortality, weather and air pollution data were obtained from four national databases. Alternating multivariable fractional polynomial (MFP) regression and stepwise multivariable linear regression analysis were used to sequentially build models of the associations between temperature variable and deaths, adjusted for the effects and interactions of age, sex, weather (6 variables), and air pollution (10 variables). The associations are explored and compared among three seasons (cold, hot and wet months) and four weather zones of Thailand (the North, Northeast, Central, and South regions). We found statistically significant associations between temperature and mortality in Thailand. The maximum temperature is the most important variable in predicting mortality. Overall, the association is nonlinear U-shape and 31 °C is the minimum-mortality temperature in Thailand. The death rates increase when maximum temperature increase with the highest rates in the North and Central during hot months. The final equation used in this study allowed estimation of the impact of a 4 °C increase in temperature as projected for Thailand by 2100; this analysis revealed that the heat-related deaths will increase more than the cold-related deaths avoided in the hot and wet months, and overall the net increase in expected mortality by region ranges from 5 to 13 % unless preventive measures were adopted. Overall, these results are useful for health impact assessment for the present situation and future public health implication of global climate change for tropical Thailand.

A stepwise model to predict monthly streamflow

NASA Astrophysics Data System (ADS)

Mahmood Al-Juboori, Anas; Guven, Aytac

2016-12-01

In this study, a stepwise model empowered with genetic programming is developed to predict the monthly flows of Hurman River in Turkey and Diyalah and Lesser Zab Rivers in Iraq. The model divides the monthly flow data to twelve intervals representing the number of months in a year. The flow of a month, t is considered as a function of the antecedent month's flow (t - 1) and it is predicted by multiplying the antecedent monthly flow by a constant value called K. The optimum value of K is obtained by a stepwise procedure which employs Gene Expression Programming (GEP) and Nonlinear Generalized Reduced Gradient Optimization (NGRGO) as alternative to traditional nonlinear regression technique. The degree of determination and root mean squared error are used to evaluate the performance of the proposed models. The results of the proposed model are compared with the conventional Markovian and Auto Regressive Integrated Moving Average (ARIMA) models based on observed monthly flow data. The comparison results based on five different statistic measures show that the proposed stepwise model performed better than Markovian model and ARIMA model. The R2 values of the proposed model range between 0.81 and 0.92 for the three rivers in this study.
An investigation of correlation between pilot scanning behavior and workload using stepwise regression analysis

NASA Technical Reports Server (NTRS)

Waller, M. C.

1976-01-01

An electro-optical device called an oculometer which tracks a subject's lookpoint as a time function has been used to collect data in a real-time simulation study of instrument landing system (ILS) approaches. The data describing the scanning behavior of a pilot during the instrument approaches have been analyzed by use of a stepwise regression analysis technique. A statistically significant correlation between pilot workload, as indicated by pilot ratings, and scanning behavior has been established. In addition, it was demonstrated that parameters derived from the scanning behavior data can be combined in a mathematical equation to provide a good representation of pilot workload.
Circulating miRNAs in Pediatric Pulmonary Hypertension Show Promise as Biomarkers of Vascular Function

PubMed Central

Sucharov, Carmen C.; Truong, Uyen; Dunning, Jamie; Ivy, Dunbar; Miyamoto, Shelley; Shandas, Robin

2017-01-01

Background/Objectives The objective of this study was to evaluate the utility of circulating miRNAs as biomarkers of vascular function in pediatric pulmonary hypertension. Method Fourteen pediatric pulmonary arterial hypertension patients underwent simultaneous right heart catheterization (RHC) and blood biochemical analysis. Univariate and stepwise multivariate linear regression was used to identify and correlate measures of reactive and resistive afterload with circulating miRNA levels. Furthermore, circulating miRNA candidates that classified patients according to a 20% decrease in resistive afterload in response to oxygen (O2) or inhaled nitric oxide (iNO) were identified using receiver-operating curves. Results Thirty-two circulating miRNAs correlated with the pulmonary vascular resistance index (PVRi), pulmonary arterial distensibility, and PVRi decrease in response to O2 and/or iNO. Multivariate models, combining the predictive capability of multiple promising miRNA candidates, revealed a good correlation with resistive (r = 0.97, P2−tailed < 0.0001) and reactive (r = 0.86, P2−tailed < 0.005) afterloads. Bland-Altman plots showed that 95% of the differences between multivariate models and RHC would fall within 0.13 (mmHg−min/L)m2 and 0.0085/mmHg for resistive and reactive afterloads, respectively. Circulating miR-663 proved to be a good classifier for vascular responsiveness to acute O2 and iNO challenges. Conclusion This study suggests that circulating miRNAs may be biomarkers to phenotype vascular function in pediatric PAH. PMID:28819545
Associations between dietary and lifestyle risk factors and colorectal cancer in the Scottish population.

PubMed

Theodoratou, Evropi; Farrington, Susan M; Tenesa, Albert; McNeill, Geraldine; Cetnarskyj, Roseanne; Korakakis, Emmanouil; Din, Farhat V N; Porteous, Mary E; Dunlop, Malcolm G; Campbell, Harry

2014-01-01

Colorectal cancer (CRC) accounts for 9.7% of all cancer cases and for 8% of all cancer-related deaths. Established risk factors include personal or family history of CRC as well as lifestyle and dietary factors. We investigated the relationship between CRC and demographic, lifestyle, food and nutrient risk factors through a case-control study that included 2062 patients and 2776 controls from Scotland. Forward and backward stepwise regression was applied and the stability of the models was assessed in 1000 bootstrap samples. The variables that were automatically selected to be included by the forward or backward stepwise regression and whose selection was verified by bootstrap sampling in the current study were family history, dietary energy, 'high-energy snack foods', eggs, juice, sugar-sweetened beverages and white fish (associated with an increased CRC risk) and NSAIDs, coffee and magnesium (associated with a decreased CRC risk). Application of forward and backward stepwise regression in this CRC study identified some already established as well as some novel potential risk factors. Bootstrap findings suggest that examination of the stability of regression models by bootstrap sampling is useful in the interpretation of study findings. 'High-energy snack foods' and high-energy drinks (including sugar-sweetened beverages and fruit juices) as risk factors for CRC have not been reported previously and merit further investigation as such snacks and beverages are important contributors in European and North American diets.
Error Covariance Penalized Regression: A novel multivariate model combining penalized regression with multivariate error structure.

PubMed

Allegrini, Franco; Braga, Jez W B; Moreira, Alessandro C O; Olivieri, Alejandro C

2018-06-29

A new multivariate regression model, named Error Covariance Penalized Regression (ECPR) is presented. Following a penalized regression strategy, the proposed model incorporates information about the measurement error structure of the system, using the error covariance matrix (ECM) as a penalization term. Results are reported from both simulations and experimental data based on replicate mid and near infrared (MIR and NIR) spectral measurements. The results for ECPR are better under non-iid conditions when compared with traditional first-order multivariate methods such as ridge regression (RR), principal component regression (PCR) and partial least-squares regression (PLS). Copyright © 2018 Elsevier B.V. All rights reserved.
Forecasting peak asthma admissions in London: an application of quantile regression models.

PubMed

Soyiri, Ireneous N; Reidpath, Daniel D; Sarran, Christophe

2013-07-01

Asthma is a chronic condition of great public health concern globally. The associated morbidity, mortality and healthcare utilisation place an enormous burden on healthcare infrastructure and services. This study demonstrates a multistage quantile regression approach to predicting excess demand for health care services in the form of asthma daily admissions in London, using retrospective data from the Hospital Episode Statistics, weather and air quality. Trivariate quantile regression models (QRM) of asthma daily admissions were fitted to a 14-day range of lags of environmental factors, accounting for seasonality in a hold-in sample of the data. Representative lags were pooled to form multivariate predictive models, selected through a systematic backward stepwise reduction approach. Models were cross-validated using a hold-out sample of the data, and their respective root mean square error measures, sensitivity, specificity and predictive values compared. Two of the predictive models were able to detect extreme number of daily asthma admissions at sensitivity levels of 76 % and 62 %, as well as specificities of 66 % and 76 %. Their positive predictive values were slightly higher for the hold-out sample (29 % and 28 %) than for the hold-in model development sample (16 % and 18 %). QRMs can be used in multistage to select suitable variables to forecast extreme asthma events. The associations between asthma and environmental factors, including temperature, ozone and carbon monoxide can be exploited in predicting future events using QRMs.
Forecasting peak asthma admissions in London: an application of quantile regression models

NASA Astrophysics Data System (ADS)

Soyiri, Ireneous N.; Reidpath, Daniel D.; Sarran, Christophe

2013-07-01

Asthma is a chronic condition of great public health concern globally. The associated morbidity, mortality and healthcare utilisation place an enormous burden on healthcare infrastructure and services. This study demonstrates a multistage quantile regression approach to predicting excess demand for health care services in the form of asthma daily admissions in London, using retrospective data from the Hospital Episode Statistics, weather and air quality. Trivariate quantile regression models (QRM) of asthma daily admissions were fitted to a 14-day range of lags of environmental factors, accounting for seasonality in a hold-in sample of the data. Representative lags were pooled to form multivariate predictive models, selected through a systematic backward stepwise reduction approach. Models were cross-validated using a hold-out sample of the data, and their respective root mean square error measures, sensitivity, specificity and predictive values compared. Two of the predictive models were able to detect extreme number of daily asthma admissions at sensitivity levels of 76 % and 62 %, as well as specificities of 66 % and 76 %. Their positive predictive values were slightly higher for the hold-out sample (29 % and 28 %) than for the hold-in model development sample (16 % and 18 %). QRMs can be used in multistage to select suitable variables to forecast extreme asthma events. The associations between asthma and environmental factors, including temperature, ozone and carbon monoxide can be exploited in predicting future events using QRMs.
Cognitive models of medical decision-making capacity in patients with mild cognitive impairment.

PubMed

Okonkwo, O C; Griffith, H R; Belue, K; Lanza, S; Zamrini, E Y; Harrell, L E; Brockington, J C; Clark, D; Raman, R; Marson, D C

2008-03-01

This study investigated cognitive predictors of medical decision-making capacity (MDC) in patients with amnestic mild cognitive impairment (MCI). A total of 56 healthy controls, 60 patients with MCI, and 31 patients with mild Alzheimer's disease (AD) were administered the Capacity to Consent to Treatment Instrument (CCTI) and a neuropsychological test battery. The CCTI assesses MDC across four established treatment consent standards--S1 (expressing choice), S3 (appreciation), S4 (reasoning), and S5 (understanding)--and one experimental standard [S2] (reasonable choice). Scores on neuropsychological measures were correlated with scores on each CCTI standard. Significant bivariate correlates were subsequently entered into stepwise regression analyses to identity group-specific multivariable predictors of MDC across CCTI standards. Different multivariable cognitive models emerged across groups and consent standards. For the MCI group, measures of short-term verbal memory were key predictors of MDC for each of the three clinically relevant standards (S3, S4, and S5). Secondary predictors were measures of executive function. In contrast, in the mild AD group, measures tapping executive function and processing speed were primary predictors of S3, S4, and S5. MDC in patients with MCI is supported primarily by short-term verbal memory. The findings demonstrate the impact of amnestic deficits on MDC in patients with MCI.
Association of pretreatment neutrophil-lymphocyte ratio and outcome in emergency colorectal cancer care.

PubMed

Palin, R P; Devine, A T; Hicks, G; Burke, D

2018-04-01

Introduction The association between the neutrophil-lymphocyte ratio (NLR) and outcome in elective colorectal cancer surgery is well established; the relationship between NLR and the emergency colorectal cancer patient is, as yet, unexplored. This paper evaluates the predictive quality of the NLR for outcome in the emergency colorectal cancer patient. Materials and Methods A total of 187 consecutive patients who underwent emergency surgery for colorectal cancer were included in the study. NLR was calculated from the haematological tests done on admission. Receiver operating characteristic analyses were used to determine the most suitable cut-off for NLR. Outcomes were assessed by mortality at 30 and 90 days using stepwise Cox proportional hazards regression. Results An NLR cut-off of 5 was found to have the highest sensitivity and specificity. At 30 days, age and time from admission to surgery were associated with increased mortality; a high NLR was associated with an increased risk of mortality in univariate but not multivariate analysis. At 90 days, age, NLR, time from admission to surgery and nodal status were all significantly associated with increased mortality on multivariate analysis. Conclusions Pre-operative NLR is a cheap, easily performed and useful clinical tool to aid prediction of outcome in the emergency colorectal cancer patient.
Prediction of the birch pollen season characteristics in Cracow, Poland using an 18-year data series.

PubMed

Dorota, Myszkowska

2013-03-01

The aim of the study was to construct the model forecasting the birch pollen season characteristics in Cracow on the basis of an 18-year data series. The study was performed using the volumetric method (Lanzoni/Burkard trap). The 98/95 % method was used to calculate the pollen season. The Spearman's correlation test was applied to find the relationship between the meteorological parameters and pollen season characteristics. To construct the predictive model, the backward stepwise multiple regression analysis was used including the multi-collinearity of variables. The predictive models best fitted the pollen season start and end, especially models containing two independent variables. The peak concentration value was predicted with the higher prediction error. Also the accuracy of the models predicting the pollen season characteristics in 2009 was higher in comparison with 2010. Both, the multi-variable model and one-variable model for the beginning of the pollen season included air temperature during the last 10 days of February, while the multi-variable model also included humidity at the beginning of April. The models forecasting the end of the pollen season were based on temperature in March-April, while the peak day was predicted using the temperature during the last 10 days of March.
Predictors of the Perception of Smoking Health Risks in Smokers With or Without Schizophrenia.

PubMed

Kowalczyk, William J; Wehring, Heidi J; Burton, George; Raley, Heather; Feldman, Stephanie; Heishman, Stephen J; Kelly, Deanna L

2017-01-01

This study sought to examine the predictors of health risk perception in smokers with or without schizophrenia. The health risk subscale from the Smoking Consequences Questionnaire was dichotomized and used to measure health risk perception in smokers with (n = 67) and without schizophrenia (n = 100). A backward stepwise logistic regression was conducted using variables associated at the bivariate level to determine multivariate predictors. Overall, 62.5% of smokers without schizophrenia and 40.3% of smokers with schizophrenia completely recognize the health risks of smoking (p ≤ .01). Multivariate predictors for smokers without schizophrenia included: sex (Exp (B) = .3; p < .05), Smoking Consequences Questionnaire state enhancement (Exp (B) = .69; p < .01), and craving relief (Exp (B) = 1.8; p < .01). Among smokers with schizophrenia, predictors were education (Exp (B) = .7; p < .05), nicotine dependence (Exp (B) = .5; p < .01), motivation to quit (Exp (B) = 1.8; p < .01), and Smoking Consequences Questionnaire craving relief (Exp (B) = 1.8; p < .01). There was overlap and differences between predictors in smokers with and without schizophrenia. Commonly used techniques for education on the health consequences of cigarettes may work in smokers with schizophrenia, but intervention efforts specifically tailored to smokers with schizophrenia might be more efficacious.
Predictors of the Perception of Smoking Health Risks in Smokers With or Without Schizophrenia

PubMed Central

Kowalczyk, William J.; Wehring, Heidi J.; Burton, George; Raley, Heather; Feldman, Stephanie; Heishman, Stephen J.; Kelly, Deanna L.

2017-01-01

Objective This study sought to examine the predictors of health risk perception in smokers with or without schizophrenia. Methods The health risk subscale from the Smoking Consequences Questionnaire was dichotomized and used to measure health risk perception in smokers with (n = 67) and without schizophrenia (n = 100). A backward stepwise logistic regression was conducted using variables associated at the bivariate level to determine multivariate predictors. Results Overall, 62.5% of smokers without schizophrenia and 40.3% of smokers with schizophrenia completely recognize the health risks of smoking (p ≤ .01). Multivariate predictors for smokers without schizophrenia included: sex (Exp (B) = .3; p < .05), Smoking Consequences Questionnaire state enhancement (Exp (B) = .69; p < .01), and craving relief (Exp (B) = 1.8; p < .01). Among smokers with schizophrenia, predictors were education (Exp (B) = .7; p < .05), nicotine dependence (Exp (B) = .5; p < .01), motivation to quit (Exp (B) = 1.8; p < .01), and Smoking Consequences Questionnaire craving relief (Exp (B) = 1.8; p < .01). Conclusions There was overlap and differences between predictors in smokers with and without schizophrenia. Commonly used techniques for education on the health consequences of cigarettes may work in smokers with schizophrenia, but intervention efforts specifically tailored to smokers with schizophrenia might be more efficacious. PMID:27858591
Impact of total body weight on acute kidney injury in patients with gram-negative bacteremia.

PubMed

Hall, Ronald G; Yoo, Eunice; Faust, Andrew; Smith, Terri; Goodman, Edward; Mortensen, Eric M; Felder, Victoria; Alvarez, Carlos A

2018-05-10

The impact of total body weight (TBW) on the development of acute kidney injury (AKI) associated with gram-negative bacteremia has not been previously evaluated. The cohort included 323 patients >/ = 18 years old with gram-negative bacteremia (1/1/2008-8/31/2011) who received >/ = 48 hours of antibiotics. We compared the incidence of AKI in patients with a TBW 80kg with a multivariable stepwise logistic regression adjusting for age >/ = 70 years, baseline serum creatinine of > 2.0 mg/dl, and receipt of a vasopressor. AKI was defined as an increase of 0.5 mg/dL or a > 50% increase from baseline for at least two consecutive days. The cohort was 62% TBW 80kg. TBW >80kg patients had higher risk of AKI (24% vs. 9%, p < 0.001), which was significant in the multivariable analysis (OR 3.41, 95% CI 1.73-6.73). A baseline serum creatinine of > 2.0 mg/dl and vasopressor use were also independently associated with AKI. TBW >80kg was associated with the development of AKI. However, the mechanism for this association is not clear.
Utility of Intermediate-Delay Washout CT Images for Differentiation of Malignant and Benign Adrenal Lesions: A Multivariate Analysis.

PubMed

Ng, Chaan S; Altinmakas, Emre; Wei, Wei; Ghosh, Payel; Li, Xiao; Grubbs, Elizabeth G; Perrier, Nancy D; Lee, Jeffrey E; Prieto, Victor G; Hobbs, Brian P

2018-06-27

The objective of this study was to identify features that impact the diagnostic performance of intermediate-delay washout CT for distinguishing malignant from benign adrenal lesions. This retrospective study evaluated 127 pathologically proven adrenal lesions (82 malignant, 45 benign) in 126 patients who had undergone portal venous phase and intermediate-delay washout CT (1-3 minutes after portal venous phase) with or without unenhanced images. Unenhanced images were available for 103 lesions. Quantitatively, lesion CT attenuation on unenhanced (UA) and delayed (DL) images, absolute and relative percentage of enhancement washout (APEW and RPEW, respectively), descriptive CT features (lesion size, margin characteristics, heterogeneity or homogeneity, fat, calcification), patient demographics, and medical history were evaluated for association with lesion status using multiple logistic regression with stepwise model selection. Area under the ROC curve (A z ) was calculated from both univariate and multivariate analyses. The predictive diagnostic performance of multivariate evaluations was ascertained through cross-validation. A z for DL, APEW, RPEW, and UA was 0.751, 0.795, 0.829, and 0.839, respectively. Multivariate analyses yielded the following significant CT quantitative features and associated A z when combined: RPEW and DL (A z = 0.861) when unenhanced images were not available and APEW and UA (A z = 0.889) when unenhanced images were available. Patient demographics and presence of a prior malignancy were additional significant factors, increasing A z to 0.903 and 0.927, respectively. The combined predictive classifier, without and with UA available, yielded 85.7% and 87.3% accuracies with cross-validation, respectively. When appropriately combined with other CT features, washout derived from intermediate-delay CT with or without additional clinical data has potential utility in differentiating malignant from benign adrenal lesions.
Self-Concept and Participation in School Activities Reanalyzed.

ERIC Educational Resources Information Center

Winne, Philip H.; Walsh, John

1980-01-01

Yarworth and Gauthier (EJ 189 606) examined whether self-concept variables enhanced predictions about students' participation in school activities, using unstructured stepwise regression techniques. A reanalysis of their data using hierarchial regression models tested their hypothesis more appropriately, and uncovered multicollinearity and…
A stepwise, multi-objective, multi-variable parameter optimization method for the APEX model

USDA-ARS?s Scientific Manuscript database

Proper parameterization enables hydrological models to make reliable estimates of non-point source pollution for effective control measures. The automatic calibration of hydrologic models requires significant computational power limiting its application. The study objective was to develop and eval...
Evaluation of interpolation techniques for the creation of gridded daily precipitation (1 × 1 km2); Cyprus, 1980-2010

NASA Astrophysics Data System (ADS)

Camera, Corrado; Bruggeman, Adriana; Hadjinicolaou, Panos; Pashiardis, Stelios; Lange, Manfred A.

2014-01-01

High-resolution gridded daily data sets are essential for natural resource management and the analyses of climate changes and their effects. This study aims to evaluate the performance of 15 simple or complex interpolation techniques in reproducing daily precipitation at a resolution of 1 km2 over topographically complex areas. Methods are tested considering two different sets of observation densities and different rainfall amounts. We used rainfall data that were recorded at 74 and 145 observational stations, respectively, spread over the 5760 km2 of the Republic of Cyprus, in the Eastern Mediterranean. Regression analyses utilizing geographical copredictors and neighboring interpolation techniques were evaluated both in isolation and combined. Linear multiple regression (LMR) and geographically weighted regression methods (GWR) were tested. These included a step-wise selection of covariables, as well as inverse distance weighting (IDW), kriging, and 3D-thin plate splines (TPS). The relative rank of the different techniques changes with different station density and rainfall amounts. Our results indicate that TPS performs well for low station density and large-scale events and also when coupled with regression models. It performs poorly for high station density. The opposite is observed when using IDW. Simple IDW performs best for local events, while a combination of step-wise GWR and IDW proves to be the best method for large-scale events and high station density. This study indicates that the use of step-wise regression with a variable set of geographic parameters can improve the interpolation of large-scale events because it facilitates the representation of local climate dynamics.
[Associated factors in newborns with intrauterine growth retardation].

PubMed

Thompson-Chagoyán, Oscar C; Vega-Franco, Leopoldo

2008-01-01

To identify the risk factors implicated in the intrauterine growth retardation (IUGR) of neonates born in a social security institution. Case controls design study in 376 neonates: 188 with IUGR (weight < 10 percentile) and 188 without IUGR. When they born, information about 30 variables of risk for IUGR were obtained from mothers. Risk analysis and logistical regression (stepwise) were used. Odds ratios were significant for 12 of the variables. The model obtains by stepwise regression included: weight gain at pregnancy, prenatal care attendance, toxemia, chocolate ingestion, father's weight, and the environmental house. Must of the variables included in the model are related to socioeconomic disadvantages related to the risk of RCIU in the population.
Relationships between depressive symptoms and self-reported unintentional injuries: the cross-sectional population–based FIN-D2D survey

PubMed Central

2012-01-01

Background There is a lack of knowledge on the influence of different levels of physical activity (PA) on unintentional injuries among those with depressive symptoms (DS). The aim of this study was to evaluate the relationship between PA categories and unintentional injuries among participants with and without DS based on a cross-sectional population–based FIN-D2D survey conducted in 2007. Methods Out of 4500, 2682 participants (60%) aged 45–74 years attended in this study. The unintentional injuries over the past year were captured in a questionnaire. DS were determined with the Beck Depression Inventory (≥ 10 points) and PA with the International Physical Activity Questionnaire. The statistical significance between DS and unintentional injury categories was evaluated by using t-test, chi-square test, or permutation test, analysis of covariance, or regression models. The factors related to unintentional injuries were estimated by univariate and multivariate logistic regression models. Results The proportion of subjects with unintentional injuries was higher among those with DS (17%) compared to those without DS (10%) (age- and gender-adjusted p = 0.023). The median (range) number of activity-loss days after injury was 22 (0–365) in participants with DS and 7 (0–120) in participants without DS ( p = 0.009). The percentage of subjects with unintentional injuries was not significantly different between PA categories in participants with DS and without DS. A stepwise multivariate logistic regression analysis showed that DS, functional ability, and musculoskeletal diseases were related to unintentional injuries. Conclusions PA level was not related to unintentional injuries, whereas those with DS had a higher prevalence of unintentional injuries and prolonged activity-loss after injury. These results underline the importance of injury prevention, especially among those who have DS and additional risk factors. PMID:22781103
Use of principal-component, correlation, and stepwise multiple-regression analyses to investigate selected physical and hydraulic properties of carbonate-rock aquifers

USGS Publications Warehouse

Brown, C. Erwin

1993-01-01

Correlation analysis in conjunction with principal-component and multiple-regression analyses were applied to laboratory chemical and petrographic data to assess the usefulness of these techniques in evaluating selected physical and hydraulic properties of carbonate-rock aquifers in central Pennsylvania. Correlation and principal-component analyses were used to establish relations and associations among variables, to determine dimensions of property variation of samples, and to filter the variables containing similar information. Principal-component and correlation analyses showed that porosity is related to other measured variables and that permeability is most related to porosity and grain size. Four principal components are found to be significant in explaining the variance of data. Stepwise multiple-regression analysis was used to see how well the measured variables could predict porosity and (or) permeability for this suite of rocks. The variation in permeability and porosity is not totally predicted by the other variables, but the regression is significant at the 5% significance level. ?? 1993.

Evaluation of a stepwise, multi-objective, multi-variable parameter optimization method for the APEX model

USDA-ARS?s Scientific Manuscript database

Hydrologic models are essential tools for environmental assessment of agricultural non-point source pollution. The automatic calibration of hydrologic models, though efficient, demands significant computational power, which can limit its application. The study objective was to investigate a cost e...
Factors related to clinical pregnancy after vitrified-warmed embryo transfer: a retrospective and multivariate logistic regression analysis of 2313 transfer cycles.

PubMed

Shi, Wenhao; Zhang, Silin; Zhao, Wanqiu; Xia, Xue; Wang, Min; Wang, Hui; Bai, Haiyan; Shi, Juanzi

2013-07-01

What factors does multivariate logistic regression show to be significantly associated with the likelihood of clinical pregnancy in vitrified-warmed embryo transfer (VET) cycles? Assisted hatching (AH) and if the reason to freeze embryos was to avoid the risk of ovarian hyperstimulation syndrome (OHSS) were significantly positively associated with a greater likelihood of clinical pregnancy. Single factor analysis has shown AH, number of embryos transferred and the reason of freezing for OHSS to be positively and damaged blastomere to be negatively significantly associated with the chance of clinical pregnancy after VET. It remains unclear what factors would be significant after multivariate analysis. The study was a retrospective analysis of 2313 VET cycles from 1481 patients performed between January 2008 and April 2012. A multivariate logistic regression analysis was performed to identify the factors to affect clinical pregnancy outcome of VET. There were 22 candidate variables selected based on clinical experiences and the literature. With the thresholds of α entry = α removal= 0.05 for both variable entry and variable removal, eight variables were chosen to contribute the multivariable model by the bootstrap stepwise variable selection algorithm (n = 1000). Eight variables were age at controlled ovarian hyperstimulation (COH), reason for freezing, AH, endometrial thickness, damaged blastomere, number of embryos transferred, number of good-quality embryos, and blood presence on transfer catheter. A descriptive comparison of the relative importance was accomplished by the proportion of explained variation (PEV). Among the reasons for freezing, the OHSS group showed a higher OR than the surplus embryo group when compared with other reasons for VET groups (OHSS versus Other, OR: 2.145; CI: 1.4-3.286; Surplus embryos versus Other, OR: 1.152; CI: 0.761-1.743) and high PEV (marginal 2.77%, P = 0.2911; partial 1.68%; CI of area under receptor operator characteristic curve (ROC): 0.5576-0.6000). AH also showed a high OR (OR: 2.105, CI: 1.554-2.85) and high PEV (marginal 1.97%; partial 1.02%; CI of area under ROC: 0.5344-0.5647). The number of good-quality embryos showed the highest marginal PEV and partial PEV (marginal 3.91%, partial 2.28%; CI of area under ROC: 0.5886-0.6343). This was a retrospective multivariate analysis of the data obtained in 5 years from a single IVF center. Repeated cycles in the same woman were treated as independent observations, which could introduce bias. Results are based on clinical pregnancy and not live births. Prospective analysis of a larger data set from a multicenter study based on live births is necessary to confirm the findings. Paying attention to the quality of embryos, the number of good embryos, AH and the reasons for freezing that are associated with clinical pregnancy after VET will assist the improvement of success rates.
Identification of molecular markers associated with mite resistance in coconut (Cocos nucifera L.).

PubMed

Shalini, K V; Manjunatha, S; Lebrun, P; Berger, A; Baudouin, L; Pirany, N; Ranganath, R M; Prasad, D Theertha

2007-01-01

Coconut mite (Aceria guerreronis 'Keifer') has become a major threat to Indian coconut (Coçcos nucifera L.) cultivators and the processing industry. Chemical and biological control measures have proved to be costly, ineffective, and ecologically undesirable. Planting mite-resistant coconut cultivars is the most effective method of preventing yield loss and should form a major component of any integrated pest management stratagem. Coconut genotypes, and mite-resistant and -susceptible accessions were collected from different parts of South India. Thirty-two simple sequence repeat (SSR) and 7 RAPD primers were used for molecular analyses. In single-marker analysis, 9 SSR and 4 RAPD markers associated with mite resistance were identified. In stepwise multiple regression analysis of SSRs, a combination of 6 markers showed 100% association with mite infestation. Stepwise multiple regression analysis for RAPD data revealed that a combination of 3 markers accounted for 83.86% of mite resistance in the selected materials. Combined stepwise multiple regression analysis of RAPD and SSR data showed that a combination of 5 markers explained 100% of the association with mite resistance in coconut. Markers associated with mite resistance are important in coconut breeding programs and will facilitate the selection of mite-resistant plants at an early stage as well as mother plants for breeding programs.
Selecting risk factors: a comparison of discriminant analysis, logistic regression and Cox's regression model using data from the Tromsø Heart Study.

PubMed

Brenn, T; Arnesen, E

1985-01-01

For comparative evaluation, discriminant analysis, logistic regression and Cox's model were used to select risk factors for total and coronary deaths among 6595 men aged 20-49 followed for 9 years. Groups with mortality between 5 and 93 per 1000 were considered. Discriminant analysis selected variable sets only marginally different from the logistic and Cox methods which always selected the same sets. A time-saving option, offered for both the logistic and Cox selection, showed no advantage compared with discriminant analysis. Analysing more than 3800 subjects, the logistic and Cox methods consumed, respectively, 80 and 10 times more computer time than discriminant analysis. When including the same set of variables in non-stepwise analyses, all methods estimated coefficients that in most cases were almost identical. In conclusion, discriminant analysis is advocated for preliminary or stepwise analysis, otherwise Cox's method should be used.
Hypnotism as a Function of Trance State Effects, Expectancy, and Suggestibility: An Italian Replication.

PubMed

Pekala, Ronald J; Baglio, Francesca; Cabinio, Monia; Lipari, Susanna; Baglio, Gisella; Mendozzi, Laura; Cecconi, Pietro; Pugnetti, Luigi; Sciaky, Riccardo

2017-01-01

Previous research using stepwise regression analyses found self-reported hypnotic depth (srHD) to be a function of suggestibility, trance state effects, and expectancy. This study sought to replicate and expand that research using a general state measure of hypnotic responsivity, the Phenomenology of Consciousness Inventory: Hypnotic Assessment Procedure (PCI-HAP). Ninety-five participants completed an Italian translation of the PCI-HAP, with srHD scores predicted from the PCI-HAP assessment items. The regression analysis replicated the previous research results. Additionally, stepwise regression analyses were able to predict the srHD score equally well using only the PCI dimension scores. These results not only replicated prior research but suggest how this methodology to assess hypnotic responsivity, when combined with more traditional neurophysiological and cognitive-behavioral methodologies, may allow for a more comprehensive understanding of that enigma called hypnosis.
Perceived Social Support as a Determinant of Quality of Life Among Medical Students: 6-Month Follow-up Study.

PubMed

Hwang, In Cheol; Park, Kwi Hwa; Kim, Jin Joo; Yim, Jun; Ko, Kwang Pil; Bae, Seung Min; Kyung, Sun Young

2017-04-01

This longitudinal study aimed to identify the relevant factors related to quality of life (QoL) changes in medical students. For this 6-month follow-up study, we enrolled 109 students from a Korean medical school. To assess students' QoL, we used the World Health Organization QoL scale. Possible determinants of student QoL included demographics, fatigue, and social support. A stepwise multivariate analysis identified factors associated with changes of student QoL. Among sources of support, the "friends" category was the main position affecting their overall QoL, and "significant other" had the strongest influence on psychological and social domains. The impact of support from friends on QoL was confirmed in the longitudinal analysis. Final regression models revealed that providing students with more social support and promoting fatigue reduction best improved medical student sense of well-being. Creating stronger student support programs to prevent social detachment and implementing strategies to reduce fatigue can improve QoL in medical students.
Independent predictors of delay in emergence from general anesthesia.

PubMed

Maeda, Shigeru; Tomoyasu, Yumiko; Higuchi, Hitoshi; Ishii-Maruhama, Minako; Egusa, Masahiko; Miyawaki, Takuya

2015-01-01

Some patients with intellectual disabilities spend longer than others in emergence from ambulatory general anesthesia for dental treatment. Although antiepileptic drugs and anesthetics might be involved, an independent predictor for delay of the emergence remains unclear. Thus, a purpose of this study is to identify independent factors affecting the delay of emergence from general anesthesia. This was a retrospective cohort study in dental patients with intellectual disabilities. Patients in need of sedative premedication were removed from participants. The outcome was time until emergence from general anesthesia. Stepwise multivariate regression analysis was used to extract independent factors affecting the outcome. Antiepileptic drugs and anesthetic parameters were included as predictor variables. The study included 102 cases. Clobazam, clonazepam, and phenobarbital were shown to be independent determinants of emergence time. Parameters relating to anesthetics, patients' backgrounds, and dental treatment were not independent factors. Delay in emergence time in ambulatory general anesthesia is likely to be related to the antiepileptic drugs of benzodiazepine or barbiturates in patients with intellectual disability.
Independent Predictors of Delay in Emergence From General Anesthesia

PubMed Central

Maeda, Shigeru; Tomoyasu, Yumiko; Higuchi, Hitoshi; Ishii-Maruhama, Minako; Egusa, Masahiko; Miyawaki, Takuya

2015-01-01

Some patients with intellectual disabilities spend longer than others in emergence from ambulatory general anesthesia for dental treatment. Although antiepileptic drugs and anesthetics might be involved, an independent predictor for delay of the emergence remains unclear. Thus, a purpose of this study is to identify independent factors affecting the delay of emergence from general anesthesia. This was a retrospective cohort study in dental patients with intellectual disabilities. Patients in need of sedative premedication were removed from participants. The outcome was time until emergence from general anesthesia. Stepwise multivariate regression analysis was used to extract independent factors affecting the outcome. Antiepileptic drugs and anesthetic parameters were included as predictor variables. The study included 102 cases. Clobazam, clonazepam, and phenobarbital were shown to be independent determinants of emergence time. Parameters relating to anesthetics, patients' backgrounds, and dental treatment were not independent factors. Delay in emergence time in ambulatory general anesthesia is likely to be related to the antiepileptic drugs of benzodiazepine or barbiturates in patients with intellectual disability. PMID:25849468
Disparities in early exposure to book sharing within immigrant families.

PubMed

Festa, Natalia; Loftus, Pooja D; Cullen, Mark R; Mendoza, Fernando S

2014-07-01

This study examined the early developmental context of children in immigrant families (CIF), measured by the frequency with which parents share books with their children. Trends in the frequency with which parents report book sharing, defined in this analysis as reading or sharing picture books with their young children, were analyzed across immigrant and nonimmigrant households by using data from the 2005, 2007, and 2009 California Health Interview Survey. Stepwise multivariate logistic regression assessed the likelihood that CIF shared books with parents daily. In this study, 57.5% of parents in immigrant families reported daily book sharing (DBS), compared with 75.8% of native-born parents. The lowest percentage of DBS was seen in Hispanic families with 2 foreign-born parents (47.1%). When controlling for independent variables, CIF with 2 foreign-born parents had the lowest odds of sharing books daily (odds ratio [OR]: 0.61; 95% confidence interval [CI]: 0.54-0.68). When stratified by race/ethnicity, separate multivariate logistic regressions revealed CIF status to be associated with lower odds of DBS for Asian (OR: 0.56; 95% CI: 0.38-0.81) and Hispanic CIF (OR: 0.49; 95% CI: 0.42-0.58). There is an association between the lower odds of DBS and parental immigrant status, especially for Hispanic and Asian children. This relationship holds after controlling for variables thought to explain differences in literacy-related practices, such as parental education and income. Because book sharing is central to children's development of early literacy and language skills, this disparity merits further exploration with the aim of informing future interventions. Copyright © 2014 by the American Academy of Pediatrics.
Is epidural analgesia during labor related to retained placenta?

PubMed

Sarit, Avraham; Sokolov, Amit; Many, Ariel

2016-05-01

To explore the influence of epidural analgesia on the course of the third stage of labor and on the incidence of the complete retained placenta as well as retained parts of the placenta. This is a population-based cohort study in a tertiary medical center. We collected data from all 4227 spontaneous singleton vaginal deliveries during 6 months and compared the incidence of retained placenta in deliveries with epidural analgesia with those without analgesia. Multivariable logistic regression was used to control for possible confounders. More than two-thirds of the women (69.25%) used epidural analgesia during their delivery. A need for intervention due to placental disorder during the third stage of labor was noted in 4.2% of all deliveries. Epidural analgesia appeared to be significantly (P=0.028) related to placental disorders compared with no analgesia: 4.8% vs. 3%, respectively. Deliveries with manual interventions during the third stage, for either complete retained placenta or suspected retained parts of the placenta, were associated with the use of epidural analgesia (P=0.008), oxytocin (P=0.002) and older age at delivery (P=0.000), but when including all factors in a multivariable analysis, using a stepwise logistic regression, the factors that were independently associated with interventions for placental disruption during the third stage of delivery were previous cesarean section, oxytocin use and, marginally, older age. Complete retained placenta and retained parts of the placenta share the same risk factors. Epidural analgesia does not directly influence the incidence of complete retained placenta or retained parts, though clinically linked through increased oxytocin use. The factors that were independently associated with interventions for placental disruption during the third stage of delivery were previous cesarean section, oxytocin use and older age.
Angiogenic and inflammatory biomarkers in mid-pregnancy and small-for-gestational age outcomes in Tanzania

PubMed Central

DARLING, Anne Marie; MCDONALD, Chloe R.; CONROY, Andrea L.; HAYFORD, Kyla T.; RAJWANS, Nimerta; WANG, Molin; ABOUD, Said; URASSA, Willy S.; KAIN, Kevin C.; FAWZI, Wafaie W.

2014-01-01

OBJECTIVE To investigate the relationship between a panel of angiogenic and inflammatory biomarkers measured in mid-pregnancy and small-for-gestational age (SGA) outcomes in sub-Saharan Africa. STUDY DESIGN Concentrations of 18 angiogenic and inflammatory biomarkers were determined in 432 pregnant women in Dar es Salaam, Tanzania who participated in a trial examining the effect of multivitamins on pregnancy outcomes. Infants falling below the 10th percentile of birth weight for gestational age relative to the applied growth standards were considered SGA. Multivariate binomial regression models with the log link function were used to determine the relative risk of SGA associated with increasing quartiles of each biomarker. Stepwise cubic restricted splines were used to test for non-linearity of these associations. Receiver operating curves obtained from multivariate logistic regression models were used to assess the discriminatory capability of selected biomarkers. RESULTS A total of 60 participants (13.9%) gave birth to SGA infants. Compared to those in the first quartile, the risk of SGA was reduced among those in the fourth quartiles of VEGF-A (adjusted risk ratio (RR) 0.38, 95% Confidence Interval (CI), 0.19-0.74), PGF (adjusted RR 0.28, 95% CI, 0.12-0.61), sFlt-1 (adjusted RR 0.48, 95% CI, 0.23-1.01), MCP-1 (adjusted RR 0.48, 95% CI, 0.25-0.92), and Leptin (adjusted RR 0.46, 95% CI, 0.22-0.96) CONCLUSION Our findings provide evidence of altered angiogenic and inflammatory mediators, at mid-pregnancy, in women who went on to deliver small for gestational age infants. PMID:24881826
Predicting critical care unit-level complications after long-segment fusion procedures for adult spinal deformity.

PubMed

De la Garza-Ramos, Rafael; Nakhla, Jonathan; Gelfand, Yaroslav; Echt, Murray; Scoco, Aleka N; Kinon, Merritt D; Yassari, Reza

2018-03-01

To identify predictive factors for critical care unit-level complications (CCU complication) after long-segment fusion procedures for adult spinal deformity (ASD). The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database [2010-2014] was reviewed. Only adult patients who underwent fusion of 7 or more spinal levels for ASD were included. CCU complications included intraoperative arrest/infarction, ventilation >48 hours, pulmonary embolism, renal failure requiring dialysis, cardiac arrest, myocardial infarction, unplanned intubation, septic shock, stroke, coma, or new neurological deficit. A stepwise multivariate regression was used to identify independent predictors of CCU complications. Among 826 patients, the rate of CCU complications was 6.4%. On multivariate regression analysis, dependent functional status (P=0.004), combined approach (P=0.023), age (P=0.044), diabetes (P=0.048), and surgery for over 8 hours (P=0.080) were significantly associated with complication development. A simple scoring system was developed to predict complications with 0 points for patients aged <50, 1 point for patients between 50-70, 2 points for patients 70 or over, 1 point for diabetes, 2 points dependent functional status, 1 point for combined approach, and 1 point for surgery over 8 hours. The rate of CCU complications was 0.7%, 3.2%, 9.0%, and 12.6% for patients with 0, 1, 2, and 3+ points, respectively (P<0.001). The findings in this study suggest that older patients, patients with diabetes, patients who depend on others for activities of daily living, and patients who undergo combined approaches or surgery for over 8 hours may be at a significantly increased risk of developing a CCU-level complication after ASD surgery.
Predicting Subnational Ebola Virus Disease Epidemic Dynamics from Sociodemographic Indicators

PubMed Central

Valeri, Linda; Patterson-Lomba, Oscar; Gurmu, Yared; Ablorh, Akweley; Bobb, Jennifer; Townes, F. William; Harling, Guy

2016-01-01

Background The recent Ebola virus disease (EVD) outbreak in West Africa has spread wider than any previous human EVD epidemic. While individual-level risk factors that contribute to the spread of EVD have been studied, the population-level attributes of subnational regions associated with outbreak severity have not yet been considered. Methods To investigate the area-level predictors of EVD dynamics, we integrated time series data on cumulative reported cases of EVD from the World Health Organization and covariate data from the Demographic and Health Surveys. We first estimated the early growth rates of epidemics in each second-level administrative district (ADM2) in Guinea, Sierra Leone and Liberia using exponential, logistic and polynomial growth models. We then evaluated how these growth rates, as well as epidemic size within ADM2s, were ecologically associated with several demographic and socio-economic characteristics of the ADM2, using bivariate correlations and multivariable regression models. Results The polynomial growth model appeared to best fit the ADM2 epidemic curves, displaying the lowest residual standard error. Each outcome was associated with various regional characteristics in bivariate models, however in stepwise multivariable models only mean education levels were consistently associated with a worse local epidemic. Discussion By combining two common methods—estimation of epidemic parameters using mathematical models, and estimation of associations using ecological regression models—we identified some factors predicting rapid and severe EVD epidemics in West African subnational regions. While care should be taken interpreting such results as anything more than correlational, we suggest that our approach of using data sources that were publicly available in advance of the epidemic or in real-time provides an analytic framework that may assist countries in understanding the dynamics of future outbreaks as they occur. PMID:27732614
Home blood-pressure monitoring among hypertensive patients in an Asian population.

PubMed

Tan, N C; Khin, L W; Pagi, R

2005-07-01

Hypertension is a principal cause of mortality and morbidity in Singapore. The use of home blood-pressure monitoring (HBPM) to assess hypertensive control with digital devices in the local multi-racial population is unknown. The study determined the factors associated with hypertensive patients' use of HBPM in primary care in a multi-racial Asian population. Randomized cross-sectional questionnaire survey of hypertensive patients managed in a district polyclinic. A model predicting use of HBPM was constructed by univariate and multivariate logistic regression. A total of 224 eligible subjects were randomly selected from 1943 patients. Response rate was 78.1% (n = 175). In all, 61.7% of them were aware of HBPM but only 24% used HBPM. Using multivariate analysis by stepwise backward regression, the final fitted model showed that HBPM was associated with higher patients' socioeconomic status: (adjusted OR for middle-income status = 2.85, 95% CI: 1.2-6.78, P = 0.018; adjusted OR for high-income status = 3.46, 95% CI: 1.22-9.87, P = 0.020) and their documented diastolic BP (adjusted OR for diastolic BP > 80 mmHg = 2.26, 95% CI: 1.06-4.82, P = 0.034). Nonusers cited failure to recognize benefits (54.1%), lack of HBPM awareness (29.3%), understanding of device operation (18.8%) and perception of inaccuracy (10.5%) as deterrents. 76.2% of users were satisfied with HBPM but lacked knowledge in maintenance of devices. In conclusion, 61.7% of the study population were aware of HBPM but only 24% used it. Patients' failure to recognize benefits, lack of awareness, cost and perception of inaccuracy were barriers. Higher socioeconomic status and patient's documented diastolic BP correlated with HBPM usage.
The association between temperature and mortality in tropical middle income Thailand from 1999 to 2008.

PubMed

Tawatsupa, Benjawan; Dear, Keith; Kjellstrom, Tord; Sleigh, Adrian

2014-03-01

We have investigated the association between tropical weather condition and age-sex adjusted death rates (ADR) in Thailand over a 10-year period from 1999 to 2008. Population, mortality, weather and air pollution data were obtained from four national databases. Alternating multivariable fractional polynomial (MFP) regression and stepwise multivariable linear regression analysis were used to sequentially build models of the associations between temperature variable and deaths, adjusted for the effects and interactions of age, sex, weather (6 variables), and air pollution (10 variables). The associations are explored and compared among three seasons (cold, hot and wet months) and four weather zones of Thailand (the North, Northeast, Central, and South regions). We found statistically significant associations between temperature and mortality in Thailand. The maximum temperature is the most important variable in predicting mortality. Overall, the association is nonlinear U-shape and 31 °C is the minimum-mortality temperature in Thailand. The death rates increase when maximum temperature increase with the highest rates in the North and Central during hot months. The final equation used in this study allowed estimation of the impact of a 4 °C increase in temperature as projected for Thailand by 2100; this analysis revealed that the heat-related deaths will increase more than the cold-related deaths avoided in the hot and wet months, and overall the net increase in expected mortality by region ranges from 5 to 13 % unless preventive measures were adopted. Overall, these results are useful for health impact assessment for the present situation and future public health implication of global climate change for tropical Thailand.
Self-care agency in systemic lupus erythematosus and its associated factors: a cross-sectional study.

PubMed

Yang, Hui; Xie, Xia; Song, Yuqing; Nie, Anliu; Chen, Hong

2018-01-01

The aim of this study was to estimate the level of self-care agency and explore its associated factors in patients with systemic lupus erythematosus (SLE). In this cross-sectional study, all patients were from a tertiary general hospital between July and October 2016 in Southwest China. The self-care agency was assessed using the Exercise of Self-care Agency Scale. Other variables were measured by the Visual Analog Scale, Systemic Lupus Erythematosus Disease Activity Index 2000, the physical component summary, and mental component summary of the 36-item Short Form Health Survey. Multivariate regression analysis was performed to explore the associated factors of self-care agency. A total of 123 patients were recruited. The mean score of Exercise of Self-care Agency Scale was 86.29. In univariate analysis, self-care agency of patients differed in regard to gender, work status, educational level, household income monthly per capita, and disease activity ( P <0.05). Additionally, higher body mass index, higher level of fatigue, and worse mental health were found in patients with lower self-care agency ( P <0.05). The stepwise multivariate regression analysis showed that male gender ( P =0.001), lower educational level ( P =0.003), lower household income monthly per capita ( P <0.001), and worse mental health ( P <0.001) could predict lower self-care agency. Patients with SLE had a middle level of self-care agency, suggesting that there is still much scope for improvement. The lower level of self-care agency was associated with male gender, lower educational level, lower household income monthly per capita, and worse mental health. Therefore, health care providers should develop targeted and comprehensive interventions to enhance self-care agency in patients with SLE.
A characterization of factors determining postoperative ileus after laparoscopic colectomy enables the generation of a novel predictive score.

PubMed

Kronberg, Udo; Kiran, Ravi P; Soliman, Mohamed S M; Hammel, Jeff P; Galway, Ursula; Coffey, John Calvin; Fazio, Victor W

2011-01-01

Postoperative ileus (POI) after colorectal surgery is associated with prolonged hospital stay and increased costs. The aim of this study is to investigate pre-, intra-, and postoperative risk factors associated with the development of POI in patients undergoing laparoscopic partial colectomy. Patients operated between 2004 and 2008 were retrospectively identified from a prospectively maintained database, and clinical, metabolic, and pharmacologic data were obtained. Postoperative ileus was defined as the absence of bowel function for 5 or more days or the need for reinsertion of a nasogastric tube after starting oral diet in the absence of mechanical obstruction. Associations between likelihood of POI and study variables were assessed univariably by using χ tests, Fisher exact tests, and logistic regression models. A scoring system for prediction of POI was constructed by using a multivariable logistic regression model based on forward stepwise selection of preoperative factors. A total of 413 patients (mean age, 58 years; 53.5% women) were included, and 42 (10.2%) of them developed POI. Preoperative albumin, postoperative deep-vein thrombosis, and electrolyte levels were associated with POI. Age, previous abdominal surgery, and chronic preoperative use of narcotics were independently correlated with POI on multivariate analysis, which allowed the creation of a predictive score. Patients with a score of 2 or higher had an 18.3% risk of POI (P < 0.001). Postoperative ileus after laparoscopic partial colectomy is associated with specific preoperative and postoperative factors. The likelihood of POI can be predicted by using a preoperative scoring system. Addressing the postoperative factors may be expected to reduce the incidence of this common complication in high-risk patients.
Obesity related factors in school-aged children.

PubMed

Soltani, Parvaneh Reza; Ghanbari, Atefeh; Rad, Afagh Hasanzadeh

2013-05-01

Overweight and obesity is becoming an increasingly prevalent problem in both developed and developing world, and is one of the most serious public health challenges of the 21(st) century. Although various studies demonstrated pediatric obesity-related factors, but, due to its ongoing hazardous effects, researchers aimed to assess obesity-related factors in school-aged children in Rasht, Iran. This was a case-control study which was performed in eight primary schools of Rasht. A cluster sampling method was used to select 320 students including 80 in case (BMI ≥85(th) percentile for age and gender) and 240 in control group (BMI = 5(th)-85(th) percentile for age and gender). Data were collected by a scale, a tape meter, and a form which consisted of obesity-related factors, and were analyzed by Chi-square, Mann-Whitney, and stepwise multivariate regression tests in SPSS 19. Findings showed that the mean and standard deviation of birth weight (g) in case and control groups were 3671 ± 5.64 and 190 ± 5.46, respectively (P = 0.000). 82.5% of case and 92.9% of control group had exclusive breastfeeding for 4-6 months (P = 0.024). Also, multivariate regression analysis indicated that birth weight, age, exclusive breastfeeding, and frequency of meals have significant effects on body mass index (BMI). It seems that more accurate interventions for primordial prevention are essential to reduce childhood obesity risk factors, including promotion of pre-pregnancy and prenatal care to have neonates who are appropriate for gestational age and also improving exclusive breastfeeding in the first 6 months of life. In addition, identifying children at risk for adolescent obesity provides physicians and midwives with an opportunity for earlier intervention with the goal of limiting the progression of abnormal weight gain.
Hyperferritinemia increases the risk of hyperuricemia in HFE-hereditary hemochromatosis.

PubMed

Flais, Jérémy; Bardou-Jacquet, Edouard; Deugnier, Yves; Coiffier, Guillaume; Perdriger, Aleth; Chalès, Gérard; Ropert, Martine; Loréal, Olivier; Guggenbuhl, Pascal

2017-05-01

Hyperuricemia is becoming increasingly frequent in the population, and is known to be sometimes the cause of gout. The impact of uric acid is still not clearly understood, however. The iron metabolism may interact with the uric acid metabolism. The aim of this study was to examine the relationship between the serum uric acid and serum ferritin levels in a cohort of hemochromatosis patients who were homozygous for the HFE p.Cys282Tyr mutation. 738 patients with the HFE gene mutation Cys282Tyr in the homozygous state were included in the study. The variables measured during the initial evaluation were compared in univariate analysis by Student's t test. In multivariate analysis, linear stepwise regression was used. In the group of hyperuricemic patients, ferritinemia was significantly higher than in the group of non-hyperuricemic patients (1576.7±1387.4μg/l vs. 1095.63±1319.24μg/l, P<0.005). With multivariate analysis, only ferritin and BMI independently explained the uricemia (R 2 =0.258) after adjustment for age, glycemia and CRP. The correlation between uricemia and log(ferritin) with partial regression correlation coefficients was 0.307 (P<0.01). The increase in uricemia is associated with the increase in ferritin in a population of patients who were homozygous for the HFE gene mutation p.Cys282Tyr and this independently of factors commonly associated with hyperuricemia. The increase in uric acid associated with hyperferritinemia, could be a response to the visceral toxicity of excess non-transferrin bound iron linked to oxidative stress via the antioxidant properties of uric acid. Copyright © 2016 Société française de rhumatologie. Published by Elsevier SAS. All rights reserved.
A statistical model for Windstorm Variability over the British Isles based on Large-scale Atmospheric and Oceanic Mechanisms

NASA Astrophysics Data System (ADS)

Kirchner-Bossi, Nicolas; Befort, Daniel J.; Wild, Simon B.; Ulbrich, Uwe; Leckebusch, Gregor C.

2016-04-01

Time-clustered winter storms are responsible for a majority of the wind-induced losses in Europe. Over last years, different atmospheric and oceanic large-scale mechanisms as the North Atlantic Oscillation (NAO) or the Meridional Overturning Circulation (MOC) have been proven to drive some significant portion of the windstorm variability over Europe. In this work we systematically investigate the influence of different large-scale natural variability modes: more than 20 indices related to those mechanisms with proven or potential influence on the windstorm frequency variability over Europe - mostly SST- or pressure-based - are derived by means of ECMWF ERA-20C reanalysis during the last century (1902-2009), and compared to the windstorm variability for the European winter (DJF). Windstorms are defined and tracked as in Leckebusch et al. (2008). The derived indices are then employed to develop a statistical procedure including a stepwise Multiple Linear Regression (MLR) and an Artificial Neural Network (ANN), aiming to hindcast the inter-annual (DJF) regional windstorm frequency variability in a case study for the British Isles. This case study reveals 13 indices with a statistically significant coupling with seasonal windstorm counts. The Scandinavian Pattern (SCA) showed the strongest correlation (0.61), followed by the NAO (0.48) and the Polar/Eurasia Pattern (0.46). The obtained indices (standard-normalised) are selected as predictors for a windstorm variability hindcast model applied for the British Isles. First, a stepwise linear regression is performed, to identify which mechanisms can explain windstorm variability best. Finally, the indices retained by the stepwise regression are used to develop a multlayer perceptron-based ANN that hindcasted seasonal windstorm frequency and clustering. Eight indices (SCA, NAO, EA, PDO, W.NAtl.SST, AMO (unsmoothed), EA/WR and Trop.N.Atl SST) are retained by the stepwise regression. Among them, SCA showed the highest linear coefficient, followed by SST in western Atlantic, AMO and NAO. The explanatory regression model (considering all time steps) provided a Coefficient of Determination (R^2) of 0.75. A predictive version of the linear model applying a leave-one-out cross-validation (LOOCV) shows an R2 of 0.56 and a relative RMSE of 4.67 counts/season. An ANN-based nonlinear hindcast model for the seasonal windstorm frequency is developed with the aim to improve the stepwise hindcast ability and thus better predict a time-clustered season over the case study. A 7 node-hidden layer perceptron is set, and the LOOCV procedure reveals a R2 of 0.71. In comparison to the stepwise MLR the RMSE is reduced a 20%. This work shows that for the British Isles case study, most of the interannual variability can be explained by certain large-scale mechanisms, considering also nonlinear effects (ANN). This allows to discern a time-clustered season from a non-clustered one - a key issue for applications e.g., in the (re)insurance industry.

Predictors of poststroke health-related quality of life in Nigerian stroke survivors: a 1-year follow-up study.

PubMed

Hamza, Ashiru Mohammad; Al-Sadat, Nabilla; Loh, Siew Yim; Jahan, Nowrozy Kamar

2014-01-01

This study aims to identify the predictors in the different aspects of the health-related quality of life (HRQoL) and to measure the changes of functional status over time in a cohort of Nigerian stroke survivors. A prospective observational study was conducted in three hospitals of Kano state of Nigeria where stroke survivors receive rehabilitation. The linguistic-validated Hausa versions of the stroke impact scale 3.0, modified Rankin scale, Barthel index and Beck depression inventory scales were used. Paired samples t-test was used to calculate the amount of changes that occur over time and the forward stepwise linear regression model was used to identify the predictors. A total of 233 stroke survivors were surveyed at 6 months, and 93% (217/233) were followed at 1 year after stroke. Functional disabilities were significantly reduced during the recovery phase. Motor impairment, disability, and level of depression were independent predictors of HRQoL in the multivariate regression analysis. The involvement of family members as caregivers is the key factor for those survivors with improved functional status. Thus, to enhance the quality of poststroke life, it is proposed that a holistic stroke rehabilitation service and an active involvement of family members are established at every possible level.
The correlations of psychological status, quality of life, self-esteem, social support and body image disturbance in Chinese patients with Systemic Lupus Erythematosus.

PubMed

Zhao, Qian; Chen, Haoyang; Yan, Hongyan; He, Yan; Zhu, Li; Fu, WenTing; Shen, Biyu

2018-01-31

This study aimed (i) to complement existing research by focusing on body image disturbance issues in Chinese Systemic Lupus Erythematosus (SLE) patients; (ii) to investigate how Chinese patients make sense of disease diagnosis and perceived cultural influences within the context of their SLE. A total of 118 SLE patients underwent standardized laboratory examinations and completed several questionnaires. Independent sample t-test, Mann-Whitney U-test, Chi-square test, and multivariate analysis using backward stepwise logistic regression model were used to analyze these data. We found 18.3% SLE patients had BID, which were significantly higher than the control group (.8%). SLE patients are more concerned about their physical changes caused by disease. There were significant correlations among personal health insurance, complication of diabetes, appearance of new rash, depression, anxiety, self-esteem and BID in patients with SLE. Meanwhile, logistic regression analysis revealed that appearance of new rash and high anxiety were significantly associated with BID in SLE patients. In conclusion, it is beneficial to pay attention to the physical and mental health of patients with rheumatic disease from the perspective of body image, to understand their needs and to provide effective and effective service for them.
Coronary risk factors of angiographically assessed patients from Syria.

PubMed

al-Kateb, H; Zarzzour, W; Shameah, M; Juoma, M

1998-02-01

Predictors of coronary artery disease in an Arab population had not been defined well. We studied 192 male patients with suspected coronary artery disease, who underwent catheterization. We defined definite coronary artery disease as > 50% stenosis in any of three vessels. The effects of age, obesity, smoking, hypertension, diabetes, and lipid fractions were assessed by means of univariate and multivariate regression analysis. Coronary artery disease was present in 153 men (80%) and absent from 39 men. Patients without coronary artery disease were slightly younger, thinner, smoked less, and had lower cholesterol, low-density lipoprotein cholesterol, and apolipoprotein B levels than did those who had coronary artery disease. By stepwise regression analysis, the best discriminators were body mass index (P = 0.0004), age (P = 0.0005), smoking (P = 0.014) and the apolipoprotein B:A-I ratio (P = 0.041). The strongest Pearson correlation coefficients for coronary artery disease were the ratio of total: high-density lipoprotein cholesterol levels (r = 0.26), the apolipoprotein B:A-I ratio (r = 0.26), and age (r = 0.25), all P < 0.0005. In this angiographically evaluated Syrian population, previously recognized, well-known risk factors appeared. Obesity, smoking, hypertension, diabetes, and elevated lipid levels are all amenable to correction. Syria should adopt the same secondary prevention strategies as those currently being practiced by non-Arab countries.
Response of dissolved trace metals to land use/land cover and their source apportionment using a receptor model in a subtropic river, China.

PubMed

Li, Siyue; Zhang, Quanfa

2011-06-15

Water samples were collected for determination of dissolved trace metals in 56 sampling sites throughout the upper Han River, China. Multivariate statistical analyses including correlation analysis, stepwise multiple linear regression models, and principal component and factor analysis (PCA/FA) were employed to examine the land use influences on trace metals, and a receptor model of factor analysis-multiple linear regression (FA-MLR) was used for source identification/apportionment of anthropogenic heavy metals in the surface water of the River. Our results revealed that land use was an important factor in water metals in the snow melt flow period and land use in the riparian zone was not a better predictor of metals than land use away from the river. Urbanization in a watershed and vegetation along river networks could better explain metals, and agriculture, regardless of its relative location, however slightly explained metal variables in the upper Han River. FA-MLR analysis identified five source types of metals, and mining, fossil fuel combustion, and vehicle exhaust were the dominant pollutions in the surface waters. The results demonstrated great impacts of human activities on metal concentrations in the subtropical river of China. Copyright © 2011 Elsevier B.V. All rights reserved.
Metabolic syndrome in Iranian patients with systemic lupus erythematosus and its determinants.

PubMed

Fatemi, Alimohammad; Ghanbarian, Azadeh; Sayedbonakdar, Zahra; Kazemi, Mehdi; Smiley, Abbas

2018-06-01

The aim of this study was to determine the prevalence of metabolic syndrome (MetS) in Iranian patients with systemic lupus erythematosus (SLE) and its determinants. In a cross-sectional study, 98 patients with SLE and 95 controls were enrolled. Prevalence of MetS was determined based on American Heart Association and National Heart, Lung, and Blood Institute (AHA/NHLBI) and 2009 harmonizing criteria. In addition, demographic features and lupus characteristics such as disease duration, pharmacological treatment, laboratory data, SLE disease activity index (SLEDAI), and Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage index (SDI) were recorded. The predictors of MetS were obtained by backward stepwise regression analysis. Using AHA/NHLBI, MetS was observed in 35 (35.7%) patients and 28 (29.8%) controls (P = 0.4). Using harmonizing criteria, MetS was observed in 37 (37.7%) patients and 33 (35.1%) controls (P = 0.7). There was no difference in frequency distribution of MetS components between the patients and the controls. In multivariate regression analysis, low C3, blood urea nitrogen (BUN), and body mass index were independent determinants of MetS in lupus patients. BUN, low C3, and body mass index were the major determinants of MetS in lupus patients.
Reduction of time-resolved space-based CCD photometry developed for MOST Fabry Imaging data*

NASA Astrophysics Data System (ADS)

Reegen, P.; Kallinger, T.; Frast, D.; Gruberbauer, M.; Huber, D.; Matthews, J. M.; Punz, D.; Schraml, S.; Weiss, W. W.; Kuschnig, R.; Moffat, A. F. J.; Walker, G. A. H.; Guenther, D. B.; Rucinski, S. M.; Sasselov, D.

2006-04-01

The MOST (Microvariability and Oscillations of Stars) satellite obtains ultraprecise photometry from space with high sampling rates and duty cycles. Astronomical photometry or imaging missions in low Earth orbits, like MOST, are especially sensitive to scattered light from Earthshine, and all these missions have a common need to extract target information from voluminous data cubes. They consist of upwards of hundreds of thousands of two-dimensional CCD frames (or subrasters) containing from hundreds to millions of pixels each, where the target information, superposed on background and instrumental effects, is contained only in a subset of pixels (Fabry Images, defocused images, mini-spectra). We describe a novel reduction technique for such data cubes: resolving linear correlations of target and background pixel intensities. This step-wise multiple linear regression removes only those target variations which are also detected in the background. The advantage of regression analysis versus background subtraction is the appropriate scaling, taking into account that the amount of contamination may differ from pixel to pixel. The multivariate solution for all pairs of target/background pixels is minimally invasive of the raw photometry while being very effective in reducing contamination due to, e.g. stray light. The technique is tested and demonstrated with both simulated oscillation signals and real MOST photometry.
Estimating extent of mortality associated with the Douglas-fir beetle in the Central and Northern Rockies

Treesearch

Jose F. Negron; Willis C. Schaupp; Kenneth E. Gibson; John Anhold; Dawn Hansen; Ralph Thier; Phil Mocettini

1999-01-01

Data collected from Douglas-fir stands infected by the Douglas-fir beetle in Wyoming, Montana, Idaho, and Utah, were used to develop models to estimate amount of mortality in terms of basal area killed. Models were built using stepwise linear regression and regression tree approaches. Linear regression models using initial Douglas-fir basal area were built for all...
Prognostic Significance of Carbohydrate Antigen 19-9 in Unresectable Locally Advanced Pancreatic Cancer Treated With Dose-Escalated Intensity Modulated Radiation Therapy and Concurrent Full-Dose Gemcitabine: Analysis of a Prospective Phase 1/2 Dose Escalation Study

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

Vainshtein, Jeffrey M., E-mail: jvainsh@med.umich.edu; Schipper, Matthew; Zalupski, Mark M.

2013-05-01

Purpose: Although established in the postresection setting, the prognostic value of carbohydrate antigen 19-9 (CA19-9) in unresectable locally advanced pancreatic cancer (LAPC) is less clear. We examined the prognostic utility of CA19-9 in patients with unresectable LAPC treated on a prospective trial of intensity modulated radiation therapy (IMRT) dose escalation with concurrent gemcitabine. Methods and Materials: Forty-six patients with unresectable LAPC were treated at the University of Michigan on a phase 1/2 trial of IMRT dose escalation with concurrent gemcitabine. CA19-9 was obtained at baseline and during routine follow-up. Cox models were used to assess the effect of baseline factorsmore » on freedom from local progression (FFLP), distant progression (FFDP), progression-free survival (PFS), and overall survival (OS). Stepwise forward regression was used to build multivariate predictive models for each endpoint. Results: Thirty-eight patients were eligible for the present analysis. On univariate analysis, baseline CA19-9 and age predicted OS, CA19-9 at baseline and 3 months predicted PFS, gross tumor volume (GTV) and black race predicted FFLP, and CA19-9 at 3 months predicted FFDP. On stepwise multivariate regression modeling, baseline CA19-9, age, and female sex predicted OS; baseline CA19-9 and female sex predicted both PFS and FFDP; and GTV predicted FFLP. Patients with baseline CA19-9 ≤90 U/mL had improved OS (median 23.0 vs 11.1 months, HR 2.88, P<.01) and PFS (14.4 vs 7.0 months, HR 3.61, P=.001). CA19-9 progression over 90 U/mL was prognostic for both OS (HR 3.65, P=.001) and PFS (HR 3.04, P=.001), and it was a stronger predictor of death than either local progression (HR 1.46, P=.42) or distant progression (HR 3.31, P=.004). Conclusions: In patients with unresectable LAPC undergoing definitive chemoradiation therapy, baseline CA19-9 was independently prognostic even after established prognostic factors were controlled for, whereas CA19-9 progression strongly predicted disease progression and death. Future trials should stratify by baseline CA19-9 and incorporate CA19-9 progression as a criterion for progressive disease.« less
Resilient Brain Aging: Characterization of Discordance between Alzheimer’s Disease Pathology and Cognition

PubMed Central

Negash, Selam; Wilson, Robert S.; Leurgans, Sue E.; Wolk, David A.; Schneider, Julie A.; Buchman, Aron S.; Bennett, David A.; Arnold, Steven. E.

2014-01-01

Background Although it is now evident that normal cognition can occur despite significant AD pathology, few studies have attempted to characterize this discordance, or examine factors that may contribute to resilient brain aging in the setting of AD pathology. Methods More than 2,000 older persons underwent annual evaluation as part of participation in the Religious Orders Study or Rush Memory Aging Project. A total of 966 subjects who had brain autopsy and comprehensive cognitive testing proximate to death were analyzed. Resilience was quantified as a continuous measure using linear regression modeling, where global cognition was entered as a dependent variable and global pathology was an independent variable. Studentized residuals generated from the model represented the discordance between cognition and pathology, and served as measure of resilience. The relation of resilience index to known risk factors for AD and related variables was examined. Results Multivariate regression models that adjusted for demographic variables revealed significant associations for early life socioeconomic status, reading ability, APOE-ε4 status, and past cognitive activity. A stepwise regression model retained reading level (estimate = 0.10, SE = 0.02; p < 0.0001) and past cognitive activity (estimate = 0.27, SE = 0.09; p = 0.002), suggesting the potential mediating role of these variables for resilience. Conclusions The construct of resilient brain aging can provide a framework for quantifying the discordance between cognition and pathology, and help identify factors that may mediate this relationship. PMID:23919768
Multivariate analysis of early and late nest sites of Abert's Towhees

Treesearch

Deborah M. Finch

1985-01-01

Seasonal variation in nest site selection by the Abert's towhee (Pipilo aberti) was studied in honey mesquite (Prosopis glandulosa) habitat along the lower Colorado River from March to July, 1981. Stepwise discriminant function analysis identified nest vegetation type, nest direction, and nest height as the three most important variables that characterized the...
Variables Associated with Communicative Participation in People with Multiple Sclerosis: A Regression Analysis

ERIC Educational Resources Information Center

Baylor, Carolyn; Yorkston, Kathryn; Bamer, Alyssa; Britton, Deanna; Amtmann, Dagmar

2010-01-01

Purpose: To explore variables associated with self-reported communicative participation in a sample (n = 498) of community-dwelling adults with multiple sclerosis (MS). Method: A battery of questionnaires was administered online or on paper per participant preference. Data were analyzed using multiple linear backward stepwise regression. The…
Prognostic Significance of Tumor Necrosis in Hilar Cholangiocarcinoma.

