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Hierarchical Logistic Regression (hierarchical + logistic_regression)
Selected AbstractsHierarchical Logistic Regression: Accounting for Multilevel Data in DIF DetectionJOURNAL OF EDUCATIONAL MEASUREMENT, Issue 3 2010Brian F. French The purpose of this study was to examine the performance of differential item functioning (DIF) assessment in the presence of a multilevel structure that often underlies data from large-scale testing programs. Analyses were conducted using logistic regression (LR), a popular, flexible, and effective tool for DIF detection. Data were simulated using a hierarchical framework, such as might be seen when examinees are clustered in schools, for example. Both standard and hierarchical LR (accounting for multilevel data) approaches to DIF detection were employed. Results highlight the differences in DIF detection rates when the analytic strategy matches the data structure. Specifically, when the grouping variable was within clusters, LR and HLR performed similarly in terms of Type I error control and power. However, when the grouping variable was between clusters, LR failed to maintain the nominal Type I error rate of .05. HLR was able to maintain this rate. However, power for HLR tended to be low under many conditions in the between cluster variable case. [source] Do cultural factors predict mammography behaviour among Korean immigrants in the USA?JOURNAL OF ADVANCED NURSING, Issue 12 2009Hanju Lee Abstract Title.,Do cultural factors predict mammography behaviour among Korean immigrants in the USA? Aim., This paper is a report of a study of the correlates of mammogram use among Korean American women. Background., Despite the increasing incidence of and mortality from breast cancer, Asian women in the United States of America report consistently low rates of mammography screening. A number of health beliefs and sociodemographic characteristics have been associated with mammogram participation among these women. However, studies systematically investigating cultural factors in relation to mammogram experience have been scarce. Methods., We measured screening-related health beliefs, modesty and use of Eastern medicine in 100 Korean American women in 2006. Hierarchical logistic regression was used to examine the unique contribution of the study variables, after accounting for sociodemographic characteristics. Findings., Only 51% reported past mammogram use. Korean American women who had previously had mammograms were statistically significantly older and had higher perceived benefit scores than those who had not. Perceived benefits (odds ratio = 6·3, 95% confidence interval = 2·12, 18·76) and breast cancer susceptibility (odds ratio = 3·18, 95% confidence interval = 1·06, 9·59) were statistically significant correlates of mammography experience, whereas cultural factors did not correlate. Post hoc analysis showed that for women with some or good English skills, cultural factors statistically significantly correlated with health beliefs and breast cancer knowledge (P < 0·05). Conclusion., Nurses should consider the inclusion in culturally tailored interventions of more targeted outreach and healthcare system navigation assistance for promoting mammography screening in Korean American women. Further research is needed to unravel the interplay between acculturation, cultural factors and health beliefs related to cancer screening behaviours of Korean American women. [source] Impact of assertive community treatment and client characteristics on criminal justice outcomes in dual disorder homeless individualsCRIMINAL BEHAVIOUR AND MENTAL HEALTH, Issue 4 2005Dr Robert J. Calsyn PhD Background People with severe mental illness and substance use disorders (dual disorder) often have considerable contact with the criminal justice system. Aims To test the effects of client characteristics on six criminal justice outcomes among homeless (at intake) people with mental illness and substance misuse disorders. Methods The sample was of participants in a randomized controlled trial comparing standard treatment, assertive community treatment (ACT) and integrated treatment (IT). Data were analysed using hierarchical logistic regression. Results Half the sample was arrested and a quarter incarcerated during the two-year follow-up period. The regression models explained between 22% and 35% of the variance of the following criminal justice measures: (1) major offences, (2) minor offences, (3) substance-use-related offences, (4) incarcerations, (5) arrests, and (6) summons. Prior criminal behaviour was the strongest predictor of all of the dependent variables; in general, demographic and diagnostic variables were not. Similarly, neither the type nor the amount of mental health treatment received predicted subsequent criminal behaviour. Conclusion Elsewhere the authors have shown that ACT and IT had advantages for health and stability of accommodation but these analyses suggest that more specialized interventions are needed to reduce criminal behaviour in dual disorder individuals. Copyright © 2005 John Wiley & Sons, Ltd. [source] Modelling species diversity through species level