PubMed

Atanasov, Georgi; Schierle, Katrin; Hau, Hans-Michael; Dietel, Corinna; Krenzien, Felix; Brandl, Andreas; Wiltberger, Georg; Englisch, Julianna Paulina; Robson, Simon C; Reutzel-Selke, Anja; Pascher, Andreas; Jonas, Sven; Pratschke, Johann; Benzing, Christian; Schmelzle, Moritz

2017-02-01

Tumor necrosis and peritumoral fibrosis have both been suggested to have a prognostic value in selected solid tumors. However, little is known regarding their influence on tumor progression and prognosis in hilar cholangiocarcinoma (HC). Surgically resected tumor specimens of HC (n = 47) were analyzed for formation of necrosis and extent of peritumoral fibrosis. Tumor necrosis and grade of fibrosis were assessed histologically and correlated with clinicopathological characteristics, tumor recurrence, and patients' survival. Univariate Kaplan-Meier analysis and a stepwise multivariable Cox regression model were applied. Mild peritumoral fibrosis was evident in 12 tumor samples, moderate peritumoral fibrosis in 20, and high-grade fibrosis in 15. Necrosis was evident in 19 of 47 tumor samples. Patients with tumors characterized by necrosis showed a significantly decreased 5-year recurrence-free survival (37.9 vs. 25.7 %; p < .05) and a significantly decreased 5-year overall survival (42.6 vs. 12.4 %; p < .05), when compared with patients with tumors showing no necrosis. R status, tumor recurrence, and tumor necrosis were of prognostic value in the univariate analysis (all p < .05). Multivariate survival analysis confirmed tumor necrosis (p = .038) as the only independent prognostic variable. The assessment of tumor necrosis appears as a valuable additional prognostic tool in routine histopathological evaluation of HC. These observations might have implications for monitoring and more individualized multimodal therapeutic strategies.
Application of Multivariate Modeling for Radiation Injury Assessment: A Proof of Concept

PubMed Central

Bolduc, David L.; Villa, Vilmar; Sandgren, David J.; Ledney, G. David; Blakely, William F.; Bünger, Rolf

2014-01-01

Multivariate radiation injury estimation algorithms were formulated for estimating severe hematopoietic acute radiation syndrome (H-ARS) injury (i.e., response category three or RC3) in a rhesus monkey total-body irradiation (TBI) model. Classical CBC and serum chemistry blood parameters were examined prior to irradiation (d 0) and on d 7, 10, 14, 21, and 25 after irradiation involving 24 nonhuman primates (NHP) (Macaca mulatta) given 6.5-Gy 60Co Υ-rays (0.4 Gy min−1) TBI. A correlation matrix was formulated with the RC3 severity level designated as the “dependent variable” and independent variables down selected based on their radioresponsiveness and relatively low multicollinearity using stepwise-linear regression analyses. Final candidate independent variables included CBC counts (absolute number of neutrophils, lymphocytes, and platelets) in formulating the “CBC” RC3 estimation algorithm. Additionally, the formulation of a diagnostic CBC and serum chemistry “CBC-SCHEM” RC3 algorithm expanded upon the CBC algorithm model with the addition of hematocrit and the serum enzyme levels of aspartate aminotransferase, creatine kinase, and lactate dehydrogenase. Both algorithms estimated RC3 with over 90% predictive power. Only the CBC-SCHEM RC3 algorithm, however, met the critical three assumptions of linear least squares demonstrating slightly greater precision for radiation injury estimation, but with significantly decreased prediction error indicating increased statistical robustness. PMID:25165485
Quantitative structure-activity relationship of the curcumin-related compounds using various regression methods

NASA Astrophysics Data System (ADS)

Khazaei, Ardeshir; Sarmasti, Negin; Seyf, Jaber Yousefi

2016-03-01

Quantitative structure activity relationship were used to study a series of curcumin-related compounds with inhibitory effect on prostate cancer PC-3 cells, pancreas cancer Panc-1 cells, and colon cancer HT-29 cells. Sphere exclusion method was used to split data set in two categories of train and test set. Multiple linear regression, principal component regression and partial least squares were used as the regression methods. In other hand, to investigate the effect of feature selection methods, stepwise, Genetic algorithm, and simulated annealing were used. In two cases (PC-3 cells and Panc-1 cells), the best models were generated by a combination of multiple linear regression and stepwise (PC-3 cells: r2 = 0.86, q2 = 0.82, pred_r2 = 0.93, and r2m (test) = 0.43, Panc-1 cells: r2 = 0.85, q2 = 0.80, pred_r2 = 0.71, and r2m (test) = 0.68). For the HT-29 cells, principal component regression with stepwise (r2 = 0.69, q2 = 0.62, pred_r2 = 0.54, and r2m (test) = 0.41) is the best method. The QSAR study reveals descriptors which have crucial role in the inhibitory property of curcumin-like compounds. 6ChainCount, T_C_C_1, and T_O_O_7 are the most important descriptors that have the greatest effect. With a specific end goal to design and optimization of novel efficient curcumin-related compounds it is useful to introduce heteroatoms such as nitrogen, oxygen, and sulfur atoms in the chemical structure (reduce the contribution of T_C_C_1 descriptor) and increase the contribution of 6ChainCount and T_O_O_7 descriptors. Models can be useful in the better design of some novel curcumin-related compounds that can be used in the treatment of prostate, pancreas, and colon cancers.
Influence of storage conditions on the stability of monomeric anthocyanins studied by reversed-phase high-performance liquid chromatography.

PubMed

Morais, Helena; Ramos, Cristina; Forgács, Esther; Cserháti, Tibor; Oliviera, José

2002-04-25

The effect of light, storage time and temperature on the decomposition rate of monomeric anthocyanin pigments extracted from skins of grape (Vitis vinifera var. Red globe) was determined by reversed-phase high-performance liquid chromatography (RP-HPLC). The impact of various storage conditions on the pigment stability was assessed by stepwise regression analysis. RP-HPLC separated well the five anthocyanins identified and proved the presence of other unidentified pigments at lower concentrations. Stepwise regression analysis confirmed that the overall decomposition rate of monomeric anthocyanins, peonidin-3-glucoside and malvidin-3-glucoside significantly depended on the time and temperature of storage, the effect of storage time being the most important. The presence or absence of light exerted a negligible impact on the decomposition rate.
Estimation of longitudinal stability and control derivatives for an icing research aircraft from flight data

NASA Technical Reports Server (NTRS)

Batterson, James G.; Omara, Thomas M.

1989-01-01

The results of applying a modified stepwise regression algorithm and a maximum likelihood algorithm to flight data from a twin-engine commuter-class icing research aircraft are presented. The results are in the form of body-axis stability and control derivatives related to the short-period, longitudinal motion of the aircraft. Data were analyzed for the baseline (uniced) and for the airplane with an artificial glaze ice shape attached to the leading edge of the horizontal tail. The results are discussed as to the accuracy of the derivative estimates and the difference between the derivative values found for the baseline and the iced airplane. Additional comparisons were made between the maximum likelihood results and the modified stepwise regression results with causes for any discrepancies postulated.
Multiple linear regression analysis

NASA Technical Reports Server (NTRS)

Edwards, T. R.

1980-01-01

Program rapidly selects best-suited set of coefficients. User supplies only vectors of independent and dependent data and specifies confidence level required. Program uses stepwise statistical procedure for relating minimal set of variables to set of observations; final regression contains only most statistically significant coefficients. Program is written in FORTRAN IV for batch execution and has been implemented on NOVA 1200.
Anal sphincter lacerations and upright delivery postures--a risk analysis from a randomized controlled trial.

PubMed

Altman, Daniel; Ragnar, Inga; Ekström, Asa; Tydén, Tanja; Olsson, Sven-Eric

2007-02-01

To evaluate obstetric sphincter lacerations after a kneeling or sitting position at second stage of labor in a multivariate risk analysis model. Two hundred and seventy-one primiparous women with normal pregnancies and spontaneous labor were randomized, 138 to a kneeling position and 133 to a sitting position. Medical data were retrieved from delivery charts and partograms. Risk factors were tested in a multivariate logistic regression model in a stepwise manner. The trial was completed by 106 subjects in the kneeling group and 112 subjects in the sitting group. There were no significant differences with regard to duration of second stage of labor or pre-trial maternal characteristics between the two groups. Obstetrical sphincter tears did not differ significantly between the two groups but an intact perineum was more common in the kneeling group (p<0.03) and episiotomy (mediolateral) was more common in the sitting group (p<0.05). Three grade IV sphincter lacerations occurred in the sitting group compared to none in the kneeling group (NS). Multivariate risk analysis indicated that prolonged duration of second stage of labor and episiotomy were associated with an increased risk of third- or fourth-degree sphincter tears (p<0.01 and p<0.05, respectively). Delivery posture, maternal age, fetal weight, use of oxytocin, and use of epidural analgesia did not increase the risk of obstetrical anal sphincter lacerations in the two upright postures. Obstetrical anal sphincter lacerations did not differ significantly between a kneeling or sitting upright delivery posture. Episiotomy was more common after a sitting delivery posture, which may be associated with an increased risk of anal sphincter lacerations. Upright delivery postures may be encouraged in healthy women with normal, full-term pregnancy.
MAOA, MTHFR, and TNF-β genes polymorphisms and personality traits in the pathogenesis of migraine.

PubMed

Ishii, Masakazu; Shimizu, Shunichi; Sakairi, Yuki; Nagamine, Ayumu; Naito, Yuika; Hosaka, Yukiko; Naito, Yuko; Kurihara, Tatsuya; Onaya, Tomomi; Oyamada, Hideto; Imagawa, Atsuko; Shida, Kenji; Takahashi, Johji; Oguchi, Katsuji; Masuda, Yutaka; Hara, Hajime; Usami, Shino; Kiuchi, Yuji

2012-04-01

Migraine is a multifactorial disease with various factors, such as genetic polymorphisms and personality traits, but the contribution of those factors is not clear. To clarify the pathogenesis of migraine, the contributions of genetic polymorphisms and personality traits were simultaneously investigated using multivariate analysis. Ninety-one migraine patients and 119 non-headache healthy volunteers were enrolled. The 12 gene polymorphisms analysis and NEO-FFI personality test were performed. At first, the univariate analysis was performed to extract the contributing factors to pathogenesis of migraine. We then extracted the factors that independently contributed to the pathogenesis of migraine using multivariate stepwise logistic regression analysis. Using the multivariate analysis, three gene polymorphisms including monoamine oxidase A (MAOA) T941G, methylenetetrahydrofolate reductase (MTHFR) C677T, and tumor necrosis factor beta (TNF-β) G252Α, and the neuroticism and conscientiousness scores in NEO-FFI were selected as significant factors that independently contributed to the pathogenesis of migraine. Their odds ratios were 1.099 (per point of neuroticism score), 1.080 (per point of conscientiousness score), 2.272 (T and T/T or T/G vs G and G/G genotype of MAOA), 1.939 (C/T or T/T vs C/C genotype of MTHFR), and 2.748 (G/A or A/A vs G/G genotype of TNF-β), respectively. We suggested that multiple factors, such as gene polymorphisms and personality traits, contribute to the pathogenesis of migraine. The contribution of polymorphisms, such as MAOA T941G, MTHFR C677T, and TNF-β G252A, were more important than personality traits in the pathogenesis of migraine, a multifactorial disorder.
The structural equation analysis of childhood abuse, adult stressful life events, and temperaments in major depressive disorders and their influence on refractoriness

PubMed Central

Toda, Hiroyuki; Inoue, Takeshi; Tsunoda, Tomoya; Nakai, Yukiei; Tanichi, Masaaki; Tanaka, Teppei; Hashimoto, Naoki; Nakato, Yasuya; Nakagawa, Shin; Kitaichi, Yuji; Mitsui, Nobuyuki; Boku, Shuken; Tanabe, Hajime; Nibuya, Masashi; Yoshino, Aihide; Kusumi, Ichiro

2015-01-01

Background Previous studies have shown the interaction between heredity and childhood stress or life events on the pathogenesis of a major depressive disorder (MDD). In this study, we tested our hypothesis that childhood abuse, affective temperaments, and adult stressful life events interact and influence the diagnosis of MDD. Patients and methods A total of 170 healthy controls and 98 MDD patients were studied using the following self-administered questionnaire surveys: the Patient Health Questionnaire-9 (PHQ-9), the Life Experiences Survey, the Temperament Evaluation of the Memphis, Pisa, Paris, and San Diego Autoquestionnaire, and the Child Abuse and Trauma Scale (CATS). The data were analyzed with univariate analysis, multivariable analysis, and structural equation modeling. Results The neglect scores of the CATS indirectly predicted the diagnosis of MDD through cyclothymic and anxious temperament scores of the Temperament Evaluation of the Memphis, Pisa, Paris, and San Diego Autoquestionnaire in the structural equation modeling. Two temperaments – cyclothymic and anxious – directly predicted the diagnosis of MDD. The validity of this result was supported by the results of the stepwise multivariate logistic regression analysis as follows: three factors – neglect, cyclothymic, and anxious temperaments – were significant predictors of MDD. Neglect and the total CATS scores were also predictors of remission vs treatment-resistance in MDD patients independently of depressive symptoms. Limitations The sample size was small for the comparison between the remission and treatment-resistant groups in MDD patients in multivariable analysis. Conclusion This study suggests that childhood abuse, especially neglect, indirectly predicted the diagnosis of MDD through increased affective temperaments. The important role as a mediator of affective temperaments in the effect of childhood abuse on MDD was suggested. PMID:26316754

Cytopathologic differential diagnosis of low-grade urothelial carcinoma and reactive urothelial proliferation in bladder washings: a logistic regression analysis.

PubMed

Cakir, Ebru; Kucuk, Ulku; Pala, Emel Ebru; Sezer, Ozlem; Ekin, Rahmi Gokhan; Cakmak, Ozgur

2017-05-01

Conventional cytomorphologic assessment is the first step to establish an accurate diagnosis in urinary cytology. In cytologic preparations, the separation of low-grade urothelial carcinoma (LGUC) from reactive urothelial proliferation (RUP) can be exceedingly difficult. The bladder washing cytologies of 32 LGUC and 29 RUP were reviewed. The cytologic slides were examined for the presence or absence of the 28 cytologic features. The cytologic criteria showing statistical significance in LGUC were increased numbers of monotonous single (non-umbrella) cells, three-dimensional cellular papillary clusters without fibrovascular cores, irregular bordered clusters, atypical single cells, irregular nuclear overlap, cytoplasmic homogeneity, increased N/C ratio, pleomorphism, nuclear border irregularity, nuclear eccentricity, elongated nuclei, and hyperchromasia (p ˂ 0.05), and the cytologic criteria showing statistical significance in RUP were inflammatory background, mixture of small and large urothelial cells, loose monolayer aggregates, and vacuolated cytoplasm (p ˂ 0.05). When these variables were subjected to a stepwise logistic regression analysis, four features were selected to distinguish LGUC from RUP: increased numbers of monotonous single (non-umbrella) cells, increased nuclear cytoplasmic ratio, hyperchromasia, and presence of small and large urothelial cells (p = 0.0001). By this logistic model of the 32 cases with proven LGUC, the stepwise logistic regression analysis correctly predicted 31 (96.9%) patients with this diagnosis, and of the 29 patients with RUP, the logistic model correctly predicted 26 (89.7%) patients as having this disease. There are several cytologic features to separate LGUC from RUP. Stepwise logistic regression analysis is a valuable tool for determining the most useful cytologic criteria to distinguish these entities. © 2017 APMIS. Published by John Wiley & Sons Ltd.
Bayesian Estimation of Multivariate Latent Regression Models: Gauss versus Laplace

ERIC Educational Resources Information Center

Culpepper, Steven Andrew; Park, Trevor

2017-01-01

A latent multivariate regression model is developed that employs a generalized asymmetric Laplace (GAL) prior distribution for regression coefficients. The model is designed for high-dimensional applications where an approximate sparsity condition is satisfied, such that many regression coefficients are near zero after accounting for all the model…
Advancing a Model-Validated Statistical Method for Decomposing the Key Oceanic Drivers of Regional Climate: Focus on Northern and Tropical African Climate Variability in the Community Earth System Model (CESM)

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

Wang, Fuyao; Yu, Yan; Notaro, Michael

This study advances the practicality and stability of the traditional multivariate statistical method, generalized equilibrium feedback assessment (GEFA), for decomposing the key oceanic drivers of regional atmospheric variability, especially when available data records are short. An advanced stepwise GEFA methodology is introduced, in which unimportant forcings within the forcing matrix are eliminated through stepwise selection. Method validation of stepwise GEFA is performed using the CESM, with a focused application to northern and tropical Africa (NTA). First, a statistical assessment of the atmospheric response to each primary oceanic forcing is carried out by applying stepwise GEFA to a fully coupled controlmore » run. Then, a dynamical assessment of the atmospheric response to individual oceanic forcings is performed through ensemble experiments by imposing sea surface temperature anomalies over focal ocean basins. Finally, to quantify the reliability of stepwise GEFA, the statistical assessment is evaluated against the dynamical assessment in terms of four metrics: the percentage of grid cells with consistent response sign, the spatial correlation of atmospheric response patterns, the area-averaged seasonal cycle of response magnitude, and consistency in associated mechanisms between assessments. In CESM, tropical modes, namely El Niño–Southern Oscillation and the tropical Indian Ocean Basin, tropical Indian Ocean dipole, and tropical Atlantic Niño modes, are the dominant oceanic controls of NTA climate. In complementary studies, stepwise GEFA is validated in terms of isolating terrestrial forcings on the atmosphere, and observed oceanic and terrestrial drivers of NTA climate are extracted to establish an observational benchmark for subsequent coupled model evaluation and development of process-based weights for regional climate projections.« less
Advancing a Model-Validated Statistical Method for Decomposing the Key Oceanic Drivers of Regional Climate: Focus on Northern and Tropical African Climate Variability in the Community Earth System Model (CESM)

DOE PAGES

Wang, Fuyao; Yu, Yan; Notaro, Michael; ...

2017-09-27

This study advances the practicality and stability of the traditional multivariate statistical method, generalized equilibrium feedback assessment (GEFA), for decomposing the key oceanic drivers of regional atmospheric variability, especially when available data records are short. An advanced stepwise GEFA methodology is introduced, in which unimportant forcings within the forcing matrix are eliminated through stepwise selection. Method validation of stepwise GEFA is performed using the CESM, with a focused application to northern and tropical Africa (NTA). First, a statistical assessment of the atmospheric response to each primary oceanic forcing is carried out by applying stepwise GEFA to a fully coupled controlmore » run. Then, a dynamical assessment of the atmospheric response to individual oceanic forcings is performed through ensemble experiments by imposing sea surface temperature anomalies over focal ocean basins. Finally, to quantify the reliability of stepwise GEFA, the statistical assessment is evaluated against the dynamical assessment in terms of four metrics: the percentage of grid cells with consistent response sign, the spatial correlation of atmospheric response patterns, the area-averaged seasonal cycle of response magnitude, and consistency in associated mechanisms between assessments. In CESM, tropical modes, namely El Niño–Southern Oscillation and the tropical Indian Ocean Basin, tropical Indian Ocean dipole, and tropical Atlantic Niño modes, are the dominant oceanic controls of NTA climate. In complementary studies, stepwise GEFA is validated in terms of isolating terrestrial forcings on the atmosphere, and observed oceanic and terrestrial drivers of NTA climate are extracted to establish an observational benchmark for subsequent coupled model evaluation and development of process-based weights for regional climate projections.« less
Multivariate Regression Analysis and Slaughter Livestock,

DTIC Science & Technology

AGRICULTURE, *ECONOMICS), (*MEAT, PRODUCTION), MULTIVARIATE ANALYSIS, REGRESSION ANALYSIS , ANIMALS, WEIGHT, COSTS, PREDICTIONS, STABILITY, MATHEMATICAL MODELS, STORAGE, BEEF, PORK, FOOD, STATISTICAL DATA, ACCURACY
Employees' negative and positive work-home interaction and their association with depressive symptoms.

PubMed

Nitzsche, Anika; Jung, Julia; Pfaff, Holger; Driller, Elke

2013-05-01

Depression is the leading cause of disability and high costs worldwide. One possibility for preventing depression in the workplace, which has received little consideration so far, is the promotion of a successful balance between work and personal life. The aim of this study was to investigate employees' negative and positive work-home interaction and their association with depressive symptoms. A cross-sectional study was conducted in the micro- and nanotechnology sector in Germany. A stepwise multivariate logistic regression analysis was performed using data from N = 213 employees. The results suggest that while negative work-home interaction is associated with an increased risk for depressive symptoms, positive work-home interaction is correlated with a lower risk. Neither positive nor negative interaction in the home-to-work direction demonstrated a significant association with depressive symptoms. When attempting to prevent mental illnesses, such as depression, it is important to develop strategies aimed at reducing conflict between work and personal life and promoting a positive exchange between these two domains. Copyright © 2012 Wiley Periodicals, Inc.
Colon cancer: personality factors predictive of onset and stage of presentation.

PubMed

Kavan, M G; Engdahl, B E; Kay, S

1995-11-01

This study examined premorbid personality correlates of colon cancer and stage of presentation of colon cancer to health care providers. Sixty-one male veterans who completed the MMPI between 1947 and 1975 and were then diagnosed with colon cancer between 1977 and 1988 were matched with control patients. A 21-factor solution of the MMPI [1] was used to seek potential personality differences between colon cancer cases and their controls in terms of presence of colon cancer and stage of presentation for this disease. A stepwise conditional regression analysis found significant differences between the colon cancer and control groups on the Aggressive Hostility variable (p < 0.018). A multivariate analysis of variance conducted across the stages of colon cancer presentation found that patients who presented later on for colon cancer had higher Phobia scores (p < 0.05). Religious Fundamentalism was also related to presentation (p < 0.05), but in a nonlinear manner. Discussion is related to previous findings regarding the relationship between personality and development of cancer, as well as to implications for patient screening.
Using foreground/background analysis to determine leaf and canopy chemistry

NASA Technical Reports Server (NTRS)

Pinzon, J. E.; Ustin, S. L.; Hart, Q. J.; Jacquemoud, S.; Smith, M. O.

1995-01-01

Spectral Mixture Analysis (SMA) has become a well established procedure for analyzing imaging spectrometry data, however, the technique is relatively insensitive to minor sources of spectral variation (e.g., discriminating stressed from unstressed vegetation and variations in canopy chemistry). Other statistical approaches have been tried e.g., stepwise multiple linear regression analysis to predict canopy chemistry. Grossman et al. reported that SMLR is sensitive to measurement error and that the prediction of minor chemical components are not independent of patterns observed in more dominant spectral components like water. Further, they observed that the relationships were strongly dependent on the mode of expressing reflectance (R, -log R) and whether chemistry was expressed on a weight (g/g) or are basis (g/sq m). Thus, alternative multivariate techniques need to be examined. Smith et al. reported a revised SMA that they termed Foreground/Background Analysis (FBA) that permits directing the analysis along any axis of variance by identifying vectors through the n-dimensional spectral volume orthonormal to each other. Here, we report an application of the FBA technique for the detection of canopy chemistry using a modified form of the analysis.
The impact of social and family-related factors on women's stress experience in household and family work.

PubMed

Sperlich, Stefanie; Geyer, Siegfried

2015-03-01

This study explores the contribution of social and family-related factors to women's experience of an effort-reward imbalance (ERI) in household and family work. Using a population-based sample of German mothers (n = 3,129), we performed stepwise logistic regression analysis in order to determine the relative impact of social and family-related factors on ERI. All factors investigated showed a significant association with at least one ERI component. Considering all predictors simultaneously in the multivariate analysis resulted in a decrease in significance of socioeconomic status in explaining the effort-reward ratio while the impact on low reward partly remained significant. In addition, age of youngest child, number of children, lower levels of perceived social support, domestic work inequity and negative work-to-family spillover, irrespective of being half- or full-time employed, revealed to be important in predicting ERI. The experience of ERI in domestic work is influenced by the social and family environment. Particularly among socially disadvantaged mothers, lack of social recognition for household and family work proved to be a relevant source of psychosocial stress.
Psychoanalysis, artistic obsession, and artistic motivation: the study of pathography.

PubMed

Kemler, David S

2014-02-01

A modern assessment of Freud's conceptualization of the creative process focusing on drives, ego psychology, and object relation theory is presented. 40 artists and musicians were interviewed employing 13 open-ended questions to provoke responses historically associated with the theoretical conceptualizations of Freud and post-Freudian theory related to the creative process. Creative process was defined as internal object relations that motivate the external connection between artist and the creative work. Measured responses concerning purpose and understanding; motivation before, during, and after performance; obstacles in performance; and needs through the creative process were assessed. Cluster analysis segregated the participants into high, medium, and low agreement groups based on similarity of responses. A multivariate stepwise regression revealed four questions (enlightenment, drives, obstacles, and ought self discrepancies) accounted for 83.9% of the variance. A post hoc discriminant function analysis identified 82.5% of the population to their correct groups. The findings support Spitz's (2005) suggestion that we regard "drives, ego psychology, and object relation theory not as separate approaches but as parts of a whole with varying stresses or accents" (p. 503).
Exercise motivation and adherence in cancer survivors after participation in a randomized controlled trial: an attribution theory perspective.

PubMed

Courneya, Kerry S; Friedenreich, Christine M; Sela, Rami A; Quinney, H Arthur; Rhodes, Ryan E; Jones, Lee W

2004-01-01

The purpose of this study was to examine postprogram exercise motivation and adherence in cancer survivors who participated in the Group Psychotherapy and Home-Based Physical Exercise (GROUP-HOPE; Courneya, Friedenreich, Sela, Quinney, & Rhodes, 2002) trial. At the completion of the GROUP-HOPE trial, 46 of 51 (90%) participants in the exercise group completed measures of attribution theory constructs. A 5-week follow-up self-report of exercise was then completed by 30 (65%) participants. Correlational analyses indicated that program exercise, perceived success, expected success, and affective reactions were strong predictors of postprogram exercise. In multivariate stepwise regression analyses, program exercise and perceived success were the strongest predictors of postprogram exercise. Additionally, perceived success was more important than objective success in understanding the attribution process, and it interacted with personal control to influence expected success and negative affect. Finally, postprogram quality of life and changes in physical fitness were correlates of perceived success. We concluded that attribution theory may have utility for understanding postprogram exercise motivation and adherence in cancer survivors.
Factors contributing to tooth loss among the elderly: A cross sectional study.

PubMed

Natto, Zuhair S; Aladmawy, Majdi; Alasqah, Mohammed; Papas, Athena

2014-12-01

The present study evaluates the influence of several demographic, health, personal, and clinical factors on the number of missing teeth in old age sample. The number of patients included was 259; they received a full mouth examination and answered a questionnaire provided by one examiner. All the variables related to teeth loss based on the literature were included. These variables focused on age, gender, race, marital status, clinical attachment level, pocket depth, year of smoking, number of cigarettes smoked per day, number of medications, root decay, coronal decay, health status, and year of education. Statistical analysis involved stepwise multivariate linear regression. Teeth loss was statistically associated with clinical attachment level (CAL)(p value 0.0001), pocket depth (PD) (0.0007) and education level (0.0048). When smoking was included in the model, age was significantly associated with teeth loss (0.0037). At least one of these four factors was also related to teeth loss in several specific groups such as diabetes mellitus, male, and White. The multiple linear regressions for all the proposed variables showed that they contributed to teeth loss by about 23%. It can be concluded that less education or increased clinical attachment level loss may increase number of missing teeth. Additionally, age may cause teeth loss in the presence of smoking. Copyright © 2014. Published by Elsevier B.V.
Plasma 8-iso-Prostaglandin F2α concentrations and outcomes after acute intracerebral hemorrhage.

PubMed

Du, Quan; Yu, Wen-Hua; Dong, Xiao-Qiao; Yang, Ding-Bo; Shen, Yong-Feng; Wang, Hao; Jiang, Li; Du, Yuan-Feng; Zhang, Zu-Yong; Zhu, Qiang; Che, Zhi-Hao; Liu, Qun-Jie

2014-11-01

Higher plasma 8-iso-Prostaglandin F2α concentrations have been associated with poor outcome of severe traumatic brain injury. We further investigated the relationships between plasma 8-iso-Prostaglandin F2α concentrations and clinical outcomes in patients with acute intracerebral hemorrhage. Plasma 8-iso-Prostaglandin F2α concentrations of 128 consecutive patients and 128 sex- and gender-matched healthy subjects were measured by enzyme-linked immunosorbent assay. We assessed their relationships with disease severity and clinical outcomes including 1-week mortality, 6-month mortality and unfavorable outcome (modified Rankin Scale score>2). Plasma 8-iso-Prostaglandin F2α concentrations were substantially higher in patients than in healthy controls. Plasma 8-iso-Prostaglandin F2α concentrations were positively associated with National Institutes of Health Stroke Scale (NIHSS) scores and hematoma volume using a multivariate linear regression. It emerged as an independent predictor for clinical outcomes of patients using a forward stepwise logistic regression. ROC curves identified the predictive values of plasma 8-iso-Prostaglandin F2α concentrations, and found its predictive value was similar to NIHSS scores and hematoma volumes. However, it just numerically added the predictive values of NIHSS score and hematoma volume. Increased plasma 8-iso-Prostaglandin F2α concentrations are associated with disease severity and clinical outcome after acute intracerebral hemorrhage. Copyright © 2014 Elsevier B.V. All rights reserved.
IL-8 predicts pediatric oncology patients with febrile neutropenia at low risk for bacteremia.

PubMed

Cost, Carrye R; Stegner, Martha M; Leonard, David; Leavey, Patrick

2013-04-01

Despite a low bacteremia rate, pediatric oncology patients are frequently admitted for febrile neutropenia. A pediatric risk prediction model with high sensitivity to identify patients at low risk for bacteremia is not available. We performed a single-institution prospective cohort study of pediatric oncology patients with febrile neutropenia to create a risk prediction model using clinical factors, respiratory viral infection, and cytokine expression. Pediatric oncology patients with febrile neutropenia were enrolled between March 30, 2010 and April 1, 2011 and managed per institutional protocol. Blood samples for C-reactive protein and cytokine expression and nasopharyngeal swabs for respiratory viral testing were obtained. Medical records were reviewed for clinical data. Statistical analysis utilized mixed multiple logistic regression modeling. During the 12-month period, 195 febrile neutropenia episodes were enrolled. There were 24 (12%) episodes of bacteremia. Univariate analysis revealed several factors predictive for bacteremia, and interleukin (IL)-8 was the most predictive variable in the multivariate stepwise logistic regression. Low serum IL-8 predicted patients at low risk for bacteremia with a sensitivity of 0.9 and negative predictive value of 0.98. IL-8 is a highly sensitive predictor for patients at low risk for bacteremia. IL-8 should be utilized in a multi-institution prospective trial to assign risk stratification to pediatric patients admitted with febrile neutropenia.
FEMALE SEX AND DISCONTINUATION OF ISONIAZID DUE TO ADVERSE EFFECTS DURING THE TREATMENT OF LATENT TUBERCULOSIS

PubMed Central

Pettit, April C.; Bethel, James; Hirsch-Moverman, Yael; Colson, Paul W.; Sterling, Timothy R.

2013-01-01

SUMMARY Objectives To determine the rate of and risk factors for discontinuation of isoniazid due to adverse effects during the treatment of latent tuberculosis infection in a large, multi-site study. Methods The Tuberculosis Epidemiologic Studies Consortium (TBESC) conducted a prospective study from March 2007–September 2008 among adults initiating isoniazid for treatment of LTBI at 12 sites in the US and Canada. The relative risk for isoniazid discontinuation due to adverse effects was determined using negative binomial regression. Adjusted models were constructed using forward stepwise regression. Results Of 1,306 persons initiating isoniazid, 617 (47.2%, 95% CI 44.5–50.0%) completed treatment and 196 (15.0%, 95% CI 13.1–17.1%) discontinued due to adverse effects. In multivariable analysis, female sex (RR 1.67, 95% CI 1.32–2.10, p<0.001) and current alcohol use (RR 1.41, 95% CI 1.13–1.77, p=0.003) were independently associated with isoniazid discontinuation due to adverse effects. Conclusions The rate of discontinuation of isoniazid due to adverse effects was substantially higher than reported earlier. Women were at increased risk of discontinuing isoniazid due to adverse effects; close monitoring of women for adverse effects may be warranted. Current alcohol use was also associated with isoniazid discontinuation; counseling patients to abstain from alcohol could decrease discontinuation due to adverse effects. PMID:23845828
Predictors of cervical lordosis loss after laminoplasty in patients with cervical spondylotic myelopathy.

PubMed

Zhang, Jing Tao; Li, Jia Qi; Niu, Rui Jie; Liu, Zhao; Tong, Tong; Shen, Yong

2017-04-01

To determine whether radiological, clinical, and demographic findings in patients with cervical spondylotic myelopathy (CSM) were independently associated with loss of cervical lordosis (LCL) after laminoplasty. The prospective study included 41 consecutive patients who underwent laminoplasty for CSM. The difference in C2-7 Cobb angle between the postoperative and preoperative films was used to evaluate change in cervical alignment. Age, sex, body mass index (BMI), smoking history, preoperative C2-7 Cobb angle, T1 slope, C2-7 range of motion (C2-7 ROM), C2-7 sagittal vertical axis (C2-7 SVA), and cephalad vertebral level undergoing laminoplasty (CVLL) were assessed. Data were analyzed using Pearson and Spearman correlation test, and univariate and stepwise multivariate linear regression. T1 slope, C2-7 SVA, and CVLL significantly correlated with LCL (P < 0.001), whereas age, BMI, and preoperative C2-7 Cobb angle did not. In multiple linear regression analysis, higher T1 slope (B = 0.351, P = 0.037), greater C2-7 SVA (B = 0.393, P < 0.001), and starting laminoplasty at C4 level (B = - 7.038, P < 0.001) were significantly associated with higher postoperative LCL. Cervical alignment was compromised after laminoplasty in patients with CSM, and the degree of LCL was associated with preoperative T1 slope, C2-7 SVA, and CVLL.
Which Frail Older People Are Dehydrated? The UK DRIE Study

PubMed Central

Bunn, Diane K.; Downing, Alice; Jimoh, Florence O.; Groves, Joyce; Free, Carol; Cowap, Vicky; Potter, John F.; Hunter, Paul R.; Shepstone, Lee

2016-01-01

Background: Water-loss dehydration in older people is associated with increased mortality and disability. We aimed to assess the prevalence of dehydration in older people living in UK long-term care and associated cognitive, functional, and health characteristics. Methods: The Dehydration Recognition In our Elders (DRIE) cohort study included people aged 65 or older living in long-term care without heart or renal failure. In a cross-sectional baseline analysis, we assessed serum osmolality, previously suggested dehydration risk factors, general health, markers of continence, cognitive and functional health, nutrition status, and medications. Univariate linear regression was used to assess relationships between participant characteristics and serum osmolality, then associated characteristics entered into stepwise backwards multivariate linear regression. Results: DRIE included 188 residents (mean age 86 years, 66% women) of whom 20% were dehydrated (serum osmolality >300 mOsm/kg). Linear and logistic regression suggested that renal, cognitive, and diabetic status were consistently associated with serum osmolality and odds of dehydration, while potassium-sparing diuretics, sex, number of recent health contacts, and bladder incontinence were sometimes associated. Thirst was not associated with hydration status. Conclusions: DRIE found high prevalence of dehydration in older people living in UK long-term care, reinforcing the proposed association between cognitive and renal function and hydration. Dehydration is associated with increased mortality and disability in older people, but trials to assess effects of interventions to support healthy fluid intakes in older people living in residential care are needed to enable us to formally assess causal direction and any health benefits of increasing fluid intakes. PMID:26553658
A novel simple QSAR model for the prediction of anti-HIV activity using multiple linear regression analysis.

PubMed

Afantitis, Antreas; Melagraki, Georgia; Sarimveis, Haralambos; Koutentis, Panayiotis A; Markopoulos, John; Igglessi-Markopoulou, Olga

2006-08-01

A quantitative-structure activity relationship was obtained by applying Multiple Linear Regression Analysis to a series of 80 1-[2-hydroxyethoxy-methyl]-6-(phenylthio) thymine (HEPT) derivatives with significant anti-HIV activity. For the selection of the best among 37 different descriptors, the Elimination Selection Stepwise Regression Method (ES-SWR) was utilized. The resulting QSAR model (R (2) (CV) = 0.8160; S (PRESS) = 0.5680) proved to be very accurate both in training and predictive stages.
A Web-based nomogram predicting para-aortic nodal metastasis in incompletely staged patients with endometrial cancer: a Korean Multicenter Study.

PubMed

Kang, Sokbom; Lee, Jong-Min; Lee, Jae-Kwan; Kim, Jae-Weon; Cho, Chi-Heum; Kim, Seok-Mo; Park, Sang-Yoon; Park, Chan-Yong; Kim, Ki-Tae

2014-03-01

The purpose of this study is to develop a Web-based nomogram for predicting the individualized risk of para-aortic nodal metastasis in incompletely staged patients with endometrial cancer. From 8 institutions, the medical records of 397 patients who underwent pelvic and para-aortic lymphadenectomy as a surgical staging procedure were retrospectively reviewed. A multivariate logistic regression model was created and internally validated by rigorous bootstrap resampling methods. Finally, the model was transformed into a user-friendly Web-based nomogram (http://http://www.kgog.org/nomogram/empa001.html). The rate of para-aortic nodal metastasis was 14.4% (57/397 patients). Using a stepwise variable selection, 4 variables including deep myometrial invasion, non-endometrioid subtype, lymphovascular space invasion, and log-transformed CA-125 levels were finally adopted. After 1000 repetitions of bootstrapping, all of these 4 variables retained a significant association with para-aortic nodal metastasis in the multivariate analysis-deep myometrial invasion (P = 0.001), non-endometrioid histologic subtype (P = 0.034), lymphovascular space invasion (P = 0.003), and log-transformed serum CA-125 levels (P = 0.004). The model showed good discrimination (C statistics = 0.87; 95% confidence interval, 0.82-0.92) and accurate calibration (Hosmer-Lemeshow P = 0.74). This nomogram showed good performance in predicting para-aortic metastasis in patients with endometrial cancer. The tool may be useful in determining the extent of lymphadenectomy after incomplete surgery.
Venous thromboembolism in women undergoing pelvic reconstructive surgery with mechanical prophylaxis alone.

PubMed

Montoya, T Ignacio; Leclaire, Edgar L; Oakley, Susan H; Crane, Andrea K; Mcpencow, Alexandra; Cichowski, Sara; Rahn, David D

2014-07-01

The objective of this study was determine the frequency of symptomatic perioperative venous thromboembolism (VTE) and risk factor(s) associated with VTE occurrence in women undergoing elective pelvic reconstructive surgery using only intermittent pneumatic compression (IPC) for VTE prophylaxis. A multi-center case-cohort retrospective review was conducted at six clinical sites over a 66-month period. All sites utilize IPC as standard VTE prophylaxis for urogynecological surgery. VTE cases occurring during the same hospitalization and up to 6 weeks postoperatively were identified by ICD9 code query. Four controls were temporally matched to each case. Information collected included demographics, medical history, route of surgery, operative time, and intraoperative characteristics. Univariate and multivariate backward stepwise logistic regression analyses were performed to identify potential risk factors for VTE. Symptomatic perioperative VTE was diagnosed in 27 subjects from a cohort of 10,627 women who underwent elective urogynecological surgery (0.25 %). Univariate analysis identified surgical route (laparotomy vs others), type of surgery ("major" vs "minor"), history of gynecological cancer, surgery time, and patient age as risk factors for VTE (P < 0.05). Multivariate analysis identified increased frequency of VTE with laparotomy, age ≥ 70, and surgery duration ≥ 5 h. In our study cohort, the frequency of symptomatic perioperative VTE was low. Laparotomy, age ≥ 70 years, and surgery duration ≥ 5 h were associated with VTE occurrence.

Preoperative galactose elimination capacity predicts complications and survival after hepatic resection.

PubMed

Redaelli, Claudio A; Dufour, Jean-François; Wagner, Markus; Schilling, Martin; Hüsler, Jürg; Krähenbühl, Lukas; Büchler, Markus W; Reichen, Jürg

2002-01-01

To analyze a single center's 6-year experience with 258 consecutive patients undergoing major hepatic resection for primary or secondary malignancy of the liver, and to examine the predictive value of preoperative liver function assessment. Despite the substantial improvements in diagnostic and surgical techniques that have made liver surgery a safer procedure, careful patient selection remains mandatory to achieve good results in patients with hepatic tumors. In this prospective study, 258 patients undergoing hepatic resection were enrolled: 111 for metastases, 78 for hepatocellular carcinoma (HCC), 21 for cholangiocellular carcinoma, and 48 for other primary hepatic tumors. One hundred fifty-eight patients underwent segment-oriented liver resection, including hemihepatectomies, and 100 had subsegmental resections. Thirty-two clinical and biochemical parameters were analyzed, including liver function assessment by the galactose elimination capacity (GEC) test, a measure of hepatic functional reserve, to predict postoperative (60-day) rates of death and complications and long-term survival. All variables were determined within 5 days before surgery. Data were subjected to univariate and multivariate analysis for two patient subgroups (HCC and non-HCC). The cutoffs for GEC in both groups were predefined. Long-term survival (>60 days) was subjected to Kaplan-Meier analysis and the Cox proportional hazard model. In the entire group of 258 patients, a GEC less than 6 mg/min/kg was the only preoperative biochemical parameter that predicted postoperative complications and death by univariate and stepwise regression analysis. A GEC of more than 6 mg/min/kg was also significantly associated with longer survival. This predictive value could also be shown in the subgroup of 180 patients with tumors other than HCC. In the subgroup of 78 patients with HCC, a GEC less than 4 mg/min/kg predicted postoperative complications and death by univariate and stepwise regression analysis. Further, a GEC of more than 4 mg/min/kg was also associated with longer survival. This prospective study establishes the preoperative determination of the hepatic reserve by GEC as a strong independent and valuable predictor for short- and long-term outcome in patients with primary and secondary hepatic tumors undergoing resection.
Preoperative Galactose Elimination Capacity Predicts Complications and Survival After Hepatic Resection

PubMed Central

Redaelli, Claudio A.; Dufour, Jean-François; Wagner, Markus; Schilling, Martin; Hüsler, Jürg; Krähenbühl, Lukas; Büchler, Markus W.; Reichen, Jürg

2002-01-01

Objective To analyze a single center’s 6-year experience with 258 consecutive patients undergoing major hepatic resection for primary or secondary malignancy of the liver, and to examine the predictive value of preoperative liver function assessment. Summary Background Data Despite the substantial improvements in diagnostic and surgical techniques that have made liver surgery a safer procedure, careful patient selection remains mandatory to achieve good results in patients with hepatic tumors. Methods In this prospective study, 258 patients undergoing hepatic resection were enrolled: 111 for metastases, 78 for hepatocellular carcinoma (HCC), 21 for cholangiocellular carcinoma, and 48 for other primary hepatic tumors. One hundred fifty-eight patients underwent segment-oriented liver resection, including hemihepatectomies, and 100 had subsegmental resections. Thirty-two clinical and biochemical parameters were analyzed, including liver function assessment by the galactose elimination capacity (GEC) test, a measure of hepatic functional reserve, to predict postoperative (60-day) rates of death and complications and long-term survival. All variables were determined within 5 days before surgery. Data were subjected to univariate and multivariate analysis for two patient subgroups (HCC and non-HCC). The cutoffs for GEC in both groups were predefined. Long-term survival (>60 days) was subjected to Kaplan-Meier analysis and the Cox proportional hazard model. Results In the entire group of 258 patients, a GEC less than 6 mg/min/kg was the only preoperative biochemical parameter that predicted postoperative complications and death by univariate and stepwise regression analysis. A GEC of more than 6 mg/min/kg was also significantly associated with longer survival. This predictive value could also be shown in the subgroup of 180 patients with tumors other than HCC. In the subgroup of 78 patients with HCC, a GEC less than 4 mg/min/kg predicted postoperative complications and death by univariate and stepwise regression analysis. Further, a GEC of more than 4 mg/min/kg was also associated with longer survival. Conclusions This prospective study establishes the preoperative determination of the hepatic reserve by GEC as a strong independent and valuable predictor for short- and long-term outcome in patients with primary and secondary hepatic tumors undergoing resection. PMID:11753045
Drought prediction using co-active neuro-fuzzy inference system, validation, and uncertainty analysis (case study: Birjand, Iran)

NASA Astrophysics Data System (ADS)

Memarian, Hadi; Pourreza Bilondi, Mohsen; Rezaei, Majid

2016-08-01

This work aims to assess the capability of co-active neuro-fuzzy inference system (CANFIS) for drought forecasting of Birjand, Iran through the combination of global climatic signals with rainfall and lagged values of Standardized Precipitation Index (SPI) index. Using stepwise regression and correlation analyses, the signals NINO 1 + 2, NINO 3, Multivariate Enso Index, Tropical Southern Atlantic index, Atlantic Multi-decadal Oscillation index, and NINO 3.4 were recognized as the effective signals on the drought event in Birjand. Based on the results from stepwise regression analysis and regarding the processor limitations, eight models were extracted for further processing by CANFIS. The metrics P-factor and D-factor were utilized for uncertainty analysis, based on the sequential uncertainty fitting algorithm. Sensitivity analysis showed that for all models, NINO indices and rainfall variable had the largest impact on network performance. In model 4 (as the model with the lowest error during training and testing processes), NINO 1 + 2(t-5) with an average sensitivity of 0.7 showed the highest impact on network performance. Next, the variables rainfall, NINO 1 + 2(t), and NINO 3(t-6) with the average sensitivity of 0.59, 0.28, and 0.28, respectively, could have the highest effect on network performance. The findings based on network performance metrics indicated that the global indices with a time lag represented a better correlation with El Niño Southern Oscillation (ENSO). Uncertainty analysis of the model 4 demonstrated that 68 % of the observed data were bracketed by the 95PPU and D-Factor value (0.79) was also within a reasonable range. Therefore, the fourth model with a combination of the input variables NINO 1 + 2 (with 5 months of lag and without any lag), monthly rainfall, and NINO 3 (with 6 months of lag) and correlation coefficient of 0.903 (between observed and simulated SPI) was selected as the most accurate model for drought forecasting using CANFIS in the climatic region of Birjand.
Remote-sensing data processing with the multivariate regression analysis method for iron mineral resource potential mapping: a case study in the Sarvian area, central Iran

NASA Astrophysics Data System (ADS)

Mansouri, Edris; Feizi, Faranak; Jafari Rad, Alireza; Arian, Mehran

2018-03-01

This paper uses multivariate regression to create a mathematical model for iron skarn exploration in the Sarvian area, central Iran, using multivariate regression for mineral prospectivity mapping (MPM). The main target of this paper is to apply multivariate regression analysis (as an MPM method) to map iron outcrops in the northeastern part of the study area in order to discover new iron deposits in other parts of the study area. Two types of multivariate regression models using two linear equations were employed to discover new mineral deposits. This method is one of the reliable methods for processing satellite images. ASTER satellite images (14 bands) were used as unique independent variables (UIVs), and iron outcrops were mapped as dependent variables for MPM. According to the results of the probability value (p value), coefficient of determination value (R2) and adjusted determination coefficient (Radj2), the second regression model (which consistent of multiple UIVs) fitted better than other models. The accuracy of the model was confirmed by iron outcrops map and geological observation. Based on field observation, iron mineralization occurs at the contact of limestone and intrusive rocks (skarn type).
Correlative and multivariate analysis of increased radon concentration in underground laboratory.

PubMed

Maletić, Dimitrije M; Udovičić, Vladimir I; Banjanac, Radomir M; Joković, Dejan R; Dragić, Aleksandar L; Veselinović, Nikola B; Filipović, Jelena

2014-11-01

The results of analysis using correlative and multivariate methods, as developed for data analysis in high-energy physics and implemented in the Toolkit for Multivariate Analysis software package, of the relations of the variation of increased radon concentration with climate variables in shallow underground laboratory is presented. Multivariate regression analysis identified a number of multivariate methods which can give a good evaluation of increased radon concentrations based on climate variables. The use of the multivariate regression methods will enable the investigation of the relations of specific climate variable with increased radon concentrations by analysis of regression methods resulting in 'mapped' underlying functional behaviour of radon concentrations depending on a wide spectrum of climate variables. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
A nomogram to predict the survival of stage IIIA-N2 non-small cell lung cancer after surgery.

PubMed

Mao, Qixing; Xia, Wenjie; Dong, Gaochao; Chen, Shuqi; Wang, Anpeng; Jin, Guangfu; Jiang, Feng; Xu, Lin

2018-04-01

Postoperative survival of patients with stage IIIA-N2 non-small cell lung cancer (NSCLC) is highly heterogeneous. Here, we aimed to identify variables associated with postoperative survival and develop a tool for survival prediction. A retrospective review was performed in the Surveillance, Epidemiology, and End Results database from January 2004 to December 2009. Significant variables were selected by use of the backward stepwise method. The nomogram was constructed with multivariable Cox regression. The model's performance was evaluated by concordance index and calibration curve. The model was validated via an independent cohort from the Jiangsu Cancer Hospital Lung Cancer Center. A total of 1809 patients with stage IIIA-N2 NSCLC who underwent surgery were included in the training cohort. Age, sex, grade, histology, tumor size, visceral pleural invasion, positive lymph nodes, lymph nodes examined, and surgery type (lobectomy vs pneumonectomy) were identified as significant prognostic variables using backward stepwise method. A nomogram was developed from the training cohort and validated using an independent Chinese cohort. The concordance index of the model was 0.673 (95% confidence interval, 0.654-0.692) in training cohort and 0.664 in validation cohort (95% confidence interval, 0.614-0.714). The calibration plot showed optimal consistency between nomogram predicted survival and observed survival. Survival analyses demonstrated significant differences between different subgroups stratified by prognostic scores. This nomogram provided the individual survival prediction for patients with stage IIIA-N2 NSCLC after surgery, which might benefit survival counseling for patients and clinicians, clinical trial design and follow-up, as well as postoperative strategy-making. Copyright © 2017 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.
Assessment and prediction of short term hospital admissions: the case of Athens, Greece

NASA Astrophysics Data System (ADS)

Kassomenos, P.; Papaloukas, C.; Petrakis, M.; Karakitsios, S.

The contribution of air pollution on hospital admissions due to respiratory and heart diseases is a major issue in the health-environmental perspective. In the present study, an attempt was made to run down the relationships between air pollution levels and meteorological indexes, and corresponding hospital admissions in Athens, Greece. The available data referred to a period of eight years (1992-2000) including the daily number of hospital admissions due to respiratory and heart diseases, hourly mean concentrations of CO, NO 2, SO 2, O 3 and particulates in several monitoring stations, as well as, meteorological data (temperature, relative humidity, wind speed/direction). The relations among the above data were studied through widely used statistical techniques (multivariate stepwise analyses) and Artificial Neural Networks (ANNs). Both techniques revealed that elevated particulate concentrations are the dominant parameter related to hospital admissions (an increase of 10 μg m -3 leads to an increase of 10.2% in the number of admissions), followed by O 3 and the rest of the pollutants (CO, NO 2 and SO 2). Meteorological parameters also play a decisive role in the formation of air pollutant levels affecting public health. Consequently, increased/decreased daily hospital admissions are related to specific types of meteorological conditions that favor/do not favor the accumulation of pollutants in an urban complex. In general, the role of meteorological factors seems to be underestimated by stepwise analyses, while ANNs attribute to them a more important role. Comparison of the two models revealed that ANN adaptation in complicate environmental issues presents improved modeling results compared to a regression technique. Furthermore, the ANN technique provides a reliable model for the prediction of the daily hospital admissions based on air quality data and meteorological indices, undoubtedly useful for regulatory purposes.
Use of preoperative CHA2 DS2 -VASc score to predict the risk of atrial fibrillation after cardiothoracic surgery: a nested case-control study from the Atrial Fibrillation Suppression Trials (AFIST) I, II, and III.

PubMed

Baker, William L; Coleman, Craig I; White, C Michael; Kluger, Jeffrey

2013-05-01

To evaluate whether the preoperative CHA2 DS2 -VASc score predicts the risk of atrial fibrillation (AF) after cardiothoracic surgery (CTS). Retrospective, nested case-control study. A total of 560 patients undergoing coronary artery bypass grafting and/or valvular surgery from the Atrial Fibrillation Suppression Trials I, II, and III. All variables showing a univariate association (p≤0.20) with AF occurrence were entered into a backward stepwise multivariate logistic regression analysis to control for potential confounders and to calculate adjusted odds ratios (AORs) with 95% confidence intervals (CIs). The population was age 67.8 ± 8.6 (mean ± SD) years and 77.1% male, with CHA2 DS2 -VASc scores of 0-1 (low) in 34 patients (6.1%), 2-3 (medium) in 261 patients (46.6%), and more than 3 (high) in 265 patients (47.3%). Post-CTS AF occurred in 177 patients (31.6%), with 27%, 23%, and 41% in the low-, medium-, and high-CHA2 DS2 -VASc score groups, respectively. The high-score group had a 2.3-fold increased odds of developing AF versus the medium-score group (p<0.0001). The differences between the high- and medium-score groups when each group was compared with the low-score group were not statistically significant. On the multivariate logistic regression analysis, CHA2 DS2 -VASc score was associated with development of AF (AOR 1.20, 95% CI 1.06-1.36). Increasing CHA2 DS2 -VASc score was an independent predictor for the development of post-CTS AF, with patients in the high-score group having the highest overall incidence. © 2013 Pharmacotherapy Publications, Inc.
Impact of Implantable Transvenous Device Lead Location on Severity of Tricuspid Regurgitation

PubMed Central

Addetia, Karima; Maffessanti, Francesco; Mediratta, Anuj; Yamat, Megan; Weinert, Lynn; Moss, Joshua D.; Nayak, Hemal M.; Burke, Martin C.; Patel, Amit R.; Kruse, Eric; Jeevanandam, Valluvan; Mor-Avi, Victor; Lang, Roberto M.

2015-01-01

Background Implantable device leads can cause tricuspid regurgitation (TR) when they interfere with leaflet motion. The aim of this study was to determine whether lead-leaflet interference is associated with TR severity, independent of other causative factors of functional TR. Methods A total of 100 patients who underwent transthoracic two-dimensional and three-dimensional (3D) echocardiography of the tricuspid valve before and after lead placement were studied. Lead position was classified on 3D echocardiography as leaflet-interfering or noninterfering. TR severity was estimated by vena contracta (VC) width. Logistic regression analysis was used to identify factors associated with postdevice TR, including predevice VC width, right ventricular end-diastolic and end-systolic areas, fractional area change, right atrial size, tricuspid annular diameter, TR gradient, device lead age, and presence or absence of lead interference. Odds ratios were used to describe the association with moderate (VC width ≥ 0.5 cm) or severe (VC width ≥ 0.7 cm) TR, separately, using bivariate and stepwise multivariate logistic regression analysis. Results Forty-five of 100 patients showed device lead tricuspid valve leaflet interference. The septal leaflet was the most commonly affected (23 patients). On bivariate analysis, preimplantation VC width, right atrial size, tricuspid annular diameter, and lead-leaflet interference were significantly associated with postdevice TR. On multivariate analysis, preimplantation VC width and the presence of an interfering lead were independently associated with postdevice TR. Furthermore, the presence of an interfering lead was the only factor associated with TR worsening, increasing the likelihood of developing moderate or severe TR by 15- and 11-fold, respectively. Conclusion Lead-leaflet interference as seen on 3D echocardiography is associated with TR after device lead placement, suggesting that 3D echocardiography should be used to assess for lead interference in patients with significant TR. PMID:25129393
Atherosclerosis is associated with erectile function and lower urinary tract symptoms, especially nocturia, in middle-aged men.

PubMed

Tsujimura, Akira; Hiramatsu, Ippei; Aoki, Yusuke; Shimoyama, Hirofumi; Mizuno, Taiki; Nozaki, Taiji; Shirai, Masato; Kobayashi, Kazuhiro; Kumamoto, Yoshiaki; Horie, Shigeo

2017-06-01

Atherosclerosis is a systematic disease in which plaque builds up inside the arteries that can lead to serious problems related to quality of life (QOL). Lower urinary tract symptoms (LUTS), erectile dysfunction (ED), and late-onset hypogonadism (LOH) are highly prevalent in aging men and are significantly associated with a reduced QOL. However, few questionnaire-based studies have fully examined the relation between atherosclerosis and several urological symptoms. The study comprised 303 outpatients who visited our clinic with symptoms of LOH. Several factors influencing atherosclerosis, including serum concentrations of triglyceride, fasting blood sugar, and total testosterone measured by radioimmunoassay, were investigated. We also measured brachial-ankle pulse wave velocity (baPWV) and assessed symptoms by specific questionnaires, including the Sexual Health Inventory for Men (SHIM), Erection Hardness Score (EHS), International Prostate Symptom Score (IPSS), QOL index, and Aging Male Symptoms rating scale (AMS). Stepwise associations between the ratio of measured/age standard baPWV and clinical factors including laboratory data and the scores of the questionnaires were compared using the Jonckheere-Terpstra test for trend. The associations between the ratio of measured/age standard baPWV and each IPSS score were assessed in a multivariate linear regression model after adjustment for serum triglyceride, fasting blood sugar, and total testosterone. Regarding ED, a higher level of the ratio of measured/age standard baPWV was associated with a lower EHS, whereas no association was found with SHIM. Regarding LUTS, a higher ratio of measured/age standard baPWV was associated with a higher IPSS and QOL index. However, there was no statistically significant difference between the ratio of measured/age standard baPWV and AMS. A multivariate linear regression model showed only nocturia to be associated with the ratio of measured/age standard baPWV for each IPSS score. Atherosclerosis is associated with erectile function and LUTS, especially nocturia.
[Relationship between quality of life and disability level in patients with occupational disease].

PubMed

Li, Hongmei; Lin, Mingjing; Zhang, Wenwen; Li, Jing; Zou, Jianfang

2015-10-01

To investigate the relationship between the quality of life (QOL) and disability level in patients with occupational disease and to investigate the influencing factors for QOL. A total of 255 patients with occupational disease were selected from three specialized hospitals dedicated to occupational disease and the department of occupational medicine of one comprehensive hospital using cluster sampling from December 2013 to May 2014. A survey was carried out using WHOQOL-BREF and general questionnaire (including disability level), and statistical analysis was also performed using t test, F test, analysis of variance, and multivariate stepwise regression analysis. The QOL scores of patients with occupational diseases, from high to low, were social domain (11.48 ± 2.86), psychological domain (10.60 ± 2.28), physiological domain (10.54 ± 1.65), and environmental domain (10.50 ± 2.55), scores of which were significantly lower than the normal levels (P<0.05). QOL showed no significant differences between patients with occupational diseases of different disability levels (P>0.05). Also, QOL showed no significant differences between stage I, II and III patients with pneumoconiosis (P>0.05). The patients with pneumoconiosis were divided into mild, moderate, and severe groups, and the QOL scores of patients with mild pneumoconiosis in psychological and environmental domains were significantly higher than those of the patients with moderate or severe pneumoconiosis (P< 0.05). Patients with occupational poisoning was divided into mild, moderate and severe groups, and the three groups showed no significant differences in QOL score (P>0.05). Multivariate regression analysis showed that the QOL score of each domain was mainly influenced by the degree of lung injury, complications, course of disease, age of onset, income, and employment status. The QOL of patients with occupational disease is significantly reduced, and disability level cannot accurately reflect their QOL. The treatment of patients with occupational disease should focus on their complications, and at the same time QOL should also be improved.
Coagulopathy and shock on admission is associated with mortality for children with traumatic injuries at combat support hospitals.

PubMed

Patregnani, Jason T; Borgman, Matthew A; Maegele, Marc; Wade, Charles E; Blackbourne, Lorne H; Spinella, Philip C

2012-05-01

In adults, early traumatic coagulopathy and shock are both common and independently associated with mortality. There are little data regarding both the incidence and association of early coagulopathy and shock on outcomes in pediatric patients with traumatic injuries. Our objective was to determine whether coagulopathy and shock on admission are independently associated with mortality in children with traumatic injuries. A retrospective review of the Joint Theater Trauma Registry from U.S. combat support hospitals in Iraq and Afghanistan from 2002 to 2009 was performed. Coagulopathy was defined as an international normalized ratio of ≥1.5 and shock as a base deficit of ≥6. Laboratory values were measured on admission. Primary outcome was inhospital mortality. Univariate analyses were performed on all admission variables followed by reverse stepwise multivariate logistic regression to determine independent associations. Combat support hospitals in Iraq and Afghanistan. Patients <18 yrs of age with Injury Severity Score, international normalized ratio, base deficit, and inhospital mortality were included. Of 1998 in the cohort, 744 (37%) had a complete set of data for analysis. None. The incidence of early coagulopathy and shock were 27% and 38.3% and associated with mortality of 22% and 16.8%, respectively. After multivariate logistic regression, early coagulopathy had an odds ratio of 2.2 (95% confidence interval 1.1-4.5) and early shock had an odds ratio of 3.0 (95% confidence interval 1.2-7.5) for mortality. Patients with coagulopathy and shock had an odds ratio of 3.8 (95% confidence interval 2.0-7.4) for mortality. In children with traumatic injuries treated at combat support hospitals, coagulopathy and shock on admission are common and independently associated with a high incidence of inhospital mortality. Future studies are needed to determine whether more rapid and accurate methods of measuring coagulopathy and shock as well as if early goal-directed treatment of these states can improve outcomes in children.
The use of machine learning for the identification of peripheral artery disease and future mortality risk.

PubMed

Ross, Elsie Gyang; Shah, Nigam H; Dalman, Ronald L; Nead, Kevin T; Cooke, John P; Leeper, Nicholas J

2016-11-01

A key aspect of the precision medicine effort is the development of informatics tools that can analyze and interpret "big data" sets in an automated and adaptive fashion while providing accurate and actionable clinical information. The aims of this study were to develop machine learning algorithms for the identification of disease and the prognostication of mortality risk and to determine whether such models perform better than classical statistical analyses. Focusing on peripheral artery disease (PAD), patient data were derived from a prospective, observational study of 1755 patients who presented for elective coronary angiography. We employed multiple supervised machine learning algorithms and used diverse clinical, demographic, imaging, and genomic information in a hypothesis-free manner to build models that could identify patients with PAD and predict future mortality. Comparison was made to standard stepwise linear regression models. Our machine-learned models outperformed stepwise logistic regression models both for the identification of patients with PAD (area under the curve, 0.87 vs 0.76, respectively; P = .03) and for the prediction of future mortality (area under the curve, 0.76 vs 0.65, respectively; P = .10). Both machine-learned models were markedly better calibrated than the stepwise logistic regression models, thus providing more accurate disease and mortality risk estimates. Machine learning approaches can produce more accurate disease classification and prediction models. These tools may prove clinically useful for the automated identification of patients with highly morbid diseases for which aggressive risk factor management can improve outcomes. Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.
Identification of International Classification of Functioning, Disability and Health categories for patients with peripheral arterial disease.

PubMed

Vyskocil, Erich; Gruther, Wolfgang; Steiner, Irene; Schuhfried, Othmar

2014-07-01

Disease-specific categories of the International Classification of Functioning, Disability and Health have not yet been described for patients with chronic peripheral arterial obstructive disease (PAD). The authors examined the relationship between the categories of the Brief Core Sets for ischemic heart diseases with the Peripheral Artery Questionnaire and the ankle-brachial index to determine which International Classification of Functioning, Disability and Health categories are most relevant for patients with PAD. This is a retrospective cohort study including 77 patients with verified PAD. Statistical analyses of the relationship between International Classification of Functioning, Disability and Health categories as independent variables and the endpoints Peripheral Artery Questionnaire or ankle-brachial index were carried out by simple and stepwise linear regression models adjusting for age, sex, and leg (left vs. right). The stepwise linear regression model with the ankle-brachial index as dependent variable revealed a significant effect of the variables blood vessel functions and muscle endurance functions. Calculating a stepwise linear regression model with the Peripheral Artery Questionnaire as dependent variable, a significant effect of age, emotional functions, energy and drive functions, carrying out daily routine, as well as walking could be observed. This study identifies International Classification of Functioning, Disability and Health categories in the Brief Core Sets for ischemic heart diseases that show a significant effect on the ankle-brachial index and the Peripheral Artery Questionnaire score in patients with PAD. These categories provide fundamental information on functioning of patients with PAD and patient-centered outcomes for rehabilitation interventions.
Clinical utility of the AlphaFIM® instrument in stroke rehabilitation.

PubMed

Lo, Alexander; Tahair, Nicola; Sharp, Shelley; Bayley, Mark T

2012-02-01

The AlphaFIM instrument is an assessment tool designed to facilitate discharge planning of stroke patients from acute care, by extrapolating overall functional status from performance in six key Functional Independence Measure (FIM) instrument items. To determine whether acute care AlphaFIM rating is correlated to stroke rehabilitation outcomes. In this prospective observational study, data were analyzed from 891 patients referred for inpatient stroke rehabilitation through an Internet-based referral system. Simple linear and stepwise regression models determined correlations between rehabilitation-ready AlphaFIM rating and rehabilitation outcomes (admission and discharge FIM ratings, FIM gain, FIM efficiency, and length of stay). Covariates including demographic data, stroke characteristics, medical history, cognitive deficits, and activity tolerance were included in the stepwise regressions. The AlphaFIM instrument was significant in predicting admission and discharge FIM ratings at rehabilitation (adjusted R² 0.40 and 0.28, respectively; P < 0.0001) and was weakly correlated with FIM gain and length of stay (adjusted R² 0.04 and 0.09, respectively; P < 0.0001), but not FIM efficiency. AlphaFIM rating was inversely related to FIM gain. Age, bowel incontinence, left hemiparesis, and previous infarcts were negative predictors of discharge FIM rating on stepwise regression. Intact executive function and physical activity tolerance of 30 to 60 mins were predictors of FIM gain. The AlphaFIM instrument is a valuable tool for triaging stroke patients from acute care to rehabilitation and predicts functional status at discharge from rehabilitation. Patients with low AlphaFIM ratings have the potential to make significant functional gains and should not be denied admission to inpatient rehabilitation programs.
Soil Cd, Cr, Cu, Ni, Pb and Zn sorption and retention models using SVM: Variable selection and competitive model.

PubMed

González Costa, J J; Reigosa, M J; Matías, J M; Covelo, E F

2017-09-01

The aim of this study was to model the sorption and retention of Cd, Cu, Ni, Pb and Zn in soils. To that extent, the sorption and retention of these metals were studied and the soil characterization was performed separately. Multiple stepwise regression was used to produce multivariate models with linear techniques and with support vector machines, all of which included 15 explanatory variables characterizing soils. When the R-squared values are represented, two different groups are noticed. Cr, Cu and Pb sorption and retention show a higher R-squared; the most explanatory variables being humified organic matter, Al oxides and, in some cases, cation-exchange capacity (CEC). The other group of metals (Cd, Ni and Zn) shows a lower R-squared, and clays are the most explanatory variables, including a percentage of vermiculite and slime. In some cases, quartz, plagioclase or hematite percentages also show some explanatory capacity. Support Vector Machine (SVM) regression shows that the different models are not as regular as in multiple regression in terms of number of variables, the regression for nickel adsorption being the one with the highest number of variables in its optimal model. On the other hand, there are cases where the most explanatory variables are the same for two metals, as it happens with Cd and Cr adsorption. A similar adsorption mechanism is thus postulated. These patterns of the introduction of variables in the model allow us to create explainability sequences. Those which are the most similar to the selectivity sequences obtained by Covelo (2005) are Mn oxides in multiple regression and change capacity in SVM. Among all the variables, the only one that is explanatory for all the metals after applying the maximum parsimony principle is the percentage of sand in the retention process. In the competitive model arising from the aforementioned sequences, the most intense competitiveness for the adsorption and retention of different metals appears between Cr and Cd, Cu and Zn in multiple regression; and between Cr and Cd in SVM regression. Copyright © 2017 Elsevier B.V. All rights reserved.
A graphical method to evaluate spectral preprocessing in multivariate regression calibrations: example with Savitzky-Golay filters and partial least squares regression

USDA-ARS?s Scientific Manuscript database

In multivariate regression analysis of spectroscopy data, spectral preprocessing is often performed to reduce unwanted background information (offsets, sloped baselines) or accentuate absorption features in intrinsically overlapping bands. These procedures, also known as pretreatments, are commonly ...
CORRELATION PURSUIT: FORWARD STEPWISE VARIABLE SELECTION FOR INDEX MODELS

PubMed Central

Zhong, Wenxuan; Zhang, Tingting; Zhu, Yu; Liu, Jun S.

2012-01-01

In this article, a stepwise procedure, correlation pursuit (COP), is developed for variable selection under the sufficient dimension reduction framework, in which the response variable Y is influenced by the predictors X1, X2, …, Xp through an unknown function of a few linear combinations of them. Unlike linear stepwise regression, COP does not impose a special form of relationship (such as linear) between the response variable and the predictor variables. The COP procedure selects variables that attain the maximum correlation between the transformed response and the linear combination of the variables. Various asymptotic properties of the COP procedure are established, and in particular, its variable selection performance under diverging number of predictors and sample size has been investigated. The excellent empirical performance of the COP procedure in comparison with existing methods are demonstrated by both extensive simulation studies and a real example in functional genomics. PMID:23243388
Calibrated Multivariate Regression with Application to Neural Semantic Basis Discovery.

PubMed

Liu, Han; Wang, Lie; Zhao, Tuo

2015-08-01

We propose a calibrated multivariate regression method named CMR for fitting high dimensional multivariate regression models. Compared with existing methods, CMR calibrates regularization for each regression task with respect to its noise level so that it simultaneously attains improved finite-sample performance and tuning insensitiveness. Theoretically, we provide sufficient conditions under which CMR achieves the optimal rate of convergence in parameter estimation. Computationally, we propose an efficient smoothed proximal gradient algorithm with a worst-case numerical rate of convergence O (1/ ϵ ), where ϵ is a pre-specified accuracy of the objective function value. We conduct thorough numerical simulations to illustrate that CMR consistently outperforms other high dimensional multivariate regression methods. We also apply CMR to solve a brain activity prediction problem and find that it is as competitive as a handcrafted model created by human experts. The R package camel implementing the proposed method is available on the Comprehensive R Archive Network http://cran.r-project.org/web/packages/camel/.
Preoperative Thromboelastometry as a Predictor of Transfusion Requirements during Adult Living Donor Liver Transplantation.

PubMed

Fayed, Nirmeen; Mourad, Wessam; Yassen, Khaled; Görlinger, Klaus

2015-03-01

The ability to predict transfusion requirements may improve perioperative bleeding management as an integral part of a patient blood management program. Therefore, the aim of our study was to evaluate preoperative thromboelastometry as a predictor of transfusion requirements for adult living donor liver transplant recipients. The correlation between preoperative thromboelastometry variables in 100 adult living donor liver transplant recipients and intraoperative blood transfusion requirements was examined by univariate and multivariate linear regression analysis. Thresholds of thromboelastometric parameters for prediction of packed red blood cells (PRBCs), fresh frozen plasma (FFP), platelets, and cryoprecipitate transfusion requirements were determined with receiver operating characteristics analysis. The attending anesthetists were blinded to the preoperative thromboelastometric analysis. However, a thromboelastometry-guided transfusion algorithm with predefined trigger values was used intraoperatively. The transfusion triggers in this algorithm did not change during the study period. Univariate analysis confirmed significant correlations between PRBCs, FFP, platelets or cryoprecipitate transfusion requirements and most thromboelastometric variables. Backward stepwise logistic regression indicated that EXTEM coagulation time (CT), maximum clot firmness (MCF) and INTEM CT, clot formation time (CFT) and MCF are independent predictors for PRBC transfusion. EXTEM CT, CFT and FIBTEM MCF are independent predictors for FFP transfusion. Only EXTEM and INTEM MCF were independent predictors of platelet transfusion. EXTEM CFT and MCF, INTEM CT, CFT and MCF as well as FIBTEM MCF are independent predictors for cryoprecipitate transfusion. Thromboelastometry-based regression equation accounted for 63% of PRBC, 83% of FFP, 61% of cryoprecipitate, and 44% of platelet transfusion requirements. Preoperative thromboelastometric analysis is helpful to predict transfusion requirements in adult living donor liver transplant recipients. This may allow for better preparation and less cross-matching prior to surgery. The findings of our study need to be re-validated in a second prospective patient population.

Risk modeling for ventricular assist device support in post-cardiotomy shock.

PubMed

Alsoufi, Bahaaldin; Rao, Vivek; Tang, Augustine; Maganti, Manjula; Cusimano, Robert

2012-04-01

Post-cardiotomy shock (PCS) has a complex etiology. Although treatment with inotrops and intra-aortic balloon pump (IABP) support improves cardiac performance, end-organ injuries are common and lead to prolonged ICU stay, extended hospitalization and increased mortality. Early consideration of mechanical circulatory support may prevent such complications and improve outcome. Between January 1997 and January 2002, 321 patients required IABP and inotropic support for PCS following coronary artery bypass grafting (CABG) at our institution. Perioperative variables including age, mixed venous saturation (MVO2), inotropic requirements and LV function were analyzed using multivariate statistical methods. All explanatory variables with a univariate p value <0.10 were entered into a stepwise logistic regression model to predict hospital mortality. Odds ratios from significant variables (p < 0.05) in the regression model were used to compose a risk score. Overall hospital mortality was 16%. The independent risk factors for mortality in this population were: MVO2 < 60% (OR = 3.2), milrinone > 0.5 μg/kg/min (OR = 3.2), age > 75 (OR = 2.7), adrenaline > 0.1 μg/kg/min (OR = 1.5). A 15-point risk score was developed based on the regression model. Hospital mortality in patients with a score >6 was 46% (n = 13/28), 3-6 was 31% (n = 9/29) and <3 was 11% (n = 29/264). A significant proportion of patients with PCS continue to face high mortality despite IABP and inotropic support. Advanced age, heavy inotropic dependency and poor oxygen delivery all predicted increased risk for death. Further investigation is needed to assess whether early institution of VAD support could improve outcome in this high-risk group of patients.
Which Frail Older People Are Dehydrated? The UK DRIE Study.

PubMed

Hooper, Lee; Bunn, Diane K; Downing, Alice; Jimoh, Florence O; Groves, Joyce; Free, Carol; Cowap, Vicky; Potter, John F; Hunter, Paul R; Shepstone, Lee

2016-10-01

Water-loss dehydration in older people is associated with increased mortality and disability. We aimed to assess the prevalence of dehydration in older people living in UK long-term care and associated cognitive, functional, and health characteristics. The Dehydration Recognition In our Elders (DRIE) cohort study included people aged 65 or older living in long-term care without heart or renal failure. In a cross-sectional baseline analysis, we assessed serum osmolality, previously suggested dehydration risk factors, general health, markers of continence, cognitive and functional health, nutrition status, and medications. Univariate linear regression was used to assess relationships between participant characteristics and serum osmolality, then associated characteristics entered into stepwise backwards multivariate linear regression. DRIE included 188 residents (mean age 86 years, 66% women) of whom 20% were dehydrated (serum osmolality >300 mOsm/kg). Linear and logistic regression suggested that renal, cognitive, and diabetic status were consistently associated with serum osmolality and odds of dehydration, while potassium-sparing diuretics, sex, number of recent health contacts, and bladder incontinence were sometimes associated. Thirst was not associated with hydration status. DRIE found high prevalence of dehydration in older people living in UK long-term care, reinforcing the proposed association between cognitive and renal function and hydration. Dehydration is associated with increased mortality and disability in older people, but trials to assess effects of interventions to support healthy fluid intakes in older people living in residential care are needed to enable us to formally assess causal direction and any health benefits of increasing fluid intakes. © The Author 2015. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Willingness to Accept HIV Pre-Exposure Prophylaxis among Chinese Men Who Have Sex with Men

PubMed Central

Li, Shuming; Li, Dongliang; Zhang, Lifen; Fan, Wensheng; Yang, Xueying; Yu, Mingrun; Xiao, Dong; Yan, Li; Zhang, Zheng; Shi, Wei; Luo, Fengji; Ruan, Yuhua; Jin, Qi

2012-01-01

Objective We investigated the awareness and acceptability of pre-exposure prophylaxis (PrEP) among men who have sex with men (MSM) and potential predicting factors. Methods This study was conducted among MSM in Beijing, China. Study participants, randomly selected from an MSM cohort, completed a structured questionnaire, and provided their blood samples to test for HIV infection and syphilis. Univariate logistic regression analyses were performed to evaluate the factors associated with willingness to accept (WTA) PrEP. Factors independently associated with willingness to accept were identified by entering variables into stepwise logistic regression analysis. Results A total of 152 MSM completed the survey; 11.2% had ever heard of PrEP and 67.8% were willing to accept it. Univariate analysis showed that age, years of education, consistent condom use in the past 6 months, heterosexual behavior in the past 6 months, having ever heard of PrEP and the side effects of antiretroviral drugs, and worry about antiretroviral drugs cost were significantly associated with willingness to accept PrEP. In the multivariate logistic regression model, only consistent condom use in the past 6 months (odds ratio [OR]: 0.31; 95% confidence interval [CI]: 0.13–0.70) and having ever heard of the side effects of antiretroviral drugs (OR: 0.30; 95% CI: 0.14–0.67) were independently associated with willingness to accept PrEP. Conclusions The awareness of PrEP in the MSM population was low. Sexual behavioral characteristics and knowledge about ART drugs may have effects on willingness to accept PrEP. Comprehensive prevention strategies should be recommended in the MSM community. PMID:22479320
New diagnostic index for sarcopenia in patients with cardiovascular diseases

PubMed Central

Kai, Hisashi; Shibata, Rei; Niiyama, Hiroshi; Nishiyama, Yasuhiro; Murohara, Toyoaki; Yoshida, Noriko; Katoh, Atsushi; Ikeda, Hisao

2017-01-01

Background Sarcopenia is an aging and disease-related syndrome characterized by progressive and generalized loss of skeletal muscle mass and strength, with the risk of frailty and poor quality of life. Sarcopenia is diagnosed by a decrease in skeletal muscle index (SMI) and reduction of either handgrip strength or gait speed. However, measurement of SMI is difficult for general physicians because it requires special equipment for bioelectrical impedance assay or dual-energy X-ray absorptiometry. The purpose of this study was, therefore, to explore a novel, simple diagnostic method of sarcopenia evaluation in patients with cardiovascular diseases (CVD). Methods We retrospectively investigated 132 inpatients with CVD (age: 72±12 years, age range: 27–93 years, males: 61%) Binomial logistic regression and correlation analyses were used to assess the associations of sarcopenia with simple physical data and biomarkers, including muscle-related inflammation makers and nutritional markers. Results Sarcopenia was present in 29.5% of the study population. Serum concentrations of adiponectin and sialic acid were significantly higher in sarcopenic than non-sarcopenic CVD patients. Stepwise multivariate binomial logistic regression analysis revealed that adiponectin, sialic acid, sex, age, and body mass index were independent factors for sarcopenia detection. Sarcopenia index, obtained from the diagnostic regression formula for sarcopenia detection including the five independent factors, indicated a high accuracy in ROC curve analysis (sensitivity 94.9%, specificity 69.9%) and the cutoff value for sarcopenia detection was -1.6134. Sarcopenia index had a significant correlation with the conventional diagnostic parameters of sarcopenia. Conclusions Our new sarcopenia index using simple parameters would be useful for diagnosing sarcopenia in CVD patients. PMID:28542531
Comparison of Nine Statistical Model Based Warfarin Pharmacogenetic Dosing Algorithms Using the Racially Diverse International Warfarin Pharmacogenetic Consortium Cohort Database

PubMed Central

Liu, Rong; Li, Xi; Zhang, Wei; Zhou, Hong-Hao

2015-01-01

Objective Multiple linear regression (MLR) and machine learning techniques in pharmacogenetic algorithm-based warfarin dosing have been reported. However, performances of these algorithms in racially diverse group have never been objectively evaluated and compared. In this literature-based study, we compared the performances of eight machine learning techniques with those of MLR in a large, racially-diverse cohort. Methods MLR, artificial neural network (ANN), regression tree (RT), multivariate adaptive regression splines (MARS), boosted regression tree (BRT), support vector regression (SVR), random forest regression (RFR), lasso regression (LAR) and Bayesian additive regression trees (BART) were applied in warfarin dose algorithms in a cohort from the International Warfarin Pharmacogenetics Consortium database. Covariates obtained by stepwise regression from 80% of randomly selected patients were used to develop algorithms. To compare the performances of these algorithms, the mean percentage of patients whose predicted dose fell within 20% of the actual dose (mean percentage within 20%) and the mean absolute error (MAE) were calculated in the remaining 20% of patients. The performances of these techniques in different races, as well as the dose ranges of therapeutic warfarin were compared. Robust results were obtained after 100 rounds of resampling. Results BART, MARS and SVR were statistically indistinguishable and significantly out performed all the other approaches in the whole cohort (MAE: 8.84–8.96 mg/week, mean percentage within 20%: 45.88%–46.35%). In the White population, MARS and BART showed higher mean percentage within 20% and lower mean MAE than those of MLR (all p values < 0.05). In the Asian population, SVR, BART, MARS and LAR performed the same as MLR. MLR and LAR optimally performed among the Black population. When patients were grouped in terms of warfarin dose range, all machine learning techniques except ANN and LAR showed significantly higher mean percentage within 20%, and lower MAE (all p values < 0.05) than MLR in the low- and high- dose ranges. Conclusion Overall, machine learning-based techniques, BART, MARS and SVR performed superior than MLR in warfarin pharmacogenetic dosing. Differences of algorithms’ performances exist among the races. Moreover, machine learning-based algorithms tended to perform better in the low- and high- dose ranges than MLR. PMID:26305568
Selecting predictors for discriminant analysis of species performance: an example from an amphibious softwater plant.

PubMed

Vanderhaeghe, F; Smolders, A J P; Roelofs, J G M; Hoffmann, M

2012-03-01

Selecting an appropriate variable subset in linear multivariate methods is an important methodological issue for ecologists. Interest often exists in obtaining general predictive capacity or in finding causal inferences from predictor variables. Because of a lack of solid knowledge on a studied phenomenon, scientists explore predictor variables in order to find the most meaningful (i.e. discriminating) ones. As an example, we modelled the response of the amphibious softwater plant Eleocharis multicaulis using canonical discriminant function analysis. We asked how variables can be selected through comparison of several methods: univariate Pearson chi-square screening, principal components analysis (PCA) and step-wise analysis, as well as combinations of some methods. We expected PCA to perform best. The selected methods were evaluated through fit and stability of the resulting discriminant functions and through correlations between these functions and the predictor variables. The chi-square subset, at P < 0.05, followed by a step-wise sub-selection, gave the best results. In contrast to expectations, PCA performed poorly, as so did step-wise analysis. The different chi-square subset methods all yielded ecologically meaningful variables, while probable noise variables were also selected by PCA and step-wise analysis. We advise against the simple use of PCA or step-wise discriminant analysis to obtain an ecologically meaningful variable subset; the former because it does not take into account the response variable, the latter because noise variables are likely to be selected. We suggest that univariate screening techniques are a worthwhile alternative for variable selection in ecology. © 2011 German Botanical Society and The Royal Botanical Society of the Netherlands.
Serum Predictors of Percent Lean Mass in Young Adults.

PubMed

Lustgarten, Michael S; Price, Lori L; Phillips, Edward M; Kirn, Dylan R; Mills, John; Fielding, Roger A

2016-08-01

Lustgarten, MS, Price, LL, Phillips, EM, Kirn, DR, Mills, J, and Fielding, RA. Serum predictors of percent lean mass in young adults. J Strength Cond Res 30(8): 2194-2201, 2016-Elevated lean (skeletal muscle) mass is associated with increased muscle strength and anaerobic exercise performance, whereas low levels of lean mass are associated with insulin resistance and sarcopenia. Therefore, studies aimed at obtaining an improved understanding of mechanisms related to the quantity of lean mass are of interest. Percent lean mass (total lean mass/body weight × 100) in 77 young subjects (18-35 years) was measured with dual-energy x-ray absorptiometry. Twenty analytes and 296 metabolites were evaluated with the use of the standard chemistry screen and mass spectrometry-based metabolomic profiling, respectively. Sex-adjusted multivariable linear regression was used to determine serum analytes and metabolites significantly (p ≤ 0.05 and q ≤ 0.30) associated with the percent lean mass. Two enzymes (alkaline phosphatase and serum glutamate oxaloacetate aminotransferase) and 29 metabolites were found to be significantly associated with the percent lean mass, including metabolites related to microbial metabolism, uremia, inflammation, oxidative stress, branched-chain amino acid metabolism, insulin sensitivity, glycerolipid metabolism, and xenobiotics. Use of sex-adjusted stepwise regression to obtain a final covariate predictor model identified the combination of 5 analytes and metabolites as overall predictors of the percent lean mass (model R = 82.5%). Collectively, these data suggest that a complex interplay of various metabolic processes underlies the maintenance of lean mass in young healthy adults.
Epidemiological characteristics and deaths of premature infants in a referral hospital for high-risk pregnancies

PubMed Central

de Freitas, Brunnella Alcantara Chagas; Sant'Ana, Luciana Ferreira da Rocha; Longo, Giana Zarbato; Siqueira-Batista, Rodrigo; Priore, Silvia Eloiza; Franceschin, Sylvia do Carmo Castro

2012-01-01

Objective To analyze the process of care provided to premature infants in a neonatal intensive care unit and the factors associated with their mortality. Methods Cross-sectional retrospective study of premature infants in an intensive care unit between 2008 and 2010. The characteristics of the mothers and premature infants were described, and a bivariate analysis was performed on the following characteristics: the study period and the "death" outcome (hospital, neonatal and early) using Pearson's chi-square test, Fisher's exact test or a chi-square test for linear trends. Bivariate and multivariable logistic regression analyses were performed using a stepwise backward logistic regression method between the variables with p<0.20 and the "death" outcome. A p value <0.05 was considered to be significant. Results In total, 293 preterm infants were studied. Increased access to complementary tests (transfontanellar ultrasound and Doppler echocardiogram) and breastfeeding rates were indicators of improving care. Mortality was concentrated in the neonatal period, especially in the early neonatal period, and was associated with extreme prematurity, small size for gestational age and an Apgar score <7 at 5 minutes after birth. The late-onset sepsis was also associated with a greater chance of neonatal death, and antenatal corticosteroids were protective against neonatal and early deaths. Conclusions Although these results are comparable to previous findings regarding mortality among premature infants in Brazil, the study emphasizes the need to implement strategies that promote breastfeeding and reduce neonatal mortality and its early component. PMID:23917938
Factors associated with multidimensional aspect of post-stroke fatigue in acute stroke period.

PubMed

Mutai, Hitoshi; Furukawa, Tomomi; Houri, Ayumi; Suzuki, Akihito; Hanihara, Tokiji

2017-04-01

Post-stroke fatigue (PSF) is a frequent and distressing consequence of stroke, and can be both acute and long lasting. We aimed to investigate multidimensional aspects of acute PSF and to determine the clinical factors relevant to acute PSF. We collected data of 101 patients admitted to the hospital for acute stroke. PSF was assessed using the Multidimensional Fatigue Inventory within 2 weeks of stroke. Measures included Mini-Mental State Examination, Hospital Anxiety and Depression Scale, and Functional Independence Measure. Stroke character, lesion location, and clinical variables that potentially influence PSF were also collected. The prevalence of pathological fatigue is 56.4% within 2 weeks of stroke. Binary logistic regression analysis revealed that anxiety was the only predictor for presence of PSF (OR=1.32, 95% CI: 1.13-1.53, P<0.001). Multivariate stepwise regression analysis showed anxiety, right lesion side, thalamus, and/or brainstem were independently associated with general fatigue, right lesion side, depression, diabetes mellitus, and anxiety with physical fatigue, depression with reduced activity, depression, and BMI with reduced motivation, depression, and diabetes mellitus with mental fatigue. PSF was highly prevalent in the acute phase, and specific factors including lesion location (right side lesion, thalamic and brainstem lesion), anxiety, and depression were independently associated with multidimensional aspects of PSF. Further study is needed to elucidate how specific structural lesions and anxiety symptoms relate to the development of early fatigue following stroke. Copyright © 2016 Elsevier B.V. All rights reserved.
Clinical Impact of Emphysema Evaluated by High-Resolution Computed Tomography on Idiopathic Pulmonary Fibrosis Diagnosed by Surgical Lung Biopsy.

PubMed

Kohashi, Yasuo; Arai, Toru; Sugimoto, Chikatoshi; Tachibana, Kazunobu; Akira, Masanori; Kitaichi, Masanori; Hayashi, Seiji; Inoue, Yoshikazu

2016-01-01

The prognosis of combined cases of pulmonary fibrosis and emphysema is unresolved partially because radiological differentiation between usual interstitial pneumonia and nonspecific interstitial pneumonia is difficult in coexisting emphysema cases. The purpose of this study was to clarify the clinical impact of emphysema on the survival of patients with idiopathic pulmonary fibrosis (IPF). One hundred and seven patients with interstitial lung diseases were diagnosed by surgical lung biopsies between 2006 and 2012, and 47 patients were diagnosed with IPF through multidisciplinary discussion. Emphysema on high-resolution computed tomography scans was evaluated semiquantitatively by visual scoring. Eight out of the 47 IPF patients showed a higher emphysema score (>3) and were diagnosed to have IPF-emphysema. The median survival time of patients with IPF-emphysema (1,734 days) from the initial diagnosis was significantly shorter than that of patients with IPF alone (2,229 days) by Kaplan-Meier analysis (p = 0.007, log-rank test). Univariate Cox proportional hazard regression analyses revealed that a higher total emphysema score (>3.0) was a significantly poor prognostic factor in addition to Krebs von den Lungen-6, surfactant protein-D, arterial oxygen tension, percent forced vital capacity, and percent diffusing capacity of carbon monoxide (%DLCO). Multivariate Cox proportional hazard regression analyses with the stepwise method showed that higher total emphysema score (>3) and %DLCO were significantly poor prognostic factors. The prognosis of IPF-emphysema was significantly worse than that of IPF alone. © 2016 S. Karger AG, Basel.
Increased serum concentrations of Nɛ-carboxymethyllysine are related to the presence and the severity of rheumatoid arthritis.

PubMed

Knani, Ines; Bouzidi, Hassan; Zrour, Saoussen; Bergaoui, Naceur; Hammami, Mohamed; Kerkeni, Mohsen

2018-07-01

Background There are limited data regarding the contribution of advanced glycation end products in the presence of rheumatoid arthritis. We investigated whether serum N ɛ -carboxymethyllysine and pentosidine were related to the presence and the severity of rheumatoid arthritis. Methods Eighty patients with rheumatoid arthritis and 30 control subjects were included in a cross-sectional study. The severity of rheumatoid arthritis was assessed using the disease activity score for 28 joints. Serum N ɛ -carboxymethyllysine and pentosidine were measured by enzyme-linked immunosorbent assay. Results Serum N ɛ -carboxymethyllysine and pentosidine concentrations were significantly higher in patients with rheumatoid arthritis vs. control subjects ( P < 0.001). Serum N ɛ -carboxymethyllysine and pentosidine concentrations were significantly higher in rheumatoid arthritis patients with high disease activity vs. rheumatoid arthritis patients with moderate disease activity ( P < 0.001, P = 0.019, respectively). A multiple logistic regression analysis demonstrated that N ɛ -carboxymethyllysine was independently associated with the presence of rheumatoid arthritis (OR = 1.21, 95% CI: 1.05-1.39, P = 0.006). Furthermore, in a multivariate stepwise regression analysis, N ɛ -carboxymethyllysine was independently correlated with disease activity score for 28 joints (standardized β = 0.43, P = 0.001). Conclusion Serum N ɛ -carboxymethyllysine and pentosidine were increased during rheumatoid arthritis, and N ɛ -carboxymethyllysine was independently associated with the presence and the severity of rheumatoid arthritis.
Use of a pretest strategy for physical therapist assistant programs to predict success rate on the national physical therapy exam.

PubMed

Sloas, Stacey B; Keith, Becky; Whitehead, Malcolm T

2013-01-01

This study investigated a pretest strategy that identified physical therapist assistant (PTA) students who were at risk of failure on the National Physical Therapy Examination (NPTE). Program assessment data from five cohorts of PTA students (2005-2009) were used to develop a stepwise multiple regression formula that predicted first-time NPTE licensure scores. Data used included the Nelson-Denny Reading Test, grades from eight core courses, grade point average upon admission to the program, and scores from three mock NPTE exams given during the program. Pearson correlation coefficients were calculated between each of the 15 variables and NPTE scores. Stepwise multiple regression analysis was performed using data collected at the ends of the first, second, and third (final) semesters of the program. Data from the class of 2010 were then used to validate the formula. The end-of-program formula accounted for the greatest variance (57%) in predicted scores. Those students scoring below a predicted scaled score of 620 were identified to be at risk of failure of the licensure exam. These students were counseled, and a remedial plan was developed based on regression predictions prior to them sitting for the licensure exam.
Greater association of peak neuromuscular performance with cortical bone geometry, bone mass and bone strength than bone density: A study in 417 older women.

PubMed

Belavý, Daniel L; Armbrecht, Gabriele; Blenk, Tilo; Bock, Oliver; Börst, Hendrikje; Kocakaya, Emine; Luhn, Franziska; Rantalainen, Timo; Rawer, Rainer; Tomasius, Frederike; Willnecker, Johannes; Felsenberg, Dieter

2016-02-01

We evaluated which aspects of neuromuscular performance are associated with bone mass, density, strength and geometry. 417 women aged 60-94years were examined. Countermovement jump, sit-to-stand test, grip strength, forearm and calf muscle cross-sectional area, areal bone mineral content and density (aBMC and aBMD) at the hip and lumbar spine via dual X-ray absorptiometry, and measures of volumetric vBMC and vBMD, bone geometry and section modulus at 4% and 66% of radius length and 4%, 38% and 66% of tibia length via peripheral quantitative computed tomography were performed. The first principal component of the neuromuscular variables was calculated to generate a summary neuromuscular variable. Percentage of total variance in bone parameters explained by the neuromuscular parameters was calculated. Step-wise regression was also performed. At all pQCT bone sites (radius, ulna, tibia, fibula), a greater percentage of total variance in measures of bone mass, cortical geometry and/or bone strength was explained by peak neuromuscular performance than for vBMD. Sit-to-stand performance did not relate strongly to bone parameters. No obvious differential in the explanatory power of neuromuscular performance was seen for DXA aBMC versus aBMD. In step-wise regression, bone mass, cortical morphology, and/or strength remained significant in relation to the first principal component of the neuromuscular variables. In no case was vBMD positively related to neuromuscular performance in the final step-wise regression models. Peak neuromuscular performance has a stronger relationship with leg and forearm bone mass and cortical geometry as well as proximal forearm section modulus than with vBMD. Copyright © 2015 Elsevier Inc. All rights reserved.
Prevalence of consistent condom use with various types of sex partners and associated factors among money boys in Changsha, China.

PubMed

Wang, Lian-Hong; Yan, Jin; Yang, Guo-Li; Long, Shuo; Yu, Yong; Wu, Xi-Lin

2015-04-01

Money boys with inconsistent condom use (less than 100% of the time) are at high risk of infection by human immunodeficiency virus (HIV) or sexually transmitted infection (STI), but relatively little research has examined their risk behaviors. We investigated the prevalence of consistent condom use (100% of the time) and associated factors among money boys. A cross-sectional study using a structured questionnaire was conducted among money boys in Changsha, China, between July 2012 and January 2013. Independent variables included socio-demographic data, substance abuse history, work characteristics, and self-reported HIV and STI history. Dependent variables included the consistent condom use with different types of sex partners. Among the participants, 82.4% used condoms consistently with male clients, 80.2% with male sex partners, and 77.1% with female sex partners in the past 3 months. A multiple stepwise logistic regression model identified four statistically significant factors associated with lower likelihoods of consistent condom use with male clients: age group, substance abuse, lack of an "employment" arrangement, and having no HIV test within the prior 6 months. In a similar model, only one factor associated significantly with lower likelihoods of consistent condom use with male sex partners was identified in multiple stepwise logistic regression analyses: having no HIV test within the prior six months. As for female sex partners, two significant variables were statistically significant in the multiple stepwise logistic regression analysis: having no HIV test within the prior 6 months and having STI history. Interventions which are linked with more realistic and acceptable HIV prevention methods are greatly warranted and should increase risk awareness and the behavior of consistent condom use in both commercial and personal relationship. © 2015 International Society for Sexual Medicine.
A model for predicting sulcus-to-sulcus diameter in posterior chamber phakic intraocular lens candidates: correlation between ocular biometric parameters.

PubMed

Ghoreishi, Mohammad; Abdi-Shahshahani, Mehdi; Peyman, Alireza; Pourazizi, Mohsen

2018-02-21

The aim of this study was to determine the correlation between ocular biometric parameters and sulcus-to-sulcus (STS) diameter. This was a cross-sectional study of preoperative ocular biometry data of patients who were candidates for phakic intraocular lens (IOL) surgery. Subjects underwent ocular biometry analysis, including refraction error evaluation using an autorefractor and Orbscan topography for white-to-white (WTW) corneal diameter and measurement. Pentacam was used to perform WTW corneal diameter and measurements of minimum and maximum keratometry (K). Measurements of STS and angle-to-angle (ATA) were obtained using a 50-MHz B-mode ultrasound device. Anterior optical coherence tomography was performed for anterior chamber depth measurement. Pearson's correlation test and stepwise linear regression analysis were used to find a model to predict STS. Fifty-eight eyes of 58 patients were enrolled. Mean age ± standard deviation of sample was 28.95 ± 6.04 years. The Pearson's correlation coefficient between STS with WTW, ATA, mean K was 0.383, 0.492, and - 0.353, respectively, which was statistically significant (all P < 0.001). Using stepwise linear regression analysis, there is a statistically significant association between STS with WTW (P = 0.011) and mean K (P = 0.025). The standardized coefficient was 0.323 and - 0.284 for WTW and mean K, respectively. The stepwise linear regression analysis equation was: (STS = 9.549 + 0.518 WTW - 0.083 mean K). Based on our result, given the correlation of STS with WTW and mean K and potential of direct and essay measurement of WTW and mean K, it seems that current IOL sizing protocols could be estimating with WTW and mean K.
Aerobic Fitness Does Not Contribute to Prediction of Orthostatic Intolerance

NASA Technical Reports Server (NTRS)

Convertino, Victor A.; Sather, Tom M.; Goldwater, Danielle J.; Alford, William R.

1986-01-01

Several investigations have suggested that orthostatic tolerance may be inversely related to aerobic fitness (VO (sub 2max)). To test this hypothesis, 18 males (age 29 to 51 yr) underwent both treadmill VO(sub 2max) determination and graded lower body negative pressures (LBNP) exposure to tolerance. VO(2max) was measured during the last minute of a Bruce treadmill protocol. LBNP was terminated based on pre-syncopal symptoms and LBNP tolerance (peak LBNP) was expressed as the cumulative product of LBNP and time (torr-min). Changes in heart rate, stroke volume cardiac output, blood pressure and impedance rheographic indices of mid-thigh-leg initial accumulation were measured at rest and during the final minute of LBNP. For all 18 subjects, mean (plus or minus SE) fluid accumulation index and leg venous compliance index at peak LBNP were 139 plus or minus 3.9 plus or minus 0.4 ml-torr-min(exp -2) x 10(exp 3), respectively. Pearson product-moment correlations and step-wise linear regression were used to investigate relationships with peak LBNP. Variables associated with endurance training, such as VO(sub 2max) and percent body fat were not found to correlate significantly (P is less than 0.05) with peak LBNP and did not add sufficiently to the prediction of peak LBNP to be included in the step-wise regression model. The step-wise regression model included only fluid accumulation index leg venous compliance index, and blood volume and resulted in a squared multiple correlation coefficient of 0.978. These data do not support the hypothesis that orthostatic tolerance as measured by LBNP is lower in individuals with high aerobic fitness.
Integrative Bayesian variable selection with gene-based informative priors for genome-wide association studies.

PubMed

Zhang, Xiaoshuai; Xue, Fuzhong; Liu, Hong; Zhu, Dianwen; Peng, Bin; Wiemels, Joseph L; Yang, Xiaowei

2014-12-10

Genome-wide Association Studies (GWAS) are typically designed to identify phenotype-associated single nucleotide polymorphisms (SNPs) individually using univariate analysis methods. Though providing valuable insights into genetic risks of common diseases, the genetic variants identified by GWAS generally account for only a small proportion of the total heritability for complex diseases. To solve this "missing heritability" problem, we implemented a strategy called integrative Bayesian Variable Selection (iBVS), which is based on a hierarchical model that incorporates an informative prior by considering the gene interrelationship as a network. It was applied here to both simulated and real data sets. Simulation studies indicated that the iBVS method was advantageous in its performance with highest AUC in both variable selection and outcome prediction, when compared to Stepwise and LASSO based strategies. In an analysis of a leprosy case-control study, iBVS selected 94 SNPs as predictors, while LASSO selected 100 SNPs. The Stepwise regression yielded a more parsimonious model with only 3 SNPs. The prediction results demonstrated that the iBVS method had comparable performance with that of LASSO, but better than Stepwise strategies. The proposed iBVS strategy is a novel and valid method for Genome-wide Association Studies, with the additional advantage in that it produces more interpretable posterior probabilities for each variable unlike LASSO and other penalized regression methods.
Lateral-Directional Parameter Estimation on the X-48B Aircraft Using an Abstracted, Multi-Objective Effector Model

NASA Technical Reports Server (NTRS)

Ratnayake, Nalin A.; Waggoner, Erin R.; Taylor, Brian R.

2011-01-01

The problem of parameter estimation on hybrid-wing-body aircraft is complicated by the fact that many design candidates for such aircraft involve a large number of aerodynamic control effectors that act in coplanar motion. This adds to the complexity already present in the parameter estimation problem for any aircraft with a closed-loop control system. Decorrelation of flight and simulation data must be performed in order to ascertain individual surface derivatives with any sort of mathematical confidence. Non-standard control surface configurations, such as clamshell surfaces and drag-rudder modes, further complicate the modeling task. In this paper, time-decorrelation techniques are applied to a model structure selected through stepwise regression for simulated and flight-generated lateral-directional parameter estimation data. A virtual effector model that uses mathematical abstractions to describe the multi-axis effects of clamshell surfaces is developed and applied. Comparisons are made between time history reconstructions and observed data in order to assess the accuracy of the regression model. The Cram r-Rao lower bounds of the estimated parameters are used to assess the uncertainty of the regression model relative to alternative models. Stepwise regression was found to be a useful technique for lateral-directional model design for hybrid-wing-body aircraft, as suggested by available flight data. Based on the results of this study, linear regression parameter estimation methods using abstracted effectors are expected to perform well for hybrid-wing-body aircraft properly equipped for the task.
Linear regression analysis and its application to multivariate chromatographic calibration for the quantitative analysis of two-component mixtures.

PubMed

Dinç, Erdal; Ozdemir, Abdil

2005-01-01

Multivariate chromatographic calibration technique was developed for the quantitative analysis of binary mixtures enalapril maleate (EA) and hydrochlorothiazide (HCT) in tablets in the presence of losartan potassium (LST). The mathematical algorithm of multivariate chromatographic calibration technique is based on the use of the linear regression equations constructed using relationship between concentration and peak area at the five-wavelength set. The algorithm of this mathematical calibration model having a simple mathematical content was briefly described. This approach is a powerful mathematical tool for an optimum chromatographic multivariate calibration and elimination of fluctuations coming from instrumental and experimental conditions. This multivariate chromatographic calibration contains reduction of multivariate linear regression functions to univariate data set. The validation of model was carried out by analyzing various synthetic binary mixtures and using the standard addition technique. Developed calibration technique was applied to the analysis of the real pharmaceutical tablets containing EA and HCT. The obtained results were compared with those obtained by classical HPLC method. It was observed that the proposed multivariate chromatographic calibration gives better results than classical HPLC.
A comparison between univariate probabilistic and multivariate (logistic regression) methods for landslide susceptibility analysis: the example of the Febbraro valley (Northern Alps, Italy)

NASA Astrophysics Data System (ADS)

Rossi, M.; Apuani, T.; Felletti, F.

2009-04-01

The aim of this paper is to compare the results of two statistical methods for landslide susceptibility analysis: 1) univariate probabilistic method based on landslide susceptibility index, 2) multivariate method (logistic regression). The study area is the Febbraro valley, located in the central Italian Alps, where different types of metamorphic rocks croup out. On the eastern part of the studied basin a quaternary cover represented by colluvial and secondarily, by glacial deposits, is dominant. In this study 110 earth flows, mainly located toward NE portion of the catchment, were analyzed. They involve only the colluvial deposits and their extension mainly ranges from 36 to 3173 m2. Both statistical methods require to establish a spatial database, in which each landslide is described by several parameters that can be assigned using a main scarp central point of landslide. The spatial database is constructed using a Geographical Information System (GIS). Each landslide is described by several parameters corresponding to the value of main scarp central point of the landslide. Based on bibliographic review a total of 15 predisposing factors were utilized. The width of the intervals, in which the maps of the predisposing factors have to be reclassified, has been defined assuming constant intervals to: elevation (100 m), slope (5 °), solar radiation (0.1 MJ/cm2/year), profile curvature (1.2 1/m), tangential curvature (2.2 1/m), drainage density (0.5), lineament density (0.00126). For the other parameters have been used the results of the probability-probability plots analysis and the statistical indexes of landslides site. In particular slope length (0 ÷ 2, 2 ÷ 5, 5 ÷ 10, 10 ÷ 20, 20 ÷ 35, 35 ÷ 260), accumulation flow (0 ÷ 1, 1 ÷ 2, 2 ÷ 5, 5 ÷ 12, 12 ÷ 60, 60 ÷27265), Topographic Wetness Index 0 ÷ 0.74, 0.74 ÷ 1.94, 1.94 ÷ 2.62, 2.62 ÷ 3.48, 3.48 ÷ 6,00, 6.00 ÷ 9.44), Stream Power Index (0 ÷ 0.64, 0.64 ÷ 1.28, 1.28 ÷ 1.81, 1.81 ÷ 4.20, 4.20 ÷ 9.40). Geological map and land use map were also used, considering geological and land use properties as categorical variables. Appling the univariate probabilistic method the Landslide Susceptibility Index (LSI) is defined as the sum of the ratio Ra/Rb calculated for each predisposing factor, where Ra is the ratio between number of pixel of class and the total number of pixel of the study area, and Rb is the ratio between number of landslides respect to the pixel number of the interval area. From the analysis of the Ra/Rb ratio the relationship between landslide occurrence and predisposing factors were defined. Then the equation of LSI was used in GIS to trace the landslide susceptibility maps. The multivariate method for landslide susceptibility analysis, based on logistic regression, was performed starting from the density maps of the predisposing factors, calculated with the intervals defined above using the equation Rb/Rbtot, where Rbtot is a sum of all Rb values. Using stepwise forward algorithms the logistic regression was performed in two successive steps: first a univariate logistic regression is used to choose the most significant predisposing factors, then the multivariate logistic regression can be performed. The univariate regression highlighted the importance of the following factors: elevation, accumulation flow, drainage density, lineament density, geology and land use. When the multivariate regression was applied the number of controlling factors was reduced neglecting the geological properties. The resulting final susceptibility equation is: P = 1 / (1 + exp-(6.46-22.34*elevation-5.33*accumulation flow-7.99* drainage density-4.47*lineament density-17.31*land use)) and using this equation the susceptibility maps were obtained. To easy compare the results of the two methodologies, the susceptibility maps were reclassified in five susceptibility intervals (very high, high, moderate, low and very low) using natural breaks. Then the maps were validated using two cumulative distribution curves, one related to the landslides (number of landslides in each susceptibility class) and one to the basin (number of pixel covering each class). Comparing the curves for each method, it results that the two approaches (univariate and multivariate) are appropriate, providing acceptable results. In both maps the distribution of high susceptibility condition is mainly localized on the left slope of the catchment in agreement with the field evidences. The comparison between the methods was obtained by subtraction of the two maps. This operation shows that about 40% of the basin is classified by the same class of susceptibility. In general the univariate probabilistic method tends to overestimate the areal extension of the high susceptibility class with respect to the maps obtained by the logistic regression method.

Simple models for estimating local removals of timber in the northeast

Treesearch

David N. Larsen; David A. Gansner

1975-01-01

Provides a practical method of estimating subregional removals of timber and demonstrates its application to a typical problem. Stepwise multiple regression analysis is used to develop equations for estimating removals of softwood, hardwood, and all timber from selected characteristics of socioeconomic structure.
Comparison of "Nil by Mouth" Versus Early Oral Intake in Three Different Diet Regimens Following Esophagectomy.

PubMed

Eberhard, Kristine Elisabeth; Achiam, Michael Patrick; Rolff, Hans Christian; Belmouhand, Mohamed; Svendsen, Lars Bo; Thorsteinsson, Morten

2017-06-01

The literature on oral intake after esophagectomy and its influence on anastomotic leakage and complications is sparse. This retrospective study included 359 patients undergoing esophagectomy between January 2011 and August 2015. Three oral intake protocols were evaluated: regimen 1, nil by mouth until postoperative day (POD) 7 followed by a normal diet; regimen 2, oral intake of clear fluids from POD 1 followed by a normal diet; regimen 3, nil by mouth until POD 7 followed by a slow increase to a blended diet. The outcome endpoints were: (1) anastomotic leakage, (2) complications [severity and number described using the Dindo-Clavien Classification and Comprehensive Complication Index (CCI)] and (3) length of stay. A multivariate logistic regression model was obtained for CCI and anastomotic leakage using Wald's stepwise selection. CCI was significantly lower in regimen 3 (16 vs. 22 and 26 in regimen 1 and 2, p = 0.027). Additionally, significantly fewer patients in regimen 3 suffered from severe complications of Dindo-Clavien grade IIIb-IV (p = 0.025). The incidence of anastomotic leakage reached its lowest in regimen 3, 2%, compared to 7-9%. Multivariate analyses revealed that high American Society of Anesthesiologist score was a predicting factor for both CCI and anastomotic leakage. The study indicates that nil by mouth until postoperative day 7 followed by a slow increase to a blended diet after esophagectomy results in less severe complications and a tendency of fewer anastomotic leakages. Multiple comorbidities proved to be an important predictive factor of the postoperative course.
Driving and off-road impairments underlying failure on road testing in Parkinson's disease.

PubMed

Devos, Hannes; Vandenberghe, Wim; Tant, Mark; Akinwuntan, Abiodun E; De Weerdt, Willy; Nieuwboer, Alice; Uc, Ergun Y

2013-12-01

Parkinson's disease (PD) affects driving ability. We aimed to determine the most critical impairments in specific road skills and in clinical characteristics leading to failure on a road test in PD. In this cross-sectional study, certified driving assessment experts evaluated specific driving skills in 104 active, licensed drivers with PD using a standardized, on-road checklist and issued a global decision of pass/fail. Participants also completed an off-road evaluation assessing demographic features, disease characteristics, motor function, vision, and cognition. The most important driving skills and off-road predictors of the pass/fail outcome were identified using multivariate stepwise regression analyses. Eighty-six (65%) passed and 36 (35%) failed the on-road driving evaluation. Persons who failed performed worse on all on-road items. When adjusted for age and gender, poor performances on lateral positioning at low speed, speed adaptations at high speed, and left turning maneuvers yielded the best model that determined the pass/fail decision (R(2) = 0.56). The fail group performed poorer on all motor, visual, and cognitive tests. Measures of visual scanning, motor severity, PD subtype, visual acuity, executive functions, and divided attention were independent predictors of pass/fail decisions in the multivariate model (R(2) = 0.60). Our study demonstrated that failure on a road test in PD is determined by impairments in specific driving skills and associated with deficits in motor, visual, executive, and visuospatial functions. These findings point to specific driving and off-road impairments that can be targeted in multimodal rehabilitation programs for drivers with PD. © 2013 Movement Disorder Society.
Risk factors for Staphylococcus aureus postpartum breast abscess.

PubMed

Branch-Elliman, Westyn; Golen, Toni H; Gold, Howard S; Yassa, David S; Baldini, Linda M; Wright, Sharon B

2012-01-01

Staphylococcus aureus (SA) breast abscesses are a complication of the postpartum period. Risk factors for postpartum SA breast abscesses are poorly defined, and literature is conflicting. Whether risk factors for methicillin-resistant SA (MRSA) and methicillin-susceptible SA (MSSA) infections differ is unknown. We describe novel risk factors associated with postpartum breast abscesses and the changing epidemiology of this infection. We conducted a cohort study with a nested case-control study (n = 216) involving all patients with culture-confirmed SA breast abscess among >30 000 deliveries at our academic tertiary care center from 2003 through 2010. Data were collected from hospital databases and through abstraction from medical records. All SA cases were compared with both nested controls and full cohort controls. A subanalysis was completed to determine whether risk factors for MSSA and MRSA breast abscess differ. Univariate analysis was completed using Student's t test, Wilcoxon rank-sum test, and analysis of variance, as appropriate. A multivariable stepwise logistic regression was used to determine final adjusted results for both the case-control and the cohort analyses. Fifty-four cases of culture-confirmed abscess were identified: 30 MRSA and 24 MSSA. Risk factors for postpartum SA breast abscess in multivariable analysis include in-hospital identification of a mother having difficulty breastfeeding (odds ratio, 5.00) and being a mother employed outside the home (odds ratio, 2.74). Risk factors did not differ between patients who developed MRSA and MSSA infections. MRSA is an increasingly important pathogen in postpartum women; risk factors for postpartum SA breast abscess have not changed with the advent of community-associated MRSA.
Preoperative Carcinoembryonic Antigen and Prognosis of Colorectal Cancer. An Independent Prognostic Factor Still Reliable

PubMed Central

Li Destri, Giovanni; Rubino, Antonio Salvatore; Latino, Rosalia; Giannone, Fabio; Lanteri, Raffaele; Scilletta, Beniamino; Di Cataldo, Antonio

2015-01-01

To evaluate whether, in a sample of patients radically treated for colorectal carcinoma, the preoperative determination of the carcinoembryonic antigen (p-CEA) may have a prognostic value and constitute an independent risk factor in relation to disease-free survival. The preoperative CEA seems to be related both to the staging of colorectal neoplasia and to the patient's prognosis, although this—to date—has not been conclusively demonstrated and is still a matter of intense debate in the scientific community. This is a retrospective analysis of prospectively collected data. A total of 395 patients were radically treated for colorectal carcinoma. The preoperative CEA was statistically compared with the 2010 American Joint Committee on Cancer (AJCC) staging, the T and N parameters, and grading. All parameters recorded in our database were tested for an association with disease-free survival (DFS). Only factors significantly associated (P < 0.05) with the DFS were used to build multivariate stepwise forward logistic regression models to establish their independent predictors. A statistically significant relationship was found between p-CEA and tumor staging (P < 0.001), T (P < 0.001) and N parameters (P = 0.006). In a multivariate analysis, the independent prognostic factors found were: p-CEA, stages N1 and N2 according to AJCC, and G3 grading (grade). A statistically significant difference (P < 0.001) was evident between the DFS of patients with normal and high p-CEA levels. Preoperative CEA makes a pre-operative selection possible of those patients for whom it is likely to be able to predict a more advanced staging. PMID:25875542
Preoperative carcinoembryonic antigen and prognosis of colorectal cancer. An independent prognostic factor still reliable.

PubMed

Li Destri, Giovanni; Rubino, Antonio Salvatore; Latino, Rosalia; Giannone, Fabio; Lanteri, Raffaele; Scilletta, Beniamino; Di Cataldo, Antonio

2015-04-01

To evaluate whether, in a sample of patients radically treated for colorectal carcinoma, the preoperative determination of the carcinoembryonic antigen (p-CEA) may have a prognostic value and constitute an independent risk factor in relation to disease-free survival. The preoperative CEA seems to be related both to the staging of colorectal neoplasia and to the patient's prognosis, although this-to date-has not been conclusively demonstrated and is still a matter of intense debate in the scientific community. This is a retrospective analysis of prospectively collected data. A total of 395 patients were radically treated for colorectal carcinoma. The preoperative CEA was statistically compared with the 2010 American Joint Committee on Cancer (AJCC) staging, the T and N parameters, and grading. All parameters recorded in our database were tested for an association with disease-free survival (DFS). Only factors significantly associated (P < 0.05) with the DFS were used to build multivariate stepwise forward logistic regression models to establish their independent predictors. A statistically significant relationship was found between p-CEA and tumor staging (P < 0.001), T (P < 0.001) and N parameters (P = 0.006). In a multivariate analysis, the independent prognostic factors found were: p-CEA, stages N1 and N2 according to AJCC, and G3 grading (grade). A statistically significant difference (P < 0.001) was evident between the DFS of patients with normal and high p-CEA levels. Preoperative CEA makes a pre-operative selection possible of those patients for whom it is likely to be able to predict a more advanced staging.
Clinical Usefulness of Measuring Red Blood Cell Distribution Width in Patients with Hepatitis B Virus-Related Acute-On-Chronic Liver Failure.

PubMed

Jin, Lei; Gao, Yufeng; Ye, Jun; Zou, Guizhou; Li, Xu

2017-09-01

The red blood cell distribution width (RDW) is increased in chronic liver disease, but its clinical significance in hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF) is still unclear. The aim of the present study was to investigate the clinical significance of RDW in HBV-ACLF patients. The medical records of HBV-ACLF patients who were admitted to The Second Affiliated Hospital of Anhui Medical University between April 2012 and December 2015 were retrospectively reviewed. Correlations between RDW, neutrophil lymphocyte ratio (NLR), and the model for end-stage liver disease (MELD) scores were analyzed using the Spearman's approach. Multivariable stepwise logistic regression test was used to evaluate independent clinical parameters predicting 3-month mortality of HBV-ACLF patients. The association between RDW and hospitalization outcome was estimated by receiver operating curve (ROC) analysis. Patient survival was estimated by Kaplan-Meier analysis and subsequently compared by log-rank test. Sixty-two HBV-ACLF patients and sixty CHB patients were enrolled. RDW were increased in HBVACLF patients and positively correlated with the NLR as well as MELD scores. Multivariate analysis demonstrated that RDW value was an independent predictor for mortality. RDW had an area under the ROC of 0.799 in predicting 3-month mortality of HBV-ACLF patients. Patients with HBV-ACLF who had RDW > 17% showed significantly poorer survival than those who had RDW ≤ 17%. RDW values are significantly increased in patients with HBV-ACLF. Moreover, RDW values are an independent predicting factor for an in-hospital mortality in patients with HBV-ACLF.
Remote sensing of soil organic matter of farmland with hyperspectral image

NASA Astrophysics Data System (ADS)

Gu, Xiaohe; Wang, Lei; Yang, Guijun; Zhang, Liyan

2017-10-01

Monitoring soil organic matter (SOM) of cultivated land quantitively and mastering its spatial change are helpful for fertility adjustment and sustainable development of agriculture. The study aimed to analyze the response between SOM and reflectivity of hyperspectral image with different pixel size and develop the optimal model of estimating SOM with imaging spectral technology. The wavelet transform method was used to analyze the correlation between the hyperspectral reflectivity and SOM. Then the optimal pixel size and sensitive wavelet feature scale were screened to develop the inversion model of SOM. Result showed that wavelet transform of soil hyperspectrum was help to improve the correlation between the wavelet features and SOM. In the visible wavelength range, the susceptible wavelet features of SOM mainly concentrated 460 603 nm. As the wavelength increased, the wavelet scale corresponding correlation coefficient increased maximum and then gradually decreased. In the near infrared wavelength range, the susceptible wavelet features of SOM mainly concentrated 762 882 nm. As the wavelength increased, the wavelet scale gradually decreased. The study developed multivariate model of continuous wavelet transforms by the method of stepwise linear regression (SLR). The CWT-SLR models reached higher accuracies than those of univariate models. With the resampling scale increasing, the accuracies of CWT-SLR models gradually increased, while the determination coefficients (R2) fluctuated from 0.52 to 0.59. The R2 of 5*5 scale reached highest (0.5954), while the RMSE reached lowest (2.41 g/kg). It indicated that multivariate model based on continuous wavelet transform had better ability for estimating SOM than univariate model.
Predicting pork loin intramuscular fat using computer vision system.

PubMed

Liu, J-H; Sun, X; Young, J M; Bachmeier, L A; Newman, D J

2018-09-01

The objective of this study was to investigate the ability of computer vision system to predict pork intramuscular fat percentage (IMF%). Center-cut loin samples (n = 85) were trimmed of subcutaneous fat and connective tissue. Images were acquired and pixels were segregated to estimate image IMF% and 18 image color features for each image. Subjective IMF% was determined by a trained grader. Ether extract IMF% was calculated using ether extract method. Image color features and image IMF% were used as predictors for stepwise regression and support vector machine models. Results showed that subjective IMF% had a correlation of 0.81 with ether extract IMF% while the image IMF% had a 0.66 correlation with ether extract IMF%. Accuracy rates for regression models were 0.63 for stepwise and 0.75 for support vector machine. Although subjective IMF% has shown to have better prediction, results from computer vision system demonstrates the potential of being used as a tool in predicting pork IMF% in the future. Copyright © 2018 Elsevier Ltd. All rights reserved.
Relationships between presenteeism and work-related musculoskeletal disorders among physical therapists in the Republic of Korea.

PubMed

Bae, Young-Hyeon

2017-12-14

This study investigated the relationship between presenteeism and work-related musculoskeletal disorders (WMSDs) among physical therapists (PTs) in the Republic of Korea. Questionnaires were given to 600 PTs in the Republic of Korea. General and occupational characteristics and the prevalence of presenteeism and absenteeism were self-reported on the questionnaire. Stepwise regression analyses were used to evaluate the effects of presenteeism and other variables on general and occupational characteristics. Of the 490 PTs who responded, 399 (81.4%) reported at least one WMSD. There was a low incidence rate of absenteeism, but work impairment scores indicate there was a high incidence of presenteeism. In the stepwise regression analyses, the incidence of WMSDs was highest in cases of presenteeism. The results of this study demonstrate that there is a high incidence rate of WMSDs in Republic of Korean PTs, that WMSDs are related to presenteeism and that PTs demonstrate high presenteeism and low absenteeism.
Impact of HLA compatibility on lung transplant survival and evidence for an HLA restriction phenomenon: a collaborative transplant study report.

PubMed

Opelz, Gerhard; Süsal, Caner; Ruhenstroth, Andrea; Döhler, Bernd

2010-10-27

Data concerning the impact of human leukocyte antigen (HLA) compatibility on lung transplant survival rates are limited. Using the Collaborative Transplant Study database, 5-year graft outcome according to HLA mismatch was examined in 8020 deceased donor lung transplants performed during 1989 to 2009. Graft survival rates showed a stepwise decrease as the combined number of HLA-A+B+DR mismatches increased from one to six (P<0.001). Surprisingly, the 28 grafts with 0 mismatches at all 3 loci had a 1-year survival rate of only 49.7%, significantly lower than for 1, 2, 3, 4, 5, or 6 mismatches (P=0.002, <0.001, <0.001, <0.001, 0.002, and 0.003, respectively). Multivariate regression analysis confirmed that, paradoxically, transplantation of grafts with zero HLA-A+B+DR mismatches was associated with a 19% increase in relative risk of failure. Donor lung preservation for up to 12 hr was not associated with inferior graft survival versus shorter preservation times (P=0.60). Our data show that a high number of HLA mismatches or zero mismatches impacts unfavorably on lung transplant survival.
The relation between sexual interest and personality characteristics in men: an eye-tracking study.

PubMed

Tsujimura, A; Miyagawa, Y; Takada, S; Nagahara, A; Matsuoka, Y; Takao, T; Nakayama, J; Matsushita, M; Nonomura, N; Okuyama, A

2010-01-01

There is a large individual deviation for men, which may be caused by a difference in personality characteristics, in sexual interest in response to sexual stimuli. In this study, we investigate whether attention to the sexual region in a video depends on the personality characteristics of men, assessing this with an eye-tracking system. The study included 30 healthy males with a normal psychological state, who viewed a sexual video in which the sexual region had been designated. Visual attention was measured across the designated region according to gaze duration. Ten types of personality characteristics were evaluated as a T-score by a questionnaire. By Pearson's correlation coefficient, the relations between gaze duration at the sexual region and T-scores of paranoia, psychasthenia and social introversion were found to be statistically significant. By multivariate stepwise regression analysis, only social introversion was negatively associated with the sexual region. Even normal variation of personality characteristics can affect the viewing period of the sexual region. This is the first report showing that subjects with a high degree of paranoia, psychasthenia and particularly social introversion have a tendency to view the sexual region for a shorter duration.
The Renal Arterial Resistance Index Predicts Worsening Renal Function in Chronic Heart Failure Patients

PubMed Central

Iacoviello, Massimo; Monitillo, Francesco; Leone, Marta; Citarelli, Gaetano; Doronzo, Annalisa; Antoncecchi, Valeria; Puzzovivo, Agata; Rizzo, Caterina; Lattarulo, Maria Silvia; Massari, Francesco; Caldarola, Pasquale; Ciccone, Marco Matteo

2016-01-01

Background/Aim The renal arterial resistance index (RRI) is a Doppler measure, which reflects abnormalities in the renal blood flow. The aim of this study was to verify the value of RRI as a predictor of worsening renal function (WRF) in a group of chronic heart failure (CHF) outpatients. Methods We enrolled 266 patients in stable clinical conditions and on conventional therapy. Peak systolic velocity and end diastolic velocity of a segmental renal artery were obtained by pulsed Doppler flow, and RRI was calculated. Creatinine serum levels were evaluated at baseline and at 1 year, and the changes were used to assess WRF occurrence. Results During follow-up, 34 (13%) patients showed WRF. RRI was associated with WRF at univariate (OR: 1.13; 95% CI: 1.07–1.20) as well as at a forward stepwise multivariate logistic regression analysis (OR: 1.09; 95% CI: 1.03–1.16; p = 0.005) including the other univariate predictors. Conclusions Quantification of arterial renal perfusion provides a new parameter that independently predicts the WRF in CHF outpatients. Its possible role in current clinical practice to better define the risk of cardiorenal syndrome progression is strengthened. PMID:27994601
Quantification of Cannabinoid Content in Cannabis

NASA Astrophysics Data System (ADS)

Tian, Y.; Zhang, F.; Jia, K.; Wen, M.; Yuan, Ch.

2015-09-01

Cannabis is an economically important plant that is used in many fields, in addition to being the most commonly consumed illicit drug worldwide. Monitoring the spatial distribution of cannabis cultivation and judging whether it is drug- or fiber-type cannabis is critical for governments and international communities to understand the scale of the illegal drug trade. The aim of this study was to investigate whether the cannabinoids content in cannabis could be spectrally quantified using a spectrometer and to identify the optimal wavebands for quantifying the cannabinoid content. Spectral reflectance data of dried cannabis leaf samples and the cannabis canopy were measured in the laboratory and in the field, respectively. Correlation analysis and the stepwise multivariate regression method were used to select the optimal wavebands for cannabinoid content quantification based on the laboratory-measured spectral data. The results indicated that the delta-9-tetrahydrocannabinol (THC) content in cannabis leaves could be quantified using laboratory-measured spectral reflectance data and that the 695 nm band is the optimal band for THC content quantification. This study provides prerequisite information for designing spectral equipment to enable immediate quantification of THC content in cannabis and to discriminate drug- from fiber-type cannabis based on THC content quantification in the field.
[Duration of breastfeeding and its relevant influencing factors on under 2-years-old in rural areas of 10 provinces in China].

PubMed

Wang, Jian-min; Li, Neng; Xie, Sheng-nan; Yang, Sen-bei; Zheng, Xiao-xuan; Zhang, Jing

2013-07-01

To understand the current status and relevant factors influencing the duration of breastfeeding in rural areas in China. Children under two years old were selected as subjects from the study on "Physical growth among the under 7-years-old children from the rural areas of ten provinces in China in 2006". Kaplan-Meier method was used to estimate the survival curves and Cox multivariate stepwise regression was used to identify the relevant factors on the duration of breastfeeding. Median of the duration for breastfeeding was 12 months in rural areas of 10 provinces in China. Results of this study suggested that factors as sex, birth order, areas of residency, nationality, initiation of formula, parents' education levels, maternal services and family income were correlated with the duration of breastfeeding. Duration of breastfeeding among rural children under 2-years of age was short in the 10 provinces of China. Factors as level of education, residential areas and family income of the parents as well as sex of the children were correlated with the duration of breastfeeding. Intervention program should be implemented to improve the current status on breastfeeding.
Relation between adherence and outcome in the group treatment of insomnia.

PubMed

Vincent, Norah K; Hameed, Hannah

2003-01-01

This study evaluated adherence to group cognitive behavioral treatment in 50 adults with chronic insomnia. Adherence was measured using questionnaire data, consistency of sleep scheduling, and % of sessions attended. Results showed that therapists' rated 48% of participants as "very much" to "extremely" adherent. Using stepwise regression, only therapist-rated adherence explained a significant amount of variance in post-treatment outcome. Therapist-rated adherence predicted post-treatment ratings of sleep-related impairment, dysfunctional beliefs about sleep, and overall sleep quality (but not actual sleep duration or efficiency). Using a multivariate analysis of variance (MANOVA) procedure, results revealed that a diagnosis of dysthymia, based on a structured clinical interview, was associated with reduced adherence and less improvement in sleep-onset latency and sleep efficiency, but that scores on a dimensional measure of depression were not associated with either adherence or outcome. Implications of these findings are that the practice of treatment techniques is related to an improved perception of sleep and more healthy and appropriate beliefs about the causes of poor sleep. Therapists should continue to pay close attention to the adherence behavior of those with insomnia, particularly if they are depressed.
Maternal infibulation and obstetrical outcome in Djibouti.

PubMed

Minsart, Anne-Frederique; N'guyen, Thai-Son; Ali Hadji, Rachid; Caillet, Martin

2015-01-01

The objective of the present study was to assess the relation between female genital mutilation and obstetric outcome in an East African urban clinic with a standardized care, taking into account medical and socioeconomic status. This was a cohort study conducted in Djibouti between October 1, 2012 and April 30, 2014. Overall 643 mothers were interviewed and clinically assessed for the presence of female genital mutilation. The prevalence of obstetric complications by infibulation status was included in a multivariate stepwise regression model. Overall, 29 of 643 women did not have any form of mutilation (4.5%), as opposed to 238 of 643 women with infibulation (37.0%), 369 with type 2 (57.4%), and 7 with type 1 mutilation (1.1%).Women with a severe type of mutilation were more likely to have socio-economic and medical risk factors. After adjustment, the only outcome that was significantly related with infibulation was the presence of meconium-stained amniotic fluid with an odds ratio of 1.58 (1.10-2.27), p value=0.014. Infibulation was not related with excess perinatal morbidity in this setting with a very high prevalence of female genital mutilation, but future research should concentrate on the relation between infibulation and meconium.
Factors associated with self-rated health among North Korean defectors residing in South Korea.

PubMed

Wang, Bo-Ram; Yu, Shieun; Noh, Jin-Won; Kwon, Young Dae

2014-09-26

The number of North Korean refugees entering South Korea has increased recently. The health status of refugees is a significant factor in determining their success in resettlement; therefore, this study examined both the self-rated health status of North Korean defectors who have settled in South Korea and the factors associated with their self-rated health status. This study utilized data gained from face-to-face interviews with 500 North Korean defectors who arrived in South Korea in 2007. The interviews were structured and conducted by 'Yonsei University Research Team for North Korean defectors'. A stepwise multivariable linear regression was performed to determine the factors associated with their self-rated health status. North Korean defectors who were female, elderly, or had low annual household income, disability or chronic diseases reported lower health status. However, self-rated health status was higher among those who had settled in South Korea for 18 months or more, who were satisfied with government support or their current life, and who had experienced more traumatic events in North Korea. Government policies and refugee assistance programs should consider and reflect the factors relevant to the health status of North Korean defectors.
Risk factors for postoperative liver failure after hepatectomy for hepatocellular carcinoma.

PubMed

Maeda, Yoshitaka; Nishida, Minekatsu; Takao, Takashi; Mori, Naohide; Tamesa, Takao; Tangoku, Akira; Oka, Masaaki

2004-01-01

Selection of patients for hepatectomy for hepatocellular carcinoma conventionally has been based upon Child-Pugh grading. However, postoperative liver failure after hepatectomy is a major cause of hospital mortality. A new predictor of postoperative liver failure is required. The objective of this study was to identify risk factors for postoperative liver failure after hepatectomy. Perioperative risk factors for liver failure after hepatectomy were analyzed in 112 patients with hepatocellular carcinoma Eight of these patients died of liver failure. Stepwise multivariate logistic regression was performed to investigate significant independent factors among 17 variables, including the serum alkaline phosphatase ratio (ALPR) on the first day after hepatectomy. ALPR was calculated as the postoperative ALP level divided by the ALP level before surgery. Significant risk factors of postoperative liver failure were ALPR on postoperative day 1 (ALPR1), sex, operative blood loss, and operative procedure. As an indicator of liver failure, the diagnostic accuracy of the ALPR1 was 93.7% when the ALPR was less than 0.4 on the first postoperative day. The ALPR and the serum total bilirubin concentration after hepatectomy were uncorrelated. ALPR1 is a useful predictor of liver failure after hepatectomy.
Validation of the Arabic Version of the Iowa Infant Feeding Attitude Scale among Lebanese Women.

PubMed

Charafeddine, Lama; Tamim, Hani; Soubra, Marwa; de la Mora, Arlene; Nabulsi, Mona

2016-05-01

There is need in the Arab world for validated instruments that can reliably assess infant feeding attitudes among women. The 17-item Iowa Infant Feeding Attitude Scale (IIFAS) has consistently shown good reliability and validity in different cultures and the ability to predict breastfeeding intention and exclusivity. This study assessed the psychometric properties of the Arabic version of the IIFAS (IIFAS-A). After translating to classical Arabic and back-translating to English, the IIFAS-A was pilot tested among 20 women for comprehension, clarity, length, and cultural appropriateness. The IIFAS-A was then validated among 170 women enrolled in a breastfeeding promotion and support clinical trial in Lebanon. The IIFAS-A showed acceptable internal consistency reliability (Cronbach's α = 0.640), with principal components analysis revealing that it is unidimensional. The 17 items had good interitem reliabilities ranging between 0.599 and 0.665. The number of breastfed children was the only predictor of the overall IIFAS-A score in a multivariate stepwise regression model (β = 1.531, P < .0001). The 17-item IIFAS-A is a reliable and valid instrument for measuring women's infant feeding attitudes in the Arab context. © The Author(s) 2015.

The Role of Auxiliary Variables in Deterministic and Deterministic-Stochastic Spatial Models of Air Temperature in Poland

NASA Astrophysics Data System (ADS)

Szymanowski, Mariusz; Kryza, Maciej

2017-02-01

Our study examines the role of auxiliary variables in the process of spatial modelling and mapping of climatological elements, with air temperature in Poland used as an example. The multivariable algorithms are the most frequently applied for spatialization of air temperature, and their results in many studies are proved to be better in comparison to those obtained by various one-dimensional techniques. In most of the previous studies, two main strategies were used to perform multidimensional spatial interpolation of air temperature. First, it was accepted that all variables significantly correlated with air temperature should be incorporated into the model. Second, it was assumed that the more spatial variation of air temperature was deterministically explained, the better was the quality of spatial interpolation. The main goal of the paper was to examine both above-mentioned assumptions. The analysis was performed using data from 250 meteorological stations and for 69 air temperature cases aggregated on different levels: from daily means to 10-year annual mean. Two cases were considered for detailed analysis. The set of potential auxiliary variables covered 11 environmental predictors of air temperature. Another purpose of the study was to compare the results of interpolation given by various multivariable methods using the same set of explanatory variables. Two regression models: multiple linear (MLR) and geographically weighted (GWR) method, as well as their extensions to the regression-kriging form, MLRK and GWRK, respectively, were examined. Stepwise regression was used to select variables for the individual models and the cross-validation method was used to validate the results with a special attention paid to statistically significant improvement of the model using the mean absolute error (MAE) criterion. The main results of this study led to rejection of both assumptions considered. Usually, including more than two or three of the most significantly correlated auxiliary variables does not improve the quality of the spatial model. The effects of introduction of certain variables into the model were not climatologically justified and were seen on maps as unexpected and undesired artefacts. The results confirm, in accordance with previous studies, that in the case of air temperature distribution, the spatial process is non-stationary; thus, the local GWR model performs better than the global MLR if they are specified using the same set of auxiliary variables. If only GWR residuals are autocorrelated, the geographically weighted regression-kriging (GWRK) model seems to be optimal for air temperature spatial interpolation.
Predictive value of grade point average (GPA), Medical College Admission Test (MCAT), internal examinations (Block) and National Board of Medical Examiners (NBME) scores on Medical Council of Canada qualifying examination part I (MCCQE-1) scores.