hierarchical modellingJOURNAL OF THE ROYAL STATISTICAL SOCIETY: SERIES C (APPLIED STATISTICS), Issue 1 2005Alan E. Gelfand Summary., Understanding spatial patterns of species diversity and the distributions of individ-ual species is a consuming problem in biogeography and conservation. The Cape floristic region of South Africa is a global hot spot of diversity and endemism, and the Protea atlas project, with about 60 000 site records across the region, provides an extraordinarily rich data set to model patterns of biodiversity. Model development is focused spatially at the scale of 1, grid cells (about 37 000 cells total for the region). We report on results for 23 species of a flowering plant family known as Proteaceae (of about 330 in the Cape floristic region) for a defined subregion. Using a Bayesian framework, we developed a two-stage, spatially explicit, hierarchical logistic regression. Stage 1 models the potential probability of presence or absence for each species at each cell, given species attributes, grid cell (site level) environmental data with species level coefficients, and a spatial random effect. The second level of the hierarchy models the probability of observing each species in each cell given that it is present. Because the atlas data are not evenly distributed across the landscape, grid cells contain variable numbers of sampling localities. Thus this model takes the sampling intensity at each site into account by assuming that the total number of times that a particular species was observed within a site follows a binomial distribution. After assigning prior distributions to all quantities in the model, samples from the posterior distribution were obtained via Markov chain Monte Carlo methods. Results are mapped as the model-estimated probability of presence for each species across the domain. This provides an alternative to customary empirical ,range-of-occupancy' displays. Summing yields the predicted richness of species over the region. Summaries of the posterior for each environmental coefficient show which variables are most important in explaining the presence of species. Our initial results describe biogeographical patterns over the modelled region remarkably well. In particular, species local population size and mode of dispersal contribute significantly to predicting patterns, along with annual precipitation, the coefficient of variation in rainfall and elevation. [source] Formal Policies and Special Informed Consent Are Associated with Higher Provider Utilization of CDC High-Risk Donor OrgansAMERICAN JOURNAL OF TRANSPLANTATION, Issue 3 2009L. M. Kucirka A new United Network for Organ Sharing (UNOS) policy mandates special informed consent (SIC) before transplanting organs from donors classified by the Public Health Service/Center for Disease Control (PHS/CDC) as high-risk donors (HRDs); however, concerns remain that this policy may cause suboptimal organ utilization. Currently, consent and disclosure policy is determined by individual centers or surgeons; as such, little is known about current practices. The goals of this study were to quantify consent and disclosure practices for HRDs in the United States, identify factors associated with SIC use and analyze associations between SIC use and HRD organ utilization. We surveyed 422 transplant surgeons about their use of HRD organs and their associated consent and disclosure practices. In total, 52.7% of surgeons use SIC, but there is a high variation in use within centers, between centers and by donor behavior. A defined HRD policy at a transplant center is strongly associated with SIC use at that center (OR = 4.68, p < 0.001 by multivariate hierarchical logistic regression). SIC use is associated with higher utilization of HRD livers (OR 3.37), and a trend toward higher utilization of HRD kidneys (OR 1.74) and pancreata (OR 1.28). We believe our findings support a formalized national policy and suggest that this policy will not result in decreased utilization. [source] Theory-Based Determinants of Youth Smoking: A Multiple Influence Approach,JOURNAL OF APPLIED SOCIAL PSYCHOLOGY, Issue 1 2004Scott C. Carvajal This study tested a broad array of determinants of smoking grounded in general social psychological theories, as well as personality and social development theories. Using data from 2,004 middle school students, all proximal and distal determinants significantly predicted smoking in the hypothesized direction. Further, hierarchical logistic regressions showed that intention to smoke, positive and negative attitudes toward smoking, impediments to smoking, self-efficacy to resist smoking, parent norms, and academic success most strongly predicted current smoking. Hierarchical linear regressions suggested that parental relatedness, maladaptive coping strategies, depression, and low academic aspirations most strongly predicted susceptibility to smoking for those who had not yet smoked a cigarette. Global expectancies were the strongest predictor of susceptibility in low socioeconomic status students. These findings may guide the development of future theory-based interventions that produce the greatest reductions in youth smoking. [source] | |||||||||||||