PubMed

Roy, Banibrata; Ripstein, Ira; Perry, Kyle; Cohen, Barry

2016-01-01

To determine whether the pre-medical Grade Point Average (GPA), Medical College Admission Test (MCAT), Internal examinations (Block) and National Board of Medical Examiners (NBME) scores are correlated with and predict the Medical Council of Canada Qualifying Examination Part I (MCCQE-1) scores. Data from 392 admitted students in the graduating classes of 2010-2013 at University of Manitoba (UofM), College of Medicine was considered. Pearson's correlation to assess the strength of the relationship, multiple linear regression to estimate MCCQE-1 score and stepwise linear regression to investigate the amount of variance were employed. Complete data from 367 (94%) students were studied. The MCCQE-1 had a moderate-to-large positive correlation with NBME scores and Block scores but a low correlation with GPA and MCAT scores. The multiple linear regression model gives a good estimate of the MCCQE-1 (R2 =0.604). Stepwise regression analysis demonstrated that 59.2% of the variation in the MCCQE-1 was accounted for by the NBME, but only 1.9% by the Block exams, and negligible variation came from the GPA and the MCAT. Amongst all the examinations used at UofM, the NBME is most closely correlated with MCCQE-1.
Optimizing separate phase light hydrocarbon recovery from contaminated unconfined aquifers

NASA Astrophysics Data System (ADS)

Cooper, Grant S.; Peralta, Richard C.; Kaluarachchi, Jagath J.

A modeling approach is presented that optimizes separate phase recovery of light non-aqueous phase liquids (LNAPL) for a single dual-extraction well in a homogeneous, isotropic unconfined aquifer. A simulation/regression/optimization (S/R/O) model is developed to predict, analyze, and optimize the oil recovery process. The approach combines detailed simulation, nonlinear regression, and optimization. The S/R/O model utilizes nonlinear regression equations describing system response to time-varying water pumping and oil skimming. Regression equations are developed for residual oil volume and free oil volume. The S/R/O model determines optimized time-varying (stepwise) pumping rates which minimize residual oil volume and maximize free oil recovery while causing free oil volume to decrease a specified amount. This S/R/O modeling approach implicitly immobilizes the free product plume by reversing the water table gradient while achieving containment. Application to a simple representative problem illustrates the S/R/O model utility for problem analysis and remediation design. When compared with the best steady pumping strategies, the optimal stepwise pumping strategy improves free oil recovery by 11.5% and reduces the amount of residual oil left in the system due to pumping by 15%. The S/R/O model approach offers promise for enhancing the design of free phase LNAPL recovery systems and to help in making cost-effective operation and management decisions for hydrogeologists, engineers, and regulators.
Nitrogen dioxide concentrations in neighborhoods adjacent to a commercial airport: a land use regression modeling study

PubMed Central

2010-01-01

Background There is growing concern in communities surrounding airports regarding the contribution of various emission sources (such as aircraft and ground support equipment) to nearby ambient concentrations. We used extensive monitoring of nitrogen dioxide (NO2) in neighborhoods surrounding T.F. Green Airport in Warwick, RI, and land-use regression (LUR) modeling techniques to determine the impact of proximity to the airport and local traffic on these concentrations. Methods Palmes diffusion tube samplers were deployed along the airport's fence line and within surrounding neighborhoods for one to two weeks. In total, 644 measurements were collected over three sampling campaigns (October 2007, March 2008 and June 2008) and each sampling location was geocoded. GIS-based variables were created as proxies for local traffic and airport activity. A forward stepwise regression methodology was employed to create general linear models (GLMs) of NO2 variability near the airport. The effect of local meteorology on associations with GIS-based variables was also explored. Results Higher concentrations of NO2 were seen near the airport terminal, entrance roads to the terminal, and near major roads, with qualitatively consistent spatial patterns between seasons. In our final multivariate model (R2 = 0.32), the local influences of highways and arterial/collector roads were statistically significant, as were local traffic density and distance to the airport terminal (all p < 0.001). Local meteorology did not significantly affect associations with principal GIS variables, and the regression model structure was robust to various model-building approaches. Conclusion Our study has shown that there are clear local variations in NO2 in the neighborhoods that surround an urban airport, which are spatially consistent across seasons. LUR modeling demonstrated a strong influence of local traffic, except the smallest roads that predominate in residential areas, as well as proximity to the airport terminal. PMID:21083910
Nitrogen dioxide concentrations in neighborhoods adjacent to a commercial airport: a land use regression modeling study.

PubMed

Adamkiewicz, Gary; Hsu, Hsiao-Hsien; Vallarino, Jose; Melly, Steven J; Spengler, John D; Levy, Jonathan I

2010-11-17

There is growing concern in communities surrounding airports regarding the contribution of various emission sources (such as aircraft and ground support equipment) to nearby ambient concentrations. We used extensive monitoring of nitrogen dioxide (NO2) in neighborhoods surrounding T.F. Green Airport in Warwick, RI, and land-use regression (LUR) modeling techniques to determine the impact of proximity to the airport and local traffic on these concentrations. Palmes diffusion tube samplers were deployed along the airport's fence line and within surrounding neighborhoods for one to two weeks. In total, 644 measurements were collected over three sampling campaigns (October 2007, March 2008 and June 2008) and each sampling location was geocoded. GIS-based variables were created as proxies for local traffic and airport activity. A forward stepwise regression methodology was employed to create general linear models (GLMs) of NO2 variability near the airport. The effect of local meteorology on associations with GIS-based variables was also explored. Higher concentrations of NO2 were seen near the airport terminal, entrance roads to the terminal, and near major roads, with qualitatively consistent spatial patterns between seasons. In our final multivariate model (R2 = 0.32), the local influences of highways and arterial/collector roads were statistically significant, as were local traffic density and distance to the airport terminal (all p < 0.001). Local meteorology did not significantly affect associations with principal GIS variables, and the regression model structure was robust to various model-building approaches. Our study has shown that there are clear local variations in NO2 in the neighborhoods that surround an urban airport, which are spatially consistent across seasons. LUR modeling demonstrated a strong influence of local traffic, except the smallest roads that predominate in residential areas, as well as proximity to the airport terminal.
Neuropsychologic predictors of competency in Alzheimer's disease using a rational reasons legal standard.

PubMed

Marson, D C; Cody, H A; Ingram, K K; Harrell, L E

1995-10-01

To identify neuropsychologic predictors of competency performance and status in Alzheimer's disease (AD) using a specific legal standard (LS). This study is a follow-up to the competency assessment research reported in this issue of the archives. Univariate and multivariate analyses of independent neuropsychologic test measures with a dependent measure of competency to consent to treatment. University medical center. Fifteen normal older control subjects and 29 patients with probable AD. Subjects were administered a battery of neuropsychologic measures theoretically linked to competency function, as well as two clinical vignettes testing their capacity to consent to medical treatment under five different LSs. The present study focused on one specific LS: the capacity to provide "rational reasons" for a treatment choice (LS4). Neuropsychologic test scores were correlated with scores on LS4 for the normal control group and the AD group. The resulting univariate predictors were then analyzed using stepwise regression and discriminant function to identify the key multivariate predictors of competency performance and status under LS4. Measures of word fluency predicted the LS4 scores of controls (R2 = .33) and the AD group (R2 = .36). A word fluency measure also emerged as the best single predictor of competency status for the full subject sample (n = 44), correctly classifying 82% of cases. Dementia severity (Mini-Mental State Examination score) did not emerge as a multivariate predictor of competency performance or status. Interestingly, measures of verbal reasoning and memory were not strongly associated with LS4. Word fluency measures predicted the normative performance and intact competency status of older control subjects and the declining performance and compromised competency status of patients with AD on a "rational reasons" standard of competency to consent to treatment. Cognitive capacities related to frontal lobe function appear to underlie the capacity to formulate rational reasons for a treatment choice. Neuropsychologic studies of competency function have important theoretical and clinical value.
Learning Curve of the Application of Huang Three-Step Maneuver in a Laparoscopic Spleen-Preserving Splenic Hilar Lymphadenectomy for Advanced Gastric Cancer

PubMed Central

Huang, Ze-Ning; Huang, Chang-Ming; Zheng, Chao-Hui; Li, Ping; Xie, Jian-Wei; Wang, Jia-Bin; Lin, Jian-Xian; Lu, Jun; Chen, Qi-Yue; Cao, Long-long; Lin, Mi; Tu, Ru-Hong

2016-01-01

Abstract To investigate the learning curve of the application of Huang 3-step maneuver, which was summarized and proposed by our center for the treatment of advanced upper gastric cancer. From April 2012 to March 2013, 130 consecutive patients who underwent a laparoscopic spleen-preserving splenic hilar lymphadenectomy (LSPL) by a single surgeon who performed Huang 3-step maneuver were retrospectively analyzed. The learning curve was analyzed based on the moving average (MA) method and the cumulative sum method (CUSUM). Surgical outcomes, short-term outcomes, and follow-up results before and after learning curve were contrastively analyzed. A stepwise multivariate logistic regression was used for a multivariable analysis to determine the factors that affect the operative time using Huang 3-step maneuver. Based on the CUSUM, the learning curve for Huang 3-step maneuver was divided into phase 1 (cases 1–40) and phase 2 (cases 41–130). The dissection time (DT) (P < 0.001), blood loss (BL) (P < 0.001), and number of vessels injured in phase 2 were significantly less than those in phase 1. There were no significant differences in the clinicopathological characteristics, short-term outcomes, or major postoperative complications between the learning curve phases. Univariate and multivariate analyses revealed that body mass index (BMI), short gastric vessels (SGVs), splenic hilar artery (SpA) type, and learning curve phase were significantly associated with DT. In the entire group, 124 patients were followed for a median time of 23.0 months (range, 3–30 months). There was no significant difference in the survival curve between phases. AUGC patients with a BMI less than 25 kg/m2, a small number of SGVs, and a concentrated type of SpA are ideal candidates for surgeons who are in phase 1 of the learning curve. PMID:27043698
Applicant Characteristics Associated With Selection for Ranking at Independent Surgery Residency Programs.

PubMed

Dort, Jonathan M; Trickey, Amber W; Kallies, Kara J; Joshi, Amit R T; Sidwell, Richard A; Jarman, Benjamin T

2015-01-01

This study evaluated characteristics of applicants selected for interview and ranked by independent general surgery residency programs and assessed independent program application volumes, interview selection, rank list formation, and match success. Demographic and academic information was analyzed for 2014-2015 applicants. Applicant characteristics were compared by ranking status using univariate and multivariable statistical techniques. Characteristics independently associated with whether or not an applicant was ranked were identified using multivariable logistic regression modeling with backward stepwise variable selection and cluster-correlated robust variance estimates to account for correlations among individuals who applied to multiple programs. The Electronic Residency Application Service was used to obtain applicant data and program match outcomes at 33 independent surgery programs. All applicants selected to interview at 33 participating independent general surgery residency programs were included in the study. Applicants were 60% male with median age of 26 years. Birthplace was well distributed. Most applicants (73%) had ≥1 academic publication. Median United States Medical Licensing Exams (USMLE) Step 1 score was 228 (interquartile range: 218-240), and median USMLE Step 2 clinical knowledge score was 241 (interquartile range: 231-250). Residency programs in some regions more often ranked applicants who attended medical school within the same region. On multivariable analysis, significant predictors of ranking by an independent residency program were: USMLE scores, medical school region, and birth region. Independent programs received an average of 764 applications (range: 307-1704). On average, 12% interviews, and 81% of interviewed applicants were ranked. Most programs (84%) matched at least 1 applicant ranked in their top 10. Participating independent programs attract a large volume of applicants and have high standards in the selection process. This information can be used by surgery residency applicants to gauge their candidacy at independent programs. Independent programs offer a select number of interviews, rank most applicants that they interview, and successfully match competitive applicants. Copyright © 2015 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.
Depression and Related Problems in University Students

ERIC Educational Resources Information Center

Field, Tiffany; Diego, Miguel; Pelaez, Martha; Deeds, Osvelia; Delgado, Jeannette

2012-01-01

Method: Depression and related problems were studied in a sample of 283 university students. Results: The students with high depression scores also had high scores on anxiety, intrusive thoughts, controlling intrusive thoughts and sleep disturbances scales. A stepwise regression suggested that those problems contributed to a significant proportion…
Analyzing Teaching Performance of Instructors Using Data Mining Techniques

ERIC Educational Resources Information Center

Mardikyan, Sona; Badur, Bertain

2011-01-01

Student evaluations to measure the teaching effectiveness of instructor's are very frequently applied in higher education for many years. This study investigates the factors associated with the assessment of instructors teaching performance using two different data mining techniques; stepwise regression and decision trees. The data collected…
DEVELOPMENT OF RESIDENTIAL WOOD COMSUMPTION ESTIMATION MODELS

EPA Science Inventory

The report gives data on the distribution and usage of firewood, obtained from a pool of household wood use surveys. ased on a series of regression models developed using the STEPWISE procedure in the SAS statistical package, two variables appear to be most predictive of wood use...
An empirical study using permutation-based resampling in meta-regression

PubMed Central

2012-01-01

Background In meta-regression, as the number of trials in the analyses decreases, the risk of false positives or false negatives increases. This is partly due to the assumption of normality that may not hold in small samples. Creation of a distribution from the observed trials using permutation methods to calculate P values may allow for less spurious findings. Permutation has not been empirically tested in meta-regression. The objective of this study was to perform an empirical investigation to explore the differences in results for meta-analyses on a small number of trials using standard large sample approaches verses permutation-based methods for meta-regression. Methods We isolated a sample of randomized controlled clinical trials (RCTs) for interventions that have a small number of trials (herbal medicine trials). Trials were then grouped by herbal species and condition and assessed for methodological quality using the Jadad scale, and data were extracted for each outcome. Finally, we performed meta-analyses on the primary outcome of each group of trials and meta-regression for methodological quality subgroups within each meta-analysis. We used large sample methods and permutation methods in our meta-regression modeling. We then compared final models and final P values between methods. Results We collected 110 trials across 5 intervention/outcome pairings and 5 to 10 trials per covariate. When applying large sample methods and permutation-based methods in our backwards stepwise regression the covariates in the final models were identical in all cases. The P values for the covariates in the final model were larger in 78% (7/9) of the cases for permutation and identical for 22% (2/9) of the cases. Conclusions We present empirical evidence that permutation-based resampling may not change final models when using backwards stepwise regression, but may increase P values in meta-regression of multiple covariates for relatively small amount of trials. PMID:22587815
Alternatives for using multivariate regression to adjust prospective payment rates

PubMed Central

Sheingold, Steven H.

1990-01-01

Multivariate regression analysis has been used in structuring three of the adjustments to Medicare's prospective payment rates. Because the indirect-teaching adjustment, the disproportionate-share adjustment, and the adjustment for large cities are responsible for distributing approximately $3 billion in payments each year, the specification of regression models for these adjustments is of critical importance. In this article, the application of regression for adjusting Medicare's prospective rates is discussed, and the implications that differing specifications could have for these adjustments are demonstrated. PMID:10113271
Electricity Consumption in the Industrial Sector of Jordan: Application of Multivariate Linear Regression and Adaptive Neuro-Fuzzy Techniques

NASA Astrophysics Data System (ADS)

Samhouri, M.; Al-Ghandoor, A.; Fouad, R. H.

2009-08-01

In this study two techniques, for modeling electricity consumption of the Jordanian industrial sector, are presented: (i) multivariate linear regression and (ii) neuro-fuzzy models. Electricity consumption is modeled as function of different variables such as number of establishments, number of employees, electricity tariff, prevailing fuel prices, production outputs, capacity utilizations, and structural effects. It was found that industrial production and capacity utilization are the most important variables that have significant effect on future electrical power demand. The results showed that both the multivariate linear regression and neuro-fuzzy models are generally comparable and can be used adequately to simulate industrial electricity consumption. However, comparison that is based on the square root average squared error of data suggests that the neuro-fuzzy model performs slightly better for future prediction of electricity consumption than the multivariate linear regression model. Such results are in full agreement with similar work, using different methods, for other countries.
Prediction of troponin-T degradation using color image texture features in 10d aged beef longissimus steaks.

PubMed

Sun, X; Chen, K J; Berg, E P; Newman, D J; Schwartz, C A; Keller, W L; Maddock Carlin, K R

2014-02-01

The objective was to use digital color image texture features to predict troponin-T degradation in beef. Image texture features, including 88 gray level co-occurrence texture features, 81 two-dimension fast Fourier transformation texture features, and 48 Gabor wavelet filter texture features, were extracted from color images of beef strip steaks (longissimus dorsi, n = 102) aged for 10d obtained using a digital camera and additional lighting. Steaks were designated degraded or not-degraded based on troponin-T degradation determined on d 3 and d 10 postmortem by immunoblotting. Statistical analysis (STEPWISE regression model) and artificial neural network (support vector machine model, SVM) methods were designed to classify protein degradation. The d 3 and d 10 STEPWISE models were 94% and 86% accurate, respectively, while the d 3 and d 10 SVM models were 63% and 71%, respectively, in predicting protein degradation in aged meat. STEPWISE and SVM models based on image texture features show potential to predict troponin-T degradation in meat. © 2013.
An Exploring Model of Intelligence and Personality in Different Culture

ERIC Educational Resources Information Center

Wu, Yufeng; Qian, Guoying

2005-01-01

Middle school subjects of 13-21 years (from 4 nationalities) were used for studying the relationship between progressive cognition and personality characteristics by Raven's Standard Progressive Matrices and Eysenk's Personality Questionnaire. The results showed: (1) the correlation and stepwise regression were completely identical: P score was…
Switchgrass biomass composition traits and their effects on its digestion by ruminants and bioconversion to ethanol

USDA-ARS?s Scientific Manuscript database

Six generations of divergent breeding in switchgrass (Panicum virgatum L.) for forage in vitro digestibility (IVDMD) resulted in significant changes in 20 biomass composition traits. Stepwise multi-regression was used to determine which of the 20 composition traits had largest significant effects on...
Spatial Representation in Blind Children. 3: Effects of Individual Differences.

ERIC Educational Resources Information Center

Fletcher, Janet F.

1981-01-01

Data from a study of spatial representation in blind children were subjected to two stepwise regression analyses to determine the relationships between several subject related variables and responses to "map" (cognitive map) and "route" (sequential memory) questions about the position of furniture in a recently explored room. (Author/SBH)
Juvenile Offender Recidivism: An Examination of Risk Factors

ERIC Educational Resources Information Center

Calley, Nancy G.

2012-01-01

One hundred and seventy three male juvenile offenders were followed two years postrelease from a residential treatment facility to assess recidivism and factors related to recidivism. The overall recidivism rate was 23.9%. Logistic regression with stepwise and backward variable selection methods was used to examine the relationship between…
Knowing When to Retire: The First Step towards Financial Planning in Malaysia

ERIC Educational Resources Information Center

Kock, Tan Hoe; Yoong, Folk Jee

2011-01-01

This article draws upon expected retirement age cohorts as a main determinant to financial planning preparation in Malaysia. The return rate was 55% from 600 questionnaires distributed. Five hypotheses were analyzed using hierarchical and stepwise regression analysis. The results revealed that expected retirement age cohort variables made…

Can the FIGO 2000 scoring system for gestational trophoblastic neoplasia be simplified? A new retrospective analysis from a nationwide dataset.

PubMed

Eysbouts, Y K; Ottevanger, P B; Massuger, L F A G; IntHout, J; Short, D; Harvey, R; Kaur, B; Sebire, N J; Sarwar, N; Sweep, F C G J; Seckl, M J

2017-08-01

Worldwide introduction of the International Fedaration of Gynaecology and Obstetrics (FIGO) 2000 scoring system has provided an effective means to stratify patients with gestational trophoblastic neoplasia to single- or multi-agent chemotherapy. However, the system is quite elaborate with an extensive set of risk factors. In this study, we re-evaluate all prognostic risk factors involved in the FIGO 2000 scoring system and examine if simplification is feasible. Between January 2003 and December 2012, 813 patients diagnosed with gestational trophoblastic neoplasia were identified at the Trophoblastic Disease Centre in London and scored using the FIGO 2000. Multivariable analysis and stepwise logistic regression were carried out to evaluate whether the FIGO 2000 scoring system could be simplified. Of the eight FIGO risk factors only pre-treatment serum human chorionic gonadotropin (hCG) levels exceeding 10 000 IU/l (OR = 5.0; 95% CI 2.5-10.4) and 100 000 IU/l (OR = 14.3; 95% CI 4.7-44.1), interval exceeding 7 months since antecedent pregnancy (OR = 4.1; 95% CI 1.0-16.2), and tumor size of over 5 cm (OR = 2.2; 95% CI 1.3-3.6) were identified as independently predictive for single-agent resistance. In addition, increased risk was apparent for antecedent term pregnancy (OR = 3.4; 95% CI 0.9-12.7) and the presence of five or more metastases (OR = 3.5; 95% CI 0.4-30.4), but patient numbers in these categories were relatively small. Stepwise logistic regression identified a simplified risk scoring model comprising age, pretreatment serum hCG, number of metastases, antecedent pregnancy, and interval but omitting tumor size, previous failed chemotherapy, and site of metastases. With this model only 1 out 725 patients was classified different from the FIGO 2000 system. Our simplified alternative using only five of the FIGO prognostic factors appears to be an accurate system for discriminating patients requiring single as opposed to multi-agent chemotherapy. Further work is urgently needed to validate these findings. © The Author 2017. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. For permissions, please email: journals.permissions@oup.com.
The association among skeletal muscle phosphocreatine recovery, adiposity, and insulin resistance in children.

PubMed

Wells, Greg D; Banks, Laura; Caterini, Jessica E; Thompson, Sara; Noseworthy, Michael D; Rayner, Tammy; Syme, Catriona; McCrindle, Brian W; Hamilton, Jill

2017-04-01

Obesity is associated with cardiometabolic disturbances, which may have significant implications for musculoskeletal health and exercise tolerance. We sought to determine the association between muscle structure, function, and metabolism in adolescents across the weight spectrum. This cross-sectional case-control study included overweight and obese participants (n = 24) 8-18 years of age with a body mass index (BMI) ≥ 85th percentile for age and gender, and non-obese participants (n = 24) with a BMI < 85 th percentile. Body composition, physical activity, peak aerobic capacity, cardiometabolic blood markers and insulin resistance (measured by the homeostatic model assessment of insulin resistance, HOMA-IR), skeletal muscle mitochondrial oxidative capacity (via 31 Phosphorous-Magnetic Resonance Spectroscopy, 31 P-MRS, to assess phosphocreatine (PCr) recovery after exercise), and extramyocellular and intramyocellular lipid (IMCL) levels (via 1 Hydrogen-MRS) were assessed. Stepwise regression was performed to examine the factors associated with oxidative capacity. bese and overweight patients had similar age, height, and physical activity to non-obese controls, but obese and overweight participants exhibited higher insulin resistance. Obese and overweight participants had longer PCr recovery than non-obese controls following 5x30s of moderate-intensity exercise (51.2 ± 20.1 s vs. 23.9 ± 7.5 s, p = 0.004). In univariate correlation analysis, impaired PCr recovery was associated with a higher BMI z-score (r s = 0.51, p < 0.001), circulating triglycerides (r s = 0.41, p = 0.005), and HOMA-IR (r s = 0.46, p = 0.001). In stepwise multivariate regression analysis, impaired PCr recovery was associated with a higher BMI z-score (β = 0.47, p = 0.002), but not insulin resistance (β = 0.07, p = 0.07) or circulating triglycerides (β = 0.16 p = 0.33). A slower phosphocreatine recovery following aerobic exercise is strongly associated with increasing adiposity. A slower metabolic recovery following aerobic exercise stress suggests that endurance exercise training in obese adolescents may be an optimal strategy to target exercise intolerance in this cohort. © 2016 World Obesity Federation.
The role of multicollinearity in landslide susceptibility assessment by means of Binary Logistic Regression: comparison between VIF and AIC stepwise selection

NASA Astrophysics Data System (ADS)

Cama, Mariaelena; Cristi Nicu, Ionut; Conoscenti, Christian; Quénéhervé, Geraldine; Maerker, Michael

2016-04-01

Landslide susceptibility can be defined as the likelihood of a landslide occurring in a given area on the basis of local terrain conditions. In the last decades many research focused on its evaluation by means of stochastic approaches under the assumption that 'the past is the key to the future' which means that if a model is able to reproduce a known landslide spatial distribution, it will be able to predict the future locations of new (i.e. unknown) slope failures. Among the various stochastic approaches, Binary Logistic Regression (BLR) is one of the most used because it calculates the susceptibility in probabilistic terms and its results are easily interpretable from a geomorphological point of view. However, very often not much importance is given to multicollinearity assessment whose effect is that the coefficient estimates are unstable, with opposite sign and therefore difficult to interpret. Therefore, it should be evaluated every time in order to make a model whose results are geomorphologically correct. In this study the effects of multicollinearity in the predictive performance and robustness of landslide susceptibility models are analyzed. In particular, the multicollinearity is estimated by means of Variation Inflation Index (VIF) which is also used as selection criterion for the independent variables (VIF Stepwise Selection) and compared to the more commonly used AIC Stepwise Selection. The robustness of the results is evaluated through 100 replicates of the dataset. The study area selected to perform this analysis is the Moldavian Plateau where landslides are among the most frequent geomorphological processes. This area has an increasing trend of urbanization and a very high potential regarding the cultural heritage, being the place of discovery of the largest settlement belonging to the Cucuteni Culture from Eastern Europe (that led to the development of the great complex Cucuteni-Tripyllia). Therefore, identifying the areas susceptible to landslides may lead to a better understanding and mitigation for government, local authorities and stakeholders to plan the economic activities, minimize the damages costs, environmental and cultural heritage protection. The results show that although the VIF Stepwise selection allows a more stable selection of the controlling factors, the AIC Stepwise selection produces better predictive performance. Moreover, when working with replicates the effect of multicollinearity are statistically reduced by the application of the AIC stepwise selection and the results are easily interpretable in geomorphologic terms.
Applied Statistics: From Bivariate through Multivariate Techniques [with CD-ROM

ERIC Educational Resources Information Center

Warner, Rebecca M.

2007-01-01

This book provides a clear introduction to widely used topics in bivariate and multivariate statistics, including multiple regression, discriminant analysis, MANOVA, factor analysis, and binary logistic regression. The approach is applied and does not require formal mathematics; equations are accompanied by verbal explanations. Students are asked…
Effect of Contact Damage on the Strength of Ceramic Materials.

DTIC Science & Technology

1982-10-01

variables that are important to erosion, and a multivariate , linear regression analysis is used to fit the data to the dimensional analysis. The...of Equations 7 and 8 by a multivariable regression analysis (room tem- perature data) Exponent Regression Standard error Computed coefficient of...1980) 593. WEAVER, Proc. Brit. Ceram. Soc. 22 (1973) 125. 39. P. W. BRIDGMAN, "Dimensional Analaysis ", (Yale 18. R. W. RICE, S. W. FREIMAN and P. F
Stepwise group sparse regression (SGSR): gene-set-based pharmacogenomic predictive models with stepwise selection of functional priors.

PubMed

Jang, In Sock; Dienstmann, Rodrigo; Margolin, Adam A; Guinney, Justin

2015-01-01

Complex mechanisms involving genomic aberrations in numerous proteins and pathways are believed to be a key cause of many diseases such as cancer. With recent advances in genomics, elucidating the molecular basis of cancer at a patient level is now feasible, and has led to personalized treatment strategies whereby a patient is treated according to his or her genomic profile. However, there is growing recognition that existing treatment modalities are overly simplistic, and do not fully account for the deep genomic complexity associated with sensitivity or resistance to cancer therapies. To overcome these limitations, large-scale pharmacogenomic screens of cancer cell lines--in conjunction with modern statistical learning approaches--have been used to explore the genetic underpinnings of drug response. While these analyses have demonstrated the ability to infer genetic predictors of compound sensitivity, to date most modeling approaches have been data-driven, i.e. they do not explicitly incorporate domain-specific knowledge (priors) in the process of learning a model. While a purely data-driven approach offers an unbiased perspective of the data--and may yield unexpected or novel insights--this strategy introduces challenges for both model interpretability and accuracy. In this study, we propose a novel prior-incorporated sparse regression model in which the choice of informative predictor sets is carried out by knowledge-driven priors (gene sets) in a stepwise fashion. Under regularization in a linear regression model, our algorithm is able to incorporate prior biological knowledge across the predictive variables thereby improving the interpretability of the final model with no loss--and often an improvement--in predictive performance. We evaluate the performance of our algorithm compared to well-known regularization methods such as LASSO, Ridge and Elastic net regression in the Cancer Cell Line Encyclopedia (CCLE) and Genomics of Drug Sensitivity in Cancer (Sanger) pharmacogenomics datasets, demonstrating that incorporation of the biological priors selected by our model confers improved predictability and interpretability, despite much fewer predictors, over existing state-of-the-art methods.
A new model for estimating total body water from bioelectrical resistance

NASA Technical Reports Server (NTRS)

Siconolfi, S. F.; Kear, K. T.

1992-01-01

Estimation of total body water (T) from bioelectrical resistance (R) is commonly done by stepwise regression models with height squared over R, H(exp 2)/R, age, sex, and weight (W). Polynomials of H(exp 2)/R have not been included in these models. We examined the validity of a model with third order polynomials and W. Methods: T was measured with oxygen-18 labled water in 27 subjects. R at 50 kHz was obtained from electrodes placed on the hand and foot while subjects were in the supine position. A stepwise regression equation was developed with 13 subjects (age 31.5 plus or minus 6.2 years, T 38.2 plus or minus 6.6 L, W 65.2 plus or minus 12.0 kg). Correlations, standard error of estimates and mean differences were computed between T and estimated T's from the new (N) model and other models. Evaluations were completed with the remaining 14 subjects (age 32.4 plus or minus 6.3 years, T 40.3 plus or minus 8 L, W 70.2 plus or minus 12.3 kg) and two of its subgroups (high and low) Results: A regression equation was developed from the model. The only significant mean difference was between T and one of the earlier models. Conclusion: Third order polynomials in regression models may increase the accuracy of estimating total body water. Evaluating the model with a larger population is needed.
Association Between Smartphone Use and Musculoskeletal Discomfort in Adolescent Students.

PubMed

Yang, Shang-Yu; Chen, Ming-De; Huang, Yueh-Chu; Lin, Chung-Ying; Chang, Jer-Hao

2017-06-01

Despite the substantial increase in the number of adolescent smartphone users, few studies have investigated the behavioural effects of smartphone use on adolescent students as it relates to musculoskeletal discomfort. The purpose of this study was to explore the association between smartphone use and musculoskeletal discomfort in students at a Taiwanese junior college. We hypothesised that the duration of smartphone use would be associated with increased instances of musculoskeletal discomfort in these students. This cross-sectional study employed a convenience sampling method to recruit students from a junior college in southern Taiwan. All the students (n = 315) were asked to answer questionnaires on smartphone use. A descriptive analysis, stepwise regression, and logistic regression were used to examine specific components of smartphone use and their relationship to musculoskeletal discomfort. Nearly half of the participants experienced neck and shoulder discomfort. The stepwise regression results indicated that the number of body parts with discomfort (F = 6.009, p < 0.05) increased with hours spent using ancillary smartphone functions. The logistic regression analysis showed that the students who talked on the phone >3 h/day had a higher risk of upper back discomfort than did those who talked on the phone <1 h/day [odds ratio (OR) = 4.23, p < 0.05]. This study revealed that the relationship between smartphone use and musculoskeletal discomfort is related to the duration of smartphone ancillary function use. Moreover, hours spent talking on the phone was a predictor of upper back discomfort.
Care-seeking patterns among families that experienced under-five child mortality in rural Rwanda.

PubMed

Kagabo, Daniel M; Kirk, Catherine M; Bakundukize, Benjamin; Hedt-Gauthier, Bethany L; Gupta, Neil; Hirschhorn, Lisa R; Ingabire, Willy C; Rouleau, Dominique; Nkikabahizi, Fulgence; Mugeni, Catherine; Sayinzoga, Felix; Amoroso, Cheryl L

2018-01-01

Over half of under-five deaths occur in sub-Saharan Africa and appropriate, timely, quality care is critical for saving children's lives. This study describes the context surrounding children's deaths from the time the illness was first noticed, through the care-seeking patterns leading up to the child's death, and identifies factors associated with care-seeking for these children in rural Rwanda. Secondary analysis of a verbal and social autopsy study of caregivers who reported the death of a child between March 2013 to February 2014 that occurred after discharge from the child's birth facility in southern Kayonza and Kirehe districts in Rwanda. Bivariate analyses using Fisher's exact tests were conducted to identify child, caregiver, and household factors associated with care-seeking from the formal health system (i.e., community health worker or health facility). Factors significant at α = 0.10 significance level were considered for backwards stepwise multivariate logistic regression, stopping when remaining factors were significantly associated with care-seeking at α = 0.05 significance level. Among the 516 eligible deaths among children under-five, 22.7% (n = 117) did not seek care from the health system. For those who did, the most common first point of contact was community health workers (45.8%). In multivariate logistic regression, higher maternal education (OR = 3.36, 95% CI: 1.89, 5.98), having diarrhea (OR = 4.21, 95%CI: 1.95, 9.07) or fever (OR = 2.03, 95%CI: 1.11, 3.72), full household insurance coverage (3.48, 95%CI: 1.79, 6.76), and longer duration of illness (OR = 22.19, 95%CI: 8.88, 55.48) were significantly associated with formal care-seeking. Interventions such as community health workers and insurance promote access to care, however a gap remains as many children had no contact with the health system prior to death and those who sought formal care still died. Further efforts are needed to respond to urgent cases in communities and further understand remaining barriers to accessing appropriate, quality care.
Risk factors for mental disorders in women survivors of human trafficking: a historical cohort study.

PubMed

Abas, Melanie; Ostrovschi, Nicolae V; Prince, Martin; Gorceag, Viorel I; Trigub, Carolina; Oram, Siân

2013-08-03

Previous studies have found high levels of symptoms of depression, anxiety, and post-traumatic stress disorder among women survivors of human trafficking. No previous research has described risk factors for diagnosed mental disorders in this population. A historical cohort study of women survivors of trafficked women aged 18 and over who returned to Moldova and registered for assistance with the International Organisation for Migration (IOM). Women were approached by IOM social workers and, if they gave informed consented to participate in the study, interviewed by the research team. At 2-12 months post-return to Moldova, a psychiatrist assessed DSM-IV mental disorders blind to information about women's pre-trafficking and post-trafficking experiences using the Structured Clinical Interview for DSM-IV (SCID). A backwards stepwise selection procedure was used to create a multivariable regression model of risk factors for DSM-IV mental disorder measured at an average of 6 months post-return. 120/176 (68%) eligible women participated. At an average of 6 months post-return, 54% met criteria for any DSM-IV mental disorder: 35.8% of women had PTSD (alone or co-morbid), 12.5% had depression without PTSD and 5.8% had another anxiety disorder. Multivariable regression analysis found that childhood sexual abuse (Adjusted Odds Ratio [AOR] 4.68, 95% CI 1.04-20.92), increased number of post-trafficking unmet needs (AOR 1.80; 95% CI 1.28-2.52) and post-trafficking social support (AOR 0.64; 95% CI 0.52-0.79) were independent risk factors for mental disorder, and that duration of trafficking showed a borderline association with mental disorder (AOR 1.12, 95% CI 0.98-1.29). Assessment for mental disorders should be part of re-integration follow-up care for women survivors of human trafficking. Mental disorders at that time, most commonly PTSD and depression, are likely to be influenced by a range of predisposing, precipitating and maintaining factors. Care plans for survivors of trafficking must be based on individual needs, and must apply clinical guidelines for the treatment of PTSD and of depression. Evidence is needed on the effectiveness of therapy for PTSD in survivors of human trafficking.
Financial validation of the European Society of Thoracic Surgeons risk score predicting prolonged air leak after video-assisted thoracic surgery lobectomy.

PubMed

Brunelli, Alessandro; Pompili, Cecilia; Dinesh, Padma; Bassi, Vinod; Imperatori, Andrea

2018-04-27

The objective of this study was to verify whether the European Society of Thoracic Surgeons prolonged air leak risk score for video-assisted thoracoscopic lobectomy was associated with incremental postoperative costs. We retrospectively analyzed 353 patients subjected to video-assisted thoracoscopic lobectomy or segmentectomy (April 2014 to March 2016). Postoperative costs were obtained from the hospital Finance Department. Patients were grouped in different classes of risk according to their prolonged air leak risk score. To verify the independent association of the prolonged air leak risk score with postoperative costs, we performed a stepwise multivariable regression analysis in which the dependent variable was postoperative cost. Prolonged air leak developed in 56 patients (15.9%). Their length of stay was 3 days longer compared with those without prolonged air leak (8.3 vs 5.4, P < .0001). Their postoperative cost was higher than that of patients without prolonged air leak: $5939.8 versus $4381.7 (P = .001). After grouping the patients according to their prolonged air leak risk score, prolonged air leak incidence was 12.3% in class A, 13.7% in class B, 28.8% in class C, and 22.2% in class D (P = .020). The average postoperative cost was $4031.0 in class A, $4498.2 in class B, $6146.6 in class C, and $6809.3 in class D (analysis of variance test, P < .001). Multivariable regression analysis showed that being in classes C and D of PAL score (P = .001) and the presence of cardiopulmonary complications (P < .0001) were the only independent factors significantly associated with postoperative costs. We financially validated the European Society of Thoracic Surgeons prolonged air leak risk score for video-assisted thoracoscopic lobectomies, which appears useful in selecting those patients in whom the application of additional intraoperative interventions to avoid prolonged air leak may be more cost-effective. Copyright © 2018 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.
Evaluation of risk factors for perforated peptic ulcer.

PubMed

Yamamoto, Kazuki; Takahashi, Osamu; Arioka, Hiroko; Kobayashi, Daiki

2018-02-15

The aim of this study was to evaluate the prediction factors for perforated peptic ulcer (PPU). At St. Luke's International Hospital in Tokyo, Japan, a case control study was performed between August 2004 and March 2016. All patients diagnosed with PPU were included. As control subjects, patients with age, sex and date of CT scan corresponding to those of the PPU subjects were included in the study at a proportion of 2 controls for every PPU subject. All data such as past medical histories, physical findings, and laboratory data were collected through chart reviews. Univariate analyses and multivariate analyses with logistic regression were conducted, and receiver operating characteristic curves (ROCs) were calculated to show validity. Sensitivity analyses were performed to confirm results using a stepwise method and conditional logistic regression. A total of 408 patients were included in this study; 136 were a group of patients with PPU, and 272 were a control group. Univariate analysis showed statistical significance in many categories. Four different models of multivariate analyses were conducted, and significant differences were found for muscular defense and a history of peptic ulcer disease (PUD) in all models. The conditional forced-entry analysis of muscular defense showed an odds ratio (OR) of 23.8 (95% confidence interval [CI]: 5.70-100.0), and the analysis of PUD history showed an OR of 6.40 (95% CI: 1.13-36.2). The sensitivity analysis showed consistent results, with an OR of 23.8-366.2 for muscular defense and an OR of 3.67-7.81 for PUD history. The area under the curve (AUC) of all models was high enough to confirm the results. However, anticoagulants, known risk factors for PUD, did not increase the risk for PPU in our study. The conditional forced-entry analysis of anticoagulant use showed an OR of 0.85 (95% CI: 0.03-22.3). The evaluation of prediction factors and development of a prediction rule for PPU may help our decision making in performing a CT scan for patients with acute abdominal pain.
Prevalence and risk factors for medical events following exercise at Australian Greyhound race meetings.

PubMed

Karamatic, S L; Anderson, G A; Parry, B W; Slocombe, R F; Mansfield, C S

2018-04-01

A prospective, observational study to determine the prevalence of post-exercise conditions at Australian Greyhound race meetings and to assess association with race performance and other environmental, race- and dog-related factors was undertaken. A total of 4020 starters were observed (2813 Greyhounds, 1009 trainers, 536 races, 52 race meets, 48 race dates and 11 race tracks) following a race. The presence of diaphragmatic flutter (DF), ataxia, seizure, collapse or sudden death was recorded. Risk factors were screened by univariable logistic regression prior to multivariable backward stepwise model building. In this study, 962 starters (n = 768 dogs) had DF (23.9%), 16 starters were ataxic (0.4%) and there were no observed cases of collapse, seizure or sudden death. Race track location, increasing race distance, race grade based on increasing 1st place prize value, lower (earlier) race number at the meeting, age, a previous observation of DF at the last start, females, colour (white) and better finishing position were all associated with an increased risk of a Greyhound being observed with DF. However, when logistic regression assessing the random effect of dog was performed, the presence of previous DF was not significant. In this cohort, DF was common following strenuous exercise in Greyhounds and on its own does not appear to result in reduced performance or distress to the animal. The incidence of ataxia was low and collapse, seizure and sudden death were not observed. However, even though uncommon, ataxia has welfare concerns for racing Greyhounds that warrants further investigation. © 2018 Australian Veterinary Association.
Impact of some field factors on inhalation exposure levels to bitumen emissions during road paving operations.

PubMed

Deygout, François; Auburtin, Guy

2015-03-01

Variability in occupational exposure levels to bitumen emissions has been observed during road paving operations. This is due to recurrent field factors impacting the level of exposure experienced by workers during paving. The present study was undertaken in order to quantify the impact of such factors. Pre-identified variables currently encountered in the field were monitored and recorded during paving surveys, and were conducted randomly covering current applications performed by road crews. Multivariate variance analysis and regressions were then used on computerized field data. The statistical investigations were limited due to the relatively small size of the study (36 data). Nevertheless, the particular use of the step-wise regression tool enabled the quantification of the impact of several predictors despite the existing collinearity between variables. The two bitumen organic fractions (particulates and volatiles) are associated with different field factors. The process conditions (machinery used and delivery temperature) have a significant impact on the production of airborne particulates and explain up to 44% of variability. This confirms the outcomes described by previous studies. The influence of the production factors is limited though, and should be complemented by studying factors involving the worker such as work style and the mix of tasks. The residual volatile compounds, being part of the bituminous binder and released during paving operations, control the volatile emissions; 73% of the encountered field variability is explained by the composition of the bitumen batch. © The Author 2014. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.
Epidemiology of Mild Traumatic Brain Injury with Intracranial Hemorrhage: Focusing Predictive Models for Neurosurgical Intervention.

PubMed

Orlando, Alessandro; Levy, A Stewart; Carrick, Matthew M; Tanner, Allen; Mains, Charles W; Bar-Or, David

2017-11-01

To outline differences in neurosurgical intervention (NI) rates between intracranial hemorrhage (ICH) types in mild traumatic brain injuries and help identify which ICH types are most likely to benefit from creation of predictive models for NI. A multicenter retrospective study of adult patients spanning 3 years at 4 U.S. trauma centers was performed. Patients were included if they presented with mild traumatic brain injury (Glasgow Coma Scale score 13-15) with head CT scan positive for ICH. Patients were excluded for skull fractures, "unspecified hemorrhage," or coagulopathy. Primary outcome was NI. Stepwise multivariable logistic regression models were built to analyze the independent association between ICH variables and outcome measures. The study comprised 1876 patients. NI rate was 6.7%. There was a significant difference in rate of NI by ICH type. Subdural hematomas had the highest rate of NI (15.5%) and accounted for 78% of all NIs. Isolated subarachnoid hemorrhages had the lowest, nonzero, NI rate (0.19%). Logistic regression models identified ICH type as the most influential independent variable when examining NI. A model predicting NI for isolated subarachnoid hemorrhages would require 26,928 patients, but a model predicting NI for isolated subdural hematomas would require only 328 patients. This study highlighted disparate NI rates among ICH types in patients with mild traumatic brain injury and identified mild, isolated subdural hematomas as most appropriate for construction of predictive NI models. Increased health care efficiency will be driven by accurate understanding of risk, which can come only from accurate predictive models. Copyright © 2017 Elsevier Inc. All rights reserved.
A predictive model for diagnosing bipolar disorder based on the clinical characteristics of major depressive episodes in Chinese population.

PubMed

Gan, Zhaoyu; Diao, Feici; Wei, Qinling; Wu, Xiaoli; Cheng, Minfeng; Guan, Nianhong; Zhang, Ming; Zhang, Jinbei

2011-11-01

A correct timely diagnosis of bipolar depression remains a big challenge for clinicians. This study aimed to develop a clinical characteristic based model to predict the diagnosis of bipolar disorder among patients with current major depressive episodes. A prospective study was carried out on 344 patients with current major depressive episodes, with 268 completing 1-year follow-up. Data were collected through structured interviews. Univariate binary logistic regression was conducted to select potential predictive variables among 19 initial variables, and then multivariate binary logistic regression was performed to analyze the combination of risk factors and build a predictive model. Receiver operating characteristic (ROC) curve was plotted. Of 19 initial variables, 13 variables were preliminarily selected, and then forward stepwise exercise produced a final model consisting of 6 variables: age at first onset, maximum duration of depressive episodes, somatalgia, hypersomnia, diurnal variation of mood, irritability. The correct prediction rate of this model was 78% (95%CI: 75%-86%) and the area under the ROC curve was 0.85 (95%CI: 0.80-0.90). The cut-off point for age at first onset was 28.5 years old, while the cut-off point for maximum duration of depressive episode was 7.5 months. The limitations of this study include small sample size, relatively short follow-up period and lack of treatment information. Our predictive models based on six clinical characteristics of major depressive episodes prove to be robust and can help differentiate bipolar depression from unipolar depression. Copyright © 2011 Elsevier B.V. All rights reserved.
Effect of Shift Work on Sleep, Health, and Quality of Life of Health-care Workers.

PubMed

Nena, Evangelia; Katsaouni, Maria; Steiropoulos, Paschalis; Theodorou, Evangelos; Constantinidis, Theodoros C; Tripsianis, Grigorios

2018-01-01

Shift work is associated with sleep disruption, impaired quality of life, and is a risk factor for several health conditions. Aim of this study was to investigate the impact of shift work on sleep and quality of life of health-care workers (HCW). Tertiary University hospital in Greece. Cross-sectional study. Included were HCW, working either in an irregular shift system or exclusively in morning shifts. All participants answered the WHO-5 Well-Being Index (WHO-5) and a questionnaire on demographics and medical history. Shift workers filled the Shift Work Disorders Screening Questionnaire (SWDSQ). Descriptive statistics, Student's t -test, one-way analysis of variance (ANOVA), Pearson's r correlation coefficient, and multivariate stepwise linear regression analysis were applied. Included were 312 employees (87.9% females), 194 working in irregular shift system and 118 in morning shifts. Most shift-workers (58.2%) were somehow or totally dissatisfied with their sleep quality. Regression analysis revealed the following independent determinants for sleep impairment: parenthood ( P < 0.001), age 36-45 years ( P < 0.001), >3 night shifts/week ( P < 0.001), work >5 years in an irregular shift system ( P < 0.001). Diabetes mellitus was the most common medical condition reported by shift workers ( P = 0.008). Comparison between the two groups revealed a significantly impairment in WHO-5 total score, as well as in 4 of 5 of its items ( P < 0.001). Shift-work impairs quality of life, whereas its duration and frequency, along with age and family status of employees can have adverse effects on sleep.
Does pelvicaliceal system anatomy affect success of percutaneous nephrolithotomy?

PubMed

Binbay, Murat; Akman, Tolga; Ozgor, Faruk; Yazici, Ozgur; Sari, Erhan; Erbin, Akif; Kezer, Cem; Sarilar, Omer; Berberoglu, Yalcın; Muslumanoglu, Ahmet Yaser

2011-10-01

To investigate the effect of the pelvicaliceal system (PCS) anatomy on the percutaneous nephrolithotomy (PCNL) success rate. Although the caliceal anatomy is effective for stone clearance after shock wave lithotripsy and retrograde intrarenal lithotripsy, the effect of the caliceal anatomy after PCNL has not been evaluated to date. A total of 498 patients who had undergone PCNL and preoperative intravenous urography were enrolled in our study. Kidney-related anatomic factors, such as the PCS surface area and type, degree of hydronephrosis, infundibulopelvic angle, upper-lower calix angle, infundibular length, and infundibular width were calculated using intravenous urography. The association between the PCNL success rate and kidney-related anatomic factors was retrospectively analyzed using chi-square tests, Fisher's exact test, Mann-Whitney U test, and forward stepwise regression analysis. A success rate of 78.1% was achieved. No difference was seen the success rates among the PCS types. The mean PCS surface area was 20.1 ± 9.7 cm(2) in patients with successful outcomes and 24.5 ± 10.2 cm(2) in patients with remaining stones (P = .001). The mean infundibulopelvic angle, upper-lower calix angle, infundibular length, and infundibular width were similar in both groups. Multivariate binary logistic regression analysis showed that stone configuration and PCS surface area were independent factors affecting the PCNL success rates. The results of our study have shown that the PCS surface area is the only anatomic factor that affects the PCNL success rate and patients with a PCS surface area <20.5 cm(2) have greater PCNL success. Copyright © 2011 Elsevier Inc. All rights reserved.
Local polynomial estimation of heteroscedasticity in a multivariate linear regression model and its applications in economics.

PubMed

Su, Liyun; Zhao, Yanyong; Yan, Tianshun; Li, Fenglan

2012-01-01

Multivariate local polynomial fitting is applied to the multivariate linear heteroscedastic regression model. Firstly, the local polynomial fitting is applied to estimate heteroscedastic function, then the coefficients of regression model are obtained by using generalized least squares method. One noteworthy feature of our approach is that we avoid the testing for heteroscedasticity by improving the traditional two-stage method. Due to non-parametric technique of local polynomial estimation, it is unnecessary to know the form of heteroscedastic function. Therefore, we can improve the estimation precision, when the heteroscedastic function is unknown. Furthermore, we verify that the regression coefficients is asymptotic normal based on numerical simulations and normal Q-Q plots of residuals. Finally, the simulation results and the local polynomial estimation of real data indicate that our approach is surely effective in finite-sample situations.
The minimal residual QR-factorization algorithm for reliably solving subset regression problems

NASA Technical Reports Server (NTRS)

Verhaegen, M. H.

1987-01-01

A new algorithm to solve test subset regression problems is described, called the minimal residual QR factorization algorithm (MRQR). This scheme performs a QR factorization with a new column pivoting strategy. Basically, this strategy is based on the change in the residual of the least squares problem. Furthermore, it is demonstrated that this basic scheme might be extended in a numerically efficient way to combine the advantages of existing numerical procedures, such as the singular value decomposition, with those of more classical statistical procedures, such as stepwise regression. This extension is presented as an advisory expert system that guides the user in solving the subset regression problem. The advantages of the new procedure are highlighted by a numerical example.

Rumination, Age, and Years of Experience: A Predictive Study of Burnout

ERIC Educational Resources Information Center

McDuffy, Moriel S.

2016-01-01

This study used a non-experimental design to examine whether job satisfaction, rumination, age and years of experience predict burnout among human service workers serving high-risk populations. The study also used a stepwise regression to assess whether job satisfaction, rumination, age, or years of experience predict burnout equally. Burnout was…
Ecological correlates of flying squirrel microhabitat use and density in temperate rainforests of southeastern Alaska

Treesearch

Winston P. Smith; Scott M. Gende; Jeffrey V. Nichols

2004-01-01

We studied habitat relations of the Prince of Wales flying squirrel (Glaucomys sabrinus griseifrons), an endemic of the temperate, coniferous rainforest of southeastern Alaska, because of concerns over population viability from extensive clear-cut logging in the region. We used stepwise logistic regression to examine relationships between...
Relationships of Reading, MCAT, and USMLE Step 1 Test Results for Medical Students

ERIC Educational Resources Information Center

Haught, Patricia; Walls, Richard

2004-01-01

Students (N = 730) took the Nelson-Denny Reading Test (current forms G or H) during orientation to medical school. Stepwise regression analyses showed the Nelson-Denny Reading Vocabulary, Comprehension, and Rate were significant predictors of MCAT (taken prior to admission to medical school) verbal reasoning. Reading Vocabulary was a significant…
Potential for Suicide and Aggression in Delinquents at Juvenile Court in a Southern City.

ERIC Educational Resources Information Center

Battile, Allen O.; And Others

1993-01-01

Questioned 263 Juvenile Court offenders about whether they wished to be dead, kill themselves, or kill others and about their existential experiences, thoughts, and feelings. Used stepwise multiple logistic regression to pinpoint experiences associated with high likelihood of verbalizing wish for destructive behavior. Found sexual abuse as risk…
Nondestructive detection of zebra chip disease in potatoes using near-infrared spectroscopy

USDA-ARS?s Scientific Manuscript database

Near-Infrared (NIR) spectroscopy in the wavelength region from 900 nm to 2600 nm was evaluated as the basis for a rapid, non-destructive method for the detection of Zebra Chip disease in potatoes and the measurement of sugar concentrations in affected tubers. Using stepwise regression in conjunction...
Student Physical Education Teachers' Well-Being: Contribution of Basic Psychological Needs

ERIC Educational Resources Information Center

Ciyin, Gülten; Erturan-Ilker, Gökçe

2014-01-01

This study adopted Self-Determination Theory tenets and aimed to explore whether student physical education (PE) teachers' satisfaction of the three basic psychological needs independently predicts well-being. 267 Turkish student PE teachers were recruited for the study. Two stepwise multiple regression analysis was performed in which each outcome…
Quality Curriculum for Under-Threes: The Impact of Structural Standards

ERIC Educational Resources Information Center

Wertfein, Monika; Spies-Kofler, Anita; Becker-Stoll, Fabienne

2009-01-01

The purpose of this study conducted in 36 infant-toddler centres ("Kinderkrippen") in the city of Munich in Bavaria/Germany was to explore structural characteristics of early child care and education and their effects on child care quality. Stepwise regressions and variance analysis (Manova) examined the relation between quality of care…
Scholarly Networking among Business Students: Structured Discussion Board Activity and Academic Outcomes

ERIC Educational Resources Information Center

Walker, Kristen; Curren, Mary T.; Kiesler, Tina; Lammers, H. Bruce; Goldenson, Jamie

2013-01-01

The authors' intent was to show the effect of student discussion board activity on academic outcomes, after accounting for past academic performance. Data were collected from 516 students enrolled in a junior-level required business course. Controlling for students' grade point average, stepwise regression showed a significant…
Factors Affecting Code Status in a University Hospital Intensive Care Unit

ERIC Educational Resources Information Center

Van Scoy, Lauren Jodi; Sherman, Michael

2013-01-01

The authors collected data on diagnosis, hospital course, and end-of-life preparedness in patients who died in the intensive care unit (ICU) with "full code" status (defined as receiving cardiopulmonary resuscitation), compared with those who didn't. Differences were analyzed using binary and stepwise logistic regression. They found no…
Variation in Environmentalism among University Students: Majoring in Outdoor Recreation, Parks, and Tourism Predicts Environmental Concerns and Behaviors

ERIC Educational Resources Information Center

Arnocky, Steven; Stroink, Mirella L.

2011-01-01

In a survey of Canadian university students (N = 205), the relationship between majoring in an outdoor recreation university program and environmental concern, cooperation, and behavior were examined. Stepwise linear regression indicated that enrollment in outdoor recreation was predictive of environmental behavior and ecological cooperation; and…
Determination of benzo[a]pyrene in cigarette mainstream smoke by using mid-infrared spectroscopy associated with a novel chemometric algorithm.

PubMed

Zhang, Yan; Zou, Hong-Yan; Shi, Pei; Yang, Qin; Tang, Li-Juan; Jiang, Jian-Hui; Wu, Hai-Long; Yu, Ru-Qin

2016-01-01

Determination of benzo[a]pyrene (BaP) in cigarette smoke can be very important for the tobacco quality control and the assessment of its harm to human health. In this study, mid-infrared spectroscopy (MIR) coupled to chemometric algorithm (DPSO-WPT-PLS), which was based on the wavelet packet transform (WPT), discrete particle swarm optimization algorithm (DPSO) and partial least squares regression (PLS), was used to quantify harmful ingredient benzo[a]pyrene in the cigarette mainstream smoke with promising result. Furthermore, the proposed method provided better performance compared to several other chemometric models, i.e., PLS, radial basis function-based PLS (RBF-PLS), PLS with stepwise regression variable selection (Stepwise-PLS) as well as WPT-PLS with informative wavelet coefficients selected by correlation coefficient test (rtest-WPT-PLS). It can be expected that the proposed strategy could become a new effective, rapid quantitative analysis technique in analyzing the harmful ingredient BaP in cigarette mainstream smoke. Copyright © 2015 Elsevier B.V. All rights reserved.
[Aggression and related factors in elementary school students].

PubMed

Ji, Eun Sun; Jang, Mi Heui

2010-10-01

This study was done to explore the relationship between aggression and internet over-use, depression-anxiety, self-esteem, all of which are known to be behavior and psychological characteristics linked to "at-risk" children for aggression. Korean-Child Behavior Check List (K-CBCL), Korean-Internet Addiction Self-Test Scale, and Self-Esteem Scale by Rosenberg (1965) were used as measurement tools with a sample of 743, 5th-6th grade students from 3 elementary schools in Jecheon city. Chi-square, t-test, ANOVA, Pearson's correlation and stepwise multiple regression with SPSS/Win 13.0 version were used to analyze the collected data. Aggression for the elementary school students was positively correlated with internet over-use and depression-anxiety, whereas self-esteem was negatively correlated with aggression. Stepwise multiple regression analysis showed that 68.4% of the variance for aggression was significantly accounted for by internet over-use, depression-anxiety, and self-esteem. The most significant factor influencing aggression was depression-anxiety. These results suggest that earlier screening and intervention programs for depression-anxiety and internet over-use for elementary student will be helpful in preventing aggression.
Nucleated red blood cells in growth-restricted fetuses: associations with short-term neonatal outcome.

PubMed

Minior, V K; Bernstein, P S; Divon, M Y

2000-01-01

To determine the utility of the neonatal nucleated red blood cell (NRBC) count as an independent predictor of short-term perinatal outcome in growth-restricted fetuses. Hospital charts of neonates with a discharge diagnosis indicating a birth weight <10th percentile were reviewed for perinatal outcome. We studied all eligible neonates who had a complete blood count on the first day of life. After multiple gestations, anomalous fetuses and diabetic pregnancies were excluded; 73 neonates comprised the study group. Statistical analysis included ANOVA, simple and stepwise regression. Elevated NRBC counts were significantly associated with cesarean section for non-reassuring fetal status, neonatal intensive care unit admission and duration of neonatal intensive care unit stay, respiratory distress and intubation, thrombocytopenia, hyperbilirubinemia, intraventricular hemorrhage and neonatal death. Stepwise regression analysis including gestational age at birth, birth weight and NRBC count demonstrated that in growth-restricted fetuses, NRBC count was the strongest predictor of neonatal intraventricular hemorrhage, neonatal respiratory distress and neonatal death. An elevated NRBC count independently predicts adverse perinatal outcome in growth-restricted fetuses. Copyright 2000 S. Karger AG, Basel.
Symptoms associated with adverse dengue fever prognoses at the time of reporting in the 2015 dengue outbreak in Taiwan.

PubMed

Yeh, Chun-Yin; Chen, Po-Lin; Chuang, Kun-Ta; Shu, Yu-Chen; Chien, Yu-Wen; Perng, Guey Chuen; Ko, Wen-Chien; Ko, Nai-Ying

2017-12-01

Tainan experienced the most severe dengue epidemic in Taiwan in 2015. This study investigates the association between the signs and symptoms at the time of reporting with the adverse dengue prognoses. A descriptive study was conducted using secondary data from the Dengue Disease Reporting System in Tainan, Taiwan, between January 1 and December 31, 2015. A multivariate stepwise logistic regression was used to identify the risk factors for the adverse prognoses: ICU admissions and mortality. There were 22,777 laboratory-confirmed reported cases (mean age 45.6 ± 21.2 years), of which 3.7% were admitted to intensive care units (ICU), and 0.8% were fatal. The most common symptoms were fever (92.8%), myalgia (26.6%), and headache (22.4%). The prevalence of respiratory distress, altered consciousness, shock, bleeding, and thrombocytopenia increased with age. The multivariate analysis indicated that being in 65-89 years old age group [Adjusted Odds Ratio (aOR):4.95], or the 90 years old and above age group (aOR: 9.06), and presenting with shock (aOR: 8.90) and respiratory distress (aOR: 5.31) were significantly associated with the risk of ICU admission. While old age (aOR: 1.11), respiratory distress (aOR: 9.66), altered consciousness (aOR: 7.06), and thrombocytopenia (aOR: 2.55) were significantly associated with the risk of mortality. Dengue patients older than 65 and those with severe and non-specific signs and symptoms at the time of reporting were at a higher risk of ICU admission and mortality. First-line healthcare providers need to be aware of the varied presentations between the different age groups to allow early diagnosis and in-time management, which would prevent ICU admissions and fatalities in dengue patients.
Multivariate analysis of factors predicting prostate dose in intensity-modulated radiotherapy

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

Tomita, Tsuneyuki; Nakamura, Mitsuhiro, E-mail: m_nkmr@kuhp.kyoto-u.ac.jp; Hirose, Yoshinori

We conducted a multivariate analysis to determine relationships between prostate radiation dose and the state of surrounding organs, including organ volumes and the internal angle of the levator ani muscle (LAM), based on cone-beam computed tomography (CBCT) images after bone matching. We analyzed 270 CBCT data sets from 30 consecutive patients receiving intensity-modulated radiation therapy for prostate cancer. With patients in the supine position on a couch with the HipFix system, data for center of mass (COM) displacement of the prostate and the state of individual organs were acquired and compared between planning CT and CBCT scans. Dose distributions weremore » then recalculated based on CBCT images. The relative effects of factors on the variance in COM, dose covering 95% of the prostate volume (D{sub 95%}), and percentage of prostate volume covered by the 100% isodose line (V{sub 100%}) were evaluated by a backward stepwise multiple regression analysis. COM displacement in the anterior-posterior direction (COM{sub AP}) correlated significantly with the rectum volume (δVr) and the internal LAM angle (δθ; R = 0.63). Weak correlations were seen for COM in the left-right (R = 0.18) and superior-inferior directions (R = 0.31). Strong correlations between COM{sub AP} and prostate D{sub 95%} and V{sub 100%} were observed (R ≥ 0.69). Additionally, the change ratios in δVr and δθ remained as predictors of prostate D{sub 95%} and V{sub 100%}. This study shows statistically that maintaining the same rectum volume and LAM state for both the planning CT simulation and treatment is important to ensure the correct prostate dose in the supine position with bone matching.« less
Risk factors for adverse outcomes after endovascular therapy for critical limb ischemia with tissue loss due to infrainguinal artery disease.

PubMed

Tnishibe, Toshiya; Yamamoto, Kiyohito; Toguchi, Kayo; Seike, Yoshimasa; Ito, Naoki; Nishibe, Masayasu; Koizumi, Jun; Dardik, Alan; Ogino, Hitoshi

2016-10-01

The purpose of this study was to analyze the risk factors for an adverse outcome after endovascular therapy (EVT) for critical limb ischemia (CLI) with tissue loss due to infrainguinal artery disease. We retrospectively reviewed the charts of patients with tissue loss (Rutherford class 5 and 6) due to infrainguinal artery disease who were managed with endovascular therapy (EVT) between January 2006 and December 2013. The primary endpoint was amputation-free survival (AFS), while the secondary endpoints were freedom from a major adverse limb event (MALE) plus perioperative (30 days) death (POD), limb salvage, and survival rates at one year. Multivariable perioperative predictors of AFS were identified using the stepwise Cox proportional hazards regression model. A total of 65 patients underwent EVT for infrainguinal artery disease on 72 limbs. The technical success rate was 94% (68/72), while the clinical success was attained in 54 of 72 limbs (72%). The AFS, MALE + POD, limb salvage, and survival rates at one year were 76%, 86%, 91%, and 81%, respectively. The multivariate analysis demonstrated that major tissue loss classified as Rutherford class 6 (HR, 5.68; 95% CI, 2.29-14.13; P<0.05) was negatively associated with decreased AFS, while clinical success (HR, 0.25; 95% CI, 0.11-0.60; P<0.05) was positively associated with increased AFS. EVT resulted in an acceptable rate of AFS, MALE+POD, limb salvage, and survival. However, we must keep in mind that there are significant limitations to be considered for EVT in patients with major tissue loss, and that, even if revascularization could be successfully performed, a significant number of the treated limbs are still in a critical situation, such as major amputation or death.
Trends in anemia management among US hemodialysis patients.

PubMed

Coladonato, Joseph A; Frankenfield, Diane L; Reddan, Donal N; Klassen, Preston S; Szczech, Lynda A; Johnson, Curtis A; Owen, William F

2002-05-01

This study was undertaken to describe the relationship between hematocrit (Hct) and changes in the prescribed dose of erythropoietin (EPO) as well as selected patient and process care measures across annual national samples of hemodialysis patients from 1994 to 1998. This study uses the cohorts identified in the ESRD Core Indicators Project, random samples of 6181, 6241, 6364, 6634, and 7660 patients, stratified by ESRD Networks drawn for each year from 1994 to 1998. Patient demographic and clinical information was collected from October to December for each year. Surrogates of iron stores and patterns of iron and EPO administration were profiled from 1996 to 1998. Multivariable stepwise linear regression analyses were performed to adjust for potential confounding variables and to identify independent variables associated with Hct and EPO dose. Mean Hct and EPO dose increased each year from 31.1 +/- 5.2% to 34.1 +/- 3.7% and from 58.2 +/- 41.8 U/kg to 68.2 +/- 55.0 U/kg, respectively (P = 0.0001). Increasing Hct was positively associated with male gender, more years on dialysis, older age, higher urea reduction ratio and transferrin saturation, prescription of intravenous iron, and lower ferritin and EPO dose in multivariable models (all P = 0.0001). Male gender, older age, diabetes, higher Hct, and increasing weight, urea reduction ration, and transferrin saturation were associated with lower EPO doses (all P < 0.01). Conversely, intravenous EPO and iron were associated with higher prescribed EPO doses (all P = 0.0001). Although increasing Hct is associated with decreasing EPO dose at the patient level, the increase in Hct seen across years among the cohorts of hemodialysis patients in the United States has been associated with increasing doses of EPO at the population level.
Intrathoracic versus cervical anastomosis and predictors of anastomotic leakage after oesophagectomy for cancer.

PubMed

Gooszen, J A H; Goense, L; Gisbertz, S S; Ruurda, J P; van Hillegersberg, R; van Berge Henegouwen, M I

2018-04-01

Studies comparing the anastomotic leak rate in patients with an intrathoracic versus a cervical anastomosis after oesophagectomy are equivocal. The aim of this study was to compare clinical outcome after oesophagectomy in patients with an intrathoracic or cervical anastomosis, and to identify predictors of anastomotic leakage in a nationwide audit. Between January 2011 and December 2015, all consecutive patients who underwent oesophagectomy for cancer were identified from the Dutch Upper Gastrointestinal Cancer Audit. For the comparison between an intrathoracic and cervical anastomosis, propensity score matching was used to adjust for potential confounders. Multivariable logistic regression modelling with backward stepwise selection was used to determine independent predictors of anastomotic leakage. Some 3348 patients were included. After propensity score matching, 654 patients were included in both the cervical and intrathoracic anastomosis groups. An intrathoracic anastomosis was associated with a lower leak rate than a cervical anastomosis (17·0 versus 21·9 per cent; P = 0·025). The percentage of patients with recurrent nerve paresis was also lower (0·6 versus 7·0 per cent; P < 0·001) and an intrathoracic anastomosis was associated with a shorter median hospital stay (12 versus 14 days; P = 0·001). Multivariable analysis revealed that ASA fitness grade III or higher, chronic obstructive pulmonary disease, cardiac arrhythmia, diabetes mellitus and proximal oesophageal tumours were independent predictors of anastomotic leakage. An intrathoracic oesophagogastric anastomosis was associated with a lower anastomotic leak rate, lower rate of recurrent nerve paresis and a shorter hospital stay. Risk factors for anastomotic leak were co-morbidities and proximal tumours. © 2018 The Authors. BJS published by John Wiley & Sons Ltd on behalf of BJS Society Ltd.
Atrial fibrillation management, outcomes and predictors of stable disease in daily practice: prospective non-interventional study.

PubMed

Bosch, Ralph F; Kirch, Wilhelm; Theuer, Juergen-Detlef; Pittrow, David; Kohlhaußen, Annette; Willich, Stefan N; Bonnemeier, Hendrik

2013-08-10

We aimed to describe the current management of patients with atrial fibrillation (AF) by cardiologists, and to identify predicting factors for a stable disease course. 2753 consecutive patients with ECG-confirmed AF in the previous 12 months were documented in a 1-year observational (non-interventional) study from 616 centers. Stable disease was defined as having neither AF related intervention nor change in antiarrhythmic therapy in the previous 12 months. Stepwise selection of parameters for multivariate regression was used to identify factors for stable AF. At baseline, paroxysmal AF was reported in 33.5%, persistent in 26.7%, and permanent in 39.7%; rate control alone was the prevailing antiarrhythmic strategy (64.2%). Drugs for thromboembolic prevention were administered in 93.8%, with a clear predominance of oral anticoagulants (OAC), alone or in combination with antiplatelet drugs. Electrical or pharmacological conversions were reported in 23.6%. A total of 96 (3.5%) patients in the total cohort experienced stroke, 72 patients (2.6%) TIA, and 24 (0.9%) arterial embolism. 26% were hospitalized during follow-up (0.4 events per patient), and 9.4% developed incident heart failure (42% prevalence at follow-up). The rate of stable patients was 43.4%. In the multivariate model male gender, history of stroke, and permanent (vs. persistent) AF were associated with stable disease. Conversely, the factors chronic heart failure, impaired left ventricular function, rhythm-control (vs. other), OAC and antiplatelet therapy were significantly correlated with unstable disease. The relatively low proportion of stable patients and in particular, the high hospitalization and stroke rate indicate difficulties in everyday management of patients with AF. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.
Suture, synthetic, or biologic in contaminated ventral hernia repair.

PubMed

Bondre, Ioana L; Holihan, Julie L; Askenasy, Erik P; Greenberg, Jacob A; Keith, Jerrod N; Martindale, Robert G; Roth, J Scott; Liang, Mike K

2016-02-01

Data are lacking to support the choice between suture, synthetic mesh, or biologic matrix in contaminated ventral hernia repair (VHR). We hypothesize that in contaminated VHR, suture repair is associated with the lowest rate of surgical site infection (SSI). A multicenter database of all open VHR performed at from 2010-2011 was reviewed. All patients with follow-up of 1 mo and longer were included. The primary outcome was SSI as defined by the Centers for Disease Control and Prevention. The secondary outcome was hernia recurrence (assessed clinically or radiographically). Multivariate analysis (stepwise regression for SSI and Cox proportional hazard model for recurrence) was performed. A total of 761 VHR were reviewed for a median (range) follow-up of 15 (1-50) mo: there were 291(38%) suture, 303 (40%) low-density and/or mid-density synthetic mesh, and 167(22%) biologic matrix repair. On univariate analysis, there were differences in the three groups including ethnicity, ASA, body mass index, institution, diabetes, primary versus incisional hernia, wound class, hernia size, prior VHR, fascial release, skin flaps, and acute repair. The unadjusted outcomes for SSI (15.1%; 17.8%; 21.0%; P = 0.280) and recurrence (17.8%; 13.5%; 21.5%; P = 0.074) were not statistically different between groups. On multivariate analysis, biologic matrix was associated with a nonsignificant reduction in both SSI and recurrences, whereas synthetic mesh associated with fewer recurrences compared to suture (hazard ratio = 0.60; P = 0.015) and nonsignificant increase in SSI. Interval estimates favored biologic matrix repair in contaminated VHR; however, these results were not statistically significant. In the absence of higher level evidence, surgeons should carefully balance risk, cost, and benefits in managing contaminated ventral hernia repair. Copyright © 2016 Elsevier Inc. All rights reserved.

Prevalence of vitamin deficiencies on admission: relationship to hospital mortality in critically ill patients.

PubMed

Corcoran, T B; O'Neill, M A; Webb, S A R; Ho, K M

2009-03-01

Vitamin deficiency is believed to be common in critical illness. Water soluble and antioxidant vitamins are those most frequently used for supplementation in these patients. There are no data to confirm the prevalence of vitamin deficiencies in high-risk emergently admitted intensive care patients, nor their association with hospital mortality. One hundred and twenty-nine consecutive, critically ill patients who were emergently admitted to intensive care were enrolled in this prospective observational cohort study. Patient data including diagnosis, source of admission and severity of illness scores were prospectively collected. Within the first 48 hours of admission, concentrations of C-reactive protein, Vitamins A, E, B1, B12 and folate were measured on arterial blood. Multivariate stepwise logistic regression modelling was performed to examine the association of vitamin concentrations with hospital mortality. Fifty-five patients (43%) had a biochemical deficiency of one of the five vitamins on admission to the intensive care unit. A total of 18 patients died (14%) during their hospital stay (15 of those in the intensive care unit). Moderate correlations with C-reactive protein concentrations were demonstrated for Vitamins B12, A and E (Spearman's r = 0.309, -0.541 and -0.299, P = 0.001, 0.001 and 0.007 respectively). Hospital mortality was significantly associated with age, APACHE II score, admission and maximum Sequential Organ Failure Assessment scores and admission source in the univariate analyses. Multivariate analysis did not demonstrate an association between biochemical deficiency and mortality. Biochemical deficiencies of water-soluble and antioxidant vitamins are common on admission in unplanned or emergency admissions to the intensive care unit, but we could not demonstrate an independent association with hospital mortality.
Malocclusion, dental aesthetic self-perception and quality of life in a 18 to 21 year-old population: a cross section study.

PubMed

Claudino, Dikson; Traebert, Jefferson

2013-01-07

Aesthetic alterations in the face can be self-perceived and can affect quality of life. For young people, physical attractiveness is an important factor affecting social relationships. The aim of this study was to estimate the prevalence of malocclusion, identify the most common types and test its association with oral aesthetic self-perception in 18 to 21 year-old population of male young adults. A cross-sectional study was carried out involving 138 Brazilian Army soldiers. Data collection included socio demographic profile, malocclusion status through the Dental Aesthetic Index (DAI) and oral aesthetic self-perception as indicated by the Oral Aesthetic Subjective Impact Scale (OASIS). The chi-square and Fisher's exact test were used to test for homogeneity of proportions. The stepwise multivariate logistic regression analysis was used to test for the relationship between the poorer oral aesthetic self-perception and parental and soldier's education, per capita income, history of caries in all teeth and only on anterior teeth, dental trauma, previous orthodontic treatment and malocclusion. The prevalence of malocclusion was 45.6%. Incisor teeth crowding and misalignment of lower incisors were the most common types of malocclusions. A statistically significant and independent association between malocclusion and poorer oral aesthetic self-perception in the multivariate analysis was observed. Subjects with severe malocclusion conditions showed 88% higher prevalence [prevalence ratio =1.88 (95% CI, 1.30 - 2.72); p = 0.001] of poorer aesthetic self-perception comparing to those with minor malocclusion. A high prevalence of malocclusion was observed. The young adults presenting severe malocclusion had a higher and independent prevalence of poorer oral aesthetic self-perception.
Factors associated with and consequences of unplanned post-operative intubation in elderly vascular and general surgery patients.

PubMed

Nafiu, Olubukola O; Ramachandran, Satya K; Ackwerh, Ray; Tremper, Kevin K; Campbell, Darrell A; Stanley, James C

2011-03-01

Unplanned post-operative intubation (UPI) may be associated with significant morbidity and/or mortality after surgery. The purpose of this investigation was to determine the incidence and predictors of UPI in elderly patients who underwent general and vascular surgical procedures. Data from the American College of Surgeons National Surgical Quality Improvement Program Participant Use Data File was used to calculate the incidence of UPI in all elderly vascular and general surgery patients undergoing operations from 2005 to 2008. UPI was defined as a requirement for the placement of an endotracheal tube and mechanical or assisted ventilation because of the onset of respiratory or cardiac failure manifested by severe respiratory distress, hypoxia, hypercarbia or respiratory acidosis within 30 days of the index operation. Univariate factors associated with UPI were identified. Multivariate stepwise logistic regression was used to calculate odds ratios (ORs) for UPI after controlling for known clinically relevant cofactors. Incidence of UPI as well as morbidity and mortality associated with UPI. Among 115 692 patients, 3.3% required UPI. Univariate predictors of UPI were older age group, chronic obstructive pulmonary disease, low pre-operative functional status as well as emergency operation. UPI was associated with an 18-fold increased risk of death as well as significantly increased hospital length of stay. Multivariate analysis identified several predictors of UPI with re-operation having the greatest odds for UPI (OR = 4.5; 95% confidence interval = 4.29-4.86, P < 0.001). Although the incidence of UPI in this elderly surgical cohort was low, it was associated with significant morbidity and mortality as well as prolonged hospital length of stay, underscoring the need for accurately identifying modifiable risk factors.
Extracolonic Cancer in Inflammatory Bowel Disease: Data from the GETECCU Eneida Registry.

PubMed

Chaparro, María; Ramas, M; Benítez, J M; López-García, A; Juan, A; Guardiola, J; Mínguez, M; Calvet, X; Márquez, L; Fernández Salazar, L I; Bujanda, L; García, C; Zabana, Y; Lorente, R; Barrio, J; Hinojosa, E; Iborra, M; Cajal, M Domínguez; Van Domselaar, M; García-Sepulcre, M F; Gomollón, F; Piqueras, M; Alcaín, G; García-Sánchez, V; Panés, J; Domènech, E; García-Esquinas, E; Rodríguez-Artalejo, F; Gisbert, J P

2017-07-01

The objective of this study was (a) To know the prevalence and distribution of extracolonic cancer (EC) in patients with inflammatory bowel disease (IBD); (b) To estimate the incidence rate of EC; (c) To evaluate the association between EC and treatment with immunosuppressants and anti-tumor necrosis factor (TNF) agents. This was an observational cohort study. IBD and inclusion in the ENEIDA Project (a prospectively maintained registry) from GETECCU. Patients with EC before the diagnosis of IBD, lack of relevant data for this study, and previous treatment with immunosuppressants other than corticosteroids, thiopurines, methotrexate, or anti-TNF agents. The Kaplan-Meier method was used to evaluate the impact of several variables on the risk of EC, and any differences between survival curves were evaluated using the log-rank test. Stepwise multivariate Cox regression analysis was used to investigate factors potentially associated with the development of EC, including drugs for the treatment of IBD, during follow-up. A total of 11,011 patients met the inclusion criteria and were followed for a median of 98 months. Forty-eight percent of patients (5,303) had been exposed to immunosuppressants or anti-TNF drugs, 45.8% had been exposed to thiopurines, 4.7% to methotrexate, and 21.6% to anti-TNF drugs. The prevalence of EC was 3.6%. In the multivariate analysis, age (HR=1.05, 95% CI=1.04-1.06) and having smoked (hazards ratio (HR)=1.47, 95% confidence interval (CI)=1.10-1.80) were the only variables associated with a higher risk of EC. Neither immunosuppressants nor anti-TNF drugs seem to increase the risk of EC. Older age and smoking were associated with a higher prevalence of EC.
Accounting for the multidimensional nature of the relationship between adult obesity and socio-economic status: the French second National Individual Survey on Food Consumption (INCA 2) dietary survey (2006-07).

PubMed

Fillol, F; Dubuisson, C; Lafay, L; Dufour, A; Bertin, M; Touvier, M; Maire, B; Volatier, J-L; Lioret, S

2011-11-01

The objective was to study the multidimensional nature of the relationship between adult obesity (OB) and socio-economic status (SES), using comprehensive indices of SES taken separately or synthesised in an overall index. A nationally representative sample of adults aged 18-79 years was taken from the French second National Individual Survey on Food Consumption (INCA 2) dietary survey (2006-07). Weight and height were measured and OB defined as BMI ≥ 30 kg/m2. SES variables were reported in questionnaires and included occupation, education and characteristics of household wealth. Composite indices of SES (household wealth and overall SES indices) were computed by correspondence analysis, and relationships with OB were investigated with logistic regression analysis. In total, 11·8 (95 % CI 10·1, 13·4) % of French adults were obese, without significant difference by sex. While no significant relationship was observed in men, all SES indicators were inversely correlated to OB in women. Both education and the household wealth index were retained in the stepwise multivariate model, confirming that different socio-economic variables are not necessarily proxies of each other regarding the OB issue. On the other hand, 'controlling for SES' while including several measures of SES in multivariate models may lead to collinearity, and thus over-adjustment. A more integrative approach may be to derive a synthetic index by including the SES factors available in a given study. Beyond this methodological perspective, understanding how OB is related to the different dimensions of SES should help to target the more vulnerable groups and increase the effectiveness of prevention.
Lung disease severity in idiopathic pulmonary fibrosis is more strongly associated with impedance measures of bolus reflux than pH parameters of acid reflux alone.

PubMed

Gavini, S; Borges, L F; Finn, R T; Lo, W-K; Goldberg, H J; Burakoff, R; Feldman, N; Chan, W W

2017-05-01

Gastroesophageal reflux (GER) has been associated with idiopathic pulmonary fibrosis (IPF). Pathogenesis may be related to chronic micro-aspiration. We aimed to assess objective measures of GER on multichannel intraluminal impedance and pH study (MII-pH) and their relationship with pulmonary function testing (PFT) results, and to compare the performance of pH/acid reflux parameters vs corresponding MII/bolus parameters in predicting pulmonary dysfunction in IPF. This was a retrospective cohort study of IPF patients undergoing prelung transplant evaluation with MII-pH off acid suppression, and having received PFT within 3 months. Patients with prior fundoplication were excluded. Severe pulmonary dysfunction was defined using diffusion capacity of the lung for carbon monoxide (DLCO) ≤40%. Six pH/acid reflux parameters with corresponding MII/bolus reflux measures were specified a priori. Multivariate analyses were applied using forward stepwise logistic regression. Predictive value of each parameter for severe pulmonary dysfunction was calculated by area-under-the-receiver-operating-characteristic-curve or c-statistic. Forty-five subjects (67% M, age 59, 15 mild-moderate vs 30 severe) met criteria for inclusion. Patient demographics and clinical characteristics were similar between pulmonary dysfunction groups. Abnormal total reflux episodes and prolonged bolus clearance time were significantly associated with pulmonary dysfunction severity on univariate and multivariate analyses. No pH parameters were significant. The c-statistic of each pH parameter was lower than its MII counterpart in predicting pulmonary dysfunction. MII/bolus reflux, but not pH/acid reflux, was associated with pulmonary dysfunction in prelung transplant patients with IPF. MII-pH may be more valuable than pH testing alone in characterizing GER in IPF. © 2016 John Wiley & Sons Ltd.
Occurrence of mastitis and associated risk factors in lactating goats under pastoral management in Borana, Southern Ethiopia.

PubMed

Megersa, Bekele; Tadesse, Chala; Abunna, Fufa; Regassa, Alemayehu; Mekibib, Berhanu; Debela, Etana

2010-08-01

Mastitis prevalence and related risk factors were studied in 1,072 udder halves of 536 lactating goats from October, 2008 to February, 2009. Clinical and subclinical mastitis were prevalent in 4.3% (95% CI = 2.8, 6.5) and 11.2% (95% CI = 8.7, 14.3) of the studied animals, respectively, resulting in an overall prevalence of 15.5% (95% CI = 12.6, 18.9). Univariate analysis of the potential risk factors has depicted that mastitis was more prevalent in does with previous mastitis history, increased parity, poor body conditions, increased milk production, late lactation stage, long teat, and housed goats. Furthermore, prevalence was significantly higher (p < 0.05) during the wet period of October to November than the dry periods of January to February. No significant variations (p > 0.05) were observed in mastitis prevalence with udder tick infestation, mixing goat with sheep and flock size. With multivariable analysis, lactation stage, teat length, body condition, and season (wet months) have showed significant association with mastitis prevalence, and these factors maintained significant in the stepwise elimination of multivariable logistic regression model. As a result, does in late stage of lactation (OR = 4.3, 1.8, 10.4), poor body condition (OR = 5.0, 1.7, 10.0), long teats (OR = 2.2, 95% CI = 1.1, 4.2) and does examined in wet period were at higher risk of udder infections than early lactation, good body condition, short teat, and examined in dry period, respectively. The study showed occurrence of mastitis and associated risk factors in studied goats, which suggests the need for control intervention. Further investigations into pathogens involved in goat mastitis will optimize our knowledge of causative agents and control interventions.
Coma and Stroke Following Surgical Treatment of Unruptured Intracranial Aneurysm: An American College of Surgeons National Surgical Quality Improvement Program Study.

PubMed

McCutcheon, Brandon A; Kerezoudis, Panagiotis; Porter, Amanda L; Rinaldo, Lorenzo; Murphy, Meghan; Maloney, Patrick; Shepherd, Daniel; Hirshman, Brian R; Carter, Bob S; Lanzino, Giuseppe; Bydon, Mohamad; Meyer, Fredric

2016-07-01

A large national surgical registry was used to establish national benchmarks and associated predictors of major neurologic complications (i.e., coma and stroke) after surgical clipping of unruptured intracranial aneurysms. The American College of Surgeons National Surgical Quality Improvement Program data set between 2007 and 2013 was used for this retrospective cohort analysis. Demographic, comorbidity, and operative characteristics associated with the development of a major neurologic complication (i.e., coma or stroke) were elucidated using a backward selection stepwise logistic regression analysis. This model was subsequently used to fit a predictive score for major neurologic complications. Inclusion criteria were met by 662 patients. Of these patients, 57 (8.61%) developed a major neurologic complication (i.e., coma or stroke) within the 30-day postoperative period. On multivariable analysis, operative time (log odds 0.004 per minute; 95% confidence interval [CI], 0.002-0.007), age (log odds 0.05 per year; 95% CI, 0.02-0.08), history of chronic obstructive pulmonary disease (log odds 1.26; 95% CI, 0.43-2.08), and diabetes (log odds 1.15; 95% CI, 0.38-1.91) were associated with an increased odds of major neurologic complications. When patients were categorized according to quartile of a predictive score generated from the multivariable analysis, rates of major neurologic complications were 1.8%, 4.3%, 6.7%, and 21.2%. Using a large, national multi-institutional cohort, this study established representative national benchmarks and a predictive scoring system for major neurologic complications following operative management of unruptured intracranial aneurysms. The model may assist with risk stratification and tailoring of decision making in surgical candidates. Copyright © 2016 Elsevier Inc. All rights reserved.
Risk Factors for Four-Year Incidence and Progression of Age-Related Macular Degeneration: The Los Angeles Latino Eye Study

PubMed Central

CHOUDHURY, FARZANA; VARMA, ROHIT; MCKEAN-COWDIN, ROBERTA; KLEIN, RONALD; AZEN, STANLEY P.

2011-01-01

PURPOSE To identify risk factors for 4-year incidence and progression of age-related macular degeneration (AMD) in adult Latinos. DESIGN Population-based prospective cohort study. METHODS Participants, aged 40 or older, from The Los Angeles Latino Eye Study (LALES) underwent standardized comprehensive ophthalmologic examinations at baseline and at 4 years of follow-up. Age-related macular degeneration was detected by grading 30-degree stereoscopic fundus photographs using the modified Wisconsin Age-Related Maculopathy Grading System. Multivariate stepwise logistic regression was used to examine the independent association of incidence and progression of AMD and baseline sociodemographic, behavioral, clinical, and ocular characteristics. RESULTS Multivariate analyses revealed that older age (OR per decade of age: 1.52; 95% CI: 1.29, 1.85) and higher pulse pressure (OR per 10 mm Hg: 2.54; 95% CI: 1.36, 4.76) were independently associated with the incidence of any AMD. The same factors were associated with early AMD, soft indistinct drusen, and retinal pigmentary abnormalities. Additionally, presence of clinically diagnosed diabetes mellitus was independently associated with increased retinal pigment (OR: 1.66; 95% CI: 1.01, 2.85), and male gender was associated with retinal pigment epithelial depigmentation (OR 2.50; 95% CI: 1.48, 4.23). Older age (OR per decade of age: 2.20; 95% CI: 1.82, 2.67) and current smoking (OR: 2.85; 95% CI: 1.66, 4.90) were independently associated with progression of AMD. CONCLUSIONS Several modifiable risk factors were associated with 4-year incidence and progression of AMD in Latinos. The results suggest that interventions aimed at reducing pulse pressure and promoting smoking cessation may reduce incidence and progression of AMD, respectively. PMID:21679916
Media exposure related to the 2008 Sichuan Earthquake predicted probable PTSD among Chinese adolescents in Kunming, China: A longitudinal study.

PubMed

Yeung, Nelson C Y; Lau, Joseph T F; Yu, Nancy Xiaonan; Zhang, Jianping; Xu, Zhening; Choi, Kai Chow; Zhang, Qi; Mak, Winnie W S; Lui, Wacy W S

2018-03-01

This study examined the prevalence and the psychosocial predictors of probable PTSD among Chinese adolescents in Kunming (approximately 444 miles from the epicenter), China, who were indirectly exposed to the Sichuan Earthquake in 2008. Using a longitudinal study design, primary and secondary school students (N = 3577) in Kunming completed questionnaires at baseline (June 2008) and 6 months afterward (December 2008) in classroom settings. Participants' exposure to earthquake-related imagery and content, perceptions and emotional reactions related to the earthquake, and posttraumatic stress symptoms were measured. Univariate and forward stepwise multivariable logistic regression models were fit to identify significant predictors of probable PTSD at the 6-month follow-up. Prevalences of probable PTSD (with a Children's Revised Impact of Event Scale score ≥30) among the participants at baseline and 6-month follow-up were 16.9% and 11.1% respectively. In the multivariable analysis, those who were frequently exposed to distressful imagery had experienced at least two types of negative life events, perceived that teachers were distressed due to the earthquake, believed that the earthquake resulted from damages to the ecosystem, and felt apprehensive and emotionally disturbed due to the earthquake reported a higher risk of probable PTSD at 6-month follow-up (all ps < .05). Exposure to distressful media images, emotional responses, and disaster-related perceptions at baseline were found to be predictive of probable PTSD several months after indirect exposure to the event. Parents, teachers, and the mass media should be aware of the negative impacts of disaster-related media exposure on adolescents' psychological health. (PsycINFO Database Record (c) 2018 APA, all rights reserved).
Variable Selection in Logistic Regression.

DTIC Science & Technology

1987-06-01

23 %. AUTIOR(.) S. CONTRACT OR GRANT NUMBE Rf.i %Z. D. Bai, P. R. Krishnaiah and . C. Zhao F49620-85- C-0008 " PERFORMING ORGANIZATION NAME AND AOORESS...d I7 IOK-TK- d 7 -I0 7’ VARIABLE SELECTION IN LOGISTIC REGRESSION Z. D. Bai, P. R. Krishnaiah and L. C. Zhao Center for Multivariate Analysis...University of Pittsburgh Center for Multivariate Analysis University of Pittsburgh Y !I VARIABLE SELECTION IN LOGISTIC REGRESSION Z- 0. Bai, P. R. Krishnaiah
Comparing lagged linear correlation, lagged regression, Granger causality, and vector autoregression for uncovering associations in EHR data.

PubMed

Levine, Matthew E; Albers, David J; Hripcsak, George

2016-01-01

Time series analysis methods have been shown to reveal clinical and biological associations in data collected in the electronic health record. We wish to develop reliable high-throughput methods for identifying adverse drug effects that are easy to implement and produce readily interpretable results. To move toward this goal, we used univariate and multivariate lagged regression models to investigate associations between twenty pairs of drug orders and laboratory measurements. Multivariate lagged regression models exhibited higher sensitivity and specificity than univariate lagged regression in the 20 examples, and incorporating autoregressive terms for labs and drugs produced more robust signals in cases of known associations among the 20 example pairings. Moreover, including inpatient admission terms in the model attenuated the signals for some cases of unlikely associations, demonstrating how multivariate lagged regression models' explicit handling of context-based variables can provide a simple way to probe for health-care processes that confound analyses of EHR data.
Do 360-degree feedback survey results relate to patient satisfaction measures?

PubMed

Hageman, Michiel G J S; Ring, David C; Gregory, Paul J; Rubash, Harry E; Harmon, Larry

2015-05-01

There is evidence that feedback from 360-degree surveys-combined with coaching-can improve physician team performance and quality of patient care. The Physicians Universal Leadership-Teamwork Skills Education (PULSE) 360 is one such survey tool that is used to assess work colleagues' and coworkers' perceptions of a physician's leadership, teamwork, and clinical practice style. The Clinician & Group-Consumer Assessment of Healthcare Providers and System (CG-CAHPS), developed by the US Department of Health and Human Services to serve as the benchmark for quality health care, is a survey tool for patients to provide feedback that is based on their recent experiences with staff and clinicians and soon will be tied to Medicare-based compensation of participating physicians. Prior research has indicated that patients and coworkers often agree in their assessment of physicians' behavioral patterns. The goal of the current study was to determine whether 360-degree, also called multisource, feedback provided by coworkers could predict patient satisfaction/experience ratings. A significant relationship between these two forms of feedback could enable physicians to take a more proactive approach to reinforce their strengths and identify any improvement opportunities in their patient interactions by reviewing feedback from team members. An automated 360-degree software process may be a faster, simpler, and less resource-intensive approach than telephoning and interviewing patients for survey responses, and it potentially could facilitate a more rapid credentialing or quality improvement process leading to greater fiscal and professional development gains for physicians. Our primary research question was to determine if PULSE 360 coworkers' ratings correlate with CG-CAHPS patients' ratings of overall satisfaction, recommendation of the physician, surgeon respect, and clarity of the surgeon's explanation. Our secondary research questions were to determine whether CG-CAHPS scores correlate with additional composite scores from the Quality PULSE 360 (eg, insight impact score, focus concerns score, leadership-teamwork index score, etc). We retrospectively analyzed existing quality improvement data from CG-CAHPS patient surveys as well as from a department quality improvement initiative using 360-degree survey feedback questionnaires (Quality PULSE 360 with coworkers). Bivariate analyses were conducted to identify significant relationships for inclusion of research variables in multivariate linear analyses (eg, stepwise regression to determine the best fitting predictive model for CG-CAHPS ratings). In all higher order analyses, CG-CAHPS ratings were treated as the dependent variables, whereas PULSE 360 scores served as independent variables. This approach led to the identification of the most predictive linear model for each CG-CAHPS' performance rating (eg, [1] overall satisfaction; [2] recommendation of the physician; [3] surgeon respect; and [4] clarity of the surgeon's explanation) regressed on all PULSE scores with which there was a significant bivariate relationship. Backward stepwise regression was then used to remove unnecessary predictors from the linear model based on changes in the variance explained by the model with or without inclusion of the predictor. The Quality PULSE 360 insight impact score correlated with patient satisfaction (0.50, p = 0.01), patient recommendation (0.58, p = 0.002), patient rating of surgeon respect (0.74, p < 0.001), and patient impression of clarity of the physician explanation (0.69, p < 0.001). Additionally, leadership-teamwork index also correlated with patient rating of surgeon respect (0.46, p = 0.019) and patient impression of clarity of the surgeon's explanation (0.39, p = 0.05). Multivariate analyses supported retention of insight impact as a predictor of patient overall satisfaction, patient recommendation of the surgeon, and patient rating of surgeon respect. Both insight impact and leadership-teamwork index were retained as predictors of patient impression of explanation. Several other PULSE 360 variables were correlated with CG-CAHPS ratings, but none were retained in the linear models post stepwise regression. The relationship between Quality PULSE 360 feedback scores and measures of patient satisfaction reaffirm that feedback from work team members may provide helpful information into how patients may be perceiving their physicians' behavior and vice versa. Furthermore, the findings provide tentative support for the use of team-based feedback to improve the quality of relationships with both coworkers and patients. The 360-degree survey process may offer an effective tool for physicians to obtain feedback about behavior that could directly impact practice reimbursement and reputation or potentially be used for bonuses to incentivize better team professionalism and patient satisfaction, ie, "pay-for-professionalism." Further research is needed to expand on this line of inquiry, determine which interventions can improve 360-degree and patient satisfaction scores, and explain the shared variance in physician performance that is captured in the perceptions of patients and coworkers.
Tibiofemoral contact forces during walking, running and sidestepping.

PubMed

Saxby, David J; Modenese, Luca; Bryant, Adam L; Gerus, Pauline; Killen, Bryce; Fortin, Karine; Wrigley, Tim V; Bennell, Kim L; Cicuttini, Flavia M; Lloyd, David G

2016-09-01

We explored the tibiofemoral contact forces and the relative contributions of muscles and external loads to those contact forces during various gait tasks. Second, we assessed the relationships between external gait measures and contact forces. A calibrated electromyography-driven neuromusculoskeletal model estimated the tibiofemoral contact forces during walking (1.44±0.22ms(-1)), running (4.38±0.42ms(-1)) and sidestepping (3.58±0.50ms(-1)) in healthy adults (n=60, 27.3±5.4years, 1.75±0.11m, and 69.8±14.0kg). Contact forces increased from walking (∼1-2.8 BW) to running (∼3-8 BW), sidestepping had largest maximum total (8.47±1.57 BW) and lateral contact forces (4.3±1.05 BW), while running had largest maximum medial contact forces (5.1±0.95 BW). Relative muscle contributions increased across gait tasks (up to 80-90% of medial contact forces), and peaked during running for lateral contact forces (∼90%). Knee adduction moment (KAM) had weak relationships with tibiofemoral contact forces (all R(2)<0.36) and the relationships were gait task-specific. Step-wise regression of multiple external gait measures strengthened relationships (0.20
Does Stepwise Voltage Ramping Protect the Kidney from Injury During Extracorporeal Shockwave Lithotripsy? Results of a Prospective Randomized Trial.

PubMed

Skuginna, Veronika; Nguyen, Daniel P; Seiler, Roland; Kiss, Bernhard; Thalmann, George N; Roth, Beat

2016-02-01

Renal damage is more frequent with new-generation lithotripters. However, animal studies suggest that voltage ramping minimizes the risk of complications following extracorporeal shock wave lithotripsy (SWL). In the clinical setting, the optimal voltage strategy remains unclear. To evaluate whether stepwise voltage ramping can protect the kidney from damage during SWL. A total of 418 patients with solitary or multiple unilateral kidney stones were randomized to receive SWL using a Modulith SLX-F2 lithotripter with either stepwise voltage ramping (n=213) or a fixed maximal voltage (n=205). SWL. The primary outcome was sonographic evidence of renal hematomas. Secondary outcomes included levels of urinary markers of renal damage, stone disintegration, stone-free rate, and rates of secondary interventions within 3 mo of SWL. Descriptive statistics were used to compare clinical outcomes between the two groups. A logistic regression model was generated to assess predictors of hematomas. Significantly fewer hematomas occurred in the ramping group(12/213, 5.6%) than in the fixed group (27/205, 13%; p=0.008). There was some evidence that the fixed group had higher urinary β2-microglobulin levels after SWL compared to the ramping group (p=0.06). Urinary microalbumin levels, stone disintegration, stone-free rate, and rates of secondary interventions did not significantly differ between the groups. The logistic regression model showed a significantly higher risk of renal hematomas in older patients (odds ratio [OR] 1.03, 95% confidence interval [CI] 1.00-1.05; p=0.04). Stepwise voltage ramping was associated with a lower risk of hematomas (OR 0.39, 95% CI 0.19-0.80; p=0.01). The study was limited by the use of ultrasound to detect hematomas. In this prospective randomized study, stepwise voltage ramping during SWL was associated with a lower risk of renal damage compared to a fixed maximal voltage without compromising treatment effectiveness. Lithotripsy is a noninvasive technique for urinary stone disintegration using ultrasonic energy. In this study, two voltage strategies are compared. The results show that a progressive increase in voltage during lithotripsy decreases the risk of renal hematomas while maintaining excellent outcomes. ISRCTN95762080. Copyright © 2015 European Association of Urology. Published by Elsevier B.V. All rights reserved.
Selecting minimum dataset soil variables using PLSR as a regressive multivariate method

NASA Astrophysics Data System (ADS)

Stellacci, Anna Maria; Armenise, Elena; Castellini, Mirko; Rossi, Roberta; Vitti, Carolina; Leogrande, Rita; De Benedetto, Daniela; Ferrara, Rossana M.; Vivaldi, Gaetano A.

2017-04-01

Long-term field experiments and science-based tools that characterize soil status (namely the soil quality indices, SQIs) assume a strategic role in assessing the effect of agronomic techniques and thus in improving soil management especially in marginal environments. Selecting key soil variables able to best represent soil status is a critical step for the calculation of SQIs. Current studies show the effectiveness of statistical methods for variable selection to extract relevant information deriving from multivariate datasets. Principal component analysis (PCA) has been mainly used, however supervised multivariate methods and regressive techniques are progressively being evaluated (Armenise et al., 2013; de Paul Obade et al., 2016; Pulido Moncada et al., 2014). The present study explores the effectiveness of partial least square regression (PLSR) in selecting critical soil variables, using a dataset comparing conventional tillage and sod-seeding on durum wheat. The results were compared to those obtained using PCA and stepwise discriminant analysis (SDA). The soil data derived from a long-term field experiment in Southern Italy. On samples collected in April 2015, the following set of variables was quantified: (i) chemical: total organic carbon and nitrogen (TOC and TN), alkali-extractable C (TEC and humic substances - HA-FA), water extractable N and organic C (WEN and WEOC), Olsen extractable P, exchangeable cations, pH and EC; (ii) physical: texture, dry bulk density (BD), macroporosity (Pmac), air capacity (AC), and relative field capacity (RFC); (iii) biological: carbon of the microbial biomass quantified with the fumigation-extraction method. PCA and SDA were previously applied to the multivariate dataset (Stellacci et al., 2016). PLSR was carried out on mean centered and variance scaled data of predictors (soil variables) and response (wheat yield) variables using the PLS procedure of SAS/STAT. In addition, variable importance for projection (VIP) statistics was used to quantitatively assess the predictors most relevant for response variable estimation and then for variable selection (Andersen and Bro, 2010). PCA and SDA returned TOC and RFC as influential variables both on the set of chemical and physical data analyzed separately as well as on the whole dataset (Stellacci et al., 2016). Highly weighted variables in PCA were also TEC, followed by K, and AC, followed by Pmac and BD, in the first PC (41.2% of total variance); Olsen P and HA-FA in the second PC (12.6%), Ca in the third (10.6%) component. Variables enabling maximum discrimination among treatments for SDA were WEOC, on the whole dataset, humic substances, followed by Olsen P, EC and clay, in the separate data analyses. The highest PLS-VIP statistics were recorded for Olsen P and Pmac, followed by TOC, TEC, pH and Mg for chemical variables and clay, RFC and AC for the physical variables. Results show that different methods may provide different ranking of the selected variables and the presence of a response variable, in regressive techniques, may affect variable selection. Further investigation with different response variables and with multi-year datasets would allow to better define advantages and limits of single or combined approaches. Acknowledgment The work was supported by the projects "BIOTILLAGE, approcci innovative per il miglioramento delle performances ambientali e produttive dei sistemi cerealicoli no-tillage", financed by PSR-Basilicata 2007-2013, and "DESERT, Low-cost water desalination and sensor technology compact module" financed by ERANET-WATERWORKS 2014. References Andersen C.M. and Bro R., 2010. Variable selection in regression - a tutorial. Journal of Chemometrics, 24 728-737. Armenise et al., 2013. Developing a soil quality index to compare soil fitness for agricultural use under different managements in the mediterranean environment. Soil and Tillage Research, 130:91-98. de Paul Obade et al., 2016. A standardized soil quality index for diverse field conditions. Sci. Total Env. 541:424-434. Pulido Moncada et al., 2014. Data-driven analysis of soil quality indicators using limited data. Geoderma, 235:271-278. Stellacci et al., 2016. Comparison of different multivariate methods to select key soil variables for soil quality indices computation. XLV Congress of the Italian Society of Agronomy (SIA), Sassari, 20-22 September 2016.
A matrix-based method of moments for fitting the multivariate random effects model for meta-analysis and meta-regression

PubMed Central

Jackson, Dan; White, Ian R; Riley, Richard D

2013-01-01

Multivariate meta-analysis is becoming more commonly used. Methods for fitting the multivariate random effects model include maximum likelihood, restricted maximum likelihood, Bayesian estimation and multivariate generalisations of the standard univariate method of moments. Here, we provide a new multivariate method of moments for estimating the between-study covariance matrix with the properties that (1) it allows for either complete or incomplete outcomes and (2) it allows for covariates through meta-regression. Further, for complete data, it is invariant to linear transformations. Our method reduces to the usual univariate method of moments, proposed by DerSimonian and Laird, in a single dimension. We illustrate our method and compare it with some of the alternatives using a simulation study and a real example. PMID:23401213
SMURC: High-Dimension Small-Sample Multivariate Regression With Covariance Estimation.

PubMed

Bayar, Belhassen; Bouaynaya, Nidhal; Shterenberg, Roman

2017-03-01

We consider a high-dimension low sample-size multivariate regression problem that accounts for correlation of the response variables. The system is underdetermined as there are more parameters than samples. We show that the maximum likelihood approach with covariance estimation is senseless because the likelihood diverges. We subsequently propose a normalization of the likelihood function that guarantees convergence. We call this method small-sample multivariate regression with covariance (SMURC) estimation. We derive an optimization problem and its convex approximation to compute SMURC. Simulation results show that the proposed algorithm outperforms the regularized likelihood estimator with known covariance matrix and the sparse conditional Gaussian graphical model. We also apply SMURC to the inference of the wing-muscle gene network of the Drosophila melanogaster (fruit fly).
An Investigation into the Roles of Theory of Mind, Emotion Regulation, and Attachment Styles in Predicting the Traits of Borderline Personality Disorder

PubMed Central

Ghiasi, Hamed; Mohammadi, Abolalfazl; Zarrinfar, Pouria

2016-01-01

Objective: Borderline personality disorder is one of the most complex and prevalent personality disorders. Many variables have so far been studied in relation to this disorder. This study aimed to investigate the role of emotion regulation, attachment styles, and theory of mind in predicting the traits of borderline personality disorder. Method: In this study, 85 patients with borderline personality disorder were selected using convenience sampling method. To measure the desired variables, the questionnaires of Gross emotion regulation, Collins and Read attachment styles, and Baron Cohen's Reading Mind from Eyes Test were applied. The data were analyzed using multivariate stepwise regression technique. Results: Emotion regulation, attachment styles, and theory of mind predicted 41.2% of the variance criterion altogether; among which, the shares of emotion regulation, attachment styles and theory of mind to the distribution of the traits of borderline personality disorder were 27.5%, 9.8%, and 3.9%, respectively.‎‎ Conclusion: The results of the study revealed that emotion regulation, attachment styles, and theory of mind are important variables in predicting the traits of borderline personality disorder and that these variables can be well applied for both the treatment and identification of this disorder. PMID:28050180
De novo malignancy is associated with renal transplant tourism.

PubMed

Tsai, Meng-Kun; Yang, Ching-Yao; Lee, Chih-Yuan; Yeh, Chi-Chuan; Hu, Rey-Heng; Lee, Po-Huang

2011-04-01

Despite the objections to transplant tourism raised by the transplant community, many patients continue travel to other countries to receive commercial transplants. To evaluate some long-term complications, we reviewed medical records of 215 Taiwanese patients (touring group) who received commercial cadaveric renal transplants in China and compared them with those of 321 transplant recipients receiving domestic cadaveric renal transplants (domestic group) over the same 20-year period. Ten years after transplant, the graft and patient survival rates of the touring group were 55 and 81.5%, respectively, compared with 60 and 89.3%, respectively, of the domestic group. The difference between the two groups was not statistically significant. The 10-year cumulative cancer incidence of the touring group (21.5%) was significantly higher than that of the domestic group (6.8%). Univariate and multivariate stepwise regression analyses (excluding time on immunosuppression, an uncontrollable factor) indicated that transplant tourism was associated with significantly higher cancer incidence. Older age at transplantation was associated with a significantly increased cancer risk; however, the risk of de novo malignancy significantly decreased with longer graft survival. Thus, renal transplant tourism may be associated with a higher risk of post-transplant malignancy, especially in patients of older age at transplantation. © 2011 International Society of Nephrology

Association between domestic violence and HIV serostatus among married and formerly married women in Kenya.

PubMed

Onsomu, Elijah O; Abuya, Benta A; Okech, Irene N; Rosen, David L; Duren-Winfield, Vanessa; Simmons, Amber C

2015-01-01

The prevalence of both domestic violence (DV) and HIV among Kenyan women is known to be high, but the relationship between them is unknown. Nationally representative cross-sectional data from married and formerly married (MFM) women responding to the Kenya Demographic and Health Survey 2008/2009 were analyzed adjusting for complex survey design. Multivariable logistic regressions were used to assess the covariate-adjusted associations between HIV serostatus and any reported DV as well as four constituent DV measures: physical, emotional, sexual, and aggravated bodily harm, adjusting for covariates entered into each model using a forward stepwise selection process. Covariates of a priori interest included those representing marriage history, risky sexual behavior, substance use, perceived HIV risk, and sociodemographic characteristics. The prevalence of HIV among MFM women was 10.7% (any DV: 13.1%, no DV: 8.6%); overall prevalence of DV was 43.4%. Among all DV measures, only physical DV was associated with HIV (11.9%; adjusted odds ratio: 2.01, p <.05). Efforts by the government and women's groups to monitor and improve policies to reduce DV, such as the Sexual Offences Act of 2006, are urgently needed to curb HIV, as are policies that seek to provide DV counseling and treatment to MFM women.
Comparison of four staging systems of lymph node metastasis in gastric cancer.

PubMed

Zhang, Ming; Zhu, Guanyu; Ma, Yan; Xue, Yingwei

2009-11-01

The classification of lymph node metastasis in patients with gastric cancer is still controversial. Our aim was to evaluate the relative merits of four staging systems of lymph node metastasis. In our study, the nodal status was classified according to the 5th edition of the tumor node metastasis (TNM) system, the Japanese Classification of Gastric Carcinoma (JCGC), the ratio of metastatic lymph nodes, and the size of the largest metastatic lymph node. Each staging system was scored as good (+2), fair (+1), or poor (0) with respect to the theoretical value (extent of the anatomical lymphatic tumor spread), convenience (simplicity), surgical applicability (extent of lymph node dissection), and prognostic value (ability to predict survival rate). In the multivariate analysis including the four staging systems and other potential prognostic factors, stepwise Cox regression revealed that the ratio of metastatic lymph nodes was the most independent prognostic factor. The TNM, ratio, and size systems were convenient because they had no consideration for the location of the tumor and lymph node. Although the JCGC system had advantages in theoretical value and surgical application, it was most optional due to the complexity of the system. Although all different staging systems are comparable, the metastatic lymph node ratio system is convenient, reproducible, and has the highest ability to predict survival.
Salivary Testosterone Levels Under Psychological Stress and Its Relationship with Rumination and Five Personality Traits in Medical Students

PubMed Central

Afrisham, Reza; Sadegh-Nejadi, Sahar; SoliemaniFar, Omid; Kooti, Wesam; Ashtary-Larky, Damoon; Alamiri, Fatima; Najjar-Asl, Sedigheh; Khaneh-Keshi, Ali

2016-01-01

Objective The purpose of this study was to evaluate the salivary testosterone levels under psychological stress and its relationship with rumination and five personality traits in medical students. Methods A total of 58 medical students, who wanted to participate in the final exam, were selected by simple random sampling. Two months before the exam, in the basal conditions, the NEO Inventory short form, and the Emotional Control Questionnaire (ECQ) were completed. Saliva samples were taken from students in both the basal conditions and under exam stress. Salivary testosterone was measured by ELISA. Data was analyzed using multivariate analysis of variance with repeated measures, paired samples t-test, Pearson correlation and stepwise regression analysis. Results Salivary testosterone level of men showed a significant increase under exam stress (p<0.05). However, a non-significant although substantial reduction observed in women. A significant correlation was found between extroversion (r=-0.33) and openness to experience (r=0.30) with salivary testosterone (p<0.05). Extraversion, aggression control and emotional inhibition predicted 28% of variance of salivary testosterone under stress. Conclusion Salivary testosterone reactivity to stress can be determined by sexual differences, personality traits, and emotional control variables which may decrease or increase stress effects on biological responses, especially the salivary testosterone. PMID:27909455
"Over my dead body?": the influence of demographics on students' willingness to participate in peer physical examination.

PubMed

Rees, Charlotte E; Bradley, Paul; Collett, Tracey; McLachlan, John C

2005-11-01

This study aims to explore quantitatively and qualitatively students' attitudes towards peer physical examination (PPE) and the influence of demographics on students' willingness to participate in PPE. A total of 296 first-year medical students from two consecutive cohorts at the Peninsula Medical School, UK completed the EFS questionnaire. Quantitative data from the questionnaire were analysed using univariate (i.e. Mann-Whitney and chi-squared tests) and multivariate statistics (i.e. stepwise multiple regression) and qualitative data were analysed using theme analysis. At least 92% of Peninsula Medical School students were willing to examine all 11 body parts (except breast and inguinal regions) of peers of same and opposite gender. Qualitative data support this by highlighting students' positive attitudes towards PPE. PPE was more acceptable within rather than across gender and students generally felt more comfortable examining their peers than being examined by peers. Qualitative data outline the range of student concerns with PPE. Significant relationships existed between students' attitudes towards PPE and various variables: gender, age and religious faith. The findings demonstrate that students may show a greater willingness to participate in PPE than previously thought. Further research is required to explore more fully the barriers to PPE.
An Investigation into the Roles of Theory of Mind, Emotion Regulation, and Attachment Styles in Predicting the Traits of Borderline Personality Disorder.

PubMed

Ghiasi, Hamed; Mohammadi, Abolalfazl; Zarrinfar, Pouria

2016-10-01

Objective: Borderline personality disorder is one of the most complex and prevalent personality disorders. Many variables have so far been studied in relation to this disorder. This study aimed to investigate the role of emotion regulation, attachment styles, and theory of mind in predicting the traits of borderline personality disorder. Method: In this study, 85 patients with borderline personality disorder were selected using convenience sampling method. To measure the desired variables, the questionnaires of Gross emotion regulation, Collins and Read attachment styles, and Baron Cohen's Reading Mind from Eyes Test were applied. The data were analyzed using multivariate stepwise regression technique. Results: Emotion regulation, attachment styles, and theory of mind predicted 41.2% of the variance criterion altogether; among which, the shares of emotion regulation, attachment styles and theory of mind to the distribution of the traits of borderline personality disorder were 27.5%, 9.8%, and 3.9%, respectively.‎‎ Conclusion : The results of the study revealed that emotion regulation, attachment styles, and theory of mind are important variables in predicting the traits of borderline personality disorder and that these variables can be well applied for both the treatment and identification of this disorder.
Investigation of the key determinants of Asian nurses' quality of life.

PubMed

Makabe, Sachiko; Kowitlawakul, Yanika; Nurumal, Mohd Said; Takagai, Junko; Wichaikhum, Orn-Anong; Wangmo, Neyzang; Yap, Suk Foon; Kunaviktikul, Wipada; Komatsu, Junko; Shirakawa, Hideko; Kimura, Yutaka; Asanuma, Yoshihiro

2018-06-01

The study aimed to compare nurses' quality of life and investigate key determinants among Asian countries with different economic status. A cross-sectional survey was conducted across five Asian countries (Japan, Singapore, Malaysia, Thailand, and Bhutan). Quality of life (WHOQOL-BREF), job stress (National Institute of Occupational Safety and Health questionnaire), and demographic data were assessed. Stepwise multivariate linear regression analysis was performed to identify the key determinants of quality of life. Participants were 3,829 nurses (response rate: 82%) with a mean age of 33 ± 10 yr and majority were women (92%). Regarding quality of life, Bhutan yielded the highest scores, followed by Malaysia, Thailand, Singapore, and Japan, and these results were statistically significant. The key determinants that were significantly related to quality of life were "stress coping ability," "life satisfaction," "Japan," "social support," "job stress," and "Singapore" (adjusted R 2 =0.46). In conclusion, nurses' quality of life differs across Asian countries and is not linked to the country's economic development. To maintain a good quality of life for nurses, an international exchange program like international nursing conferences for work environment and staff coping strategies is recommended to broaden institution' minds and share experiences and exchange views to be able to realize their own problems and discover global solutions to them.
Edmondson-Steiner grade: A crucial predictor of recurrence and survival in hepatocellular carcinoma without microvascular invasio.

PubMed

Zhou, Li; Rui, Jing-An; Zhou, Wei-Xun; Wang, Shao-Bin; Chen, Shu-Guang; Qu, Qiang

2017-07-01

Microvascular invasion (MVI), an important pathologic parameter, has been proven to be a powerful predictor of long-term prognosis in hepatocellular carcinoma (HCC). However, prognostic factors in HCC without MVI remain unknown. The present study aimed to identify the risk factors of recurrence and poor post-resectional survival in this type of HCC. A total of 109 patients with MVI-absent HCC underwent radical hepatectomy were enrolled. The influence of clinicopathologic variables on recurrence and patient survival was assessed using univariate and multivariate analyses. Chi-square test found that Edmondson-Steiner grade and satellite nodule were significantly associated with recurrence, while the former was the single marker for early recurrence. Stepwise logistic regression analysis demonstrated the independent predictive role of Edmondson-Steiner grade for recurrence. On the other hand, Edmondson-Steiner grade, serum AFP level and satellite nodule were significant for overall and disease-free survival in univariate analysis, whereas tumor size was linked to disease-free survival. Of the variables, Edmondson-Steiner grade, serum AFP level and satellite nodule were independent indicators. Edmondson-Steiner grade, a histological classification, carries robust prognostic implications for all the endpoints for prognosis, thus being potential to be a crucial prognosticator in HCC without MVI. Copyright © 2017 Elsevier GmbH. All rights reserved.
The impact of obesity on 30-day complications in pediatric surgery.

PubMed

Train, A T; Cairo, S B; Meyers, H A; Harmon, C M; Rothstein, D H

2017-11-01

To examine the effects of obesity on specialty-specific surgical outcomes in children. Retrospective cohort study using the National Surgical Quality Improvement Program, Pediatric, 2012-2014. Patients included those aged 2-17 years who underwent a surgical procedure in one of six specialties. Obesity was the primary patient variable of interest. Outcomes of interest were postoperative complications and operative times. Odds ratios for development of postoperative complications were calculated using stepwise multivariate regression analysis. Obesity was associated with a significantly greater risk of wound complications (OR 1.24, 95% CI 1.13-1.36), but decreased risk of non-wound complications (OR 0.68, 95% CI 0.63-0.73) and morbidity (OR 0.79, 95% CI 0.75-0.84). Obesity was not a significant factor in predicting postoperative complications in patients undergoing otolaryngology or plastic surgery procedures. Anesthesia times and operative times were significantly longer for obese patients undergoing most types of pediatric surgical procedures. Obesity confers an increased risk of wound complications in some pediatric surgical specialties and is associated with overall decreased non-wound complications and morbidity. These findings suggest that the relationship between obesity and postoperative complications is complex and may be more dependent on underlying procedure- or specialty-related factors than previously suspected.
Sources of meaning in cancer patients - influences on global meaning, anxiety and depression in a longitudinal study.

PubMed

Scheffold, K; Mehnert, A; Müller, V; Koch, U; Härter, M; Vehling, S

2014-07-01

Although existential needs are highly prevalent in patients with cancer, specific sources of meaning have been little explored. We investigated whether specific sources of meaning predict global meaning and psychological distress. N = 258 patients with breast (45%), lung (39%) and gynaecological cancer (16%) completed a battery of validated questionnaires at T1. Six months later (T2), n = 183 (78%) patients participated again. The primary outcomes - sources of meaning, global meaning and psychosocial distress - were measured with the Sources of Meaning Profile-Revised (SOMP-R), Life Attitude Profile-Revised (LAP-R) and modules for depression and anxiety of the Patient Health Questionnaire (PHQ-9, GAD-7). Most important sources of meaning were 'engaging in personal relationships', 'preserving human values and ideals' and 'feeling financially secure'. Stepwise multivariate regression analyses controlling for demographic and medical factors revealed that 'engaging in personal relationships', 'preservation of culture and tradition' and 'interest in social and/or political causes' predicted lower depression. 'Leaving a legacy for the next generation' and 'feeling financially secure' predicted both higher depression and anxiety. The findings highlight the relevance of sources of meaning for the psychological well-being of cancer patients and point towards specific sources of meaning that should be focused in psychosocial interventions. © 2013 John Wiley & Sons Ltd.
Association between domestic violence and HIV serostatus among married and formerly married women in Kenya

PubMed Central

Abuya, Benta A; Okech, Irene N; Rosen, David L; Duren-Winfield, Vanessa; Simmons, Amber C

2014-01-01

The prevalence of both domestic violence (DV) and HIV among Kenyan women is known to be high, but the relationship between them is unknown. Nationally representative cross-sectional data from married and formerly married (MFM) women responding to the Kenya Demographic and Health Survey 2008/2009 were analyzed adjusting for complex survey design. Multivariable logistic regressions were used to assess the covariate-adjusted associations between HIV serostatus and any reported DV as well as four constituent DV measures: physical, emotional, sexual, and aggravated bodily harm, adjusting for co-variates entered into each model using a forward stepwise selection process. Co-variates of a priori interest included those representing marriage history, risky sexual behavior, substance use, perceived HIV risk, and socio-demographic characteristics. The prevalence of HIV among MFM women was 10.7% (any DV: 13.1%, no DV: 8.6%); overall prevalence of DV was 43.4%. Among all DV measures, only physical DV was associated with HIV (11.9%; adjusted odds ratio: 2.01, p < 0.05). Efforts by the government and women's groups to monitor and improve policies to reduce DV, such as the Sexual Offences Act of 2006, are urgently needed to curb HIV, as are policies that seek to provide DV counseling and treatment to MFM women. PMID:25127397
Risk factors related to methicillin-resistant Staphylococcus aureus infection among inpatients at Prof. dr. R. D. Kandou general hospital Manado

NASA Astrophysics Data System (ADS)

Utomo, H. T.; Nugroho, A.; Harijanto, P. N.

2018-03-01

Methicillin-resistant Staphylococcus aureus (MRSA) presents nosocomial infection problemsin hospitals. Identification of risk factors related to MRSA infection is a concern among healthcare provider. A retrospective case-control study was conducted to identify MRSA infection proportion among isolates, also to identify risk factors amonginpatients at Prof. dr.R. D. Kandou General Hospital, Manado. Data were from themedical record, from patient’s culture isolateswith positive Staphylococcus aureus infection from January-December 2015. Case subject isolated cultures of MRSA and control subject isolated cultures of non-MRSA. Bivariate analysis were performed in 10 independent variables (age, length of stay, prior use of antibiotics before cultures, history of HIV infection, prior use of corticosteroid, history of malignancy, history of chronic disease, prior use of medical tools (catheter, ventilator, etc), history of invasive medical procedure, history of hospitalization before). All variables with a p-value<0.05 were into multivariate analysis with forwarding stepwise logistic regression. Mean subjects age were 48.13 ± 2.05 years old and length of stay were 8.65 ± 0.25 days, and only prior antibiotic use-variable were considered statistically significant (p = 0.017; OR 1.889; 95%CI 1.595 – 2.238).
Increasing likelihood of advanced pulmonary tuberculosis at initial diagnosis in a low-incidence US state.

PubMed

Yang, Z-H; Gorden, T; Liu, D-P; Mukasa, L; Patil, N; Bates, J H

2018-06-01

Arkansas, USA. To investigate the relationship between an increase in the proportion of cases with advanced disease at first diagnosis and the recently observed slowing of the decline in tuberculosis (TB) incidence in low-incidence US states. We conducted descriptive statistical analyses of de-identified surveillance data of 1246 culture-confirmed TB patients reported in Arkansas during 1996-2013. We then fitted stepwise, multivariate logistic regression models to identify predictors for advanced disease at diagnosis, defined as having either smear-positive sputum or lung cavitation. From 1996 to 2013, the proportion of new cases with positive sputum smear and cases with lung cavitation increased from 51.6% to 75% and from 37.7% to 50%, respectively. Patients diagnosed during 2006-2013 were more likely to have positive sputum smears (adjusted odds ratio [aOR] 2.55, 95%CI 1.95-3.35) or lung cavitation (aOR 1.49, 95%CI 1.14-1.95) than those diagnosed during 1996-2005. During 1996-2013, age 15-64 years and excessive alcohol use were predictive of positive sputum smear or lung cavitation. Measures to reduce the proportion of cases with advanced disease at first diagnosis may be helpful to achieve further decline in TB incidence in low-incidence settings.
A real-time prediction model for post-irradiation malignant cervical lymph nodes.

PubMed

Lo, W-C; Cheng, P-W; Shueng, P-W; Hsieh, C-H; Chang, Y-L; Liao, L-J

2018-04-01

To establish a real-time predictive scoring model based on sonographic characteristics for identifying malignant cervical lymph nodes (LNs) in cancer patients after neck irradiation. One-hundred forty-four irradiation-treated patients underwent ultrasonography and ultrasound-guided fine-needle aspirations (USgFNAs), and the resultant data were used to construct a real-time and computerised predictive scoring model. This scoring system was further compared with our previously proposed prediction model. A predictive scoring model, 1.35 × (L axis) + 2.03 × (S axis) + 2.27 × (margin) + 1.48 × (echogenic hilum) + 3.7, was generated by stepwise multivariate logistic regression analysis. Neck LNs were considered to be malignant when the score was ≥ 7, corresponding to a sensitivity of 85.5%, specificity of 79.4%, positive predictive value (PPV) of 82.3%, negative predictive value (NPV) of 83.1%, and overall accuracy of 82.6%. When this new model and the original model were compared, the areas under the receiver operating characteristic curve (c-statistic) were 0.89 and 0.81, respectively (P < .05). A real-time sonographic predictive scoring model was constructed to provide prompt and reliable guidance for USgFNA biopsies to manage cervical LNs after neck irradiation. © 2017 John Wiley & Sons Ltd.
Investigating the Underlying Factors of Corruption in the Public Construction Sector: Evidence from China.

PubMed

Shan, Ming; Le, Yun; Yiu, Kenneth T W; Chan, Albert P C; Hu, Yi

2017-12-01

Over recent years, the issue of corruption in the public construction sector has attracted increasing attention from both practitioners and researchers worldwide. However, limited efforts are available for investigating the underlying factors of corruption in this sector. Thus, this study attempted to bridge this knowledge gap by exploring the underlying factors of corruption in the public construction sector of China. To achieve this goal, a total of 14 structured interviews were first carried out, and a questionnaire survey was then administered to 188 professionals in China. Two iterations of multivariate analysis approaches, namely, stepwise multiple regression analysis and partial least squares structural equation modeling were successively utilized to analyze the collected data. In addition, a case study was also conducted to triangulate the findings obtained from the statistical analysis. The results generated from these three research methods achieve the same conclusion: the most influential underlying factor leading to corruption was immorality, followed by opacity, unfairness, procedural violation, and contractual violation. This study has contributed to the body of knowledge by exploring the properties of corruption in the public construction sector. The findings from this study are also valuable to the construction authorities as they can assist in developing more effective anti-corruption strategies.
Aetiology of Bacteraemia as a Risk Factor for Septic Shock at the Onset of Febrile Neutropaenia in Adult Cancer Patients

PubMed Central

Rosa, Regis Goulart; Goldani, Luciano Zubaran

2014-01-01

Septic shock (SS) at the onset of febrile neutropaenia (FN) is an emergency situation that is associated with high morbidity and mortality. The impact of the specific aetiology of bloodstream infections (BSIs) in the development of SS at the time of FN is not well established. The aim of this study was to evaluate the association between the aetiology of BSIs and SS at the time of FN in hospitalised adult cancer patients. This prospective cohort study was performed at a single tertiary hospital from October 2009 to August 2011. All adult cancer patients admitted consecutively to the haematology ward with FN were evaluated. A stepwise logistic regression was conducted to verify the association between the microbiological characteristics of BSIs and SS at the onset of FN. In total, 307 cases of FN in adult cancer patients were evaluated. There were 115 cases with documented BSI. A multivariate analysis showed that polymicrobial bacteraemia (P = 0.01) was associated with SS. The specific blood isolates independently associated with SS were viridans streptococci (P = 0.02) and Escherichia coli (P = 0.01). Neutropaenic cancer patients with polymicrobial bacteraemia or BSI by viridans streptococci or Escherichia coli are at increased risk for SS at the time of FN. PMID:24804223
Variable Resistance to Plasminogen Activator Initiated Fibrinolysis for Intermediate-Risk Pulmonary Embolism.

PubMed

Stubblefield, William B; Alves, Nathan J; Rondina, Matthew T; Kline, Jeffrey A

2016-01-01

We examine the clinical significance and biomarkers of tissue plasminogen activator (tPA)-catalyzed clot lysis time (CLT) in patients with intermediate-risk pulmonary embolism (PE). Platelet-poor, citrated plasma was obtained from patients with PE. Healthy age- and sex-matched patients served as disease-negative controls. Fibrinogen, α2-antiplasmin, plasminogen, thrombin activatable fibrinolysis inhibitor (TAFI), plasminogen activator Inhibitor 1 (PAI-1), thrombin time and D-dimer were quantified. Clotting was induced using CaCl2, tissue factor, and phospholipid. Lysis was induced using 60 ng/mL tPA. Time to 50% clot lysis (CLT) was assessed by both thromboelastography (TEG) and turbidimetry (A405). Compared with disease-negative controls, patients with PE exhibited significantly longer mean CLT on TEG (+2,580 seconds, 95% CI 1,380 to 3,720 sec). Patients with PE and a short CLT who were treated with tenecteplase had increased risk of bleeding, whereas those with long CLT had significantly worse exercise tolerance and psychometric testing for quality of life at 3 months. A multivariate stepwise removal regression model selected PAI-1 and TAFI as predictive biomarkers of CLT. The CLT from TEG predicted increased risk of bleeding and clinical failure with tenecteplase treatment for intermediate-risk PE. Plasmatic PAI-1 and TAFI were independent predictors of CLT.
Needs of the Learning Effect on Instructional Website for Vocational High School Students

ERIC Educational Resources Information Center

Lo, Hung-Jen; Fu, Gwo-Liang; Chuang, Kuei-Chih

2013-01-01

The purpose of study was to understand the correlation between the needs of the learning effect on instructional website for the vocational high school students. Our research applied the statistic methods of product-moment correlation, stepwise regression, and structural equation method to analyze the questionnaire with the sample size of 377…
Asynchronous Knowledge Sharing and Conversation Interaction Impact on Grade in an Online Business Course

ERIC Educational Resources Information Center

Strang, Kenneth David

2011-01-01

Student knowledge sharing and conversation theory interactions were coded from asynchronous discussion forums to measure the effect of learning-oriented utterances on academic performance. The sample was 3 terms of an online business course (in an accredited MBA program) at a U.S.-based university. Correlation, stepwise regression, and multiple…
Information Scent Determines Attention Allocation and Link Selection among Multiple Information Patches on a Webpage

ERIC Educational Resources Information Center

Blackmon, Marilyn Hughes

2012-01-01

This paper draws from cognitive psychology and cognitive neuroscience to develop a preliminary similarity-choice theory of how people allocate attention among information patches on webpages while completing search tasks in complex informational websites. Study 1 applied stepwise multiple regression to a large dataset and showed that success rate…
Advances in variable selection methods I: Causal selection methods versus stepwise regression and principal component analysis on data of known and unknown functional relationships

EPA Science Inventory

Hydrological predictions at a watershed scale are commonly based on extrapolation and upscaling of hydrological behavior at plot and hillslope scales. Yet, dominant hydrological drivers at a hillslope may not be as dominant at the watershed scale because of the heterogeneity of w...

Handling Missing Data: Analysis of a Challenging Data Set Using Multiple Imputation

ERIC Educational Resources Information Center

Pampaka, Maria; Hutcheson, Graeme; Williams, Julian

2016-01-01

Missing data is endemic in much educational research. However, practices such as step-wise regression common in the educational research literature have been shown to be dangerous when significant data are missing, and multiple imputation (MI) is generally recommended by statisticians. In this paper, we provide a review of these advances and their…
Heterosexual Risk Behaviors Among Urban Young Adolescents

ERIC Educational Resources Information Center

O'Donnell, Lydia; Stueve, Ann; Wilson-Simmons, Renee; Dash, Kim; Agronick, Gail; JeanBaptiste, Varzi

2006-01-01

Urban 6th graders (n = 294) participate in a survey assessing early heterosexual risk behaviors as part of the Reach for Health Middle Childhood Study. About half the boys (47%) and 20% of girls report having a girlfriend or boyfriend; 42% of boys and 10% of girls report kissing and hugging for a long time. Stepwise regressions model the…
Beyond the Black-White Test Score Gap: Latinos' Early School Experiences and Literacy Outcomes

ERIC Educational Resources Information Center

Delgado, Enilda A.; Stoll, Laurie Cooper

2015-01-01

Data from the Early Childhood Longitudinal Survey-Birth Cohort are used to analyze the factors that lead to the reading readiness of children who participate in nonparental care the year prior to kindergarten (N = 4,550), with a specific focus on Latino children (N = 800). Stepwise multiple linear regression analysis demonstrates that reading…
Consequences of ignoring geologic variation in evaluating grazing impacts

Treesearch

Jonathan W. Long; Alvin L. Medina

2006-01-01

The geologic diversity of landforms in the Southwest complicates efforts to evaluate impacts of land uses such as livestock grazing. We examined a research study that evaluated relationships between trout biomass and stream habitat in the White Mountains of east-central Arizona. That study interpreted results of stepwise regressions and a nonparametric test of âgrazed...
The Relationship of Selected Supply- and Demand-Side Factors to Forms of Perceived Discrimination among Adults with Multiple Sclerosis

ERIC Educational Resources Information Center

Roessler, Richard T.; Neath, Jeanne; McMahon, Brian T.; Rumrill, Phillip D.

2007-01-01

Single-predictor and stepwise multinomial logistic regression analyses and an external validation were completed on 3,082 allegations of employment discrimination by adults with multiple sclerosis. Women filed two thirds of the allegations, and individuals between 31 and 50 made the vast majority of discrimination charges (73%). Allegations…
Age, Sex, and Body Composition as Predictors of Children's Performance on Basic Motor Abilities and Health-Related Fitness Items.

ERIC Educational Resources Information Center

Pissanos, Becky W.; And Others

1983-01-01

Step-wise linear regressions were used to relate children's age, sex, and body composition to performance on basic motor abilities including balance, speed, agility, power, coordination, and reaction time, and to health-related fitness items including flexibility, muscle strength and endurance and cardiovascular functions. Eighty subjects were in…
Disorganized Symptoms Predicted Worse Functioning Outcome in Schizophrenia Patients with Established Illness.

PubMed

Ortiz, Bruno Bertolucci; Gadelha, Ary; Higuchi, Cinthia Hiroko; Noto, Cristiano; Medeiros, Daiane; Pitta, José Cássio do Nascimento; de Araújo Filho, Gerardo Maria; Hallak, Jaime Eduardo Cecílio; Bressan, Rodrigo Affonseca

Most patients with schizophrenia will have subsequent relapses of the disorder, with continuous impairments in functioning. However, evidence is lacking on how symptoms influence functioning at different phases of the disease. This study aims to investigate the relationship between symptom dimensions and functioning at different phases: acute exacerbation, nonremission and remission. Patients with schizophrenia were grouped into acutely ill (n=89), not remitted (n=89), and remitted (n=69). Three exploratory stepwise linear regression analyses were performed for each phase of schizophrenia, in which the five PANSS factors and demographic variables were entered as the independent variables and the total Global Assessment of Functioning Scale (GAF) score was entered as the dependent variable. An additional exploratory stepwise logistic regression analysis was performed to predict subsequent remission at discharge in the inpatient population. The Disorganized factor was the most significant predictor for acutely ill patients (p<0.001), while the Hostility factor was the most significant for not-remitted patients and the Negative factor was the most significant for remitted patients (p=0.001 and p<0.001, respectively). In the logistic regression, the Disorganized factor score presented a significant negative association with remission (p=0.007). Higher disorganization symptoms showed the greatest impact in functioning at acute phase, and prevented patients from achieving remission, suggesting it may be a marker of symptom severity and worse outcome in schizophrenia.
Delineating chalk sand distribution of Ekofisk formation using probabilistic neural network (PNN) and stepwise regression (SWR): Case study Danish North Sea field

NASA Astrophysics Data System (ADS)

Haris, A.; Nafian, M.; Riyanto, A.

2017-07-01

Danish North Sea Fields consist of several formations (Ekofisk, Tor, and Cromer Knoll) that was started from the age of Paleocene to Miocene. In this study, the integration of seismic and well log data set is carried out to determine the chalk sand distribution in the Danish North Sea field. The integration of seismic and well log data set is performed by using the seismic inversion analysis and seismic multi-attribute. The seismic inversion algorithm, which is used to derive acoustic impedance (AI), is model-based technique. The derived AI is then used as external attributes for the input of multi-attribute analysis. Moreover, the multi-attribute analysis is used to generate the linear and non-linear transformation of among well log properties. In the case of the linear model, selected transformation is conducted by weighting step-wise linear regression (SWR), while for the non-linear model is performed by using probabilistic neural networks (PNN). The estimated porosity, which is resulted by PNN shows better suited to the well log data compared with the results of SWR. This result can be understood since PNN perform non-linear regression so that the relationship between the attribute data and predicted log data can be optimized. The distribution of chalk sand has been successfully identified and characterized by porosity value ranging from 23% up to 30%.
Periodontitis in coronary heart disease patients: strong association between bleeding on probing and systemic biomarkers.

PubMed

Bokhari, Syed Akhtar H; Khan, Ayyaz A; Butt, Arshad K; Hanif, Mohammad; Izhar, Mateen; Tatakis, Dimitris N; Ashfaq, Mohammad

2014-11-01

Few studies have examined the relationship of individual periodontal parameters with individual systemic biomarkers. This study assessed the possible association between specific clinical parameters of periodontitis and systemic biomarkers of coronary heart disease risk in coronary heart disease patients with periodontitis. Angiographically proven coronary heart disease patients with periodontitis (n = 317), aged >30 years and without other systemic illness were examined. Periodontal clinical parameters of bleeding on probing (BOP), probing depth (PD), and clinical attachment level (CAL) and systemic levels of high-sensitivity C-reactive protein (CRP), fibrinogen (FIB) and white blood cells (WBC) were noted and analyzed to identify associations through linear and stepwise multiple regression analyses. Unadjusted linear regression showed significant associations between periodontal and systemic parameters; the strongest association (r = 0.629; p < 0.001) was found between BOP and CRP levels, the periodontal and systemic inflammation marker, respectively. Stepwise regression analysis models revealed that BOP was a predictor of systemic CRP levels (p < 0.0001). BOP was the only periodontal parameter significantly associated with each systemic parameter (CRP, FIB, and WBC). In coronary heart disease patients with periodontitis, BOP is strongly associated with systemic CRP levels; this association possibly reflects the potential significance of the local periodontal inflammatory burden for systemic inflammation. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Joint effect of unlinked genotypes: application to type 2 diabetes in the EPIC-Potsdam case-cohort study.

PubMed

Knüppel, Sven; Meidtner, Karina; Arregui, Maria; Holzhütter, Hermann-Georg; Boeing, Heiner

2015-07-01

Analyzing multiple single nucleotide polymorphisms (SNPs) is a promising approach to finding genetic effects beyond single-locus associations. We proposed the use of multilocus stepwise regression (MSR) to screen for allele combinations as a method to model joint effects, and compared the results with the often used genetic risk score (GRS), conventional stepwise selection, and the shrinkage method LASSO. In contrast to MSR, the GRS, conventional stepwise selection, and LASSO model each genotype by the risk allele doses. We reanalyzed 20 unlinked SNPs related to type 2 diabetes (T2D) in the EPIC-Potsdam case-cohort study (760 cases, 2193 noncases). No SNP-SNP interactions and no nonlinear effects were found. Two SNP combinations selected by MSR (Nagelkerke's R² = 0.050 and 0.048) included eight SNPs with mean allele combination frequency of 2%. GRS and stepwise selection selected nearly the same SNP combinations consisting of 12 and 13 SNPs (Nagelkerke's R² ranged from 0.020 to 0.029). LASSO showed similar results. The MSR method showed the best model fit measured by Nagelkerke's R² suggesting that further improvement may render this method a useful tool in genetic research. However, our comparison suggests that the GRS is a simple way to model genetic effects since it does not consider linkage, SNP-SNP interactions, and no non-linear effects. © 2015 John Wiley & Sons Ltd/University College London.
Multivariate regression model for predicting lumber grade volumes of northern red oak sawlogs

Treesearch

Daniel A. Yaussy; Robert L. Brisbin

1983-01-01

A multivariate regression model was developed to predict green board-foot yields for the seven common factory lumber grades processed from northern red oak (Quercus rubra L.) factory grade logs. The model uses the standard log measurements of grade, scaling diameter, length, and percent defect. It was validated with an independent data set. The model...
Predictive and mechanistic multivariate linear regression models for reaction development

PubMed Central

Santiago, Celine B.; Guo, Jing-Yao

2018-01-01

Multivariate Linear Regression (MLR) models utilizing computationally-derived and empirically-derived physical organic molecular descriptors are described in this review. Several reports demonstrating the effectiveness of this methodological approach towards reaction optimization and mechanistic interrogation are discussed. A detailed protocol to access quantitative and predictive MLR models is provided as a guide for model development and parameter analysis. PMID:29719711
Multivariate regression model for predicting yields of grade lumber from yellow birch sawlogs

Treesearch

Andrew F. Howard; Daniel A. Yaussy

1986-01-01

A multivariate regression model was developed to predict green board-foot yields for the common grades of factory lumber processed from yellow birch factory-grade logs. The model incorporates the standard log measurements of scaling diameter, length, proportion of scalable defects, and the assigned USDA Forest Service log grade. Differences in yields between band and...
G/SPLINES: A hybrid of Friedman's Multivariate Adaptive Regression Splines (MARS) algorithm with Holland's genetic algorithm

NASA Technical Reports Server (NTRS)

Rogers, David

1991-01-01

G/SPLINES are a hybrid of Friedman's Multivariable Adaptive Regression Splines (MARS) algorithm with Holland's Genetic Algorithm. In this hybrid, the incremental search is replaced by a genetic search. The G/SPLINE algorithm exhibits performance comparable to that of the MARS algorithm, requires fewer least squares computations, and allows significantly larger problems to be considered.
Validation of cross-sectional time series and multivariate adaptive regression splines models for the prediction of energy expenditure in children and adolescents using doubly labeled water

USDA-ARS?s Scientific Manuscript database

Accurate, nonintrusive, and inexpensive techniques are needed to measure energy expenditure (EE) in free-living populations. Our primary aim in this study was to validate cross-sectional time series (CSTS) and multivariate adaptive regression splines (MARS) models based on observable participant cha...
DOE Office of Scientific and Technical Information (OSTI.GOV)

Tang, Kunkun, E-mail: ktg@illinois.edu; Inria Bordeaux – Sud-Ouest, Team Cardamom, 200 avenue de la Vieille Tour, 33405 Talence; Congedo, Pietro M.

The Polynomial Dimensional Decomposition (PDD) is employed in this work for the global sensitivity analysis and uncertainty quantification (UQ) of stochastic systems subject to a moderate to large number of input random variables. Due to the intimate connection between the PDD and the Analysis of Variance (ANOVA) approaches, PDD is able to provide a simpler and more direct evaluation of the Sobol' sensitivity indices, when compared to the Polynomial Chaos expansion (PC). Unfortunately, the number of PDD terms grows exponentially with respect to the size of the input random vector, which makes the computational cost of standard methods unaffordable formore » real engineering applications. In order to address the problem of the curse of dimensionality, this work proposes essentially variance-based adaptive strategies aiming to build a cheap meta-model (i.e. surrogate model) by employing the sparse PDD approach with its coefficients computed by regression. Three levels of adaptivity are carried out in this paper: 1) the truncated dimensionality for ANOVA component functions, 2) the active dimension technique especially for second- and higher-order parameter interactions, and 3) the stepwise regression approach designed to retain only the most influential polynomials in the PDD expansion. During this adaptive procedure featuring stepwise regressions, the surrogate model representation keeps containing few terms, so that the cost to resolve repeatedly the linear systems of the least-squares regression problem is negligible. The size of the finally obtained sparse PDD representation is much smaller than the one of the full expansion, since only significant terms are eventually retained. Consequently, a much smaller number of calls to the deterministic model is required to compute the final PDD coefficients.« less
Analytical framework for reconstructing heterogeneous environmental variables from mammal community structure.

PubMed

Louys, Julien; Meloro, Carlo; Elton, Sarah; Ditchfield, Peter; Bishop, Laura C

2015-01-01

We test the performance of two models that use mammalian communities to reconstruct multivariate palaeoenvironments. While both models exploit the correlation between mammal communities (defined in terms of functional groups) and arboreal heterogeneity, the first uses a multiple multivariate regression of community structure and arboreal heterogeneity, while the second uses a linear regression of the principal components of each ecospace. The success of these methods means the palaeoenvironment of a particular locality can be reconstructed in terms of the proportions of heavy, moderate, light, and absent tree canopy cover. The linear regression is less biased, and more precisely and accurately reconstructs heavy tree canopy cover than the multiple multivariate model. However, the multiple multivariate model performs better than the linear regression for all other canopy cover categories. Both models consistently perform better than randomly generated reconstructions. We apply both models to the palaeocommunity of the Upper Laetolil Beds, Tanzania. Our reconstructions indicate that there was very little heavy tree cover at this site (likely less than 10%), with the palaeo-landscape instead comprising a mixture of light and absent tree cover. These reconstructions help resolve the previous conflicting palaeoecological reconstructions made for this site. Copyright © 2014 Elsevier Ltd. All rights reserved.
Higher-order Multivariable Polynomial Regression to Estimate Human Affective States

NASA Astrophysics Data System (ADS)

Wei, Jie; Chen, Tong; Liu, Guangyuan; Yang, Jiemin

2016-03-01

From direct observations, facial, vocal, gestural, physiological, and central nervous signals, estimating human affective states through computational models such as multivariate linear-regression analysis, support vector regression, and artificial neural network, have been proposed in the past decade. In these models, linear models are generally lack of precision because of ignoring intrinsic nonlinearities of complex psychophysiological processes; and nonlinear models commonly adopt complicated algorithms. To improve accuracy and simplify model, we introduce a new computational modeling method named as higher-order multivariable polynomial regression to estimate human affective states. The study employs standardized pictures in the International Affective Picture System to induce thirty subjects’ affective states, and obtains pure affective patterns of skin conductance as input variables to the higher-order multivariable polynomial model for predicting affective valence and arousal. Experimental results show that our method is able to obtain efficient correlation coefficients of 0.98 and 0.96 for estimation of affective valence and arousal, respectively. Moreover, the method may provide certain indirect evidences that valence and arousal have their brain’s motivational circuit origins. Thus, the proposed method can serve as a novel one for efficiently estimating human affective states.
Higher-order Multivariable Polynomial Regression to Estimate Human Affective States

PubMed Central

Wei, Jie; Chen, Tong; Liu, Guangyuan; Yang, Jiemin

2016-01-01

From direct observations, facial, vocal, gestural, physiological, and central nervous signals, estimating human affective states through computational models such as multivariate linear-regression analysis, support vector regression, and artificial neural network, have been proposed in the past decade. In these models, linear models are generally lack of precision because of ignoring intrinsic nonlinearities of complex psychophysiological processes; and nonlinear models commonly adopt complicated algorithms. To improve accuracy and simplify model, we introduce a new computational modeling method named as higher-order multivariable polynomial regression to estimate human affective states. The study employs standardized pictures in the International Affective Picture System to induce thirty subjects’ affective states, and obtains pure affective patterns of skin conductance as input variables to the higher-order multivariable polynomial model for predicting affective valence and arousal. Experimental results show that our method is able to obtain efficient correlation coefficients of 0.98 and 0.96 for estimation of affective valence and arousal, respectively. Moreover, the method may provide certain indirect evidences that valence and arousal have their brain’s motivational circuit origins. Thus, the proposed method can serve as a novel one for efficiently estimating human affective states. PMID:26996254
[Satellite remote sensing retrieval of canopy nitrogen nutritional status of apple trees at blossom stage].

PubMed

Wang, Ling; Zhao, Geng-Xing; Zhu, Xi-Cun; Wang, Rui-Yan; Chang, Chun-Yan

2013-10-01

Taking Qixia City of Shandong, China as the study area, and based on the Landsat-5 TM and ALOS AVNIR-2 images, the canopy retrieval reflectance of apple trees at blossom stage was acquired. In combining with the measured reflectance of sample trees, the nitrogen-sensitive spectral indices were constructed and selected. By using the sensitive spectral indices as the independent variables, the nitrogen retrieval models were established, and the model with the best accuracy was used for spatial retrieve. The correlations between the spectral indices and the nitrogen nutritional status were in the order of canopy > leaf > flower. The sensitive indices were mainly composed of green, red, and near infrared bands. The accuracy of the retrieval models was in the order of support vector regression > multi-variable stepwise regression > one-variable regression. The retrieval results based on different images were similar, and showed that the leaf nitrogen content was mainly of grades 3-4 (27-33 g x kg(-1)), and the canopy nitrogen nutrient indices were mainly of grades 2-4 (TM: 38-47 g x kg(-1); ALOS: 32-41 g x kg(-1)). The spatial distribution of the retrieval nitrogen nutritional status based on different images also showed the similar trend, i. e., the nitrogen nutritional status was higher in the north and south than that in the middle part of the study area, and the areas with the high grades of leaf nitrogen and canopy nitrogen were mainly located in Sujiadian Town and Songshan subdistrict in the northwest, Zangjiazhuang Town and Tingkou Town in the northeast, and Shewopo Town in the south, which were consistent with the distribution of the key towns for apple production in Qixia City. This study provided a feasible method for the acquisition of nitrogen nutritional status of apple trees on macroscopic scale, and also, provided reference for other similar remote sensing retrievals.

Care burden and its predictive factors in parents of newly diagnosed children with acute lymphoblastic leukemia in academic hospitals in China.

PubMed

Wang, Jingting; Shen, Nanping; Zhang, Xiaoyan; Shen, Min; Xie, Anwei; Howell, Doris; Yuan, Changrong

2017-12-01

Caring for children with acute lymphoblastic leukemia (ALL) is a distressing experience for parents without medical training. The experience can lead to parents' care burden. This study explored care burden among parents of children with ALL and its related factors. A total of 130 parents were surveyed with the Zarit Burden Inventory (ZBI), Perceived Social Support Scale (PSSS), Zung's Self-rating Anxiety Scale (SAS), Zung's Self-rating Depression Scale (SDS), Medical Outcome Study Short Form 36 (SF-36), and a study specific demographic information questionnaire. Independent-samples T test, one-way ANOVA, Pearson correlation analysis and multivariate linear regression analysis (stepwise method), and binomial logistic regression were used in data analysis. The mean score of parents' care burden overall was 37.74 ± 16.57, 17 (13.08%) had little or no burden, 57 (43.85%) had mild-to-moderate burden, 44 (33.84%) had moderate-to-severe burden, and 12 (9.23%) had severe burden. Regression analyses indicated daily care time, anxiety, general health, average monthly family income, social support, and number of co-caregivers were factors associated with care burden. These variables accounted for 51% of the variance in care burden. Other demographic information of parents and children, depression, and other dimensions of SF-36 were not related to care burden. The severe burden level was associated the increase risk of emotional distress compared with little or no burden group (OR = 37.500, 95% CI = 4.515-311.348, P = 0.001). The results indicated that care burden in parents of children newly diagnosed with ALL is high. Parents with lower levels of care burden tend to have less daily care time, more co-caregivers, higher income, less anxiety, better general health, and social support. Strategies are needed to help reduce parents' care burden.
Regression Models For Multivariate Count Data

PubMed Central

Zhang, Yiwen; Zhou, Hua; Zhou, Jin; Sun, Wei

2016-01-01

Data with multivariate count responses frequently occur in modern applications. The commonly used multinomial-logit model is limiting due to its restrictive mean-variance structure. For instance, analyzing count data from the recent RNA-seq technology by the multinomial-logit model leads to serious errors in hypothesis testing. The ubiquity of over-dispersion and complicated correlation structures among multivariate counts calls for more flexible regression models. In this article, we study some generalized linear models that incorporate various correlation structures among the counts. Current literature lacks a treatment of these models, partly due to the fact that they do not belong to the natural exponential family. We study the estimation, testing, and variable selection for these models in a unifying framework. The regression models are compared on both synthetic and real RNA-seq data. PMID:28348500
Regression Models For Multivariate Count Data.

PubMed

Zhang, Yiwen; Zhou, Hua; Zhou, Jin; Sun, Wei

2017-01-01

Data with multivariate count responses frequently occur in modern applications. The commonly used multinomial-logit model is limiting due to its restrictive mean-variance structure. For instance, analyzing count data from the recent RNA-seq technology by the multinomial-logit model leads to serious errors in hypothesis testing. The ubiquity of over-dispersion and complicated correlation structures among multivariate counts calls for more flexible regression models. In this article, we study some generalized linear models that incorporate various correlation structures among the counts. Current literature lacks a treatment of these models, partly due to the fact that they do not belong to the natural exponential family. We study the estimation, testing, and variable selection for these models in a unifying framework. The regression models are compared on both synthetic and real RNA-seq data.
Association between childhood atopic dermatitis, malnutrition, and low bone mineral density: a US population-based study.

PubMed

Silverberg, Jonathan I

2015-02-01

Children with atopic dermatitis (AD) have multiple risk factors for low bone mineral density (BMD). We analyzed data from 3049 children and adolescents aged 8-19 yrs from the 2005-2006 National Health and Nutrition Examination Survey, including a cross-sectional questionnaire, dual energy X-ray absorptiometry, and blood samples. In multivariate models that controlled for age, sex, race/ethnicity, level of education and household income, body mass index (BMI), and smoking in the household, AD was associated with lower BMD z-score for the total femur (survey linear regression; adjusted β [95% CI]: -0.42 [0.68, -0.16]), including trochanter (-0.29 [-0.54, -0.05]) and femoral neck (-0.29 [-0.53, -0.05]) and total lumbar spine (-0.31 [-0.52, -0.11]). Children with AD had higher median levels of serum IgE (110.0 vs. 53.0 kU/l), peripheral lymphocyte (2.9 vs. 2.5 × 10(3) cells/μl), and eosinophil counts (0.3 vs. 0.2 × 10(3) cells/μl) (Mann-Whitney U-test, p ≤ 0.003 for all), but not CRP levels (0.03 vs. 0.04 mg/dl) and higher odds of 25-OH vitamin D deficiency (survey logistic regression; odds ratio [OR] [95% CI]: 4.81 [1.21, 20.81]), low calcium (2.56 [1.24, 5.28]), low alkaline phosphatase (2.56 [1.20, 5.44]), and higher tertiles of LDH (tertile 2: 6.36 [1.75, 23.18]; tertile-3: 4.57 [1.32, 15.85]), but not parathyroid hormone (PTH) or albumin. Finally, children with AD had higher rates of low BMD, that is, BMD z-score <-2, of the femur (23.4% vs. 18.4%) and spine (35.3% vs. 24.5%). In multivariate logistic regression models of low BMD of femur and/or spine using stepwise selection of the 30 sociodemographic and clinical factors, laboratory values, and medications used, AD remained a significant covariate (1.33 [1.32-1.34]). The covariates with the largest effects on low BMD were low PTH and albumin, higher basophil count, Hispanic ethnicity, and BMI <5th percentile. Among children with AD, 56.2% of those with Hispanic origin, 52.8% with BMI <5th percentile, 75.0% with low albumin, and 54.0% with low PTH had low BMD. Children with AD have lower BMD, particularly those with malnutrition and Hispanic ethnicity. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Risk stratification personalised model for prediction of life-threatening ventricular tachyarrhythmias in patients with chronic heart failure.

PubMed

Frolov, Alexander Vladimirovich; Vaikhanskaya, Tatjana Gennadjevna; Melnikova, Olga Petrovna; Vorobiev, Anatoly Pavlovich; Guel, Ludmila Michajlovna

2017-01-01

The development of prognostic factors of life-threatening ventricular tachyarrhythmias (VTA) and sudden cardiac death (SCD) continues to maintain its priority and relevance in cardiology. The development of a method of personalised prognosis based on multifactorial analysis of the risk factors associated with life-threatening heart rhythm disturbances is considered a key research and clinical task. To design a prognostic and mathematical model to define personalised risk for life-threatening VTA in patients with chronic heart failure (CHF). The study included 240 patients with CHF (mean-age of 50.5 ± 12.1 years; left ventricular ejection fraction 32.8 ± 10.9%; follow-up period 36.8 ± 5.7 months). The participants received basic therapy for heart failure. The elec-trocardiogram (ECG) markers of myocardial electrical instability were assessed including microvolt T-wave alternans, heart rate turbulence, heart rate deceleration, and QT dispersion. Additionally, echocardiography and Holter monitoring (HM) were performed. The cardiovascular events were considered as primary endpoints, including SCD, paroxysmal ventricular tachycardia/ventricular fibrillation (VT/VF) based on HM-ECG data, and data obtained from implantable device interrogation (CRT-D, ICD) as well as appropriated shocks. During the follow-up period, 66 (27.5%) subjects with CHF showed adverse arrhythmic events, including nine SCD events and 57 VTAs. Data from a stepwise discriminant analysis of cumulative ECG-markers of myocardial electrical instability were used to make a mathematical model of preliminary VTA risk stratification. Uni- and multivariate Cox logistic regression analysis were performed to define an individualised risk stratification model of SCD/VTA. A binary logistic regression model demonstrated a high prognostic significance of discriminant function with a classification sensitivity of 80.8% and specificity of 99.1% (F = 31.2; c2 = 143.2; p < 0.0001). The method of personalised risk stratification using Cox logistic regression allows correct classification of more than 93.9% of CHF cases. A robust body of evidence concerning logistic regression prognostic significance to define VTA risk allows inclusion of this method into the algorithm of subsequent control and selection of the optimal treatment modality to treat patients with CHF.
Assessing the response of area burned to changing climate in western boreal North America using a Multivariate Adaptive Regression Splines (MARS) approach

Treesearch

Michael S. Balshi; A. David McGuire; Paul Duffy; Mike Flannigan; John Walsh; Jerry Melillo

2009-01-01

We developed temporally and spatially explicit relationships between air temperature and fuel moisture codes derived from the Canadian Fire Weather Index System to estimate annual area burned at 2.5o (latitude x longitude) resolution using a Multivariate Adaptive Regression Spline (MARS) approach across Alaska and Canada. Burned area was...
Predictors of Global Self-Worth and Academic Performance among Regular Education, Learning Disabled, and Continuation High School Students.

ERIC Educational Resources Information Center

Wiest, Dudley J.; Wong, Eugene H.; Kreil, Dennis A.

1998-01-01

The ability of measures of perceived competence, control, and autonomy support to predict self-worth and academic performance was studied across groups of high school students. Stepwise regression analyses indicate these variables in model predict self-worth and grade point average. In addition, levels of school status and depression predict…
Tailoring Multimedia Instruction to Soldier Needs

DTIC Science & Technology

2014-12-01

Pretest Score (Mean % Items Correct) 39% 34% 48% 51% 51% 45% Posttest (Mean % Items Correct) 47% 44% 66% 60% 63% 56...Stepwise regression was used to examine the relationship between Soldiers’ posttest scores (criterion) and their pretest scores, training time, type of...differences among IMI types had no effect.) Pretest scores predicted posttest scores for both Adjust Indirect Fire (βstandardized = .66, t = 6.36
The Effect of College Selection Factors on Persistence: An Examination of Black and Latino Males in the Community College

ERIC Educational Resources Information Center

Wood, J. Luke; Harris, Frank, III

2015-01-01

The purpose of this study was to understand the relationship (if any) between college selection factors and persistence for Black and Latino males in the community college. Using data derived from the Educational Longitudinal Study, backwards stepwise logistic regression models were developed for both groups. Findings are contextualized in light…
Factors influencing storm-generated suspended-sediment concentrations and loads in four basins of contrasting land use, humid-tropical Puerto Rico

Treesearch

A. C. Gellis; NO-VALUE

2013-01-01

The significant characteristics controlling the variability in storm-generated suspended-sediment loads and concentrations were analyzed for four basins of differing land use (forest, pasture, cropland, and urbanizing) in humid-tropical Puerto Rico. Statistical analysis involved stepwise regression on factor scores. The explanatory variables were attributes of flow,...
Illuminating Tradespace Decisions Using Efficient Experimental Space-Filling Designs for the Engineered Resilient System Architecture

DTIC Science & Technology

2015-06-30

7. Building Statistical Metamodels using Simulation Experimental Designs ............................................... 34 7.1. Statistical Design...system design drivers across several different domain models, our methodology uses statistical metamodeling to approximate the simulations’ behavior. A...output. We build metamodels using a number of statistical methods that include stepwise regression, boosted trees, neural nets, and bootstrap forest
Illuminating Tradespace Decisions Using Efficient Experimental Space-Filling Designs for the Engineered Resilient System Architecture

DTIC Science & Technology

2015-06-01

7. Building Statistical Metamodels using Simulation Experimental Designs ............................................... 34 7.1. Statistical Design...system design drivers across several different domain models, our methodology uses statistical metamodeling to approximate the simulations’ behavior. A...output. We build metamodels using a number of statistical methods that include stepwise regression, boosted trees, neural nets, and bootstrap forest
Analysis of oscillatory motion of a light airplane at high values of lift coefficient

NASA Technical Reports Server (NTRS)

Batterson, J. G.

1983-01-01

A modified stepwise regression is applied to flight data from a light research air-plane operating at high angles at attack. The well-known phenomenon referred to as buckling or porpoising is analyzed and modeled using both power series and spline expansions of the aerodynamic force and moment coefficients associated with the longitudinal equations of motion.
"Hits" (Not "Discussion Posts") Predict Student Success in Online Courses: A Double Cross-Validation Study

ERIC Educational Resources Information Center

Ramos, Cheryl; Yudko, Errol

2008-01-01

The efficacy of individual components of an online course on positive course outcome was examined via stepwise multiple regression analysis. Outcome was measured as the student's total score on all exams given during the course. The predictors were page hits, discussion posts, and discussion reads. The vast majority of the variance of outcome was…
Factors Associated with Level of Living in Washington County, Mississippi. Technical Bulletin No. 1501.

ERIC Educational Resources Information Center

McCoy, John L.

Step-wise multiple regression and typological analysis were used to analyze the extent to which selected factors influence vertical mobility and achieved level of living. A sample of 418 male household heads who were 18 to 45 years old in Washington County, Mississippi were interviewed during 1971. A prescreening using census and local housing…
The Role of Perceived Learning and Communities of Inquiry in Predicting International Students' Course Grades in Computer-Mediated Graduate Courses

ERIC Educational Resources Information Center

Wendt, Jillian L.; Nisbet, Deanna L.

2017-01-01

This study examined the predictive relationship among international students' sense of community, perceived learning, and end-of-course grades in computer-mediated, U.S. graduate-level courses. The community of inquiry (CoI) framework served as the theoretical foundation for the study. Step-wise hierarchical multiple regression showed no…
Assessment of weather-associated causes of red spruce winter injury and consequences to aboveground carbon sequestration

Treesearch

Paul G. Schaberg; Brynne E. Lazarus; Gary J. Hawley; Joshua M. Halman; Catherine H. Borer; Christopher F. Hansen

2011-01-01

Despite considerable study, it remains uncertain what environmental factors contribute to red spruce (Picea rubens Sarg.) foliar winter injury and how much this injury influences tree C stores. We used a long-term record of winter injury in a plantation in New Hampshire and conducted stepwise linear regression analyses with local weather and regional...
Assessment of plant species diversity based on hyperspectral indices at a fine scale.

PubMed

Peng, Yu; Fan, Min; Song, Jingyi; Cui, Tiantian; Li, Rui

2018-03-19

Fast and nondestructive approaches of measuring plant species diversity have been a subject of excessive scientific curiosity and disquiet to environmentalists and field ecologists worldwide. In this study, we measured the hyperspectral reflectances and plant species diversity indices at a fine scale (0.8 meter) in central Hunshandak Sandland of Inner Mongolia, China. The first-order derivative value (FD) at each waveband and 37 hyperspectral indices were used to assess plant species diversity. Results demonstrated that the stepwise linear regression of FD can accurately estimate the Simpson (R 2 = 0.83), Pielou (R 2 = 0.87) and Shannon-Wiener index (R 2 = 0.88). Stepwise linear regression of FD (R 2 = 0.81, R 2 = 0.82) and spectral vegetation indices (R 2 = 0.51, R 2 = 0.58) significantly predicted the Margalef and Gleason index. It was proposed that the Simpson, Pielou and Shannon-Wiener indices, which are widely used as plant species diversity indicators, can be precisely estimated through hyperspectral indices at a fine scale. This research promotes the development of methods for assessment of plant diversity using hyperspectral data.
Comparison of bioavailable vanadium in alfalfa rhizosphere soil extracted by an improved BCR procedure and EDTA, HCl, and NaNO₃ single extractions in a pot experiment with V-Cd treatments.

PubMed

Yang, Jie; Teng, Yanguo; Zuo, Rui; Song, Liuting

2015-06-01

The BCR sequential extraction procedure was compared with EDTA, HCl, and NaNO3 single extractions for evaluating vanadium bioavailability in alfalfa rhizosphere soil. The amounts of vanadium extracted by these methods were in the following order: BCR (bioavailable V) > EDTA ≈ HCl > NaNO3. Both correlation analysis and stepwise regression were adopted to illustrate the extractable vanadium between different reagents. The correlation coefficients between extracted vanadium and the vanadium contents in alfalfa roots were R NaNO3 = 0.948, R HCl = 0.902, R EDTA = 0.816, and R bioavailable V = 0.819. The stepwise multiple regression equation of the NaNO3 extraction was the most significant at a 95 % confidence interval. The influence of pH, total organic carbon, and cadmium content of soil to vanadium bioavailability were not definite. In summary, both the BCR sequential extraction and the single extraction methods were valid approaches for predicting vanadium bioavailability in alfalfa rhizosphere soil, especially the single extractions.
Environmental influences on alcohol consumption practices of alcoholic beverage servers.

PubMed

Nusbaumer, Michael R; Reiling, Denise M

2002-11-01

Public drinking establishments have long been associated with heavy drinking among both their patrons and servers. Whether these environments represent locations where heavy drinking is learned (learning hypothesis) or simply places where already-heavy drinkers gather in a supportive environment (selection hypothesis) remains an important question. A sample of licensed alcoholic beverage servers in the state of Indiana, USA, was surveyed to better understand the drinking behaviors of servers within the alcohol service industry. Responses (N = 938) to a mailed questionnaire were analyzed to assess the relative influence of environmental and demographic factors on the drinking behavior of servers. Stepwise regression revealed "drinking on the job" as the most influential environmental factor on heavy drinking behaviors, followed by age and gender as influential demographic factors. Support was found for the selection hypothesis, but not for the learning hypothesis. Policy implications are discussed. factors on the drinking behavior of servers. Stepwise regression revealed "drinking on the job" as the most influential environmental factor on heavy drinking behaviors, followed by age and gender as influential demographic factors. Support was found for the selection hypothesis, but not for the learning hypothesis. Policy implications are discussed.

Handheld Tissue Hardness Meters for Assessing the Mechanical Properties of Skeletal Muscle: A Feasibility Study.

PubMed

Chino, Kentaro; Takahashi, Hideyuki

2016-09-01

The purpose of this study was to examine the feasibility of using handheld tissue hardness meters to assess the mechanical properties of skeletal muscle. This observational study included 33 healthy men (age, 22.4 ± 4.4 years) and 33 healthy women (age, 23.7 ± 4.2 years). Participants were placed in a supine position, and tissue hardness overlying the rectus femoris and the shear modulus of the muscle were measured on the right side of the body at 50% thigh length. In the same position, subcutaneous adipose tissue thickness and muscle thickness were measured using B-mode ultrasonography. To examine the associations of subcutaneous adipose tissue thickness, muscle thickness, and muscle shear modulus with tissue hardness, linear regression using a stepwise bidirectional elimination approach was performed. Stepwise linear regression revealed that subcutaneous adipose tissue thickness (r = -0.38, P = .002) and muscle shear modulus (r = 0.27, P = .03) were significantly associated with tissue hardness. Significant associations among adipose tissue thickness, muscle shear modulus, and tissue hardness show the limitations and feasibility of handheld tissue hardness meters for assessing the mechanical properties of skeletal muscles. Copyright © 2016. Published by Elsevier Inc.
Satisfaction among early and mid-career dentists in a metropolitan dental hospital in China

PubMed Central

Cui, Xiaoxi; Dunning, David G; An, Na

2017-01-01

A growing body of research has examined career satisfaction among dentists using a standardized instrument, dentist satisfaction survey (DSS). This project examined career satisfaction of early to mid-career dentists in China, a population whose career satisfaction, heretofore, has not been studied. This is an especially critical time to examine career satisfaction because of health care reform measures being implemented in China. A culturally sensitive Chinese-language version of the DSS (CDSS) was developed and electronically administered to 367 early and mid-career dentists in a tertiary dental hospital in Beijing, China. One hundred and seventy respondents completed the survey. The average total career score was 123, with a range of 82–157. Data analysis showed some significant differences in total career score and several subscales based on gender, working hours per week, and years in practice. A stepwise regression model revealed that two variables predicted total career score: working hours per week and gender. Stepwise regression also demonstrated that four subscales significantly predicted the overall professional satisfaction subscale score: respect, delivery of care, income and patient relations. Implications of these results are discussed in light of the health care delivery system and dentist career paths in China. PMID:29355243
Satisfaction among early and mid-career dentists in a metropolitan dental hospital in China.

PubMed

Cui, Xiaoxi; Dunning, David G; An, Na

2017-01-01

A growing body of research has examined career satisfaction among dentists using a standardized instrument, dentist satisfaction survey (DSS). This project examined career satisfaction of early to mid-career dentists in China, a population whose career satisfaction, heretofore, has not been studied. This is an especially critical time to examine career satisfaction because of health care reform measures being implemented in China. A culturally sensitive Chinese-language version of the DSS (CDSS) was developed and electronically administered to 367 early and mid-career dentists in a tertiary dental hospital in Beijing, China. One hundred and seventy respondents completed the survey. The average total career score was 123, with a range of 82-157. Data analysis showed some significant differences in total career score and several subscales based on gender, working hours per week, and years in practice. A stepwise regression model revealed that two variables predicted total career score: working hours per week and gender. Stepwise regression also demonstrated that four subscales significantly predicted the overall professional satisfaction subscale score: respect, delivery of care, income and patient relations. Implications of these results are discussed in light of the health care delivery system and dentist career paths in China.
Improving Prediction Accuracy for WSN Data Reduction by Applying Multivariate Spatio-Temporal Correlation

PubMed Central

Carvalho, Carlos; Gomes, Danielo G.; Agoulmine, Nazim; de Souza, José Neuman

2011-01-01

This paper proposes a method based on multivariate spatial and temporal correlation to improve prediction accuracy in data reduction for Wireless Sensor Networks (WSN). Prediction of data not sent to the sink node is a technique used to save energy in WSNs by reducing the amount of data traffic. However, it may not be very accurate. Simulations were made involving simple linear regression and multiple linear regression functions to assess the performance of the proposed method. The results show a higher correlation between gathered inputs when compared to time, which is an independent variable widely used for prediction and forecasting. Prediction accuracy is lower when simple linear regression is used, whereas multiple linear regression is the most accurate one. In addition to that, our proposal outperforms some current solutions by about 50% in humidity prediction and 21% in light prediction. To the best of our knowledge, we believe that we are probably the first to address prediction based on multivariate correlation for WSN data reduction. PMID:22346626
Characterizing multivariate decoding models based on correlated EEG spectral features

PubMed Central

McFarland, Dennis J.

2013-01-01

Objective Multivariate decoding methods are popular techniques for analysis of neurophysiological data. The present study explored potential interpretative problems with these techniques when predictors are correlated. Methods Data from sensorimotor rhythm-based cursor control experiments was analyzed offline with linear univariate and multivariate models. Features were derived from autoregressive (AR) spectral analysis of varying model order which produced predictors that varied in their degree of correlation (i.e., multicollinearity). Results The use of multivariate regression models resulted in much better prediction of target position as compared to univariate regression models. However, with lower order AR features interpretation of the spectral patterns of the weights was difficult. This is likely to be due to the high degree of multicollinearity present with lower order AR features. Conclusions Care should be exercised when interpreting the pattern of weights of multivariate models with correlated predictors. Comparison with univariate statistics is advisable. Significance While multivariate decoding algorithms are very useful for prediction their utility for interpretation may be limited when predictors are correlated. PMID:23466267
Early and late fracture following extensive limb lengthening in patients with achondroplasia and hypochondroplasia.

PubMed

Kitoh, H; Mishima, K; Matsushita, M; Nishida, Y; Ishiguro, N

2014-09-01

Two types of fracture, early and late, have been reported following limb lengthening in patients with achondroplasia (ACH) and hypochondroplasia (HCH). We reviewed 25 patients with these conditions who underwent 72 segmental limb lengthening procedures involving the femur and/or tibia, between 2003 and 2011. Gender, age at surgery, lengthened segment, body mass index, the shape of the callus, the amount and percentage of lengthening and the healing index were evaluated to determine predictive factors for the occurrence of early (within three weeks after removal of the fixation pins) and late fracture (> three weeks after removal of the pins). The Mann‑Whitney U test and Pearson's chi-squared test for univariate analysis and stepwise regression model for multivariate analysis were used to identify the predictive factor for each fracture. Only one patient (two tibiae) was excluded from the analysis due to excessively slow formation of the regenerate, which required supplementary measures. A total of 24 patients with 70 limbs were included in the study. There were 11 early fractures in eight patients. The shape of the callus (lateral or central callus) was the only statistical variable related to the occurrence of early fracture in univariate and multivariate analyses. Late fracture was observed in six limbs and the mean time between removal of the fixation pins and fracture was 18.3 weeks (3.3 to 38.4). Lengthening of the tibia, larger healing index, and lateral or central callus were related to the occurrence of a late fracture in univariate analysis. A multivariate analysis demonstrated that the shape of the callus was the strongest predictor for late fracture (odds ratio: 19.3, 95% confidence interval: 2.91 to 128). Lateral or central callus had a significantly larger risk of fracture than fusiform, cylindrical, or concave callus. Radiological monitoring of the shape of the callus during distraction is important to prevent early and late fracture of lengthened limbs in patients with ACH or HCH. In patients with thin callus formation, some measures to stimulate bone formation should be considered as early as possible. ©2014 The British Editorial Society of Bone & Joint Surgery.
Impact of livestock Scale on Rice Production in Battambang of Cambodia

NASA Astrophysics Data System (ADS)

Siek, D.; Xu, S. W.; Wyu; Ahmed, A.-G.

2017-10-01

Increasing the awareness of environmental protection especially in the rural regions is important as most the farmers reside in that region. Crop-livestock proudciton has proven in many ways to encourage environmental protection. This study analyzes among other factors the impacto of livestock scale on rice production. Two regressions: Ordinary Least Square (OLS) and stepwise regression was applied to investigate these interrelationship. The result stress of three factors encouraging livestock production namely size of farmland, scale of livestock and income acquired from other jobs. The study further provides recommends to the government based on the findings of the study.
Anthropometric Survey of US Army Personnel (1988): Correlation Coefficients and Regression Equations. Part 5. Stepwise and Standard Multiple Regression Tables

DTIC Science & Technology

1990-05-01

0.759 0.744 0.768 0.753 106 (THUMBBR) THUMB BREADTH -0.652 -0.673 -0.539 -0.663 217 (LIPLGTHH) LIP LENGTH HEADBOARD 0.017 0.019 0.020 51 (FTBRHOR) FOOT...DEPENDENT VARIABLE: (106) THUMB BREADTH (THUBBR) MODEL INDEPENDENT VARIABLE 1 2 3 4 5 INTERCEPT 6.621 5.016 6.267 5.697 4.528 59 (HANDCIRC) HAND...95 (SLLSPEL) SLEEVE LENGTH: SPINE-ELBOW -0.020 -0.019 -C.018 9 (BLFTCIRC) BALL OF FOOT CIRCUMFERENCE -0.032 -0.039 106 (THUMBBR) THUMB BREADTH 0.228
Relationship between COMLEX-USA scores and performance on the American Osteopathic Board of Emergency Medicine Part I certifying examination.

PubMed

Li, Feiming; Gimpel, John R; Arenson, Ethan; Song, Hao; Bates, Bruce P; Ludwin, Fredric

2014-04-01

Few studies have investigated how well scores from the Comprehensive Osteopathic Medical Licensing Examination-USA (COMLEX-USA) series predict resident outcomes, such as performance on board certification examinations. To determine how well COMLEX-USA predicts performance on the American Osteopathic Board of Emergency Medicine (AOBEM) Part I certification examination. The target study population was first-time examinees who took AOBEM Part I in 2011 and 2012 with matched performances on COMLEX-USA Level 1, Level 2-Cognitive Evaluation (CE), and Level 3. Pearson correlations were computed between AOBEM Part I first-attempt scores and COMLEX-USA performances to measure the association between these examinations. Stepwise linear regression analysis was conducted to predict AOBEM Part I scores by the 3 COMLEX-USA scores. An independent t test was conducted to compare mean COMLEX-USA performances between candidates who passed and who failed AOBEM Part I, and a stepwise logistic regression analysis was used to predict the log-odds of passing AOBEM Part I on the basis of COMLEX-USA scores. Scores from AOBEM Part I had the highest correlation with COMLEX-USA Level 3 scores (.57) and slightly lower correlation with COMLEX-USA Level 2-CE scores (.53). The lowest correlation was between AOBEM Part I and COMLEX-USA Level 1 scores (.47). According to the stepwise regression model, COMLEX-USA Level 1 and Level 2-CE scores, which residency programs often use as selection criteria, together explained 30% of variance in AOBEM Part I scores. Adding Level 3 scores explained 37% of variance. The independent t test indicated that the 397 examinees passing AOBEM Part I performed significantly better than the 54 examinees failing AOBEM Part I in all 3 COMLEX-USA levels (P<.001 for all 3 levels). The logistic regression model showed that COMLEX-USA Level 1 and Level 3 scores predicted the log-odds of passing AOBEM Part I (P=.03 and P<.001, respectively). The present study empirically supported the predictive and discriminant validities of the COMLEX-USA series in relation to the AOBEM Part I certification examination. Although residency programs may use COMLEX-USA Level 1 and Level 2-CE scores as partial criteria in selecting residents, Level 3 scores, though typically not available at the time of application, are actually the most statistically related to performances on AOBEM Part I.
Antidiabetic pharmacotherapy and anamnestic hypoglycemia in a large cohort of type 2 diabetic patients - an analysis of the DiaRegis registry

PubMed Central

2011-01-01

Background We aimed to identify predictors of anamnestic hypoglycaemia in type-2 diabetic patients on oral mono- or dual oral combination antidiabetic pharmacotherapy. Methods DiaRegis is a prospective registry in type-2 diabetic patients in primary care. Odds ratios (OR) with 95% confidence intervals were determined from univariate logistic regression. Using multivariate logistic regression analysis with stepwise backward selection at an alpha of 0.05 independent predictors of hypoglycaemia were determined. Results 3,808 patients had data on hypoglycaemia available (median age 65.9 years, 46.6% female). 10.8% had at least one anamnestic hypoglycaemic episode within the previous 12 months. Patients with hypoglycaemia received more sulfonylureas (OR 2.16; 95%CI 1.75-2.67) and less metformin (OR 0.64; 95%CI 0.50-0.82). On top of metformin, patients with thiazolidine (OR 0.50; 95%CI 0.28-0.89) and DPP-4 inhibitor use (OR 0.34; 95%CI 0.16-0.70) had a decreased risk for hypoglycaemia while it was again increased with sulfonylureas (OR 2.08; 95%CI 1.44-2.99). Age < 65 years was an independent predictor of a reduced hypoglycaemia incidence (OR 0.76; 95%CI 0.59-0.96), low HbA1c (OR 1.68; 95%CI 1.31-2.14), stroke/TIA (OR 1.72; 95%CI 1.08-2.72), heart failure (OR 1.77; 95%CI 1.28-2.45), and the use of sulfonylureas (OR 2.58; 95%CI 2.03-3.29) were independent predictors of increased risk. Conclusions The results indicate that the risk of hypoglycaemia might be substantially reduced by carefully selecting antidiabetic pharmacotherapy in patients with type-2 diabets in primary care. PMID:21756359
Insomnia, psychiatric disorders and suicidal ideation in a National Representative Sample of active Canadian Forces members.

PubMed

Richardson, J D; Thompson, A; King, L; Corbett, B; Shnaider, P; St Cyr, K; Nelson, C; Sareen, J; Elhai, J; Zamorski, M

2017-06-06

Past research on the association between insomnia and suicidal ideation (SI) has produced mixed findings. The current study explored the relationship between insomnia, SI, and past-year mental health status among a large Canadian Forces (CF) sample. Data was obtained from the 2013 Canadian Forces Mental Health Survey (CFMHS), and included a large representative sample of Canadian Regular Forces personnel (N = 6700). A series of univariate logistic regressions were conducted to test individual associations between past-year mental health status, insomnia, and potential confounds and SI. Mental health status included three groups: 0, 1, or two or more probable diagnoses of posttraumatic stress disorder (PTSD), major depressive disorder (MDD), generalized anxiety disorder (GAD), panic disorder (PD) and alcohol abuse/dependence. Stepwise multivariate logistic regression was used to assess the relationship between insomnia and SI with mental health status as a moderator. 40.8% of respondents reported experiencing insomnia. Both insomnia and number of mental health conditions incrementally increased the risk of SI. However, past-year mental health status was a significant moderator of this relationship, such that for CF personnel with either no (AOR = 1.61, 1.37-1.89) or only one past-year mental health condition (AOR = 1.39, 1.12-1.73), an incremental increase in insomnia was associated with an increased likelihood of SI. However, in personnel with two or more past-year mental health disorders, insomnia was no longer significantly associated with SI (AOR = 1.04, 0.81-1.33). Insomnia significantly increased the odds of SI, but only among individuals with no or one mental health condition. Findings highlight the importance of assessing insomnia among CF members in order to further suicide prevention efforts.
Sleep stage distribution in persons with mild traumatic brain injury: a polysomnographic study according to American Academy of Sleep Medicine standards.

PubMed

Mollayeva, Tatyana; Colantonio, Angela; Cassidy, J David; Vernich, Lee; Moineddin, Rahim; Shapiro, Colin M

2017-06-01

Sleep stage disruption in persons with mild traumatic brain injury (mTBI) has received little research attention. We examined deviations in sleep stage distribution in persons with mTBI relative to population age- and sex-specific normative data and the relationships between such deviations and brain injury-related, medical/psychiatric, and extrinsic factors. We conducted a cross-sectional polysomnographic investigation in 40 participants diagnosed with mTBI (mean age 47.54 ± 11.30 years; 56% males). At the time of investigation, participants underwent comprehensive clinical and neuroimaging examinations and one full-night polysomnographic study. We used the 2012 American Academy of Sleep Medicine recommendations for recording, scoring, and summarizing sleep stages. We compared participants' sleep stage data with normative data stratified by age and sex to yield z-scores for deviations from available population norms and then employed stepwise multiple regression analyses to determine the factors associated with the identified significant deviations. In patients with mTBI, the mean duration of nocturnal wakefulness was higher and consolidated sleep stage N2 and REM were lower than normal (p < 0.0001, p = 0.018, and p = 0.010, respectively). In multivariate regression analysis, several covariates accounted for the variance in the relative changes in sleep stage duration. No sex differences were observed in the mean proportion of non-REM or REM sleep. We observed longer relative nocturnal wakefulness and shorter relative N2 and REM sleep in patients with mTBI, and these outcomes were associated with potentially modifiable variables. Addressing disruptions in sleep architecture in patients with mTBI could improve their health status. Copyright © 2017 Elsevier B.V. All rights reserved.
Predicting Low Accrual in the National Cancer Institute’s Cooperative Group Clinical Trials

PubMed Central

Bennette, Caroline S.; Ramsey, Scott D.; McDermott, Cara L.; Carlson, Josh J.; Basu, Anirban; Veenstra, David L.

2016-01-01

Background: The extent to which trial-level factors differentially influence accrual to trials has not been comprehensively studied. Our objective was to evaluate the empirical relationship and predictive properties of putative risk factors for low accrual in the National Cancer Institute’s (NCI’s) Cooperative Group Program, now the National Clinical Trials Network (NCTN). Methods: Data from 787 phase II/III adult NCTN-sponsored trials launched between 2000 and 2011 were used to develop a logistic regression model to predict low accrual, defined as trials that closed with or were accruing at less than 50% of target; 46 trials opened between 2012 and 2013 were used for prospective validation. Candidate predictors were identified from a literature review and expert interviews; final predictors were selected using stepwise regression. Model performance was evaluated by calibration and discrimination via the area under the curve (AUC). All statistical tests were two-sided. Results: Eighteen percent (n = 145) of NCTN-sponsored trials closed with low accrual or were accruing at less than 50% of target three years or more after initiation. A multivariable model of twelve trial-level risk factors had good calibration and discrimination for predicting trials with low accrual (AUC in trials launched 2000–2011 = 0.739, 95% confidence interval [CI] = 0.696 to 0.783]; 2012–2013: AUC = 0.732, 95% CI = 0.547 to 0.917). Results were robust to different definitions of low accrual and predictor selection strategies. Conclusions: We identified multiple characteristics of NCTN-sponsored trials associated with low accrual, several of which have not been previously empirically described, and developed a prediction model that can provide a useful estimate of accrual risk based on these factors. Future work should assess the role of such prediction tools in trial design and prioritization decisions. PMID:26714555
Relationship between increased arterial stiffness and other markers of target organ damage.

PubMed

Rodilla, Enrique; Costa, José Antonio; Pérez-Lahiguera, Francisco; González, Carmen; Pascual, José María

2010-04-24

The purpose of the present study was to assess the relationship of arterial stiffness with other markers of target organ damage, and the clinical factors related to it. Cross-sectional study that included 208 (115 men) never treated hypertensive, non-diabetic patients (mean age, 49+/-12 years). In addition to a full clinical study, 24h ambulatory blood pressure (BP), and determination of left ventricular hypertrophy (LVH) and microalbuminuria were performed. Clinical arterial stiffness was assessed by carotid-femoral pulse wave velocity (PWV) obtained with applanation tonometry (SphygmoCor-System). PWV was 8.3 (7.3-9.9)m/s (median, interquartile range). Stepwise regression analysis revealed that age (beta=0.086, p<0.001), 24-h pulse pressure (beta=0.058, p<0.001), and low-density lipoprotein (LDL) cholesterol (beta=0.009, p<0.013) were independent determinants of PWV. PWV>12m/s (indicating target organ lesion) was present in only 16 (7.7%) patients, less frequent than LVH (28% of the patients) and microalbuminuria (16%). However, of the 16 patients with elevated PWV, 10 (62%) had neither LVH or microalbuminuria. In a logistic multivariate regression analysis the factors related to elevated PWV were age > or =45 in man and > or =55 in women (OR: 23.8, 95% CI: 2.7-195.5; p=0.004), LDL cholesterol > or =160mg/dl (OR: 10.6, 95% CI: 2.6-42.7; p=0.001) and increased 24-h pulse pressure > or =55mmHg (OR: 3.9, 95% CI: 1.2-12.9; p=0.03). In untreated middle age hypertensives arterial stiffness assessed by PWV is less frequent than LVH or microalbuminuria. PWV is mainly related to age, LDL cholesterol, and pulse pressure values. 2009 Elsevier España, S.L. All rights reserved.
Frequent condom use with casual partners varies by sexual position among younger gay and bisexual men in New Zealand: national behavioural surveillance 2006-2011.

PubMed

Lachowsky, Nathan J; Saxton, Peter J W; Hughes, Anthony J; Dickson, Nigel P; Milhausen, Robin R; Dewey, Cate E; Summerlee, Alastair J S

2016-02-01

Background Condom promotion remains a cornerstone of HIV/STI control, but must be informed by evidence of uptake and address disparities in use. This study sought to determine the prevalence of, and demographic, behavioural and relational factors associated with, condom use during insertive and receptive anal intercourse with casual partners among younger gay, bisexual and other men who have sex with men (YMSM) in New Zealand. The 2006-2011 national HIV behavioural surveillance data for YMSM aged 16-29 years was pooled. Separately for each sexual position, frequent (always/almost always) versus infrequent condom use was regressed onto explanatory variables using manual backward stepwise multivariable logistic regression analysis. Three-quarters of YMSM reported frequent condom use during insertive (76.0%) and receptive (73.8%) anal intercourse. YMSM who were exclusively insertive were more likely to report frequent condom use than versatile YMSM. Factors positively associated with frequent condom use, irrespective of sexual position were: in-person versus web-based recruitment, testing HIV negative versus never testing or testing HIV positive, having no recent sex with women, reporting two to five versus one male sexual partner in the past 6 months, reporting no current regular partner, but if in a regular relationship, reporting a boyfriend-type versus fuckbuddy-type partner, and frequent versus infrequent regular partner condom use. Pacific ethnicity and less formal education were negatively associated with frequent condom use only during receptive anal intercourse. The findings from this study demonstrate that condom norms can be actively established and maintained among YMSM. Condom promotion efforts must increase YMSM's capacity, agency and skills to negotiate condom use, especially for the receptive partner.
Faculty motivations to use active learning among pharmacy educators.

PubMed

Rockich-Winston, Nicole; Train, Brian C; Rudolph, Michael J; Gillette, Chris

2018-03-01

Faculty motivations to use active learning have been limited to surveys evaluating faculty perceptions within active learning studies. Our objective in this study was to evaluate the relationship between faculty intrinsic motivation, extrinsic motivation, and demographic variables and the extent of active learning use in the classroom. An online survey was administered to individual faculty members at 137 colleges and schools of pharmacy across the United States. The survey assessed intrinsic and extrinsic motivations, active learning strategies, classroom time dedicated to active learning, and faculty development resources. Bivariate associations and multivariable stepwise linear regression were used to analyze the results. In total, 979 faculty members completed the questionnaire (23.6% response rate). All motivation variables were significantly correlated with percent active learning use (p < 0.001). Intrinsic motivation demonstrated the highest correlation (r = 0.447) followed by current extrinsic motivations (r = 0.245) and ideal extrinsic motivations (r = 0.291). Variables associated with higher intrinsic motivation included the number of resources used (r = 0.233, p < 0.001) and the number of active learning methods used in the last year (r = 0.259, p < 0.001). Years of teaching experience was negatively associated with intrinsic motivation (r = -0.177, p < 0.001). Regression analyses confirmed the importance of intrinsic and extrinsic motivations in predicting active learning use. Our results suggest that faculty members who are intrinsically motivated to use active learning are more likely to dedicate additional class time to active learning. Furthermore, intrinsic motivation may be positively associated with encouraging faculty members to attend active learning workshops and supporting faculty to use various active learning strategies in the classroom. Copyright © 2017 Elsevier Inc. All rights reserved.
Microbial cultures in open globe injuries in southern India.

PubMed

Gupta, Arvind; Srinivasan, Renuka; Kaliaperumal, Subashini; Setia, Sajita

2007-07-01

To determine the risk factors leading to positive intraocular culture in patients with open globe injury. A prospective interventional study involving 110 eyes of 110 patients of more than 15 years of age, presenting with open globe injury, was undertaken. Emergency repair of the injured globe was done. Prolapsed intraocular tissue or aqueous humour was sent for microbial work up before repair. In endophthalmitis cases intravitreal antibiotics were given according to the antimicrobial sensitivity. Chi-square and logistic regression analysis were used to determine the risk factors. Fifty-six patients showed microbial contamination. Bacteria were cultured in 42 patients and fungi in 14 patients. Nineteen patients developed endophthalmitis, of which 18 patients showed microbial growth initially. In univariate analysis, initial visual acuity (<6/360, P = 0.002), presence of uveal tissue prolapse (P < 0.001), vitreous prolapse (P < 0.001) and length of laceration (>8 mm, P < 0.001) were significantly associated with positive microbial culture, however, in the multivariate stepwise logistic regression delay in surgical intervention (>72 h, P < 0.001), uveal tissue prolapse (P = 0.004) and corneosclearal laceration (>8 mm, P = 0.013) were associated with increased risk of positive microbial culture. Six patients had intraocular foreign body but were culture negative. Age, gender, site of injury and presence of cataract did not significantly affect the culture positivity. Microbial contamination is a risk factor for the development for endophthalmitis. Despite the high frequency of microbial contamination, it develops only in few cases. Systemic antibiotics, virulence of the organism and host factors play a role in the manifestation of endophthalmitis. Prophylaxis with intraocular antibiotics should be strongly considered in cases with poor vision at presentation, larger corneoscleral laceration, delayed surgical intervention and uveal tissue or vitreous prolapse.
Risk of Hospitalization Due to Unintentional Fall Injury in British Columbia, Canada, 1999-2008: Ecological Associations with Socioeconomic Status, Geographic Place, and Aboriginal Ethnicity.

PubMed

Jin, Andrew; Brussoni, Mariana; George, M Anne; Lalonde, Christopher E; McCormick, Rod

2017-08-01

Aboriginal people in British Columbia (BC), especially those residing on Indian reserves, have higher risk of unintentional fall injury than the general population. We test the hypothesis that the disparities are attributable to a combination of socioeconomic status, geographic place, and Aboriginal ethnicity. Within each of 16 Health Service Delivery Areas in BC, we identified three population groups: total population, Aboriginal off-reserve, and Aboriginal on-reserve. We calculated age and gender-standardized relative risks (SRR) of hospitalization due to unintentional fall injury (relative to the total population of BC), during time periods 1999-2003 and 2004-2008, and we obtained custom data from the 2001 and 2006 censuses (long form), describing income, education, employment, housing, proportions of urban and rural dwellers, and prevalence of Aboriginal ethnicity. We studied association of census characteristics with SRR of fall injury, by multivariable linear regression. The best-fitting model was an excellent fit (R 2 = 0.854, p < 0.001) and predicted SRRs very close to observed values for the total, Aboriginal off-reserve, and Aboriginal on-reserve populations of BC. After stepwise regression, the following terms remained: population per room, urban residence, labor force participation, income per capita, and multiplicative interactions of Aboriginal ethnicity with population per room and labor force participation. The disparities are predictable by the hypothesized risk markers. Aboriginal ethnicity is not an independent risk marker: it modifies the effects of socioeconomic factors. Closing the gap in fall injury risk between the general and Aboriginal populations is likely achievable by closing the gaps in socioeconomic conditions.
[Development of the Spanish brief-version of the University of California Performance Skills Assessment (Sp-UPSA-Brief) in patients with schizophrenia and bipolar disorder].

PubMed

Garcia-Portilla, María Paz; Gomar, Jesús; Bobes-Bascaran, María Teresa; Menendez-Miranda, Isabel; Saiz, Pilar Alejandra; Muñiz, José; Arango, Celso; Patterson, Thomas; Harvey, Philip; Bobes, Julio; Goldberg, Terry

2014-01-01

In patients with severe mental disorders outcome measurement should include symptoms, cognition, functioning and quality of life at least. Shorter and efficient instruments have greater potential for pragmatic and valid clinical utility. Our aim was to develop the Spanish UPSA Brief scale (Sp-UPSA-Brief). Naturalistic, 6-month follow-up, multicentre study. 139 patients with schizophrenia, 57 with bipolar disorder and 31 controls were evaluated using the Sp-UPSA, CGI-S, GAF, and PSP. We conducted a multivariate linear regression model to identify candidate subscales for the Sp-UPSA-Brief. The stepwise regression model for patients with schizophrenia showed that communication and transportation Sp-UPSA subscales entered first and second at p<0.0001 (R(2)=0.88, model df=2, F=395.05). In patients with bipolar disorder transportation and communication Sp-UPSA subscales entered first and second at p<0.0001 (R(2)=0.87, model df=2, F=132.32). Cronbach's alpha was 0.78 in schizophrenia and 0.64 in bipolar patients. Test-retest was 0.66 and 0.64 (p<0.0001) respectively. Pearson correlation coefficients between Sp-UPSA and Sp-UPSA-Brief were 0.93 for schizophrenia and 0.92 for bipolar patients (p<0.0001).The Sp-UPSA-Brief discriminated between patients and controls. In schizophrenia patients it also discriminated among different levels of illness severity according to CGI-S scores. The Sp-UPSA-Brief is an alternate instrument to evaluate functional capacity that is valid and reliable. Having a shorter instrument makes it more feasible to assess functional capacity in patients with severe mental disorders, especially in everyday clinical practice. Copyright © 2013 SEP y SEPB. Published by Elsevier España. All rights reserved.
Multiscale characterization and prediction of monsoon rainfall in India using Hilbert-Huang transform and time-dependent intrinsic correlation analysis

NASA Astrophysics Data System (ADS)

Adarsh, S.; Reddy, M. Janga

2017-07-01

In this paper, the Hilbert-Huang transform (HHT) approach is used for the multiscale characterization of All India Summer Monsoon Rainfall (AISMR) time series and monsoon rainfall time series from five homogeneous regions in India. The study employs the Complete Ensemble Empirical Mode Decomposition with Adaptive Noise (CEEMDAN) for multiscale decomposition of monsoon rainfall in India and uses the Normalized Hilbert Transform and Direct Quadrature (NHT-DQ) scheme for the time-frequency characterization. The cross-correlation analysis between orthogonal modes of All India monthly monsoon rainfall time series and that of five climate indices such as Quasi Biennial Oscillation (QBO), El Niño Southern Oscillation (ENSO), Sunspot Number (SN), Atlantic Multi Decadal Oscillation (AMO), and Equatorial Indian Ocean Oscillation (EQUINOO) in the time domain showed that the links of different climate indices with monsoon rainfall are expressed well only for few low-frequency modes and for the trend component. Furthermore, this paper investigated the hydro-climatic teleconnection of ISMR in multiple time scales using the HHT-based running correlation analysis technique called time-dependent intrinsic correlation (TDIC). The results showed that both the strength and nature of association between different climate indices and ISMR vary with time scale. Stemming from this finding, a methodology employing Multivariate extension of EMD and Stepwise Linear Regression (MEMD-SLR) is proposed for prediction of monsoon rainfall in India. The proposed MEMD-SLR method clearly exhibited superior performance over the IMD operational forecast, M5 Model Tree (MT), and multiple linear regression methods in ISMR predictions and displayed excellent predictive skill during 1989-2012 including the four extreme events that have occurred during this period.

Factors Affecting Sexual Function in Midlife Women: Results from the Midlife Women's Health Study.

PubMed

Smith, Rebecca L; Gallicchio, Lisa; Flaws, Jodi A

2017-09-01

The objective of this study was to estimate the importance of risk factors affecting sexual function in sexually active midlife women. A cohort of 780 women undergoing the menopausal transition was surveyed each year for up to 7 years. Data were collected from sexually active women on sexual function, including frequencies of enjoyment, arousal, orgasm, passion for partner, satisfaction with partner, pain, lack of lubrication, fantasizing, and sexual activity. Data were also collected on a large number of potential risk factors for sexual dysfunction, including behaviors (smoking and alcohol use), health status (overall and frequency of different disorders), and demographic information (race, education, income, etc.). Height and weight were measured at an annual clinic visit; serum hormone concentrations were assayed using blood samples donated annually. Data on individual outcomes were examined with ordinal logistic regression models using individual as a random effect. An overall sexual function score was constructed from individual outcome responses, and this score was examined with linear regression. All factors with univariate associations of p < 0.1 were considered in multivariate model building with stepwise addition. A total of 1,927 women-years were included in the analysis. Women with much more physical work than average had higher sexual function scores and higher rates of enjoyment, passion, and satisfaction. Higher family income was associated with lower sexual function score and more frequent dry sex. Married women had significantly lower sexual function scores, as did those with frequent irritability or vaginal dryness. A higher step on the Ladder of Life was associated with a higher sexual function score and higher frequency of sexual activity. The factors associated with sexual outcome in menopausal women are complex and vary depending on the sexual outcome.
Evaluation of pre-implantation kidney biopsies: comparison of Banff criteria to a morphometric approach.

PubMed

Lopes, José António; Moreso, Francesc; Riera, Luis; Carrera, Marta; Ibernon, Meritxell; Fulladosa, Xavier; Grinyó, Josep Maria; Serón, Daniel

2005-04-01

Donor glomerulosclerosis, interstitial fibrosis, and fibrous intimal thickening correlate with graft outcome. We evaluate chronic lesions in donor biopsies according to Banff criteria and with a morphometric technique to ascertain their predictive value on graft outcome. We evaluated 77 cadaveric donor biopsies according to Banff criteria. Glomerulosclerosis was expressed as the percentage of global sclerotic glomeruli. The following morphometric parameters were obtained: cortical interstitial volume fraction (Vvint/c), cortical glomerular volume fraction (Vvglom/c), mean glomerular volume (Vg), mean and maximal intimal arterial volume fraction (Vvintima/art), and Vvintima/art of the largest artery. We evaluated the correlation of histologic lesions with delayed graft function, 3 months' glomerular filtration rate (GFR), and death-censored graft survival. Multivariate logistic regression showed that delayed graft function was associated with cv score [relative risk (RR) 4.2 and 95% CI 1.1 to 16.0) and glomerulosclerosis (RR 1.06 and 95% CI 1.01 to 1.13). Stepwise regression showed that Vvint/c and glomerulosclerosis were independent predictors of 3 months' GFR (R= 0.62, P= 0.0001). Repeated analysis not considering morphometric parameters showed that glomerulosclerosis, cv score and ci score were independent predictors of 3 months' GFR (R= 0.64, P= 0.0001). A donor chronic damage score was generated considering glomerulosclerosis, cv score and ci score. This score after adjusting for clinical variables was associated with 3 months' GFR (R= 0.71, P < 0.0001) and death-censored graft survival (RR 2.2 and 95% CI 1.3 to 3.7). Combined evaluation of donor glomerulosclerosis, chronic vascular and interstitial damage according to Banff criteria allows a precise prediction of graft outcome. Morphometric evaluation of donor biopsies does not improve the predictive value of semiquantitative grading.
Ethnic differences in cognitive development in the first 7 years: does maternal generational status matter?

PubMed

Smith, Neil R; Kelly, Yvonne J; Nazroo, James Y

2016-05-01

Differences in cognitive development have been observed across a variety of ethnic minority groups but relatively little is known about the persistence of these developmental inequalities over time or generations. A repeat cross-sectional analysis assessed cognitive ability scores of children aged 3, 5 and 7 years from the longitudinal UK Millennium Cohort Study (white UK born n=7630; Indian n=248; Pakistani n=328; Bangladeshi n=87; black Caribbean n=172; and black African n=136). Linear regression estimated ethnic differences in age normed scores at each time point. Multivariable logistic regression estimated within-group generational differences in test scores at each age adjusting stepwise for sociodemographic factors, maternal health behaviours, indicators of the home learning environment and parenting styles. The majority of ethnic minority groups scored lower than the white UK born reference group at 3 years with these differences narrowing incrementally at ages 5 and 7 years. However, the black Caribbean group scored significantly lower than the white UK born reference group throughout early childhood. At 3 years, Pakistani, black Caribbean and black African children with UK born mothers had significantly higher test scores than those with foreign born mothers after baseline adjustment for maternal age and child gender. Controlling for social, behavioural and parenting factors attenuated this generational advantage. By 7 years there were no significant generational differences in baseline models. Ethnic differences in cognitive development diminish throughout childhood for the majority of groups. Cumulative exposure to the UK environment may be associated with higher cognitive development scores. 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/
[Population of Lytechinus variegatus (Echinoidea: Toxopneustidae) and structural characteristics of seagrass of Thalassia testudinum in Mochima Bay, Venezuela)].

PubMed

Noriega, Nicida; Cróquer, Aldo; Pauls, Sheila M

2002-03-01

To compare the general features of Thalassia testudinum seagrass at Mochima Bay with sea urchin (Lxtechinus variegatus) abundance and distribution, three T. testudinum seagrass beds were selected, from the mouth (strong wave exposure) to the inner bay (calm waters). Each site was surveyed by using 5 line transects (20 m long) parallel to the coast and 1 m2 quadrats. In situ measurements of T. testudinum cover, shoot and leaf density were taken. Estimation of dry biomass for each seagrass fraction (leaves, rhizomes and roots) and leaf length were obtained from 25 vegetation samples extracted per site using cores (15 cm diameter). A multivariate analysis of variance (Manova) and a less significative difference test (LSD) were performed to examine differences between sites and within sites at different depths. A stepwise multiple regression analysis was done, dependent variable was sea urchin density; independent variables: vegetation values at each site. The only seagrass species found in the three sites was T. testudinum, and cover was 56-100%, leaf density 100-1000 leaf/m2, lengths 6-18.8 cm and shoot density 20-475 shoots/m2. The highest sea urchin densities were found at Isla Redonda and Ensenada Toporo (1-3.6 ind/m2), the lowest at Playa Colorada (0.6-0.8 ind/m2). Significant differences in seagrass features between sites were obtained (Manova p < 0.001), but not between depths (Manova p < 0.320). The regression coefficient between sea urchin density and seagrass parameters was statistically significant (r2 = 0.154, p < 0.007), however, total biomass was the only variable with a significant effect on sea urchin distribution (beta = 0.308, p < 0.032). The other variables did not explain satisfactorily L. variegatus abundance and distribution.
Identifying the bleeding trauma patient: predictive factors for massive transfusion in an Australasian trauma population.

PubMed

Hsu, Jeremy Ming; Hitos, Kerry; Fletcher, John P

2013-09-01

Military and civilian data would suggest that hemostatic resuscitation results in improved outcomes for exsanguinating patients. However, identification of those patients who are at risk of significant hemorrhage is not clearly defined. We attempted to identify factors that would predict the need for massive transfusion (MT) in an Australasian trauma population, by comparing those trauma patients who did receive massive transfusion with those who did not. Between 1985 and 2010, 1,686 trauma patients receiving at least 1 U of packed red blood cells were identified from our prospectively maintained trauma registry. Demographic, physiologic, laboratory, injury, and outcome variables were reviewed. Univariate analysis determined significant factors between those who received MT and those who did not. A predictive multivariate logistic regression model with backward conditional stepwise elimination was used for MT risk. Statistical analysis was performed using SPSS PASW. MT patients had a higher pulse rate, lower Glasgow Coma Scale (GCS) score, lower systolic blood pressure, lower hemoglobin level, higher Injury Severity Score (ISS), higher international normalized ratio (INR), and longer stay. Initial logistic regression identified base deficit (BD), INR, and hemoperitoneum at laparotomy as independent predictive variables. After assigning cutoff points of BD being greater than 5 and an INR of 1.5 or greater, a further model was created. A BD greater than 5 and either INR of 1.5 or greater or hemoperitoneum was associated with 51 times increase in MT risk (odds ratio, 51.6; 95% confidence interval, 24.9-95.8). The area under the receiver operating characteristic curve for the model was 0.859. From this study, a combination of BD, INR, and hemoperitoneum has demonstrated good predictability for MT. This tool may assist in the determination of those patients who might benefit from hemostatic resuscitation. Prognostic study, level III.
Assessing the socio-economic and demographic impact on health-related quality of life: evidence from Greece.

PubMed

Pappa, Evelina; Kontodimopoulos, Nick; Papadopoulos, Angelos A; Niakas, Dimitris

2009-01-01

The impact of socioeconomic status on health has been extensively studied and studies have shown that low socio-economic status is related to lower values of various health and quality-of-health measures. The aim of this study was to assess the influence of demographic and socio-economic factors on health- related quality of life (HRQoL). A cross-sectional study was carried out in 2003 using a representative sample of a Greek general population (n = 1007, 18+ years old), living in Athens area. Multivariate stepwise linear regression analyses were performed to investigate the influence of socio-demographic and economic variables on HRQoL, measured by eight scales of the SF-36. Interaction effects between socioeconomic status (SES) and demographic variables were also performed. Females and elderly people were associated with impaired HRQoL in all SF-36 scales. Disadvantaged SES i. e. primary education and low total household income was related to important decline in HRQoL and a similar relation was identified among men and women. Only the interaction effects between age and SES was statistically significant for some SF-36 scales. Multiple regression analyses produced models explaining significant portions of the variance in SF-36 scales, especially physical functioning. The analysis presented here gives evidence of a relationship existing between SES and HRQoL similar to what has been found elsewhere. In order to protect people from the damaging effects of poverty in health it is important to formulate health promotion educational programs or to direct policies to empower the disposable income etc. Helping people in disadvantaged SES to achieve the good health that people in more advantaged SES attained would help to prevent the widening of health inequalities.
Circulating asprosin concentrations are increased in type 2 diabetes mellitus and independently associated with fasting glucose and triglyceride.

PubMed

Zhang, Lei; Chen, Chao; Zhou, Nan; Fu, Yuming; Cheng, Xingbo

2017-11-03

Asprosin has been identified as a novel hormone enriched in white adipose tissue and is pathologically increased in insulin-resistant mice and humans. However, information regarding the role of asprosin in type 2 diabetes mellitus (T2DM) remains unavailable. Via conducting a hospital-based study, we purposed to ascertain the potential relationship between circulating asprosin concentrations and T2DM. The study recruited 84 adults with T2DM and 86 controls with normal glucose tolerance. They matched in age, body mass index (BMI), and sex. Serum asprosin concentrations were measured via ELISA method. Compared to the controls, serum asprosin concentrations were significantly increased in the T2DM adults (P<0.001). As asprosin concentrations increased across its tertiles, the percentage of T2DM increased (39.28, 37.50, and 70.68%; P value for trend <0.001). Multivariate logistic regression models demonstrated that compared with the 1st tertile of asprosin, the odds ratio of T2DM was 3.278(95% CI 1.053-10.200, P=0.040) for the 3rd tertile after adjustment for potential confounders. Area under ROC curve of asprosin (sex and age adjusted) for predicting the presence of T2DM was 0.707[95% CI 0.628-0.786]. Finally, multiple stepwise regression analysis indicated that fasting glucose and triglyceride were independently associated with serum asprosin in T2DM. Asprosin concentrations are increased in adults with T2DM. The results suggest that asprosin might serve as a risk factor associated with the pathogenesis of T2DM, but not an ideal biomarker for predicting T2DM. Copyright © 2017 Elsevier B.V. All rights reserved.
Multivariate Boosting for Integrative Analysis of High-Dimensional Cancer Genomic Data

PubMed Central

Xiong, Lie; Kuan, Pei-Fen; Tian, Jianan; Keles, Sunduz; Wang, Sijian

2015-01-01

In this paper, we propose a novel multivariate component-wise boosting method for fitting multivariate response regression models under the high-dimension, low sample size setting. Our method is motivated by modeling the association among different biological molecules based on multiple types of high-dimensional genomic data. Particularly, we are interested in two applications: studying the influence of DNA copy number alterations on RNA transcript levels and investigating the association between DNA methylation and gene expression. For this purpose, we model the dependence of the RNA expression levels on DNA copy number alterations and the dependence of gene expression on DNA methylation through multivariate regression models and utilize boosting-type method to handle the high dimensionality as well as model the possible nonlinear associations. The performance of the proposed method is demonstrated through simulation studies. Finally, our multivariate boosting method is applied to two breast cancer studies. PMID:26609213
Quantitative monitoring of sucrose, reducing sugar and total sugar dynamics for phenotyping of water-deficit stress tolerance in rice through spectroscopy and chemometrics

NASA Astrophysics Data System (ADS)

Das, Bappa; Sahoo, Rabi N.; Pargal, Sourabh; Krishna, Gopal; Verma, Rakesh; Chinnusamy, Viswanathan; Sehgal, Vinay K.; Gupta, Vinod K.; Dash, Sushanta K.; Swain, Padmini

2018-03-01

In the present investigation, the changes in sucrose, reducing and total sugar content due to water-deficit stress in rice leaves were modeled using visible, near infrared (VNIR) and shortwave infrared (SWIR) spectroscopy. The objectives of the study were to identify the best vegetation indices and suitable multivariate technique based on precise analysis of hyperspectral data (350 to 2500 nm) and sucrose, reducing sugar and total sugar content measured at different stress levels from 16 different rice genotypes. Spectral data analysis was done to identify suitable spectral indices and models for sucrose estimation. Novel spectral indices in near infrared (NIR) range viz. ratio spectral index (RSI) and normalised difference spectral indices (NDSI) sensitive to sucrose, reducing sugar and total sugar content were identified which were subsequently calibrated and validated. The RSI and NDSI models had R2 values of 0.65, 0.71 and 0.67; RPD values of 1.68, 1.95 and 1.66 for sucrose, reducing sugar and total sugar, respectively for validation dataset. Different multivariate spectral models such as artificial neural network (ANN), multivariate adaptive regression splines (MARS), multiple linear regression (MLR), partial least square regression (PLSR), random forest regression (RFR) and support vector machine regression (SVMR) were also evaluated. The best performing multivariate models for sucrose, reducing sugars and total sugars were found to be, MARS, ANN and MARS, respectively with respect to RPD values of 2.08, 2.44, and 1.93. Results indicated that VNIR and SWIR spectroscopy combined with multivariate calibration can be used as a reliable alternative to conventional methods for measurement of sucrose, reducing sugars and total sugars of rice under water-deficit stress as this technique is fast, economic, and noninvasive.
The PIT-trap-A "model-free" bootstrap procedure for inference about regression models with discrete, multivariate responses.

PubMed

Warton, David I; Thibaut, Loïc; Wang, Yi Alice

2017-01-01

Bootstrap methods are widely used in statistics, and bootstrapping of residuals can be especially useful in the regression context. However, difficulties are encountered extending residual resampling to regression settings where residuals are not identically distributed (thus not amenable to bootstrapping)-common examples including logistic or Poisson regression and generalizations to handle clustered or multivariate data, such as generalised estimating equations. We propose a bootstrap method based on probability integral transform (PIT-) residuals, which we call the PIT-trap, which assumes data come from some marginal distribution F of known parametric form. This method can be understood as a type of "model-free bootstrap", adapted to the problem of discrete and highly multivariate data. PIT-residuals have the key property that they are (asymptotically) pivotal. The PIT-trap thus inherits the key property, not afforded by any other residual resampling approach, that the marginal distribution of data can be preserved under PIT-trapping. This in turn enables the derivation of some standard bootstrap properties, including second-order correctness of pivotal PIT-trap test statistics. In multivariate data, bootstrapping rows of PIT-residuals affords the property that it preserves correlation in data without the need for it to be modelled, a key point of difference as compared to a parametric bootstrap. The proposed method is illustrated on an example involving multivariate abundance data in ecology, and demonstrated via simulation to have improved properties as compared to competing resampling methods.
The PIT-trap—A “model-free” bootstrap procedure for inference about regression models with discrete, multivariate responses

PubMed Central

Thibaut, Loïc; Wang, Yi Alice

2017-01-01

Bootstrap methods are widely used in statistics, and bootstrapping of residuals can be especially useful in the regression context. However, difficulties are encountered extending residual resampling to regression settings where residuals are not identically distributed (thus not amenable to bootstrapping)—common examples including logistic or Poisson regression and generalizations to handle clustered or multivariate data, such as generalised estimating equations. We propose a bootstrap method based on probability integral transform (PIT-) residuals, which we call the PIT-trap, which assumes data come from some marginal distribution F of known parametric form. This method can be understood as a type of “model-free bootstrap”, adapted to the problem of discrete and highly multivariate data. PIT-residuals have the key property that they are (asymptotically) pivotal. The PIT-trap thus inherits the key property, not afforded by any other residual resampling approach, that the marginal distribution of data can be preserved under PIT-trapping. This in turn enables the derivation of some standard bootstrap properties, including second-order correctness of pivotal PIT-trap test statistics. In multivariate data, bootstrapping rows of PIT-residuals affords the property that it preserves correlation in data without the need for it to be modelled, a key point of difference as compared to a parametric bootstrap. The proposed method is illustrated on an example involving multivariate abundance data in ecology, and demonstrated via simulation to have improved properties as compared to competing resampling methods. PMID:28738071
Finding structure in data using multivariate tree boosting

PubMed Central

Miller, Patrick J.; Lubke, Gitta H.; McArtor, Daniel B.; Bergeman, C. S.

2016-01-01

Technology and collaboration enable dramatic increases in the size of psychological and psychiatric data collections, but finding structure in these large data sets with many collected variables is challenging. Decision tree ensembles such as random forests (Strobl, Malley, & Tutz, 2009) are a useful tool for finding structure, but are difficult to interpret with multiple outcome variables which are often of interest in psychology. To find and interpret structure in data sets with multiple outcomes and many predictors (possibly exceeding the sample size), we introduce a multivariate extension to a decision tree ensemble method called gradient boosted regression trees (Friedman, 2001). Our extension, multivariate tree boosting, is a method for nonparametric regression that is useful for identifying important predictors, detecting predictors with nonlinear effects and interactions without specification of such effects, and for identifying predictors that cause two or more outcome variables to covary. We provide the R package ‘mvtboost’ to estimate, tune, and interpret the resulting model, which extends the implementation of univariate boosting in the R package ‘gbm’ (Ridgeway et al., 2015) to continuous, multivariate outcomes. To illustrate the approach, we analyze predictors of psychological well-being (Ryff & Keyes, 1995). Simulations verify that our approach identifies predictors with nonlinear effects and achieves high prediction accuracy, exceeding or matching the performance of (penalized) multivariate multiple regression and multivariate decision trees over a wide range of conditions. PMID:27918183
Is Heart Rate Variability Better Than Routine Vital Signs for Prehospital Identification of Major Hemorrhage

DTIC Science & Technology

2015-01-01

different PRBC transfusion volumes. We performed multivariate regression analysis using HRV metrics and routine vital signs to test the hypothesis that...study sponsors did not have any role in the study design, data collection, analysis and interpretation of data, report writing, or the decision to...primary outcome was hemorrhagic injury plus different PRBC transfusion volumes. We performed multivariate regression analysis using HRV metrics and
Multivariate statistical analysis of the polyphenolic constituents in kiwifruit juices to trace fruit varieties and geographical origins.

PubMed

Guo, Jing; Yuan, Yahong; Dou, Pei; Yue, Tianli

2017-10-01

Fifty-one kiwifruit juice samples of seven kiwifruit varieties from five regions in China were analyzed to determine their polyphenols contents and to trace fruit varieties and geographical origins by multivariate statistical analysis. Twenty-one polyphenols belonging to four compound classes were determined by ultra-high-performance liquid chromatography coupled with ultra-high-resolution TOF mass spectrometry. (-)-Epicatechin, (+)-catechin, procyanidin B1 and caffeic acid derivatives were the predominant phenolic compounds in the juices. Principal component analysis (PCA) allowed a clear separation of the juices according to kiwifruit varieties. Stepwise linear discriminant analysis (SLDA) yielded satisfactory categorization of samples, provided 100% success rate according to kiwifruit varieties and 92.2% success rate according to geographical origins. The result showed that polyphenolic profiles of kiwifruit juices contain enough information to trace fruit varieties and geographical origins. Copyright © 2017 Elsevier Ltd. All rights reserved.
Improving prediction of metal uptake by Chinese cabbage (Brassica pekinensis L.) based on a soil-plant stepwise analysis.

PubMed

Zhang, Sha; Song, Jing; Gao, Hui; Zhang, Qiang; Lv, Ming-Chao; Wang, Shuang; Liu, Gan; Pan, Yun-Yu; Christie, Peter; Sun, Wenjie

2016-11-01

It is crucial to develop predictive soil-plant transfer (SPT) models to derive the threshold values of toxic metals in contaminated arable soils. The present study was designed to examine the heavy metal uptake pattern and to improve the prediction of metal uptake by Chinese cabbage grown in agricultural soils with multiple contamination by Cd, Cu, Ni, Pb, and Zn. Pot experiments were performed with 25 historically contaminated soils to determine metal accumulation in different parts of Chinese cabbage. Different soil bioavailable metal fractions were determined using different extractants (0.43M HNO3, 0.01M CaCl2, 0.005M DTPA, and 0.01M LWMOAs), soil moisture samplers, and diffusive gradients in thin films (DGT), and the fractions were compared with shoot metal uptake using both direct and stepwise multiple regression analysis. The stepwise approach significantly improved the prediction of metal uptake by cabbage over the direct approach. Strongly pH dependent or nonlinear relationships were found for the adsorption of root surfaces and in root-shoot uptake processes. Metals were linearly translocated from the root surface to the root. Therefore, the nonlinearity of uptake pattern is an important explanation for the inadequacy of the direct approach in some cases. The stepwise approach offers an alternative and robust method to study the pattern of metal uptake by Chinese cabbage (Brassica pekinensis L.). Copyright © 2016. Published by Elsevier B.V.
Assessment of craniometric traits in South Indian dry skulls for sex determination.

PubMed

Ramamoorthy, Balakrishnan; Pai, Mangala M; Prabhu, Latha V; Muralimanju, B V; Rai, Rajalakshmi

2016-01-01

The skeleton plays an important role in sex determination in forensic anthropology. The skull bone is considered as the second best after the pelvic bone in sex determination due to its better retention of morphological features. Different populations have varying skeletal characteristics, making population specific analysis for sex determination essential. Hence the objective of this investigation is to obtain the accuracy of sex determination using cranial parameters of adult skulls to the highest percentage in South Indian population and to provide a baseline data for sex determination in South India. Seventy adult preserved human skulls were taken and based on the morphological traits were classified into 43 male skulls and 27 female skulls. A total of 26 craniometric parameters were studied. The data were analyzed by using the SPSS discriminant function. The analysis of stepwise, multivariate, and univariate discriminant function gave an accuracy of 77.1%, 85.7%, and 72.9% respectively. Multivariate direct discriminant function analysis classified skull bones into male and female with highest levels of accuracy. Using stepwise discriminant function analysis, the most dimorphic variable to determine sex of the skull, was biauricular breadth followed by weight. Subjecting the best dimorphic variables to univariate discriminant analysis, high levels of accuracy of sexual dimorphism was obtained. Percentage classification of high accuracies were obtained in this study indicating high level of sexual dimorphism in the crania, setting specific discriminant equations for the gender determination in South Indian people. Copyright © 2015 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.
Predicting the demand of physician workforce: an international model based on "crowd behaviors".

PubMed

Tsai, Tsuen-Chiuan; Eliasziw, Misha; Chen, Der-Fang

2012-03-26

Appropriateness of physician workforce greatly influences the quality of healthcare. When facing the crisis of physician shortages, the correction of manpower always takes an extended time period, and both the public and health personnel suffer. To calculate an appropriate number of Physician Density (PD) for a specific country, this study was designed to create a PD prediction model, based on health-related data from many countries. Twelve factors that could possibly impact physicians' demand were chosen, and data of these factors from 130 countries (by reviewing 195) were extracted. Multiple stepwise-linear regression was used to derive the PD prediction model, and a split-sample cross-validation procedure was performed to evaluate the generalizability of the results. Using data from 130 countries, with the consideration of the correlation between variables, and preventing multi-collinearity, seven out of the 12 predictor variables were selected for entry into the stepwise regression procedure. The final model was: PD = (5.014 - 0.128 × proportion under age 15 years + 0.034 × life expectancy)2, with R2 of 80.4%. Using the prediction equation, 70 countries had PDs with "negative discrepancy", while 58 had PDs with "positive discrepancy". This study provided a regression-based PD model to calculate a "norm" number of PD for a specific country. A large PD discrepancy in a country indicates the needs to examine physician's workloads and their well-being, the effectiveness/efficiency of medical care, the promotion of population health and the team resource management.
Development of a Bayesian model to estimate health care outcomes in the severely wounded

PubMed Central

Stojadinovic, Alexander; Eberhardt, John; Brown, Trevor S; Hawksworth, Jason S; Gage, Frederick; Tadaki, Douglas K; Forsberg, Jonathan A; Davis, Thomas A; Potter, Benjamin K; Dunne, James R; Elster, E A

2010-01-01

Background: Graphical probabilistic models have the ability to provide insights as to how clinical factors are conditionally related. These models can be used to help us understand factors influencing health care outcomes and resource utilization, and to estimate morbidity and clinical outcomes in trauma patient populations. Study design: Thirty-two combat casualties with severe extremity injuries enrolled in a prospective observational study were analyzed using step-wise machine-learned Bayesian belief network (BBN) and step-wise logistic regression (LR). Models were evaluated using 10-fold cross-validation to calculate area-under-the-curve (AUC) from receiver operating characteristics (ROC) curves. Results: Our BBN showed important associations between various factors in our data set that could not be developed using standard regression methods. Cross-validated ROC curve analysis showed that our BBN model was a robust representation of our data domain and that LR models trained on these findings were also robust: hospital-acquired infection (AUC: LR, 0.81; BBN, 0.79), intensive care unit length of stay (AUC: LR, 0.97; BBN, 0.81), and wound healing (AUC: LR, 0.91; BBN, 0.72) showed strong AUC. Conclusions: A BBN model can effectively represent clinical outcomes and biomarkers in patients hospitalized after severe wounding, and is confirmed by 10-fold cross-validation and further confirmed through logistic regression modeling. The method warrants further development and independent validation in other, more diverse patient populations. PMID:21197361
Estimation of standard liver volume in Chinese adult living donors.

PubMed

Fu-Gui, L; Lu-Nan, Y; Bo, L; Yong, Z; Tian-Fu, W; Ming-Qing, X; Wen-Tao, W; Zhe-Yu, C

2009-12-01

To determine a formula predicting the standard liver volume based on body surface area (BSA) or body weight in Chinese adults. A total of 115 consecutive right-lobe living donors not including the middle hepatic vein underwent right hemi-hepatectomy. No organs were used from prisoners, and no subjects were prisoners. Donor anthropometric data including age, gender, body weight, and body height were recorded prospectively. The weights and volumes of the right lobe liver grafts were measured at the back table. Liver weights and volumes were calculated from the right lobe graft weight and volume obtained at the back table, divided by the proportion of the right lobe on computed tomography. By simple linear regression analysis and stepwise multiple linear regression analysis, we correlated calculated liver volume and body height, body weight, or body surface area. The subjects had a mean age of 35.97 +/- 9.6 years, and a female-to-male ratio of 60:55. The mean volume of the right lobe was 727.47 +/- 136.17 mL, occupying 55.59% +/- 6.70% of the whole liver by computed tomography. The volume of the right lobe was 581.73 +/- 96.137 mL, and the estimated liver volume was 1053.08 +/- 167.56 mL. Females of the same body weight showed a slightly lower liver weight. By simple linear regression analysis and stepwise multiple linear regression analysis, a formula was derived based on body weight. All formulae except the Hong Kong formula overestimated liver volume compared to this formula. The formula of standard liver volume, SLV (mL) = 11.508 x body weight (kg) + 334.024, may be applied to estimate liver volumes in Chinese adults.
Evaluating Disease Severity in Chronic Pain Patients with and without Fibromyalgia: A Comparison of the Symptom Impact Questionnaire and the Polysymptomatic Distress Scale.

PubMed

Friend, Ronald; Bennett, Robert M

2015-12-01

To compare the relative effectiveness of the Polysymptomatic Distress Scale (PSD) with the Symptom Impact Questionnaire (SIQR), the disease-neutral revision of the updated Fibromyalgia Impact Questionnaire (FIQR), in their ability to assess disease activity in patients with rheumatic disorders both with and without fibromyalgia (FM). The study included 321 patients from 8 clinical practices with some 16 different chronic pain disorders. Disease severity was assessed by the Medical Outcomes Study Short Form-36 (SF-36). Univariate analyses were used to assess the magnitude of PSD and SIQR correlations with SF-36 subscales. Hierarchical stepwise regression was used to evaluate the unique contribution of the PSD and SIQR to the SF-36. Random forest regression probed the relative importance of the SIQR and PSD components as predictors of SF-36. The correlations with the SF-36 subscales were significantly higher for the SIQR (0.48 to 0.78) than the PSD (0.29 to 0.56; p < 0.001). Stepwise regression revealed that the SIQR was contributing additional unique variance on SF-36 subscales, which was not the case for the PSD. Random forest regression showed SIQR Function, Symptoms, and Global Impact subscales were more important predictors of SF-36 than the PSD. The single SIQR pain item contributed 55% of SF-36 pain variance compared to 23% with the 19-point WPI (the Widespread Pain Index component of PSD). The SIQR, the disease-neutral revision of the updated FIQ, has several important advantages over the PSD in the evaluation of disease severity in chronic pain disorders.

Adaptive surrogate modeling by ANOVA and sparse polynomial dimensional decomposition for global sensitivity analysis in fluid simulation

NASA Astrophysics Data System (ADS)

Tang, Kunkun; Congedo, Pietro M.; Abgrall, Rémi

2016-06-01

The Polynomial Dimensional Decomposition (PDD) is employed in this work for the global sensitivity analysis and uncertainty quantification (UQ) of stochastic systems subject to a moderate to large number of input random variables. Due to the intimate connection between the PDD and the Analysis of Variance (ANOVA) approaches, PDD is able to provide a simpler and more direct evaluation of the Sobol' sensitivity indices, when compared to the Polynomial Chaos expansion (PC). Unfortunately, the number of PDD terms grows exponentially with respect to the size of the input random vector, which makes the computational cost of standard methods unaffordable for real engineering applications. In order to address the problem of the curse of dimensionality, this work proposes essentially variance-based adaptive strategies aiming to build a cheap meta-model (i.e. surrogate model) by employing the sparse PDD approach with its coefficients computed by regression. Three levels of adaptivity are carried out in this paper: 1) the truncated dimensionality for ANOVA component functions, 2) the active dimension technique especially for second- and higher-order parameter interactions, and 3) the stepwise regression approach designed to retain only the most influential polynomials in the PDD expansion. During this adaptive procedure featuring stepwise regressions, the surrogate model representation keeps containing few terms, so that the cost to resolve repeatedly the linear systems of the least-squares regression problem is negligible. The size of the finally obtained sparse PDD representation is much smaller than the one of the full expansion, since only significant terms are eventually retained. Consequently, a much smaller number of calls to the deterministic model is required to compute the final PDD coefficients.
Concurrent Validity of Hill's Educational Cognitive Style Model as a Prototype for Successful Academic Programs Among Lower-Class Students.

ERIC Educational Resources Information Center

London, David T.

Data from the stepwise multiple regression of four educational cognitive style predictor sets on each of six academic competence criteria were used to define the concurrent validity of Hill's educational cognitive style model. The purpose was to determine how appropriate it may be to use this model as a prototype for successful academic programs…
Do Basic Skills Predict Youth Unemployment (16- to 24-Year-Olds) Also when Controlled for Accomplished Upper-Secondary School? A Cross-Country Comparison

ERIC Educational Resources Information Center

Lundetrae, Kjersti; Gabrielsen, Egil; Mykletun, Reidar

2010-01-01

Basic skills and educational level are closely related, and both might affect employment. Data from the Adult Literacy and Life Skills Survey were used to examine whether basic skills in terms of literacy and numeracy predicted youth unemployment (16-24 years) while controlling for educational level. Stepwise logistic regression showed that in…
Objective Quantification of Pre-and Postphonosurgery Vocal Fold Vibratory Characteristics Using High-Speed Videoendoscopy and a Harmonic Waveform Model

ERIC Educational Resources Information Center

Ikuma, Takeshi; Kunduk, Melda; McWhorter, Andrew J.

2014-01-01

Purpose: The model-based quantitative analysis of high-speed videoendoscopy (HSV) data at a low frame rate of 2,000 frames per second was assessed for its clinical adequacy. Stepwise regression was employed to evaluate the HSV parameters using harmonic models and their relationships to the Voice Handicap Index (VHI). Also, the model-based HSV…
A statistical model of expansion in a colony of black-tailed prairie dogs

Treesearch

R. P. Cincotta; Daniel W. Uresk; R. M. Hansen

1988-01-01

To predict prairie dog establishment in areas adjacent to a colony we sample: (1) VISIBILITY through the vegetation using a target, (2) POPULATION DENSITY at the cology edge, (3) DISTANCE from the edge to the potential site of settlement, and (4) % FORB COVER. Step-wise regression analysis indicated that establishment of prairie dogs in adjacent prairie was most likely...
[Analysis on sleep duration of 6-12 years old school children in school-day in 8 provinces, China].

PubMed

Shi, Wenhui; Zhai, Yi; Li, Weirong; Shen, Chong; Shi, Xiaoming

2015-05-01

To analyze the influencing factors for sleep duration of school children aged 6-12 years in school-day in 8 provinces in China. The cross sectional study was conducted among 20,603 children aged 6-12 years and selected through stratified random cluster sampling in 8 provinces (municipality and autonomous region) with different geographic characteristics and economic development level in China from September to November, 2010 to understand their sleep duration in school-day and related habits. t test and χ2 test were used to compare the sleep duration of the children. Multivariate stepwise logistic regression analysis was conducted to identify the influencing factors. The survey indicated that the daily average sleep duration of the children in school days was 9.11 hours. The proportions of the children with serious insufficient sleep, insufficient sleep and sufficient sleep were 32.82% (7,672/20,603), 39.70% (8,179/20,603) and 27.48% (5,662/20,603), the children's sleep duration declined with age, so did proportion of children with serious insufficient sleep. There were no sex, urban or rural area and household income level specific significant differences in sleep duration among the children surveyed, and there were no sex specific differences in the proportion of children with serious insufficient sleep, insufficient sleep and sufficient sleep, however, these proportions were statistically different between urban area and rural area and among the regions with different economic level. The proportions of children with serious insufficient sleep and sufficient sleep was higher in rural area than in urban area (χ2=59.96, χ2=45.47, P<0.05), while the proportion of children with insufficient sleep was lower in rural area than in urban area. In the economy developed region, the proportion of children with insufficient sleep was lowest, the difference was statistical significant. After adjusting for sex, weight, diet and exercise time, multivariate logistic regression analysis showed that the factors benefiting children to have 10 hours sleep every day included having high protein diet, exercise, high household economic status and living in urban area. The problem of school children having insufficient sleep was serious in China, especially in the rural area.
[Factors influencing the quality of life of elderly living in a pre-fabricated housing complex in the Sichuan earthquake area].

PubMed

Guo, Hong-Xia; Chen, Hong; Wong, Teresa Bik-Kwan Tsien; Chen, Qian; Au, May-Lan; Li, Yun

2012-02-01

The 2008 Sichuan Earthquake caused great damage to the environment and property. In the aftermath, many citizens were relocated to live in newly constructed prefabricated (prefab) communities. This paper explored the current quality of life (QOL) of elderly residents living in prefabricated communities in areas damaged by the Sichuan earthquake and identified factors of influence on QOL values. The ultimate objective was to provide evidence-based guidance for heath improvement measures. The authors used the short form WHOQOL-BREF to assess the quality of life of 191 elderly residents of prefabricated communities in the Sichuan Province 2008 earthquake zone. A Student's t-test, variance analysis, and stepwise multivariate regression methods were used to test the impact of various factors on QOL. Results indicate the self-assessed QOL of participants as good, although scores in the physical (average 56.2) and psychological (average 45.7) domains were significantly lower than the norm in China. Marital status, capital loss in the earthquake, number of children, level of perceived stress, income, interest, and family harmony each correlated with at least one of the short form WHOQOL-BREF domains in t-test and one-way analyses. After excluding for factor interaction effects using multivariate regression, we found interest, family harmony, monthly income and stress to be significant predictors of physical domain QOL, explaining 13.8% of total variance. Family harmony and interest explained 15.3% of total variance for psychological domain QOL; stress, marital status, family harmony, capital loss in the earthquake, number of children and interest explained 19.5% of total variance for social domain QOL; and stress, family harmony and interest explained 16.5% of total variance for environmental domain QOL. Family harmony and interest were significant factors across all domains, while others influenced a smaller proportion. Quality of life for elderly living in prefab communities should be improved. The authors hope study findings will increase awareness among healthcare providers regarding the quality of life of this vulnerable population. Study results suggest that key steps to promoting QOL in this population include improving family harmony, helping to cultivate well-rounded interests, alleviating economic stresses, providing necessary medical and psychological counseling services, and affording more social support.
Anxiety symptoms among Chinese nurses and the associated factors: a cross sectional study.

PubMed

Gao, Yu-Qin; Pan, Bo-Chen; Sun, Wei; Wu, Hui; Wang, Jia-Na; Wang, Lie

2012-09-14

Nurses are an indispensable component of the work force in the health care system. However, many of them are known to work in a stressful environment which may affect their mental well-being; the situation could be worse in rapidly transforming societies such as China. The purpose of this study was to investigate anxiety symptoms and the associated factors in Chinese nurses working in public city hospitals. A cross-sectional survey was performed for Chinese nurses in public city hospitals of Liaoning Province, northeast China. Seven hospitals in different areas of the province were randomly selected for the study. The Zung Self-Rating Anxiety Scale was used to measure anxiety symptoms. Effort-reward imbalance questionnaire and Job Content Questionnaire were used to assess the work stressors. Univariate analysis and stepwise multivariate logistic regression analysis were used to identify the factors associated with anxiety symptoms. All registered nurses in the seven city hospitals, totaling 1807 registered nurses were surveyed. Of the returned questionnaires, 1437 were valid (79.5%) for analysis. Utilizing the total raw score ≥ 40 as the cut-off point, the prevalence of anxiety symptoms in these nurses was 43.4%. Demographic factors (education, chronic disease and life event), lifestyle factors (regular meals and physical exercise), work conditions (hospital grade, job rank, monthly salary, nurse-patient relationships, job satisfaction and intention of leaving), job content (social support and decision latitude), effort-reward imbalance and overcommitment were all significantly related to the anxiety symptoms. Multivariate logistic regression analysis showed main factors associated with anxiety symptoms were lower job rank (OR 2.501), overcommitment (OR 2.018), chronic diseases (OR 1.541), worse nurse-patient relationship (OR 1.434), higher social support (OR 0.573), lower hospital grade (OR 0.629), taking regular meals (OR 0.719) and higher level of job satisfaction (OR 0.722). A large proportion of Chinese nurses working in public city hospitals had anxiety symptoms, which warrants immediate investigation and intervention from the hospital administrators. Meanwhile, results of the study suggest that proper counseling, promotion of healthy lifestyle behavior and improvements to the social environment in the work place may be helpful toward reducing or preventing the anxiety symptoms.
Risk factors for mental disorders in women survivors of human trafficking: a historical cohort study

PubMed Central

2013-01-01

Background Previous studies have found high levels of symptoms of depression, anxiety, and post-traumatic stress disorder among women survivors of human trafficking. No previous research has described risk factors for diagnosed mental disorders in this population. Methods A historical cohort study of women survivors of trafficked women aged 18 and over who returned to Moldova and registered for assistance with the International Organisation for Migration (IOM). Women were approached by IOM social workers and, if they gave informed consented to participate in the study, interviewed by the research team. At 2–12 months post-return to Moldova, a psychiatrist assessed DSM-IV mental disorders blind to information about women’s pre-trafficking and post-trafficking experiences using the Structured Clinical Interview for DSM-IV (SCID). A backwards stepwise selection procedure was used to create a multivariable regression model of risk factors for DSM-IV mental disorder measured at an average of 6 months post-return. Results 120/176 (68%) eligible women participated. At an average of 6 months post-return, 54% met criteria for any DSM-IV mental disorder: 35.8% of women had PTSD (alone or co-morbid), 12.5% had depression without PTSD and 5.8% had another anxiety disorder. Multivariable regression analysis found that childhood sexual abuse (Adjusted Odds Ratio [AOR] 4.68, 95% CI 1.04-20.92), increased number of post-trafficking unmet needs (AOR 1.80; 95% CI 1.28-2.52) and post-trafficking social support (AOR 0.64; 95% CI 0.52-0.79) were independent risk factors for mental disorder, and that duration of trafficking showed a borderline association with mental disorder (AOR 1.12, 95% CI 0.98-1.29). Conclusions Assessment for mental disorders should be part of re-integration follow-up care for women survivors of human trafficking. Mental disorders at that time, most commonly PTSD and depression, are likely to be influenced by a range of predisposing, precipitating and maintaining factors. Care plans for survivors of trafficking must be based on individual needs, and must apply clinical guidelines for the treatment of PTSD and of depression. Evidence is needed on the effectiveness of therapy for PTSD in survivors of human trafficking. PMID:23914952
Anxiety symptoms among Chinese nurses and the associated factors: a cross sectional study

PubMed Central

2012-01-01

Background Nurses are an indispensable component of the work force in the health care system. However, many of them are known to work in a stressful environment which may affect their mental well-being; the situation could be worse in rapidly transforming societies such as China. The purpose of this study was to investigate anxiety symptoms and the associated factors in Chinese nurses working in public city hospitals. Methods A cross-sectional survey was performed for Chinese nurses in public city hospitals of Liaoning Province, northeast China. Seven hospitals in different areas of the province were randomly selected for the study. The Zung Self-Rating Anxiety Scale was used to measure anxiety symptoms. Effort-reward imbalance questionnaire and Job Content Questionnaire were used to assess the work stressors. Univariate analysis and stepwise multivariate logistic regression analysis were used to identify the factors associated with anxiety symptoms. Results All registered nurses in the seven city hospitals, totaling 1807 registered nurses were surveyed. Of the returned questionnaires, 1437 were valid (79.5%) for analysis. Utilizing the total raw score ≥ 40 as the cut-off point, the prevalence of anxiety symptoms in these nurses was 43.4%. Demographic factors (education, chronic disease and life event), lifestyle factors (regular meals and physical exercise), work conditions (hospital grade, job rank, monthly salary, nurse-patient relationships, job satisfaction and intention of leaving), job content (social support and decision latitude), effort-reward imbalance and overcommitment were all significantly related to the anxiety symptoms. Multivariate logistic regression analysis showed main factors associated with anxiety symptoms were lower job rank (OR 2.501), overcommitment (OR 2.018), chronic diseases (OR 1.541), worse nurse-patient relationship (OR 1.434), higher social support (OR 0.573), lower hospital grade (OR 0.629), taking regular meals (OR 0.719) and higher level of job satisfaction (OR 0.722). Conclusions A large proportion of Chinese nurses working in public city hospitals had anxiety symptoms, which warrants immediate investigation and intervention from the hospital administrators. Meanwhile, results of the study suggest that proper counseling, promotion of healthy lifestyle behavior and improvements to the social environment in the work place may be helpful toward reducing or preventing the anxiety symptoms. PMID:22978466
Characterizing multivariate decoding models based on correlated EEG spectral features.

PubMed

McFarland, Dennis J

2013-07-01

Multivariate decoding methods are popular techniques for analysis of neurophysiological data. The present study explored potential interpretative problems with these techniques when predictors are correlated. Data from sensorimotor rhythm-based cursor control experiments was analyzed offline with linear univariate and multivariate models. Features were derived from autoregressive (AR) spectral analysis of varying model order which produced predictors that varied in their degree of correlation (i.e., multicollinearity). The use of multivariate regression models resulted in much better prediction of target position as compared to univariate regression models. However, with lower order AR features interpretation of the spectral patterns of the weights was difficult. This is likely to be due to the high degree of multicollinearity present with lower order AR features. Care should be exercised when interpreting the pattern of weights of multivariate models with correlated predictors. Comparison with univariate statistics is advisable. While multivariate decoding algorithms are very useful for prediction their utility for interpretation may be limited when predictors are correlated. Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.
Explanation of the variance in quality of life and activity capacity of patients with heart failure by laboratory data.

PubMed

Athanasopoulos, Leonidas V; Dritsas, Athanasios; Doll, Helen A; Cokkinos, Dennis V

2010-08-01

This study was conducted to explain the variance in quality of life (QoL) and activity capacity of patients with congestive heart failure from pathophysiological changes as estimated by laboratory data. Peak oxygen consumption (peak VO2) and ventilation (VE)/carbon dioxide output (VCO2) slope derived from cardiopulmonary exercise testing, plasma N-terminal prohormone of B-type natriuretic peptide (NT-proBNP), and echocardiographic markers [left atrium (LA), left ventricular ejection fraction (LVEF)] were measured in 62 patients with congestive heart failure, who also completed the Minnesota Living with Heart Failure Questionnaire and the Specific Activity Questionnaire. All regression models were adjusted for age and sex. On linear regression analysis, peak VO2 with P value less than 0.001, VE/VCO2 slope with P value less than 0.01, LVEF with P value less than 0.001, LA with P=0.001, and logNT-proBNP with P value less than 0.01 were found to be associated with QoL. On stepwise multiple linear regression, peak VO2 and LVEF continued to be predictive, accounting for 40% of the variability in Minnesota Living with Heart Failure Questionnaire score. On linear regression analysis, peak VO2 with P value less than 0.001, VE/VCO2 slope with P value less than 0.001, LVEF with P value less than 0.05, LA with P value less than 0.001, and logNT-proBNP with P value less than 0.001 were found to be associated with activity capacity. On stepwise multiple linear regression, peak VO2 and LA continued to be predictive, accounting for 53% of the variability in Specific Activity Questionnaire score. Peak VO2 is independently associated both with QoL and activity capacity. In addition to peak VO2, LVEF is independently associated with QoL, and LA with activity capacity.
SPReM: Sparse Projection Regression Model For High-dimensional Linear Regression *

PubMed Central

Sun, Qiang; Zhu, Hongtu; Liu, Yufeng; Ibrahim, Joseph G.

2014-01-01

The aim of this paper is to develop a sparse projection regression modeling (SPReM) framework to perform multivariate regression modeling with a large number of responses and a multivariate covariate of interest. We propose two novel heritability ratios to simultaneously perform dimension reduction, response selection, estimation, and testing, while explicitly accounting for correlations among multivariate responses. Our SPReM is devised to specifically address the low statistical power issue of many standard statistical approaches, such as the Hotelling’s T2 test statistic or a mass univariate analysis, for high-dimensional data. We formulate the estimation problem of SPREM as a novel sparse unit rank projection (SURP) problem and propose a fast optimization algorithm for SURP. Furthermore, we extend SURP to the sparse multi-rank projection (SMURP) by adopting a sequential SURP approximation. Theoretically, we have systematically investigated the convergence properties of SURP and the convergence rate of SURP estimates. Our simulation results and real data analysis have shown that SPReM out-performs other state-of-the-art methods. PMID:26527844
Farm Work-Related Injuries and Risk Factors in South Korean Agriculture.

PubMed

Kim, Hyocher; Räsänen, Kimmo; Chae, Hyeseon; Kim, Kyungsu; Kim, Kyungran; Lee, Kyungsuk

2016-01-01

Agriculture is known to be a risk-filled industry in South Korea, as it is worldwide. The aims of this study were to identify the magnitude of farm work-related injuries and evaluate the association between injury and possible risk factors. Farmers, including farm members (N = 16,160), were surveyed. After excluding 7 subjects with missing data in questions about injury, 16,153 farmer responses were used for the analysis. Of the 16,153 farmers, 3.6% answered having at least one farm work-related injury requiring outpatient treatment or hospitalization during 2012. The proportion of injured men (4.3%) was 1.5 times higher than women (2.9%). From an age perspective, the proportion was 1.3% of those aged 49 or below, 2.7% of those aged 50-59, 4.2% of those aged 60-69, 4.2% of those aged 70-79, and 3.1% of those aged 80 or above. We used a multivariate logistic regression analysis with a stepwise model (forward) for risk factors (gender, age, farm ownership, farm type, work years in agriculture, work months during 2012, night work experience, and work experience under the influence of alcohol). The increased risk of farm work-related injuries significantly remained associated with age, farm ownership, and experience of night work. Further studies should be conducted to consistently identify injury characteristics, especially for old farmers, considering the crop cultivation in Asian countries.
Transcardiac increase in norepinephrine and prognosis in patients with chronic heart failure.

PubMed

Tsutamoto, Takayoshi; Nishiyama, Keizo; Sakai, Hiroshi; Tanaka, Toshinari; Fujii, Masanori; Yamamoto, Takashi; Yamaji, Masayuki; Horie, Minoru

2008-12-01

No previous study has compared the transcardiac gradient of norepinephrine (NE) and the prognosis of patients with chronic heart failure (CHF). To evaluate the prognostic role of the transcardiac gradient of NE in patients with CHF. We measured haemodynamic parameters and plasma levels of NE, brain natriuretic peptide (BNP) and N-terminal proBNP (NT-proBNP) in the aortic root (AO) and coronary sinus (CS) in 356 consecutive patients with CHF. During a median follow-up of 3.5 years, 40 patients died. Transcardiac gradients of BNP (273+/-276 vs. 472+/-433 pg/mL, p<0.0001), NT-proBNP (417+/-700 vs. 928+/-1093 pg/mL, p<0.0001) and NE (114+/-160 vs. 473+/-992 pg/mL, p<0.0001) were significantly higher in non-survivors than survivors. After adjustment for clinical variables associated with CHF including haemodynamics and neurohumoral factors, the transcardiac gradient of NE (p<0.0001) and plasma log NT-proBNP (p<0.0001) were independent prognostic predictors. Among 67 patients in whom 123I-metaiodobenzylguanidine (MIBG) could be performed, transcardiac increase in NE was correlated with the washout rate (r=0.398, p=0.0009) and was a superior predictor of mortality than MIBG parameters on stepwise multivariable Cox proportional hazards regression analyses. The transcardiac increase in NE is an independent and useful prognostic predictor for evaluating the prognosis of CHF patients.
Dietary recommendations for infants and toddlers among pediatric dentists in North Carolina.

PubMed

Sim, Chien J; Iida, Hiroko; Vann, William F; Quinonez, Rocio B; Steiner, Michael J

2014-01-01

The purposes of this study were to: describe practice patterns, knowledge, and attitudes of pediatric dentists in North Carolina (N.C.) in delivering dietary recommendations to the parents/caregivers of infants and toddlers; and identify barriers that limit the implementation of related recommendations. Our survey instrument included 30 questions covering eight domains of barriers to guideline adherence. Surveys were mailed to 150 practicing pediatric dentists in N.C. Descriptive and bivariate analyses were performed. Exploratory factor analysis was used to identify subscales and inform the multivariable model. The response rate was 57 percent (86/150), 80 percent of whom reported providing infant and toddler feeding recommendations routinely. Knowledge of and agreement with the recommendation regarding breast-feeding duration was lower than that for bottle-feeding recommendations. Stepwise logistic regression analysis indicated that survey respondents were less likely to provide dietary recommendations regularly to the parents/caregivers of infants and toddlers when they have practice constraints and the respondents disagree with American Academy of Pediatrics (AAP) and American Academy of Pediatric Dentistry (AAPD) recommendations on bottle and juice consumption. Most respondents routinely provide dietary recommendations to the parents/caregivers of infants and toddlers. Disagreement with AAP and AAPD recommendations on bottle, and juice consumption as well as practice constraints impedes practitioners from providing dietary recommendations regularly to the parents/caregivers of infants and toddlers.
Trends in presentation, management and survival of patients with de novo metastatic breast cancer in a Southeast Asian setting.

PubMed

Bhoo-Pathy, Nirmala; Verkooijen, Helena Marieke; Tan, Ern-Yu; Miao, Hui; Taib, Nur Aishah Mohd; Brand, Judith S; Dent, Rebecca A; See, Mee-Hoong; Subramaniam, ShriDevi; Chan, Patrick; Lee, Soo-Chin; Hartman, Mikael; Yip, Cheng-Har

2015-11-05

Up to 25% of breast cancer patients in Asia present with de novo metastatic disease. We examined the survival trends of Asian patients with metastatic breast cancer over fifteen years. The impact of changes in patient's demography, tumor characteristics, tumor burden, and treatment on survival trend were examined. Patients with de novo metastatic breast cancer from three hospitals in Malaysia and Singapore (N = 856) were grouped by year of diagnosis: 1996-2000, 2001-2005 and 2006-2010. Step-wise multivariable Poisson regression was used to estimate the contribution of above-mentioned factors on the survival trend. Proportions of patients presenting with metastatic breast cancer were 10% in 1996-2000, 7% in 2001-2005, and 9% in 2006-2010. Patients in 2006-2010 were significantly older, appeared to have higher disease burden, and received more chemotherapy, endocrine therapy, and surgery of primary tumor. The three-year relative survival in the above periods were 20·6% (95% CI: 13·9%-28·2%), 28·8% (95% CI: 23·4%-34·2%), and 33·6% (95% CI: 28·8%-38·5%), respectively. Adjustment for treatment considerably attenuated the relative excess risk of mortality in recent years, compared to other factors. Substantial improvements in survival were observed in patients with de novo metastatic breast cancer in this study.
Prediction of thyroidal 131I effective half-life in patients with Graves' disease.

PubMed

Zhang, Ruiguo; Zhang, Guizhi; Wang, Renfei; Tan, Jian; He, Yajing; Meng, Zhaowei

2017-10-06

Calculation of effective thyroidal half-life (Teff) of iodine-131( 131 I) is cumbersome and tedious. The aim of this study was to investigate factors that could be used to predict Teff and to develop a Teff prediction model in Graves' disease patients. A total of 256 patients with GD were involved in this study. We investigated the influences of age, gender, disease duration, thyroid weight, antithyroid drugs, antithyroid drugs discontinuation period (ADP), thyroid function indexes, thyroid autoantibodies, thyroid-stimulating hormone receptor antibody (TRAb) level and radioactive iodine uptake (RAIU) values before 131 I therapy on Teff, applying univariate and multivariate analyses. Teff correlated negatively with thyroid peroxidase antibody, TRAb and thyroid weight, as well as positively with 24-hour, 48-hour, and 72-hour RAIU. Additionally, a longer ADP (especially≥ 14d) or without antithyroid drugs before 131 I therapy led to a longer Teff. Stepwise multiple linear regression analysis showed that 24-hour and 72-hour RAIU were statistically significant predictors of Teff ( P <0.001). The relationship was: predictive Teff=5.277+0.295×72-hour RAIU-0.217×24-hour RAIU (r =0.865, P < 0.001). The present results indicate that prediction of Teff from 24-hour and 72-hour RAIU is feasible in patients with Graves' disease, with high prediction accuracy.
Determinants of Emergency Medical Services Utilization Among Acute Ischemic Stroke Patients in Hubei Province in China.

PubMed

Yin, Xiaoxv; Yang, Tingting; Gong, Yanhong; Zhou, Yanfeng; Li, Wenzhen; Song, Xingyue; Wang, Mengdie; Hu, Bo; Lu, Zuxun

2016-03-01

Emergency medical services (EMS) can effectively shorten the prehospital delay for patients with acute ischemic stroke. This study aimed to investigate EMS utilization and its associated factors in patients with acute ischemic stroke in China. A cross-sectional study was conducted from October 1, 2014, to January 31, 2015, which included 2096 patients admitted for acute ischemic stroke from 66 hospitals in Hubei province in China. A multivariable stepwise logistic regression model was undertaken to identify the factors associated with EMS utilization. Of the 2096 participants, only 323 cases (15.4%) used EMS. Those acute ischemic stroke patients who previously used EMS (odds ratio [OR] =9.8), whose National Institutes of Health Stroke Scale score was ≥10 (OR=3.7), who lived in urban communities (OR=2.5), who had sudden onset of symptoms (OR=2.4), who experienced their first stroke (OR=1.8), and who recognized initial symptom as stroke (OR=1.4) were more likely to use EMS. Additionally, when acute ischemic stroke patients' stroke symptom were noticed first by others (OR=2.1), rather than by the patients, EMS was more likely to be used. A very low proportion of patients with acute ischemic stroke used the EMS in Hubei province in China. Considerable education programs are required regarding knowledge of potential symptoms and the importance of EMS for stroke. © 2016 American Heart Association, Inc.
Ratio of C-Reactive Protein to Albumin Predicts Muscle Mass in Adult Patients Undergoing Hemodialysis

PubMed Central

Chen, Yu-Tong; Wu, Pei-Yu; Chen, Hsi-Hsien; Chen, Tso-Hsiao; Hsu, Yung-Ho

2016-01-01

Recent studies have indicated that the ratio of C-reactive protein to albumin (CRP–Alb ratio) is associated with clinical outcomes in patients with disease. We examined the predictive value of this ratio in patients undergoing hemodialysis (HD). In this cross-sectional study, 91 eligible adult HD patients were analyzed, and the correlation between the CRP–Alb ratio and skeletal muscle mass normalized for body weight (SMM/wt; estimated using a bioelectrical impedance analyzer) was investigated. The mean age of the study participants was 54.9 ± 6.6 years (ranging from 27 to 64 years); 43 (47.2%) were men. The mean values for the SMM/wt were 39.1% ± 5.4%. The CRP–Alb ratio was found to be negatively correlated with SMM/wt (r = −0.33, P = 0.002) and creatinine (r = −0.20, P = 0.056). All the univariate significant and nonsignificant relevant covariates were selected for multivariable stepwise regression analysis. We determined that the homeostasis model assessment-estimated insulin resistance and CRP–Alb ratio were independent risk determinants for SMM/wt (βHOMA-IR = −0.18 and βCRP–Alb ratio = −3.84, adjusted R2 = 0.32). This study indicated that the CRP–Alb ratio may help clinicians in predicting muscle mass in adult patients undergoing HD. PMID:27768746

Factors Associated with Blunt Cerebrovascular Injury in Patients with Cervical Spine Injury

PubMed Central

NAKAJIMA, Hiroyuki; NEMOTO, Manabu; TORIO, Tetsuya; TAKEDA, Ririko; OOIGAWA, Hidetoshi; ARAKI, Ryuichiro; KURITA, Hiroki

2014-01-01

Blunt cerebrovascular injury (BCVI) is known to be a potentially fatal complication of cervical spine injury (CSI). Methods for screening the appropriate population remain to be elucidated, especially in Japan. This retrospective study was conducted to predict the risk factors relevant to BCVIs. Among 92 patients with CSI transferred to our institution from April 2007 to March 2012, 40 patients (35 men, 5 women) with neurological deficits and/or significant cervical spine fracture including fracture of transversarium, facet, body, lamina, and spinous process, underwent multi-detector computed tomography angiography (MDCTA) and magnetic resonance angiography (MRA), which identified 10 patients with BCVI [2 carotid artery injuries (BCAIs) and 9 vertebral artery injuries (BVAIs); 1 patient suffered both]. Univariate analyses exploring associations between individual risk factors and BCVI and BVAI were performed using Fisher's exact test and Chi-square test for dichotomous variables and the unpaired t-test for continuous variables. Multiple logistic regression analyses for BCVI and BVAI were carried out using stepwise methods. On univariate and multivariate analysis, hyperextension injury was significantly associated with BVAI (p = 0.01 and p = 0.02), and subluxation (dislocation of vertebral body > 5 mm) was a significant predictor of BCVI (p = 0.04 and p = 0.03) and BVAI (p = 0.01 and p = 0.01). Prompt evaluation for BCVIs is recommended in CSI patients with hyperextension injury and dislocation of the vertebral body. PMID:24390186
Prognostic value of 6-minute walk corridor test in patients with mild to moderate heart failure: comparison with other methods of functional evaluation.

PubMed

Rostagno, Carlo; Olivo, Giuseppe; Comeglio, Marco; Boddi, Vieri; Banchelli, Michela; Galanti, Giorgio; Gensini, Gian Franco

2003-06-01

The study was designed to evaluate the prognostic value of the 6-min walk test (6MWT) in patients with mild to moderate congestive heart failure (CHF). Two hundred and fourteen patients (119 men and 95 women, mean age 64 years) were followed for a mean period of 34 months to assess event-free survival (death, heart transplantation). Sixty-six patients (34%) died (63 cardiovascular causes, 2 cancer and 1 stroke) and five patients underwent heart transplantation. For patients who walked <300 m during the 6MWT, survival was 62% compared with 82% in patients who walked 300-450 m or>450 m. With univariate analysis, NYHA class was the strongest predictor of death. LVEF (P<0.0001), aetiology of heart failure (P<0.001), LV filling pattern (P=0.002) and 6MWT distance (P<0.01) were all significantly related to survival. No significant relationship was found between survival, peak oxygen consumption or anaerobic threshold. Multivariate analysis using the Cox-stepwise regression model showed that LV fractional shortening (P<0.009) and 6MWT distance (P<0.0005) were the strongest prognostic markers. A 6MWT distance of <300 m is a simple and useful prognostic marker of subsequent cardiac death in unselected patients with mild to moderate CHF.
Associations of childhood eczema severity: A US population based study

PubMed Central

Silverberg, Jonathan I.; Simpson, Eric L.

2014-01-01

Little is known about predictors of eczema severity in the US population. We sought to determine the distribution and associations of childhood eczema severity in the US. We analyzed data from the 2007 National Survey of Children's Health, a prospective questionnaire-based study of a nationally representative sample of 91,642 children (0-17yr). The prevalence of childhood eczema was 12.97% (95% confidence interval [95% CI]=12.42–13.53); 67.0% (95% CI: 64.8–69.2) had mild, 26.0% (95% CI: 23.9–28.1) moderate and 7.0% (95% CI: 5.8–8.3) severe disease. There was significant statewide-variation of the distribution of eczema severity (Rao-Scott chi square, P=0.004), with highest rates of severe disease in Northeastern and Midwestern states. In univariate models, eczema severity was increased with older age, African-American and Hispanic race/ethnicity, lower household income, oldest child in the family, home with a single mother, lower paternal/maternal education level, maternal general health, maternal/paternal emotional health, dilapidated housing and garbage on the streets. In multivariate survey logistic regression models using stepwise and backward selection, moderate–severe eczema was associated with older age, lower household income and fair or poor maternal health, but inversely associated with birthplace outside the US. These data indicate that environmental and/or lifestyle factors play an important role in eczema severity. PMID:24819283
Influence of body mass index on the growth hormone response to provocative testing in short children without growth hormone deficiency.

PubMed

Lee, Jieun; Yoon, Juyoung; Kang, Min Jae; Lee, Young Ah; Lee, Seong Yong; Shin, Choong Ho; Yang, Sei Won

2013-09-01

Obesity and its related factors are known to suppress the secretion of growth hormone (GH). We aimed to evaluate the influence of body mass index (BMI) on the peak GH response to provocative testing in short children without GH deficiency. We conducted a retrospective review of medical records of 88 children (2-15 yr old) whose height was less than 3 percentile for one's age and sex, with normal results (peak GH level > 10 ng/mL) of GH provocative testing with clonidine and dopamine. Peak stimulated GH level, height, weight, pubertal status and serum IGF-1 level were measured. Univariate analysis showed that the BMI standard deviation score (SDS) correlated negatively with the natural log (ln) of the peak stimulated GH level (ln peak GH). BMI SDS did not correlate significantly with sex, age, pubertal status, or ln IGF-1 level. BMI SDS correlated negatively with ln peak GH level induced by clonidine but not by dopamine. In stepwise multivariate regression analysis, BMI SDS was the only significant predictor of ln peak GH level in the combination of tests and the clonidine test, but not in the dopamine test. In children without GH deficiency, BMI SDS correlates negatively with the peak GH level. BMI SDS should be included in the analysis of the results of GH provocation tests, especially tests with clonidine.
Physicians' reactions to uncertainty in the context of shared decision making.

PubMed

Politi, Mary C; Légaré, France

2010-08-01

Physicians' reactions towards uncertainty may influence their willingness to engage in shared decision making (SDM). This study aimed to identify variables associated with physician's anxiety from uncertainty and reluctance to disclose uncertainty to patients. We conducted a cross-sectional secondary analysis of longitudinal data of an implementation study of SDM among primary care professionals (n=122). Outcomes were anxiety from uncertainty and reluctance to disclose uncertainty to patients. Hypothesized factors that would be associated with outcomes included attitude, social norm, perceived behavioral control, intention to implement SDM in practice, and socio-demographics. Stepwise linear regression was used to identify predictors of anxiety from uncertainty and reluctance to disclose uncertainty to patients. In multivariate analyses, anxiety from uncertainty was influenced by female gender (beta=0.483; p=0.0039), residency status (1st year: beta=0.600; p=0.001; 2nd year: beta=0.972; p<0.001), and number of hours worked per week (beta=-0.012; p=0.048). Reluctance to disclose uncertainty to patients was influenced by having more years in formal education (beta=-1.996; p=0.012). Variables associated with anxiety from uncertainty differ from those associated with reluctance to disclose uncertainty to patients. Given the importance of communicating uncertainty during SDM, measuring physicians' reactions to uncertainty is essential in SDM implementation studies. Copyright 2009 Elsevier Ireland Ltd. All rights reserved.
Subjective cognitive complaints, psychosocial factors and nursing work function in nurses providing direct patient care.

PubMed

Barbe, Tammy; Kimble, Laura P; Rubenstein, Cynthia

2018-04-01

The aim of this study was to examine relationships among subjective cognitive complaints, psychosocial factors and nursing work function in nurses providing direct patient care. Cognitive functioning is a critical component for nurses in the assurance of error prevention, identification and correction when caring for patients. Negative changes in nurses' cognitive and psychosocial functioning can adversely affect nursing care and patient outcomes. A descriptive correlational design with stratified random sampling. The sample included 96 nurses from the major geographic regions of the United States. Over 9 months in 2016-2017, data were collected using a web-based survey. Stepwise multiple linear regression analyses were used to examine relationships among subjective cognitive complaints, psychosocial factors and nursing work function. Overall, participants reported minimal work function impairment and low levels of subjective cognitive complaints, depression and stress. In multivariate analyses, depression was not associated with nurses' work function. However, perceived stress and subjective concerns about cognitive function were associated with greater impairment of work function. Nurses experiencing subjective cognitive complaints should be encouraged to address personal and environmental factors that are associated with their cognitive status. Additionally, stress reduction in nurses should be a high priority as a potential intervention to promote optimal functioning of nurses providing direct patient care. Healthcare institutions should integrate individual and institutional strategies to reduce factors contributing to workplace stress. © 2017 John Wiley & Sons Ltd.
Predictor variables of performance in recreational male long-distance inline skaters.

PubMed

Knechtle, Beat; Knechtle, Patrizia; Rüst, Christoph Alexander; Senn, Oliver; Rosemann, Thomas; Lepers, Romuald

2011-06-01

We investigated the associations between selected anthropometric and training characteristics with race time in 84 recreational male long-distance inline skaters at the longest inline marathon in Europe, the 'Inline One-eleven' over 111 km in Switzerland, using bi- and multivariate analysis. The mean (s) race time was 264 (41) min. The bivariate analysis showed that age (r = 0.30), body mass (r = 0.42), body mass index (r = 0.35), circumference of upper arm (r = 0.32), circumference of thigh (r = 0.29), circumference of calf (r = 0.38), skin-fold of thigh (r = 0.22), skin-fold of calf (r = 0.27), the sum of skin-folds (r = 0.43), percent body fat (r = 0.45), duration per training unit in inline skating (r = 0.33), and speed during training (r = -0.46) were significantly and positively correlated to race time. Stepwise multiple regression showed that duration per training unit (P = 0.003), age (P = 0.029) and percent body fat (P = 0.016) were the best correlated with race time. Race time in a long-distance inline race such as the 'Inline One-eleven' over 111 km with a mean race time of ∼260 min might be predicted by the following equation (r(2) = 0.41): Race time (min) = 114.91 + 0:51* (duration per training unit, min) + 0:85* (age, years) +3:78* (body fat, %) for recreational long-distance inline skaters.
Household food insecurity is associated with depressive symptoms among low-income pregnant Latinas

PubMed Central

Hromi-Fiedler, Amber; Bermúdez-Millán, Angela; Segura-Pérez, Sofia; Pérez-Escamilla, Rafael

2010-01-01

Latinas experience high rates of poverty, household food insecurity, and prenatal depression. To date, only one U.S. study has examined the relationship between household food insecurity and prenatal depression, yet it focused primarily on non-Latina white and non-Latina Black populations. Therefore, this study examined the independent association of household food insecurity with depressive symptoms among low-income pregnant Latinas. This cross-sectional study included 135 low income pregnant Latinas living in Hartford, Connecticut. Women were assessed at enrollment for household food security during pregnancy using an adapted and validated version of the U.S. Household Food Security Survey Module. Prenatal depressive symptoms were assessed using the Center for Epidemiological Studies Depression Scale (CES-D). A cutoff of ≥ 21 was used to indicate elevated levels of prenatal depressive symptoms (EPDS). Multivariate backwards stepwise logistic regression was used to identify risk factors for EPDS. Almost one third of participants had EPDS. Women who were food insecure were more likely to experience EPDS compared to food secure women (OR=2.59; 95% CI=1.03–6.52). Being primiparous, experiencing heartburn and reporting poor/fair health during pregnancy, as well as having a history of depression were also independent risk factors for experiencing EPDS. Findings from this study suggest the importance of assessing household food insecurity when evaluating depression risk among pregnant Latinas. PMID:20735732
Predictors of Enteral Tube Feeding in Hospitalized Older Adults.

PubMed

Crenitte, Milton Roberto Furst; Avelino-Silva, Thiago Junqueira; Apolinario, Daniel; Curiati, Jose Antonio Esper; Campora, Flavia; Jacob-Filho, Wilson

2017-11-01

Despite general recognition that enteral tube feeding (ETF) is frequently employed in long-term care facilities and patients with dementia, remarkably little research has determined which factors are associated with its use in acutely ill older adults. In this study, we aimed to investigate determinants of ETF introduction in hospitalized older adults. We examined a retrospective cohort of acutely ill patients, aged 60 years and older, admitted to a university hospital's geriatric ward from 2014-2015, in São Paulo, Brazil. The main outcome was the introduction of ETF during hospitalization. Predictors of interest included age, sex, referring unit, comorbidity burden, functional status, malnutrition, depression, dementia severity, and delirium. Multivariate analysis was performed using backward stepwise logistic regression. A total of 214 cases were included. Mean age was 81 years, and 63% were women. Malnutrition was detected in 47% of the cases, dementia in 46%, and delirium in 36%. ETF was initiated in 44 (21%) admissions. Independent predictors of ETF were delirium (odds ratio [OR], 4.83; 95% CI, 2.12-11.01; P < .001) and total functional dependency (OR, 8.95; 95% CI, 2.87-27.88; P < .001). Malnutrition was not independently associated with ETF. One in five acutely ill older adults used ETF while hospitalized. Delirium and functional dependency were independent predictors of its introduction. Risks and benefits of enteral nutrition in this particular context need to be further explored.
Prognostic features and clinical presentation of acute idiopathic enterocolitis in horses

PubMed Central

Staempfli, Henry R.; Townsend, Hugh G.G.; Prescott, John F.

1991-01-01

Clinical and hematological changes observed on presentation of 47 horses referred to the Ontario Veterinary College with acute idiopathic colitis were analyzed for their prognostic features. Cases of acute enterocolitis were characterized by fever, dehydration, abnormalities of serum electrolyte concentrations, azotemia, hypoalbuminemia, and increased serum concentrations of muscle enzymes. Severely dehydrated horses were seven times more likely to die or be euthanized than those that were not dehydrated. Other factors associated with failure to survive included the following: increased hematocrit, increased number of band neutrophils, increased serum creatinine and urea concentrations, and decreased blood pH and increasingly negative base excess. The results of multivariate variable analysis (stepwise logistic regression) suggested that, among the variables tested, base excess was the best predictor of death or survival. Twenty of 47 horses died or were euthanized. Reasons for death or euthanasia included: severe disseminated intravascular coagulation, unresponsiveness of severe metabolic acidosis and hypoproteinemia to treatments, and severity of colonic lesions on exploratory laparotomy. Of the surviving horses, three developed chronic laminitis (two were destroyed) and five developed jugular vein thrombosis. Fourteen of 16 horses for which subsequent histories were available returned to normal function. Early recognition of the disease, combined with early and aggressive correction of dehydration and of acid-base imbalance, may be important determinants of survival in horses with acute idiopathic colitis. PMID:17423769
Investigation of the key determinants of Asian nurses’ quality of life

PubMed Central

MAKABE, Sachiko; KOWITLAWAKUL, Yanika; NURUMAL, Mohd Said; TAKAGAI, Junko; WICHAIKHUM, Orn-Anong; WANGMO, Neyzang; YAP, Suk Foon; KUNAVIKTIKUL, Wipada; KOMATSU, Junko; SHIRAKAWA, Hideko; KIMURA, Yutaka; ASANUMA, Yoshihiro

2018-01-01

The study aimed to compare nurses’ quality of life and investigate key determinants among Asian countries with different economic status. A cross-sectional survey was conducted across five Asian countries (Japan, Singapore, Malaysia, Thailand, and Bhutan). Quality of life (WHOQOL-BREF), job stress (National Institute of Occupational Safety and Health questionnaire), and demographic data were assessed. Stepwise multivariate linear regression analysis was performed to identify the key determinants of quality of life. Participants were 3,829 nurses (response rate: 82%) with a mean age of 33 ± 10 yr and majority were women (92%). Regarding quality of life, Bhutan yielded the highest scores, followed by Malaysia, Thailand, Singapore, and Japan, and these results were statistically significant. The key determinants that were significantly related to quality of life were “stress coping ability,” “life satisfaction,” “Japan,” “social support,” “job stress,” and “Singapore” (adjusted R2=0.46). In conclusion, nurses’ quality of life differs across Asian countries and is not linked to the country’s economic development. To maintain a good quality of life for nurses, an international exchange program like international nursing conferences for work environment and staff coping strategies is recommended to broaden institution’ minds and share experiences and exchange views to be able to realize their own problems and discover global solutions to them. PMID:29491251
Lesion symptom map of cognitive-postural interference in multiple sclerosis.

PubMed

Ruggieri, Serena; Fanelli, Fulvia; Castelli, Letizia; Petsas, Nikolaos; De Giglio, Laura; Prosperini, Luca

2018-04-01

To investigate the disease-altered structure-function relationship underlying the cognitive-postural interference (CPI) phenomenon in multiple sclerosis (MS). We measured postural sway of 96 patients and 48 sex-/age-matched healthy controls by force platform in quiet standing (single-task (ST)) while performing the Stroop test (dual-task (DT)) to estimate the dual-task cost (DTC) of balance. In patient group, binary T2 and T1 lesion masks and their corresponding lesion volumes were obtained from magnetic resonance imaging (MRI) of brain. Normalized brain volume (NBV) was also estimated by SIENAX. Correlations between DTC and lesion location were determined by voxel-based lesion symptom mapping (VLSM) analyses. Patients had greater DTC than controls ( p < 0.001). Among whole brain MRI metrics, only T1 lesion volume correlated with DTC ( r = -0.27; p < 0.01). However, VLSM analysis did not reveal any association with DTC using T1 lesion masks. By contrast, we found clusters of T2 lesions in distinct anatomical regions (anterior and superior corona radiata, bilaterally) to be correlated with DTC ( p < 0.01 false discovery rate (FDR)-corrected). A multivariable stepwise regression model confirmed findings from VLSM analysis. NBV did not contribute to fit the model. Our findings suggest that the CPI phenomenon in MS can be explained by disconnection along specific areas implicated in task-switching abilities and divided attention.
Knowledge of and Attitudes to Influenza Vaccination among Community Pharmacists in Catalonia (Spain). 2013-2014 Season: A Cross Sectional Study.

PubMed

Toledo, Diana; Soldevila, Núria; Guayta-Escolies, Rafel; Lozano, Pau; Rius, Pilar; Gascón, Pilar; Domínguez, Angela

2017-07-11

Annual recommendations on influenza seasonal vaccination include community pharmacists, who have low vaccination coverage. The aim of this study was to investigate the relationship between influenza vaccination in community pharmacists and their knowledge of and attitudes to vaccination. An online cross-sectional survey of community pharmacists in Catalonia, Spain, was conducted between September and November 2014. Sociodemographic, professional and clinical variables, the history of influenza vaccination and knowledge of and attitudes to influenza and seasonal influenza vaccination were collected. The survey response rate was 7.33% (506 out of 6906); responses from 463 community pharmacists were included in the final analyses. Analyses were performed using multivariable logistic regression models and stepwise backward selection method for variable selection. The influenza vaccination coverage in season 2013-2014 was 25.1%. There was an association between vaccination and correct knowledge of the virus responsible for epidemics (adjusted Odds Ratio (aOR) = 1.74; 95% CI 1.03-2.95), recommending vaccination in the postpartum (aOR = 3.63; 95% CI 2.01-6.55) and concern about infecting their clients (aOR = 5.27; 95% CI 1.88-14.76). In conclusion, community pharmacists have a very low influenza vaccination coverage, are not very willing to recommend vaccination to all their customers but they are concerned about infecting their clients.
Increased Risk for Falling Associated with Subtle Cognitive Impairment: Secondary Analysis of a Randomized Clinical Trial

PubMed Central

Gleason, Carey E.; Gangnon, Ronald E.; Fischer, Barbara L.; Mahoney, Jane E.

2009-01-01

Background/Aims Having dementia increases patients’ risk for accidental falls. However, it is unknown if having mild cognitive deficits also elevates a person's risk for falls. This study sought to clarify the relationship between subtle cognitive impairment, measured with a widely-used, clinic-based assessment, the Mini Mental State Exam (MMSE), and risk for falls. Methods In a secondary analysis of the Kenosha County Falls Prevention Study, a randomized controlled trial targeting older adults at risk for falls, we examined the association between baseline MMSE and prospective rate of falls over 12 months in 172 subjects randomized to control group. Results Using univariate analysis, the rate of falls increased with each unit decrease in MMSE score down to at least 22 (rate ratio 1.25, 95% confidence interval (CI) 1.09–1.45, p = 0.0026). Using stepwise multivariate regression, controlling for ability to perform activities of daily living, use of assistive device, current exercise, and arthritis, the association between MMSE score and falls rate persisted (rate ratio 1.20, 95% CI 1.03–1.40, p = 0.021). Conclusion Minimal decrements on the MMSE were associated with elevations in rate of falls, suggesting that subtle cognitive deficits reflected in MMSE scores above a cut-off consistent with a diagnosis of dementia, can influence risk for falls. PMID:19602883
Airway structural alterations selectively associated with severe asthma.

PubMed

Benayoun, Laurent; Druilhe, Anne; Dombret, Marie-Christine; Aubier, Michel; Pretolani, Marina

2003-05-15

To identify airway pathologic abnormalities selectively associated with severe asthma, we examined 10 control subjects, 10 patients with intermittent asthma, 15 patients with mild-to-moderate persistent asthma, 15 patients with severe persistent asthma, and 10 patients with chronic obstructive pulmonary disease. Bronchial biopsies were assessed for epithelial integrity; subepithelial basement membrane (SBM) thickness; collagen type III deposition; eosinophil, neutrophil, and fibroblast numbers; mucous gland and airway smooth muscle (ASM) areas; SBM-ASM distance; ASM hypertrophy (increased cell size); and the expression of the contractile proteins alpha-actin, smooth muscle myosin heavy-chain isoforms, myosin light-chain kinase, and the phosphorylated form of the regulatory light chain of myosin. Neither mucosal eosinophilia nor neutrophilia, epithelial damage, or SBM thickness reflected asthma severity. In contrast, higher numbers of fibroblasts (p < 0.001), an increase in collagen type III deposition (p < 0.020), larger mucous gland (p < 0.040) and ASM (p < 0.001) areas, augmented ASM cell size (p < 0.001), and myosin light-chain kinase expression (p < 0.005) distinguished patients with severe persistent asthma from patients with milder disease or with chronic obstructive pulmonary disease. Stepwise multivariate regression analysis established that fibroblast numbers and ASM cell size were negatively associated with prebronchodilator and postbronchodilator FEV1 values in patients with asthma. We conclude that fibroblast accumulation and ASM hypertrophy in proximal airways are selective determinants of severe persistent asthma.
Variable Resistance to Plasminogen Activator Initiated Fibrinolysis for Intermediate-Risk Pulmonary Embolism

PubMed Central

Stubblefield, William B.; Alves, Nathan J.; Rondina, Matthew T.; Kline, Jeffrey A.

2016-01-01

Background We examine the clinical significance and biomarkers of tissue plasminogen activator (tPA)-catalyzed clot lysis time (CLT) in patients with intermediate-risk pulmonary embolism (PE). Methods Platelet-poor, citrated plasma was obtained from patients with PE. Healthy age- and sex-matched patients served as disease-negative controls. Fibrinogen, α2-antiplasmin, plasminogen, thrombin activatable fibrinolysis inhibitor (TAFI), plasminogen activator Inhibitor 1 (PAI-1), thrombin time and D-dimer were quantified. Clotting was induced using CaCl2, tissue factor, and phospholipid. Lysis was induced using 60 ng/mL tPA. Time to 50% clot lysis (CLT) was assessed by both thromboelastography (TEG) and turbidimetry (A405). Results Compared with disease-negative controls, patients with PE exhibited significantly longer mean CLT on TEG (+2,580 seconds, 95% CI 1,380 to 3,720 sec). Patients with PE and a short CLT who were treated with tenecteplase had increased risk of bleeding, whereas those with long CLT had significantly worse exercise tolerance and psychometric testing for quality of life at 3 months. A multivariate stepwise removal regression model selected PAI-1 and TAFI as predictive biomarkers of CLT. Conclusion The CLT from TEG predicted increased risk of bleeding and clinical failure with tenecteplase treatment for intermediate-risk PE. Plasmatic PAI-1 and TAFI were independent predictors of CLT. PMID:26866684
Obesity as a risk factor for developing functional limitation among older adults: A conditional inference tree analysis.

PubMed

Cheng, Feon W; Gao, Xiang; Bao, Le; Mitchell, Diane C; Wood, Craig; Sliwinski, Martin J; Smiciklas-Wright, Helen; Still, Christopher D; Rolston, David D K; Jensen, Gordon L

2017-07-01

To examine the risk factors of developing functional decline and make probabilistic predictions by using a tree-based method that allows higher order polynomials and interactions of the risk factors. The conditional inference tree analysis, a data mining approach, was used to construct a risk stratification algorithm for developing functional limitation based on BMI and other potential risk factors for disability in 1,951 older adults without functional limitations at baseline (baseline age 73.1 ± 4.2 y). We also analyzed the data with multivariate stepwise logistic regression and compared the two approaches (e.g., cross-validation). Over a mean of 9.2 ± 1.7 years of follow-up, 221 individuals developed functional limitation. Higher BMI, age, and comorbidity were consistently identified as significant risk factors for functional decline using both methods. Based on these factors, individuals were stratified into four risk groups via the conditional inference tree analysis. Compared to the low-risk group, all other groups had a significantly higher risk of developing functional limitation. The odds ratio comparing two extreme categories was 9.09 (95% confidence interval: 4.68, 17.6). Higher BMI, age, and comorbid disease were consistently identified as significant risk factors for functional decline among older individuals across all approaches and analyses. © 2017 The Obesity Society.
Basic principles of Hasse diagram technique in chemistry.

PubMed

Brüggemann, Rainer; Voigt, Kristina

2008-11-01

Principles of partial order applied to ranking are explained. The Hasse diagram technique (HDT) is the application of partial order theory based on a data matrix. In this paper, HDT is introduced in a stepwise procedure, and some elementary theorems are exemplified. The focus is to show how the multivariate character of a data matrix is realized by HDT and in which cases one should apply other mathematical or statistical methods. Many simple examples illustrate the basic theoretical ideas. Finally, it is shown that HDT is a useful alternative for the evaluation of antifouling agents, which was originally performed by amoeba diagrams.
EXTENDING MULTIVARIATE DISTANCE MATRIX REGRESSION WITH AN EFFECT SIZE MEASURE AND THE ASYMPTOTIC NULL DISTRIBUTION OF THE TEST STATISTIC

PubMed Central

McArtor, Daniel B.; Lubke, Gitta H.; Bergeman, C. S.

2017-01-01

Person-centered methods are useful for studying individual differences in terms of (dis)similarities between response profiles on multivariate outcomes. Multivariate distance matrix regression (MDMR) tests the significance of associations of response profile (dis)similarities and a set of predictors using permutation tests. This paper extends MDMR by deriving and empirically validating the asymptotic null distribution of its test statistic, and by proposing an effect size for individual outcome variables, which is shown to recover true associations. These extensions alleviate the computational burden of permutation tests currently used in MDMR and render more informative results, thus making MDMR accessible to new research domains. PMID:27738957
Extending multivariate distance matrix regression with an effect size measure and the asymptotic null distribution of the test statistic.

PubMed

McArtor, Daniel B; Lubke, Gitta H; Bergeman, C S

2017-12-01

Person-centered methods are useful for studying individual differences in terms of (dis)similarities between response profiles on multivariate outcomes. Multivariate distance matrix regression (MDMR) tests the significance of associations of response profile (dis)similarities and a set of predictors using permutation tests. This paper extends MDMR by deriving and empirically validating the asymptotic null distribution of its test statistic, and by proposing an effect size for individual outcome variables, which is shown to recover true associations. These extensions alleviate the computational burden of permutation tests currently used in MDMR and render more informative results, thus making MDMR accessible to new research domains.

Logistic models--an odd(s) kind of regression.

PubMed

Jupiter, Daniel C

2013-01-01

The logistic regression model bears some similarity to the multivariable linear regression with which we are familiar. However, the differences are great enough to warrant a discussion of the need for and interpretation of logistic regression. Copyright © 2013 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.
Influence of overstory on snow depth and density in hemlock-spruce stands: implications for management of deer habitat in Southeastern Alaska.

Treesearch

Thomas A. Hanley; Cathy L. Rose

1987-01-01

Snow depth and density were measured in 33 stands of western hemlock-Sitka spruce (Tsuga heterophylla [Rat] Sarg.-Picea sitchensis [Bong.] Carr.) over a 3-year period. The stands, near Juneau, Alaska, provided broad ranges of species composition, age, over-story canopy coverage, tree density, and wood volume. Stepwise multiple regression analyses indicated that both...
Patient satisfaction in Dental Healthcare Centers.

PubMed

Ali, Dena A

2016-01-01

This study aimed to (1) measure the degree of patient satisfaction among the clinical and nonclinical dental services offered at specialty dental centers and (2) investigate the factors associated with the degree of overall satisfaction. Four hundred and ninety-seven participants from five dental centers were recruited for this study. Each participant completed a self-administered questionnaire to measure patient satisfaction with clinical and nonclinical dental services. Analysis of variance, t-tests, a general linear model, and stepwise regression analysis was applied. The respondents were generally satisfied, but internal differences were observed. The exhibited highest satisfaction with the dentists' performance, followed by the dental assistants' services, and the lowest satisfaction with the center's physical appearance and accessibility. Females, participants with less than a bachelor's degree, and younger individuals were more satisfied with the clinical and nonclinical dental services. The stepwise regression analysis revealed that the coefficient of determination (R (2)) was 40.4%. The patient satisfaction with the performance of the dentists explained 42.6% of the overall satisfaction, whereas their satisfaction with the clinical setting explained 31.5% of the overall satisfaction. Additional improvements with regard to the accessibility and physical appearance of the dental centers are needed. In addition, interventions regarding accessibility, particularly when booking an appointment, are required.
Psychophysiological responses to competition and the big five personality traits.

PubMed

Binboga, Erdal; Guven, Senol; Catıkkaş, Fatih; Bayazıt, Onur; Tok, Serdar

2012-06-01

This study examines the relationship between psychophysiological arousal, cognitive anxiety, and personality traits in young taekwondo athletes. A total of 20 male and 10 female taekwondo athletes (mean age = 18.6 years; ± 1.8) volunteered for the study. The Five Factor Personality Inventory and the state scale of the Spielberger State-Trait Anxiety Inventory (STAI) were used to measure personality and cognitive state anxiety. Electrodermal activity (EDA) was measured twice, one day and approximately one hour prior to the competition, to determine psychophysiological arousal. Descriptive statistics, Pearson product-moment correlations, and stepwise regression were used to analyze the data. Several "Big Five" facets were related to the EDA delta scores that were measured both one day and one hour before the competition. Two stepwise regressions were conducted to examine whether personality traits could significantly predict both EDA delta scores. The final model, containing only neuroticism from the Big Five factors, can significantly explain the variations in the EDA delta scores measured one day before the competition. Agreeableness can significantly explain variations in the EDA delta scores measured one hour before the competition. No relationship was found between cognitive anxiety and the EDA delta scores measured one hour before the competition. In conclusion, personality traits, especially agreeableness and neuroticism, might be useful in understanding arousal responses to competition.
Feet deformities are correlated with impaired balance and postural stability in seniors over 75

PubMed Central

Puszczalowska-Lizis, Ewa; Bujas, Przemyslaw; Omorczyk, Jaroslaw; Jandzis, Slawomir

2017-01-01

Objective Understanding the factors and mechanisms that determine balance in seniors appears vital in terms of their self-reliance and overall safety. The study aimed to determine the relationship between the features of feet structure and the indicators of postural stability in the elderly. Methods The study group comprised 80 seniors (41F, 39M; aged 75–85 years). CQ-ST podoscope and the CQ-Stab 2P two-platform posturograph were used as primary research tools. The data were analyzed based on Spearman’s rank correlation and forward stepwise regression. Results Analysis of forward stepwise regression identified the left foot length in females and Clarke’s angle of the left foot in men as significant and independent predictors of postural up to 30% of the variance of dependent variables. Conclusions Longer feet provide older women with better stability, whereas in men, the lowering of the longitudinal arch results in postural deterioration. In the elderly, the left lower limb shows greater activity in the stabilizing processes in the standing position than the right one. In gerontological rehabilitation special attention should be paid to the individually tailored, gender-specific treatment, with a view to enhancing overall safety and quality of seniors’ lives. PMID:28877185
Psychophysiological Responses to Competition and the Big Five Personality Traits

PubMed Central

Binboga, Erdal; Guven, Senol; Çatıkkaş, Fatih; Bayazıt, Onur; Tok, Serdar

2012-01-01

This study examines the relationship between psychophysiological arousal, cognitive anxiety, and personality traits in young taekwondo athletes. A total of 20 male and 10 female taekwondo athletes (mean age = 18.6 years; ± 1.8) volunteered for the study. The Five Factor Personality Inventory and the state scale of the Spielberger State-Trait Anxiety Inventory (STAI) were used to measure personality and cognitive state anxiety. Electrodermal activity (EDA) was measured twice, one day and approximately one hour prior to the competition, to determine psychophysiological arousal. Descriptive statistics, Pearson product-moment correlations, and stepwise regression were used to analyze the data. Several “Big Five” facets were related to the EDA delta scores that were measured both one day and one hour before the competition. Two stepwise regressions were conducted to examine whether personality traits could significantly predict both EDA delta scores. The final model, containing only neuroticism from the Big Five factors, can significantly explain the variations in the EDA delta scores measured one day before the competition. Agreeableness can significantly explain variations in the EDA delta scores measured one hour before the competition. No relationship was found between cognitive anxiety and the EDA delta scores measured one hour before the competition. In conclusion, personality traits, especially agreeableness and neuroticism, might be useful in understanding arousal responses to competition. PMID:23486906
Motor Nerve Conduction Velocity In Postmenopausal Women with Peripheral Neuropathy.

PubMed

Singh, Akanksha; Asif, Naiyer; Singh, Paras Nath; Hossain, Mohd Mobarak

2016-12-01

The post-menopausal phase is characterized by a decline in the serum oestrogen and progesterone levels. This phase is also associated with higher incidence of peripheral neuropathy. To explore the relationship between the peripheral motor nerve status and serum oestrogen and progesterone levels through assessment of Motor Nerve Conduction Velocity (MNCV) in post-menopausal women with peripheral neuropathy. This cross-sectional study was conducted at Jawaharlal Nehru Medical College during 2011-2013. The study included 30 post-menopausal women with peripheral neuropathy (age: 51.4±7.9) and 30 post-menopausal women without peripheral neuropathy (control) (age: 52.5±4.9). They were compared for MNCV in median, ulnar and common peroneal nerves and serum levels of oestrogen and progesterone estimated through enzyme immunoassays. To study the relationship between hormone levels and MNCV, a stepwise linear regression analysis was done. The post-menopausal women with peripheral neuropathy had significantly lower MNCV and serum oestrogen and progesterone levels as compared to control subjects. Stepwise linear regression analysis showed oestrogen with main effect on MNCV. The findings of the present study suggest that while the post-menopausal age group is at a greater risk of peripheral neuropathy, it is the decline in the serum estrogen levels which is critical in the development of peripheral neuropathy.
STEP and STEPSPL: Computer programs for aerodynamic model structure determination and parameter estimation

NASA Technical Reports Server (NTRS)

Batterson, J. G.

1986-01-01

The successful parametric modeling of the aerodynamics for an airplane operating at high angles of attack or sideslip is performed in two phases. First the aerodynamic model structure must be determined and second the associated aerodynamic parameters (stability and control derivatives) must be estimated for that model. The purpose of this paper is to document two versions of a stepwise regression computer program which were developed for the determination of airplane aerodynamic model structure and to provide two examples of their use on computer generated data. References are provided for the application of the programs to real flight data. The two computer programs that are the subject of this report, STEP and STEPSPL, are written in FORTRAN IV (ANSI l966) compatible with a CDC FTN4 compiler. Both programs are adaptations of a standard forward stepwise regression algorithm. The purpose of the adaptation is to facilitate the selection of a adequate mathematical model of the aerodynamic force and moment coefficients of an airplane from flight test data. The major difference between STEP and STEPSPL is in the basis for the model. The basis for the model in STEP is the standard polynomial Taylor's series expansion of the aerodynamic function about some steady-state trim condition. Program STEPSPL utilizes a set of spline basis functions.
Relation between trinucleotide GAA repeat length and sensory neuropathy in Friedreich's ataxia.

PubMed

Santoro, L; De Michele, G; Perretti, A; Crisci, C; Cocozza, S; Cavalcanti, F; Ragno, M; Monticelli, A; Filla, A; Caruso, G

1999-01-01

To verify if GAA expansion size in Friedreich's ataxia could account for the severity of sensory neuropathy. Retrospective study of 56 patients with Friedreich's ataxia selected according to homozygosity for GAA expansion and availability of electrophysiological findings. Orthodromic sensory conduction velocity in the median nerve was available in all patients and that of the tibial nerve in 46 of them. Data of sural nerve biopsy and of a morphometric analysis were available in 12 of the selected patients. The sensory action potential amplitude at the wrist (wSAP) and at the medial malleolus (m mal SAP) and the percentage of myelinated fibres with diameter larger than 7, 9, and 11 microm in the sural nerve were correlated with disease duration and GAA expansion size on the shorter (GAA1) and larger (GAA2) expanded allele in each pair. Pearson's correlation test and stepwise multiple regression were used for statistical analysis. A significant inverse correlation between GAA1 size and wSAP, m mal SAP, and percentage of myelinated fibres was found. Stepwise multiple regression showed that GAA1 size significantly affects electrophysiological and morphometric data, whereas duration of disease has no effect. The data suggest that the severity of the sensory neuropathy is probably genetically determined and that it is not progressive.
Quantifying Parkinson's disease finger-tapping severity by extracting and synthesizing finger motion properties.

PubMed

Sano, Yuko; Kandori, Akihiko; Shima, Keisuke; Yamaguchi, Yuki; Tsuji, Toshio; Noda, Masafumi; Higashikawa, Fumiko; Yokoe, Masaru; Sakoda, Saburo

2016-06-01

We propose a novel index of Parkinson's disease (PD) finger-tapping severity, called "PDFTsi," for quantifying the severity of symptoms related to the finger tapping of PD patients with high accuracy. To validate the efficacy of PDFTsi, the finger-tapping movements of normal controls and PD patients were measured by using magnetic sensors, and 21 characteristics were extracted from the finger-tapping waveforms. To distinguish motor deterioration due to PD from that due to aging, the aging effect on finger tapping was removed from these characteristics. Principal component analysis (PCA) was applied to the age-normalized characteristics, and principal components that represented the motion properties of finger tapping were calculated. Multiple linear regression (MLR) with stepwise variable selection was applied to the principal components, and PDFTsi was calculated. The calculated PDFTsi indicates that PDFTsi has a high estimation ability, namely a mean square error of 0.45. The estimation ability of PDFTsi is higher than that of the alternative method, MLR with stepwise regression selection without PCA, namely a mean square error of 1.30. This result suggests that PDFTsi can quantify PD finger-tapping severity accurately. Furthermore, the result of interpreting a model for calculating PDFTsi indicated that motion wideness and rhythm disorder are important for estimating PD finger-tapping severity.
Patient satisfaction in Dental Healthcare Centers

PubMed Central

Ali, Dena A.

2016-01-01

Objectives: This study aimed to (1) measure the degree of patient satisfaction among the clinical and nonclinical dental services offered at specialty dental centers and (2) investigate the factors associated with the degree of overall satisfaction. Materials and Methods: Four hundred and ninety-seven participants from five dental centers were recruited for this study. Each participant completed a self-administered questionnaire to measure patient satisfaction with clinical and nonclinical dental services. Analysis of variance, t-tests, a general linear model, and stepwise regression analysis was applied. Results: The respondents were generally satisfied, but internal differences were observed. The exhibited highest satisfaction with the dentists’ performance, followed by the dental assistants’ services, and the lowest satisfaction with the center's physical appearance and accessibility. Females, participants with less than a bachelor's degree, and younger individuals were more satisfied with the clinical and nonclinical dental services. The stepwise regression analysis revealed that the coefficient of determination (R2) was 40.4%. The patient satisfaction with the performance of the dentists explained 42.6% of the overall satisfaction, whereas their satisfaction with the clinical setting explained 31.5% of the overall satisfaction. Conclusion: Additional improvements with regard to the accessibility and physical appearance of the dental centers are needed. In addition, interventions regarding accessibility, particularly when booking an appointment, are required. PMID:27403045
[Key physical parameters of hawthorn leaf granules by stepwise regression analysis method].

PubMed

Jiang, Qie-Ying; Zeng, Rong-Gui; Li, Zhe; Luo, Juan; Zhao, Guo-Wei; Lv, Dan; Liao, Zheng-Gen

2017-05-01

The purpose of this study was to investigate the effect of key physical properties of hawthorn leaf granule on its dissolution behavior. Hawthorn leaves extract was utilized as a model drug. The extract was mixed with microcrystalline cellulose or starch with the same ratio by using different methods. Appropriate amount of lubricant and disintegrating agent was added into part of the mixed powder, and then the granules were prepared by using extrusion granulation and high shear granulation. The granules dissolution behavior was evaluated by using equilibrium dissolution quantity and dissolution rate constant of the hypericin as the indicators. Then the effect of physical properties on dissolution behavior was analyzed through the stepwise regression analysis method. The equilibrium dissolution quantity of hypericin and adsorption heat constant in hawthorn leaves were positively correlated with the monolayer adsorption capacity and negatively correlated with the moisture absorption rate constant. The dissolution rate constants were decreased with the increase of Hausner rate, monolayer adsorption capacity and adsorption heat constant, and were increased with the increase of Carr index and specific surface area. Adsorption heat constant, monolayer adsorption capacity, moisture absorption rate constant, Carr index and specific surface area were the key physical properties of hawthorn leaf granule to affect its dissolution behavior. Copyright© by the Chinese Pharmaceutical Association.
Predicting Retention Times of Naturally Occurring Phenolic Compounds in Reversed-Phase Liquid Chromatography: A Quantitative Structure-Retention Relationship (QSRR) Approach

PubMed Central

Akbar, Jamshed; Iqbal, Shahid; Batool, Fozia; Karim, Abdul; Chan, Kim Wei

2012-01-01

Quantitative structure-retention relationships (QSRRs) have successfully been developed for naturally occurring phenolic compounds in a reversed-phase liquid chromatographic (RPLC) system. A total of 1519 descriptors were calculated from the optimized structures of the molecules using MOPAC2009 and DRAGON softwares. The data set of 39 molecules was divided into training and external validation sets. For feature selection and mapping we used step-wise multiple linear regression (SMLR), unsupervised forward selection followed by step-wise multiple linear regression (UFS-SMLR) and artificial neural networks (ANN). Stable and robust models with significant predictive abilities in terms of validation statistics were obtained with negation of any chance correlation. ANN models were found better than remaining two approaches. HNar, IDM, Mp, GATS2v, DISP and 3D-MoRSE (signals 22, 28 and 32) descriptors based on van der Waals volume, electronegativity, mass and polarizability, at atomic level, were found to have significant effects on the retention times. The possible implications of these descriptors in RPLC have been discussed. All the models are proven to be quite able to predict the retention times of phenolic compounds and have shown remarkable validation, robustness, stability and predictive performance. PMID:23203132
Predictors of competitive achievement among pubescent synchronized swimmers: an analysis of the solo-figure competition.

PubMed

Peric, M; Cavar, M; Zenic, N; Sekulic, D; Sajber, D

2014-02-01

This study examined the applicability of sport-specific fitness tests (SSTs), anthropometrics, and respiratory parameters in predicting competitive results among pubescent synchronized swimmers. A total of 25 synchronized swimmers (16-17 years; 166.2 ± 5.4 cm; and 58.4 ± 4.3 kg) volunteered for this study. The independent variables were body mass, body height, Body Mass Index (BMI), body fat percentage (BF%), lean body mass percentage, respiratory variables, and four SSTs (two specific power tests plus one aerobic- and one anaerobic-endurance test). The dependent variable was competitive achievement in the solo figure competition. The reliability analyses, Pearson's correlation coefficient and forward stepwise regression were calculated. The SSTs were reliable for testing fitness status among pubescent synchronized swimmers. The forward stepwise regression retained two SSTs, BF% and forced vital capacity (FVC, relative for age and stature) in a set of predictors of competitive achievement. Significant Beta coefficients are found for aerobic-endurance, SST and FVC. The sport-specific measure of aerobic endurance and FVC appropriately predicted competitive achievement with regard to the figures used in the competition when competitive results (the dependent variable) were obtained. Athletes and coaches should be aware of the probable negative influence of very low body fat levels on competitive achievement.
Patterns of risk for anxiety-depression amongst Vietnamese-immigrants: a comparison with source and host populations

PubMed Central

2013-01-01

Background Studies suggest that immigrants have higher rates of anxiety-depression than compatriots in low-middle income countries and lower rates than populations in host high income countries. Elucidating the factors that underlie these stepwise variations in prevalence may throw new light on the pathogenesis of anxiety-depressive disorders globally. This study aimed to examine whether quantitative differences in exposure to, or the interaction between, risk factors account for these anxiety-depression prevalence differences amongst immigrant relative to source and host country populations. Methods Multistage population mental health surveys were conducted in three groups: 1) a Vietnamese-immigrant sample settled in Australia (n = 1161); 2) a Vietnamese source country sample residing in the Mekong Delta region (n = 3039); 3) an Australian-born host country sample (n = 7964). Multivariable logistic regression analyses compared risk factors between the Vietnamese-immigrant group and: 1) the Mekong Delta Vietnamese; and 2) the Australian-born group. Twelve month anxiety-depression diagnoses were the main outcome measures, derived from the Composite International Diagnostic Interview (CIDI), supplemented by an indigenously derived measure - the Phan Vietnamese Psychiatric Scale (PVPS) in both Vietnamese groups. Results The 12-month prevalence of anxiety-depression showed a stepwise increase across groups: Mekong Delta Vietnamese 4.8%; Vietnamese-immigrants 7.0%; Australian-born 10.2%. The two Vietnamese populations showed a similar risk profile with older age, exposure to potentially traumatic events (PTEs), multiple physical illnesses and substance use disorder (SUD) being associated with anxiety-depression, with the older Vietnamese-immigrants reporting greater exposure to these factors. The interaction between key risk factors differed fundamentally when comparing Vietnamese-immigrant and Australian-born samples. Age emerged as the major discriminator, with young Vietnamese-immigrants exhibiting particularly low rates of anxiety-depression. Conclusions The findings reported here suggest that core risk factors for anxiety-depression may be universal, but their patterning and interaction may differ according to country-of-origin. The study also highlights the importance of including both standard international and culturally-specific measures to index cross-cultural manifestations of common mental disorders. PMID:24294940
Linear Multivariable Regression Models for Prediction of Eddy Dissipation Rate from Available Meteorological Data

NASA Technical Reports Server (NTRS)

MCKissick, Burnell T. (Technical Monitor); Plassman, Gerald E.; Mall, Gerald H.; Quagliano, John R.

2005-01-01

Linear multivariable regression models for predicting day and night Eddy Dissipation Rate (EDR) from available meteorological data sources are defined and validated. Model definition is based on a combination of 1997-2000 Dallas/Fort Worth (DFW) data sources, EDR from Aircraft Vortex Spacing System (AVOSS) deployment data, and regression variables primarily from corresponding Automated Surface Observation System (ASOS) data. Model validation is accomplished through EDR predictions on a similar combination of 1994-1995 Memphis (MEM) AVOSS and ASOS data. Model forms include an intercept plus a single term of fixed optimal power for each of these regression variables; 30-minute forward averaged mean and variance of near-surface wind speed and temperature, variance of wind direction, and a discrete cloud cover metric. Distinct day and night models, regressing on EDR and the natural log of EDR respectively, yield best performance and avoid model discontinuity over day/night data boundaries.
Assessing Principal Component Regression Prediction of Neurochemicals Detected with Fast-Scan Cyclic Voltammetry

PubMed Central

2011-01-01

Principal component regression is a multivariate data analysis approach routinely used to predict neurochemical concentrations from in vivo fast-scan cyclic voltammetry measurements. This mathematical procedure can rapidly be employed with present day computer programming languages. Here, we evaluate several methods that can be used to evaluate and improve multivariate concentration determination. The cyclic voltammetric representation of the calculated regression vector is shown to be a valuable tool in determining whether the calculated multivariate model is chemically appropriate. The use of Cook’s distance successfully identified outliers contained within in vivo fast-scan cyclic voltammetry training sets. This work also presents the first direct interpretation of a residual color plot and demonstrated the effect of peak shifts on predicted dopamine concentrations. Finally, separate analyses of smaller increments of a single continuous measurement could not be concatenated without substantial error in the predicted neurochemical concentrations due to electrode drift. Taken together, these tools allow for the construction of more robust multivariate calibration models and provide the first approach to assess the predictive ability of a procedure that is inherently impossible to validate because of the lack of in vivo standards. PMID:21966586
Parameter estimation of multivariate multiple regression model using bayesian with non-informative Jeffreys’ prior distribution

NASA Astrophysics Data System (ADS)

Saputro, D. R. S.; Amalia, F.; Widyaningsih, P.; Affan, R. C.

2018-05-01

Bayesian method is a method that can be used to estimate the parameters of multivariate multiple regression model. Bayesian method has two distributions, there are prior and posterior distributions. Posterior distribution is influenced by the selection of prior distribution. Jeffreys’ prior distribution is a kind of Non-informative prior distribution. This prior is used when the information about parameter not available. Non-informative Jeffreys’ prior distribution is combined with the sample information resulting the posterior distribution. Posterior distribution is used to estimate the parameter. The purposes of this research is to estimate the parameters of multivariate regression model using Bayesian method with Non-informative Jeffreys’ prior distribution. Based on the results and discussion, parameter estimation of β and Σ which were obtained from expected value of random variable of marginal posterior distribution function. The marginal posterior distributions for β and Σ are multivariate normal and inverse Wishart. However, in calculation of the expected value involving integral of a function which difficult to determine the value. Therefore, approach is needed by generating of random samples according to the posterior distribution characteristics of each parameter using Markov chain Monte Carlo (MCMC) Gibbs sampling algorithm.
Field applications of stand-off sensing using visible/NIR multivariate optical computing

NASA Astrophysics Data System (ADS)

Eastwood, DeLyle; Soyemi, Olusola O.; Karunamuni, Jeevanandra; Zhang, Lixia; Li, Hongli; Myrick, Michael L.

2001-02-01

12 A novel multivariate visible/NIR optical computing approach applicable to standoff sensing will be demonstrated with porphyrin mixtures as examples. The ultimate goal is to develop environmental or counter-terrorism sensors for chemicals such as organophosphorus (OP) pesticides or chemical warfare simulants in the near infrared spectral region. The mathematical operation that characterizes prediction of properties via regression from optical spectra is a calculation of inner products between the spectrum and the pre-determined regression vector. The result is scaled appropriately and offset to correspond to the basis from which the regression vector is derived. The process involves collecting spectroscopic data and synthesizing a multivariate vector using a pattern recognition method. Then, an interference coating is designed that reproduces the pattern of the multivariate vector in its transmission or reflection spectrum, and appropriate interference filters are fabricated. High and low refractive index materials such as Nb2O5 and SiO2 are excellent choices for the visible and near infrared regions. The proof of concept has now been established for this system in the visible and will later be extended to chemicals such as OP compounds in the near and mid-infrared.
Assessing principal component regression prediction of neurochemicals detected with fast-scan cyclic voltammetry.

PubMed

Keithley, Richard B; Wightman, R Mark

2011-06-07

Principal component regression is a multivariate data analysis approach routinely used to predict neurochemical concentrations from in vivo fast-scan cyclic voltammetry measurements. This mathematical procedure can rapidly be employed with present day computer programming languages. Here, we evaluate several methods that can be used to evaluate and improve multivariate concentration determination. The cyclic voltammetric representation of the calculated regression vector is shown to be a valuable tool in determining whether the calculated multivariate model is chemically appropriate. The use of Cook's distance successfully identified outliers contained within in vivo fast-scan cyclic voltammetry training sets. This work also presents the first direct interpretation of a residual color plot and demonstrated the effect of peak shifts on predicted dopamine concentrations. Finally, separate analyses of smaller increments of a single continuous measurement could not be concatenated without substantial error in the predicted neurochemical concentrations due to electrode drift. Taken together, these tools allow for the construction of more robust multivariate calibration models and provide the first approach to assess the predictive ability of a procedure that is inherently impossible to validate because of the lack of in vivo standards.

Serum chemerin levels are independently associated with quality of life in colorectal cancer survivors: A pilot study

PubMed Central

Lee, Jee-Yon; Lee, Mi-Kyung; Kim, Nam-Kyu; Chu, Sang-Hui; Lee, Duk-Chul; Lee, Hye-Sun

2017-01-01

Background Colorectal cancer (CRC) survivors are known to experience various symptoms that significantly affect their quality of life (QOL); therefore, it is important to identify clinical markers related with CRC survivor QOL. Here we investigated the relationship between serum chemerin levels, a newly identified proinflammatory adipokine, and QOL in CRC survivors. Methods A data of total of 110 CRC survivors were analysed in the study. Serum chemerin levels were measured with an enzyme immunoassay analyser. Functional Assessment of Cancer Therapy (FACT) scores were used as an indicator of QOL in CRC survivors. Results Weak but not negligible relationships were observed between serum chemerin levels and FACT-General (G) (r = -0.22, p<0.02), FACT-Colorectal cancer (C) (r = -0.23, p<0.02) and FACT-Fatigue (F) scores (r = -0.27, p<0.01) after adjusting for confounding factors. Both stepwise and enter method multiple linear regression analyses confirmed that serum chemerin levels were independently associated with FACT-G (stepwise: β = -0.15, p<0.01; enter: β = -0.12, p = 0.02), FACT-C (stepwise: β = -0.19, p<0.01; enter; β = -0.14, p = 0.02) and FACT-F scores (stepwise: β = -0.23, p<0.01; enter: β = -0.20, p<0.01). Conclusions Our results demonstrate a weak inverse relationship between serum chemerin and CRC survivor QOL. Although it is impossible to determine causality, our findings suggest that serum chemerin levels may have a significant association with CRC survivor QOL. Further prospective studies are required to confirm the clinical significance of our pilot study. PMID:28475614
A refined method for multivariate meta-analysis and meta-regression.

PubMed

Jackson, Daniel; Riley, Richard D

2014-02-20

Making inferences about the average treatment effect using the random effects model for meta-analysis is problematic in the common situation where there is a small number of studies. This is because estimates of the between-study variance are not precise enough to accurately apply the conventional methods for testing and deriving a confidence interval for the average effect. We have found that a refined method for univariate meta-analysis, which applies a scaling factor to the estimated effects' standard error, provides more accurate inference. We explain how to extend this method to the multivariate scenario and show that our proposal for refined multivariate meta-analysis and meta-regression can provide more accurate inferences than the more conventional approach. We explain how our proposed approach can be implemented using standard output from multivariate meta-analysis software packages and apply our methodology to two real examples. Copyright © 2013 John Wiley & Sons, Ltd.
Newer classification and regression tree techniques: Bagging and Random Forests for ecological prediction

Treesearch

Anantha M. Prasad; Louis R. Iverson; Andy Liaw; Andy Liaw

2006-01-01

We evaluated four statistical models - Regression Tree Analysis (RTA), Bagging Trees (BT), Random Forests (RF), and Multivariate Adaptive Regression Splines (MARS) - for predictive vegetation mapping under current and future climate scenarios according to the Canadian Climate Centre global circulation model.
The Prevalence and Significance of Abnormal Vital Signs Prior to In-Hospital Cardiac Arrest

PubMed Central

Andersen, Lars W.; Kim, Won Young; Chase, Maureen; Berg, Katherine; Mortensen, Sharri J.; Moskowitz, Ari; Novack, Victor; Cocchi, Michael N.; Donnino, Michael W.

2015-01-01

Background Patients suffering in-hospital cardiac arrest often show signs of physiological deterioration before the event. The purpose of this study was to determine the prevalence of abnormal vital signs 1–4 hours before cardiac arrest, and to evaluate the association between these vital sign abnormalities and inhospital mortality. Methods We included adults from the Get With the Guidelines® - Resuscitation registry with an in-hospital cardiac arrest. We used two a priori definitions for vital signs: abnormal (heart rate (HR) ≤ 60 or ≥ 100 min−1, respiratory rate (RR) ≤ 10 or > 20 min−1 and systolic blood pressure (SBP) ≤ 90 mm Hg) and severely abnormal (HR ≤ 50 or ≥ 130 min−1, RR ≤ 8 or ≥ 30 min−1 and SBP ≤80 mm Hg). We evaluated the association between the number of abnormal vital signs and in-hospital mortality using a multivariable logistic regression model. Results 7,851 patients were included. Individual vital signs were associated with in-hospital mortality. The majority of patients (59.4%) had at least one abnormal vital sign 1–4 hours before the arrest and 13.4% had at least one severely abnormal sign. We found a step-wise increase in mortality with increasing number of abnormal vital signs within the abnormal (odds ratio (OR) 1.53 (CI: 1.42 – 1.64) and severely abnormal groups (OR 1.62 [CI: 1.38 – 1.90]). This remained in multivariable analysis (abnormal: OR 1.38 [CI: 1.28 – 1.48], and severely abnormal: OR 1.40 [CI: 1.18 – 1.65]). Conclusion Abnormal vital signs are prevalent 1–4 hours before in-hospital cardiac arrest on hospital wards. Inhospital mortality increases with increasing number of pre-arrest abnormal vital signs as well as increased severity of vital sign derangements. PMID:26362486
Factors associated with consistent condom use and STIs among foreign female entertainment workers: results from a cross-sectional survey in Singapore.

PubMed

Lim, Raymond Boon Tar; Wong, Mee Lian; Cheung, Olive N Y; Tham, Dede Kam Tyng; Tai, Bee Choo; Chan, Roy

2017-03-01

We assessed the prevalence of consistent condom use and laboratory-confirmed STIs among foreign female entertainment workers (FEWs) who engaged in paid or casual sex in Singapore and the factors associated with these characteristics. A cross-sectional survey, using time-location sampling, was conducted on 220 FEWs (115 Vietnamese and 105 Thai) in 2015. For multivariable analysis, we used a mixed-effects Poisson regression model with backward stepwise approach to account for clustering by venue and to obtain the adjusted prevalence ratios (aPRs) of factors associated with consistent condom use and STI positivity, respectively. Consistent condom use with paid or casual partners in the past month was 39.6% and 36.2% for vaginal and oral sex, respectively. The prevalence of STI (cervical chlamydia, cervical gonorrhoea or pharyngeal gonorrhoea) positivity was 13.6%. In multivariable analysis, consistent condom use for both vaginal and oral sex increased with high self-perceived risk of getting STI/HIV (vaginal: aPR 2.09; 95% CI 1.26 to 3.46; oral: aPR 2.41; 95% CI 1.23 to 4.69) and condom negotiation (vaginal: aPR 3.74; 95% CI 2.07 to 6.75; oral: aPR 2.81; 95% CI 1.51 to 5.26). STI positivity decreased with consistent condom use for vaginal sex (aPR 0.22; 95% CI 0.07 to 0.75) and increased with number of sexual partners (aPR 1.43; 95% CI 1.07 to 1.92). In addition to advocating for policy decisions to provide a safer work environment, behavioural interventions on condom negotiation skills and condom use and biomedical interventions on STI/HIV testing and treatment interventions are needed among the FEWs in Singapore. NCT02780986; pre-results. 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/.
Aneurysm Characteristics Associated with the Rupture Risk of Intracranial Aneurysms: A Self-Controlled Study.

PubMed

Kang, Huibin; Ji, Wenjun; Qian, Zenghui; Li, Youxiang; Jiang, Chuhan; Wu, Zhongxue; Wen, Xiaolong; Xu, Wenjuan; Liu, Aihua

2015-01-01

This study analyzed the rupture risk of intracranial aneurysms (IAs) according to aneurysm characteristics by comparing the differences between two aneurysms in different locations within the same patient. We utilized this self-controlled model to exclude potential interference from all demographic factors to study the risk factors related to IA rupture. A total of 103 patients were diagnosed with IAs between January 2011 and April 2015 and were enrolled in this study. All enrolled patients had two IAs. One IA (the case) was ruptured, and the other (the control) was unruptured. Aneurysm characteristics, including the presence of a daughter sac, the aneurysm neck, the parent artery diameter, the maximum aneurysm height, the maximum aneurysm width, the location, the aspect ratio (AR, maximum perpendicular height/average neck diameter), the size ratio (SR, maximum aneurysm height/average parent diameter) and the width/height ratio (WH ratio, maximum aneurysm width/maximum aneurysm height), were collected and analyzed to evaluate the rupture risks of the two IAs within each patient and to identify the independent risk factors associated with IA rupture. Multivariate, conditional, backward, stepwise logistic regression analysis was performed to identify the independent risk factors associated with IA rupture. The multivariate analysis identified the presence of a daughter sac (odds ratio [OR], 13.80; 95% confidence interval [CI], 1.65-115.87), a maximum aneurysm height ≥7 mm (OR, 4.80; 95% CI, 1.21-18.98), location on the posterior communicating artery (PCOM) or anterior communicating artery (ACOM; OR, 3.09; 95% CI, 1.34-7.11) and SR (OR, 2.13; 95% CI, 1.16-3.91) as factors that were significantly associated with IA rupture. The presence of a daughter sac, the maximum aneurysm height, PCOM or ACOM locations and SR (>1.5±0.7) of unruptured IAs were significantly associated with IA rupture.
Post-transplant lymphoceles: a critical look into the risk factors, pathophysiology and management.

PubMed

Khauli, R B; Stoff, J S; Lovewell, T; Ghavamian, R; Baker, S

1993-07-01

To define better the prevalence and pathophysiology of lymphoceles following renal transplantation, we prospectively evaluated 118 consecutive renal transplants performed in 115 patients (96 cadaveric, 22 living-related, 7 secondary and 111 primary). Ultrasonography was performed post-operatively and during rehospitalizations or whenever complications occurred. Perirenal fluid collections were identified in 43 patients (36%). Lymphoceles with a diameter of 5 cm. or greater were identified in 26 of 118 cases (22%). Eight patients (6.8%) had symptomatic lymphoceles requiring therapy. The interval for development of symptomatic lymphoceles was 1 week to 3.7 years (median 10 months). Risk factors for the development of lymphoceles were examined by univariate and multivariate analysis, and included patient age, sex, source of transplants (cadaver versus living-related donor), retransplantation, tissue match (HLA-B/DR), type of preservation, arterial anastomosis, occurrence of acute tubular necrosis-delayed graft function, occurrence of rejection, and use of high dose corticosteroids. Univariate analysis showed a significant risk for the development of lymphoceles in transplants with acute tubular necrosis-delayed graft function (odds ratio 4.5, p = 0.004), rejection (odds ratio 25.1 p < 0.001) and high dose steroids (odds ratio 16.4, p < 0.001). When applying multivariate analyses using stepwise logistic regression, only rejection was associated with a significant risk for lymphoceles (symptomatic lymphoceles--odds ratio 25.08, p = 0.0003, all lymphoceles--odds ratio 75.24, p < 0.0001). When adjusting for rejection, no other risk factor came close to being significant (least p = 0.4). Therapy included laparoscopic peritoneal marsupialization and drainage in 1 patient, incisional peritoneal drainage in 4 and percutaneous external drainage in 3 (infected). All symptomatic lymphoceles were successfully treated without sequelae to grafts or patients. We conclude that allograft rejection is the most significant factor contributing to the development of lymphoceles. Therapy of symptomatic lymphoceles should be individualized according to the presence or absence of infection.
Intimate partner violence after the diagnosis of sexually transmitted diseases

PubMed Central

Andrade, Roumayne Fernandes Vieira; Araújo, Maria Alix Leite; Vieira, Luiza Jane Eyre de Souza; Reis, Cláudia Bastos Silveira; Miranda, Angélica Espinosa

2015-01-01

OBJECTIVE To assess the prevalence and factors associated with intimate partner violence after the diagnosis of sexually transmitted diseases. METHODS This cross-sectional study was conducted in Fortaleza, CE, Northeastern Brazil, in 2012 and involved 221 individuals (40.3% male and 59.7% female) attended to at reference health care units for the treatment of sexually transmitted diseases. Data were collected using a questionnaire applied during interviews with each participant. A multivariate analysis with a logistic regression model was conducted using the stepwise technique. Only the variables with a p value < 0.05 were included in the adjusted analysis. The odds ratio (OR) with 95% confidence interval (CI) was used as the measure of effect. RESULTS A total of 30.3% of the participants reported experiencing some type of violence (27.6%, psychological; 5.9%, physical; and 7.2%, sexual) after the diagnosis of sexually transmitted disease. In the multivariate analysis adjusted to assess intimate partner violence after the revelation of the diagnosis of sexually transmitted diseases, the following variables remained statistically significant: extramarital relations (OR = 3.72; 95%CI 1.91;7.26; p = 0.000), alcohol consumption by the partner (OR = 2.16; 95%CI 1.08;4.33; p = 0.026), history of violence prior to diagnosis (OR = 2.87; 95%CI 1.44;5.69; p = 0.003), and fear of disclosing the diagnosis to the partner (OR = 2.66; 95%CI 1.32;5.32; p = 0.006). CONCLUSIONS Individuals who had extramarital relations, experienced violence prior to the diagnosis of sexually transmitted disease, feared disclosing the diagnosis to the partner, and those whose partner consumed alcohol had an increased likelihood of suffering violence. The high prevalence of intimate partner violence suggests that this population is vulnerable and therefore intervention efforts should be directed to them. Referral health care services for the treatment of sexually transmitted diseases can be strategic places to identify and prevent intimate partner violence. PMID:25741656
Factors associated with a bad functional prognosis in early inflammatory back pain: results from the DESIR cohort.

PubMed

Lukas, C; Dougados, M; Combe, B

2016-01-01

Spondyloarthritis (SpA) is a heterogeneous disease with hardly predictable potential courses. We aimed at determining prognostic factors of bad functional outcome at 2 years in patients with early inflammatory back pain (IBP). Data from patients included in the French multicentre devenir des spondylarthropathies indifférenciées récentes (DESIR) cohort, that is, suffering from IBP starting before 50 years of age and lasting for 3-36 months, were used. A bad functional outcome at 24 months was defined as an increase in bath ankylosing spondylitis functional index (BASFI), or BASFI at 2 years higher than the 75th centile in the cohort. Demographic, clinical, biological and radiological data collected at inclusion were compared in patients with bad functional outcome versus others, by χ(2) test, then by a multivariate logistic regression model with stepwise selection of relevant factors. 513 patients (54.4% females, 72.2% fulfilling ASAS criteria) were assessed. Of those, 130 (25.3%) fulfilled the aforementioned criteria of a bad functional outcome (BASFI increase ≥4 units or ≥36 at 2 years). Multivariate analysis revealed that not fulfilling ASAS criteria, female sex, age >33 years, lower educational level, active smoking status and high disease activity according to bath ankylosing spondylitis disease activity index (BASDAI) at baseline were independently associated with a bad functional outcome at 24 months. Sensitivity analyses restricted to patients fulfilling ASAS criteria for SpA resulted in similar results. We observed, in a large prospective cohort of patients with early IBP, formerly described bad prognostic factors, especially a low educational level, an older age and a high disease activity at onset, and revealed that active smoking status and female sex were also independently associated with a poor outcome. Fulfilment of ASAS criteria, on the other hand, was predictive of a better outcome, most likely due to the more consensual management of a defined disease.
Does intrapleural length and position of the intercostal drain affect the frequency of residual hemothorax? A prospective study from north India

PubMed Central

Kumar, Sunil; Agarwal, Nitin; Rattan, Amulya; Rathi, Vinita

2014-01-01

Context: Thoracic trauma causes significant morbidity; however, many deaths are preventable and few patients require surgery. Intercostal chest drainage (ICD) for hemo/pneumothorax is simple and effective; the main problem is residual hemothorax, which can cause lung collapse and empyema. Aims: Our study aimed to analyze the relationship between radiological chest tube parameters (position and intrathoracic length) and the frequency of residual hemothorax. Settings and Design: This prospective analytical study was conducted in a large tertiary care hospital in north India over 2 years till March 2013. Materials and Methods: Patients of chest trauma aged 18-60 years, with hemothorax or hemopneumothorax requiring ICD insertion were included in the study. Bedside ICD insertion was performed as per current standards. Immediate post-ICD chest radiographs were used to record lung status and ICD position (chest tube zone and intrapleural length). Residual hemothorax was defined as any collection identified on radiological investigations after 48 hours of ICD placement. Statistical Analysis: Univariate analysis was performed with the chi-square test or Student's t-test as appropriate, while multivariate analysis using stepwise logistic regression; a P-value < 0.05 was significant. Results: Out of 170 patients of chest trauma, 154 underwent ICD insertion. Most patients were young (mean age: 31.7 ± 12 years) males (M:F = 14:1). Ninety-seven patients (57.1%) had isolated chest injuries. Blunt trauma (n = 119; 77.3%) and motor vehicle accidents (n = 72; 46.7%) were the commonest causes. Mean hospital stay was 9 ± 3.94 days, and mortality 2/154 (1.1%). Residual hemothorax was seen in 48 (31%). No ICD zone or length was significantly associated with residual hemothorax on univariate or multivariate analysis. Conclusion: Intrapleural ICD zone or length does not affect the frequency of residual hemothorax. PMID:25400388
The Val158Met COMT polymorphism is a modifier of the age at onset in Parkinson's disease with a sexual dimorphism

PubMed Central

Klebe, Stephan; Golmard, Jean-Louis; Nalls, Michael A; Saad, Mohamad; Singleton, Andrew B; Bras, Jose M; Hardy, John; Simon-Sanchez, Javier; Heutink, Peter; Kuhlenbäumer, Gregor; Charfi, Rim; Klein, Christine; Hagenah, Johann; Gasser, Thomas; Wurster, Isabel; Lesage, Suzanne; Lorenz, Delia; Deuschl, Günther; Durif, Franck; Pollak, Pierre; Damier, Philippe; Tison, François; Durr, Alexandra; Amouyel, Philippe; Lambert, Jean-Charles; Tzourio, Christophe; Maubaret, Cécilia; Charbonnier-Beaupel, Fanny; Tahiri, Khadija; Vidailhet, Marie; Martinez, Maria; Brice, Alexis; Corvol, Jean-Christophe

2013-01-01

The catechol-O-methyltranferase (COMT) is one of the main enzymes that metabolise dopamine in the brain. The Val158Met polymorphism in the COMT gene (rs4680) causes a trimodal distribution of high (Val/Val), intermediate (Val/Met) and low (Met/Met) enzyme activity. We tested whether the Val158Met polymorphism is a modifier of the age at onset (AAO) in Parkinson's disease (PD). The rs4680 was genotyped in a total of 16 609 subjects from five independent cohorts of European and North American origin (5886 patients with PD and 10 723 healthy controls). The multivariate analysis for comparing PD and control groups was based on a stepwise logistic regression, with gender, age and cohort origin included in the initial model. The multivariate analysis of the AAO was a mixed linear model, with COMT genotype and gender considered as fixed effects and cohort and cohort-gender interaction as random effects. COMT genotype was coded as a quantitative variable, assuming a codominant genetic effect. The distribution of the COMT polymorphism was not significantly different in patients and controls (p=0.22). The Val allele had a significant effect on the AAO with a younger AAO in patients with the Val/Val (57.1±13.9, p=0.03) than the Val/Met (57.4±13.9) and the Met/Met genotypes (58.3±13.5). The difference was greater in men (1.9 years between Val/Val and Met/Met, p=0.007) than in women (0.2 years, p=0.81). Thus, the Val158Met COMT polymorphism is not associated with PD in the Caucasian population but acts as a modifier of the AAO in PD with a sexual dimorphism: the Val allele is associated with a younger AAO in men with idiopathic PD. PMID:23408064
The Gutenberg health study: associations between occupational and private stress factors and work-privacy conflict.

PubMed

Garthus-Niegel, Susan; Hegewald, Janice; Seidler, Andreas; Nübling, Matthias; Espinola-Klein, Christine; Liebers, Falk; Wild, Philipp S; Latza, Ute; Letzel, Stephan

2016-02-29

Work-privacy conflict (WPC) is no longer a rarity but constitutes a societal problem. The objectives of the present study were (1) to investigate the distribution and prevalence of WPC among the employed participants in the Gutenberg Health Study at baseline and (2) to study the dependence of WPC on a broad range of private life and occupational characteristics as well as on psychosocial working conditions. This analysis is based on a representative, population-based sample of 3,709 employees participating in the Gutenberg Health Study. Descriptive and bivariable analyses were carried out separately for women and men. Distribution and prevalence of WPC were examined according to socio-demographic and occupational characteristics as well as psychosocial working conditions. Further, stepwise selection of Poisson log-linear regression models were performed to determine which socio-demographic and occupational characteristics were most associated with the outcome variable WPC and to obtain adjusted prevalence ratios from the final model. The multivariable analyses were conducted both separately for women and men and with all subjects together in one analysis. There was a high prevalence of WPC in the present study (27.4 % of the men and 23.0 % of the women reported a high or very high WPC). A variety of factors was associated with WPC, e.g. full-time employment, depression and many of the psychosocial risk factors at work. Also, the multivariable results showed that women were of higher risk for a WPC. By affecting the individual work life, home life, and the general well-being and health, WPC may lead to detrimental effects in employees, their families, employers, and society as a whole. Therefore, the high prevalence of WPC in our sample should be of concern. Among women, the risk for suffering from WPC was even higher, most likely due to multiple burdens.
Diabetes mellitus may affect the long-term survival of hepatitis B virus-related hepatocellular carcinoma patients after liver transplantation.

PubMed

Zhang, Qing; Deng, Yong-Lin; Liu, Chang; Huang, Li-Hong; Shang, Lei; Chen, Xin-Guo; Wang, Le-Tian; Du, Jin-Zan; Wang, Ying; Wang, Pei-Xiao; Zhang, Hui; Shen, Zhong-Yang

2016-11-21

To determine whether diabetes mellitus (DM) affects prognosis/recurrence after liver transplantation (LT) for hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC). A retrospective study was conducted between January 2000 and August 2013 on 1631 patients with HBV-related HCC who underwent LT with antiviral prophylaxis. Patient data were obtained from the China Liver Transplant Registry (https://www.cltr.org/). To compare the outcomes and tumor recurrence in the HBV-related HCC patients with or without DM, statistical analyses were conducted using χ 2 tests, Mann-Whitney tests, the Kaplan-Meier method, log-rank tests and multivariate step-wise Cox regression analysis. Univariate analysis of 1631 patients who underwent LT found overall 1-, 3- and 5-year survival rates of 79%, 73% and 71% respectively in the DM patients, and 84%, 78% and 76% in the non-DM patients respectively. Overall survival rate differences after LT between the two groups were significant ( P = 0.041), but recurrence-free survival rates were not ( P = 0.096). By stratified analysis, the overall survival rates in DM patients for age > 50 years ( P = 0.002), the presence of vascular invasion ( P = 0.096), tumors ≤ 3 cm ( P = 0.047), two to three tumor nodules ( P = 0.007), Child-Pugh grade B ( P = 0.018), and pre-LT alanine aminotransferase levels between 40 and 80 IU/L ( P = 0.017) were significantly lower than in non-DM patients. Additionally, serum α-fetoprotein level > 2000 ng/mL ( P = 0.052) was associated with a significant survival difference trend between DM and non-DM patients. Multivariate analysis showed that the presence of DM ( P < 0.001, HR = 1.591; 95%CI: 1.239-2.041) was an independent predictor associated with poor survival after LT. HBV-related HCC patients with DM have decreased long-term overall survival and poor LT outcomes. Prevention strategies for HCC patients with DM are recommended.
Predictors of Nondiagnostic Ultrasound for Appendicitis.

PubMed

Keller, Christine; Wang, Nancy E; Imler, Daniel L; Vasanawala, Shreyas S; Bruzoni, Matias; Quinn, James V

2017-03-01

Ionizing radiation and cost make ultrasound (US), when available, the first imaging study for the diagnosis of suspected pediatric appendicitis. US is less sensitive and specific than computed tomography (CT) or magnetic resonance imaging (MRI) scans, which are often performed after nondiagnostic US. We sought to determine predictors of nondiagnostic US in order to guide efficient ordering of imaging studies. A prospective cohort study of consecutive patients 4 to 30 years of age with suspected appendicitis took place at an emergency department with access to 24/7 US, MRI, and CT capabilities. Patients with US as their initial study were identified. Clinical (i.e., duration of illness, highest fever, and right lower quadrant pain) and demographic (i.e., age and sex) variables were collected. Body mass index (BMI) was calculated based on Centers for Disease Control and Prevention criteria; BMI >85th percentile was categorized as overweight. Patients were followed until day 7. Univariate and stepwise multivariate logistic regression analysis was performed. Over 3 months, 106 patients had US first for suspected appendicitis; 52 (49%) had nondiagnostic US results. Eighteen patients had appendicitis, and there were no missed cases after discharge. On univariate analysis, male sex, a yearly increase in age, and overweight BMI were associated with nondiagnostic US (p < 0.05). In the multivariate model, only BMI (odds ratio 4.9 [95% CI 2.0-12.2]) and age (odds ratio 1.1 [95% CI 1.02-1.20]) were predictors. Sixty-eight percent of nondiagnostic US results occurred in overweight patients. Overweight and older patients are more likely to have a nondiagnostic US or appendicitis, and it may be more efficient to consider alternatives to US first for these patients. Also, this information about the accuracy of US to diagnose suspected appendicitis may be useful to clinicians who wish to engage in shared decision-making with the parents or guardians of children regarding imaging options for children with acute abdominal pain. Copyright © 2016 Elsevier Inc. All rights reserved.
The impact of resident involvement on post-operative morbidity and mortality following orthopaedic procedures: a study of 43,343 cases.

PubMed

Schoenfeld, Andrew J; Serrano, Jose A; Waterman, Brian R; Bader, Julia O; Belmont, Philip J

2013-11-01

Few studies have addressed the role of residents' participation in morbidity and mortality after orthopaedic surgery. The present study utilized the 2005-2010 National Surgical Quality Improvement Program (NSQIP) dataset to assess the risk of 30-day post-operative complications and mortality associated with resident participation in orthopaedic procedures. The NSQIP dataset was queried using codes for 12 common orthopaedic procedures. Patients identified as having received one of the procedures had their records abstracted to obtain demographic data, medical history, operative time, and resident involvement in their surgical care. Thirty-day post-operative outcomes, including complications and mortality, were assessed for all patients. A step-wise multivariate logistic regression model was constructed to evaluate the impact of resident participation on mortality- and complication-risk while controlling for other factors in the model. Primary analyses were performed comparing cases where the attending surgeon operated alone to all other case designations, while a subsequent sensitivity analysis limited inclusion to cases where resident participation was reported by post-graduate year. In the NSQIP dataset, 43,343 patients had received one of the 12 orthopaedic procedures queried. Thirty-five percent of cases were performed with resident participation. The mortality rate, overall, was 2.5 and 10 % sustained one or more complications. Multivariate analysis demonstrated a significant association between resident participation and the risk of one or more complications [OR 1.3 (95 % CI 1.1, 1.4); p < 0.001] as well as major systemic complications [OR 1.6 (95 % CI 1.3, 2.0); p < 0.001] for primary joint arthroplasty procedures only. These findings persisted even after sensitivity testing. A mild to moderate risk for complications was noted following resident involvement in joint arthroplasty procedures. No significant risk of post-operative morbidity or mortality was appreciated for the other orthopaedic procedures studied. II (Prognostic).
Age and prostate volume are risk factors for transient urinary incontinence after transurethral enucleation with bipolar for benign prostatic hyperplasia.

PubMed

Hirasawa, Yosuke; Kato, Yuji; Fujita, Kiichiro

2018-01-01

To investigate the predictive factors for transient urinary incontinence after transurethral enucleation with bipolar. We retrospectively analyzed the data of 584 patients who underwent transurethral enucleation with bipolar between December 2011 and September 2016 operated by a single surgeon. Urinary incontinence after transurethral enucleation with bipolar was defined as involuntary leakage of urine that required the use of pads. It was evaluated at 1 week, and 1, 3, 6, 12 and 24 months after transurethral enucleation with bipolar. We defined transient urinary incontinence as urinary incontinence persisting up to 1 month after transurethral enucleation with bipolar. Based on independent risk factors identified by a multivariate stepwise logistic regression analysis, a nomogram to predict transient urinary incontinence was developed. Of the 584 patients, 17.3%, 13.5%, 3.1%, 0.41%, and 0% patients had urinary incontinence at 1 week, 1, 3, 6 and 12 months after transurethral enucleation with bipolar, respectively. The mean (±standard error) age was 69.6 ± 0.26 years, estimated prostate volume was 54.7 ± 0.91 cm 3 , operative time was 58.0 ± 1.1 min and the prostate specimen weight was 30.6 ± 0.69 g. On univariate analysis, age, prostate volume estimated by transrectal ultrasonography, prostate-specific antigen, prostate specimen weight, operative time, prostate specimen weight/prostate volume and prostate specimen weight/operative time were significant predictive factors for transient urinary incontinence after transurethral enucleation with bipolar. On multivariate analysis, age (hazard ratio 1.07, P-value = 0.0034) and prostate volume (hazard ratio 1.03, P-value < 0.0001) were independent risk factors for transient urinary incontinence after transurethral enucleation with bipolar. Age and prostate volume estimated by transrectal ultrasonography seem to represent significant independent risk factors for transient urinary incontinence after transurethral enucleation with bipolar. This should be well discussed with the patient before surgery. © 2017 The Japanese Urological Association.
Systemic lupus erythaematosus in a multiethnic US cohort (LUMINA) LIII: disease expression and outcome in acute onset lupus.

PubMed

Bertoli, A M; Vilá, L M; Reveille, J D; Alarcón, G S

2008-04-01

To determine the features associated with acute onset systemic lupus erythaematosus (SLE). A total of 631 SLE patients from LUMINA (for "lupus in minority populations: nature vs nurture"), a multiethnic (Hispanics, African-Americans and Caucasians) cohort, were studied. Acute disease onset was defined as the accrual of > or = 4 American College of Rheumatology (ACR) criteria for the classification of SLE in < or = 4 weeks. Socioeconomic demographic features, clinical manifestations, disease activity, damage accrual, mortality, autoantibodies, HLA class II and FCGR alleles, behavioural/psychological variables were compared between patients with acute and insidious disease onset by univariable (chi(2) and Student t test) and multivariable (stepwise logistic regression) analyses. A total of 94 (15%) patients had acute disease onset. In the multivariable analysis, patients with acute onset lupus had more renal involvement (odds ratio (OR) = 1.845, 95% CI 1.076-3.162; p = 0.026) and higher disease activity (OR = 1.057, 95% CI 1.005-1.112; p = 0.030). By contrast, age (OR = 0.976, 95% CI 0.956-0.997; p = 0.025), education (OR = 0.901, 95% CI 0.827-0.983, p = 0.019), health insurance (OR = 0.423, 95% CI 0.249-0.718; p = 0.001) and skin involvement (OR = 0.346, 95% CI 0.142-0.843; p = 0.019) were negatively associated with acute onset lupus. No differences were found regarding the serological, genetic and behavioural/psychological features; this was also the case for damage accrual and mortality. Patients with acute onset lupus seem to be younger, have a lower socio-economic status and display more severe disease in terms of clinical manifestations and disease activity. However, intermediate (damage) and long-term (mortality) outcomes appear not to be influenced by the type of disease onset in SLE.
Systemic lupus erythaematosus in a multiethnic US cohort (LUMINA) LIII: disease expression and outcome in acute onset lupus

PubMed Central

Bertoli, A M; Vilá, L M; Reveille, J D; Alarcón, G S

2009-01-01

Objective To determine the features associated with acute onset systemic lupus erythaematosus (SLE). Methods A total of 631 SLE patients from LUMINA (for “lupus in minority populations: nature vs nurture”), a multiethnic (Hispanics, African–Americans and Caucasians) cohort, were studied. Acute disease onset was defined as the accrual of ≥4 American College of Rheumatology (ACR) criteria for the classification of SLE in ≤4 weeks. Socioeconomic demographic features, clinical manifestations, disease activity, damage accrual, mortally, autoantibodies. HLA class II and FCGR alleles, behavioural/psychological variables were compared between patients with acute and insidious disease onset by univariable (χ2 and Student t test) and multivariable (stepwise logistic regression) analyses. Results A total of 94 (15%) patients had acute disease onset. In the multivariable analysis, patients with acute onset lupus had more renal involvement (odds ratio (OR) = 1.845, 95% CI 1.076–3.162; p = 0.026) and higher disease activity (OR = 1.057, 95% CI 1.005–1.112; p = 0.030). By contrast, age (OR = 0.976, 95% CI 0.956–0.997; p = 0.025), education (OR = 0.901, 95% CI 0.827–0.983, p = 0.019), health insurance (OR = 0.423, 95% CI 0.249–0.718; p = 0.001) and skin involvement (OR = 0.346, 95% CI 0.142–0.843; p = 0.019) were negatively associated with acute onset lupus. No differences were found regarding the serological, genetic and behavioural/psychological features; this was also the case for damage accrual and mortality. Conclusions Patients with acute onset lupus seem to be younger, have a lower socio-economic status and display more severe disease in terms of clinical manifestations and disease activity. However, intermediate (damage) and long-term (mortality) outcomes appear not to be influenced by the type of disease onset in SLE. PMID:17720721
Spatial and temporal variability of reference evapotranspiration and influenced meteorological factors in the Jialing River Basin, China

NASA Astrophysics Data System (ADS)

Herath, Imali Kaushalya; Ye, Xuchun; Wang, Jianli; Bouraima, Abdel-Kabirou

2018-02-01

Reference evapotranspiration (ETr) is one of the important parameters in the hydrological cycle. The spatio-temporal variation of ETr and other meteorological parameters that influence ETr were investigated in the Jialing River Basin (JRB), China. The ETr was estimated using the CROPWAT 8.0 computer model based on the Penman-Montieth equation for the period 1964-2014. Mean temperature (MT), relative humidity (RH), sunshine duration (SD), and wind speed (WS) were the main input parameters of CROPWAT while 12 meteorological stations were evaluated. Linear regression and Mann-Kendall methods were applied to study the spatio-temporal trends while the inverse distance weighted (IDW) method was used to identify the spatial distribution of ETr. Stepwise regression and partial correlation methods were used to identify the meteorological variables that most significantly influenced the changes in ETr. The highest annual ETr was found in the northern part of the basin, whereas the lowest rate was recorded in the western part. In the autumn, the highest ETr was recorded in the southeast part of JRB. The annual ETr reflected neither significant increasing nor decreasing trends. Except for the summer, ETr is slightly increasing in other seasons. The MT significantly increased whereas SD and RH were significantly decreased during the 50-year period. Partial correlation and stepwise regression methods found that the impact of meteorological parameters on ETr varies on an annual and seasonal basis while SD, MT, and RH contributed to the changes of annual and seasonal ETr in the JRB.
Reliability of a Bayesian network to predict an elevated aldosterone-to-renin ratio.

PubMed

Ducher, Michel; Mounier-Véhier, Claire; Lantelme, Pierre; Vaisse, Bernard; Baguet, Jean-Philippe; Fauvel, Jean-Pierre

2015-05-01

Resistant hypertension is common, mainly idiopathic, but sometimes related to primary aldosteronism. Thus, most hypertension specialists recommend screening for primary aldosteronism. To optimize the selection of patients whose aldosterone-to-renin ratio (ARR) is elevated from simple clinical and biological characteristics. Data from consecutive patients referred between 1 June 2008 and 30 May 2009 were collected retrospectively from five French 'European excellence hypertension centres' institutional registers. Patients were included if they had at least one of: onset of hypertension before age 40 years, resistant hypertension, history of hypokalaemia, efficient treatment by spironolactone, and potassium supplementation. An ARR>32 ng/L and aldosterone>160 ng/L in patients treated without agents altering the renin-angiotensin system was considered as elevated. Bayesian network and stepwise logistic regression were used to predict an elevated ARR. Of 334 patients, 89 were excluded (31 for incomplete data, 32 for taking agents that alter the renin-angiotensin system and 26 for other reasons). Among 245 included patients, 110 had an elevated ARR. Sensitivity reached 100% or 63.3% using Bayesian network or logistic regression, respectively, and specificity reached 89.6% or 67.2%, respectively. The area under the receiver-operating-characteristic curve obtained with the Bayesian network was significantly higher than that obtained by stepwise regression (0.93±0.02 vs. 0.70±0.03; P<0.001). In hypertension centres, Bayesian network efficiently detected patients with an elevated ARR. An external validation study is required before use in primary clinical settings. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

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