Medical Marijuana Laws and Marijuana Use Among U.S. Adolescents: Evidence From Michigan Youth Risk Behavior Surveillance Data.

Research findings are inconsistent regarding a positive association between the passage of state medical marijuana laws (MML) and adolescent access and use marijuana. We utilized a novel analytical approach to examine this issue with multi-year data from the 1997–2013 Youth Risk Behavior Surveillance System (YRBSS) of the State of Michigan. After controlling for the historically declining trend in marijuana use prior to the passages of MML in Michigan, we found that marijuana use among adolescents had increased subsequent to the passage of state MML.

Quantum changes in self-efficacy and condom-use intention among youth: A chained cusp catastrophe model.

Introduction: The complex relationships among HIV knowledge, condom-use skills, self-efficacy, peer influence and intention to use condoms have been rigorously investigated. However, studies guided by a linear behavior change model often explain only a limited amount of variances. This study aims to advance our understanding of the relationships through a nonlinear quantum change paradigm.

Self-management intervention for long-term indwelling urinary catheter users: randomized clinical trial.

Background: People using long-term indwelling urinary catheters experience multiple recurrent catheter problems. Self-management approaches are needed to avoid catheter-related problems.

Objectives: The aim was to determine effectiveness of a self-management intervention in prevention of adverse outcomes (catheter-related urinary tract infection, blockage, and accidental dislodgement).

Cusp Catastrophe Polynomial Model: Power and Sample Size Estimation.

Guastello's polynomial regression method for solving cusp catastrophe model has been widely applied to analyze nonlinear behavior outcomes. However, no statistical power analysis for this modeling approach has been reported probably due to the complex nature of the cusp catastrophe model. Since statistical power analysis is essential for research design, we propose a novel method in this paper to fill in the gap.

On the implication of structural zeros as independent variables in regression analysis: applications to alcohol research.

In alcohol studies, drinking outcomes such as number of days of any alcohol drinking (DAD) over a period of time do not precisely capture the differences among subjects in a study population of interest. For example, the value of 0 on DAD could mean that the subject was continually abstinent from drinking such as lifetime abstainers or the subject was alcoholic, but happened not to use any alcohol during the period of interest. In statistics, zeros of the first kind are called structural zeros, to distinguish them from the sampling zeros of the second type.

Evaluation of objective and perceived mental fatigability in older adults with vascular risk.

Objectives: Mental fatigability refers to the failure to sustain participation in tasks requiring mental effort. Older adults with vascular risk are at particular risk for experiencing mental fatigability. The present study (1) tested a new way of measuring objective mental fatigability by examining its association with perceived mental fatigability; and (2) identified associated psychological, physiological, and situational predictors.

Cusp catastrophe model: a nonlinear model for health outcomes in nursing research.

Background: Although health outcomes may have fundamentally nonlinear relationships with relevant behavioral, psychological, cognitively, or biological predictors, most analytical models assume a linear relationship. Furthermore, some health outcomes may have multimodal distributions, but most statistical models in common use assume a unimodal, normal distribution. Suitable nonlinear models should be developed to explain health outcomes.

Linking cognition and frailty in middle and old age: metabolic syndrome matters.

Objectives: This study examined whether metabolic syndrome (MetS) would moderate the association of cognition with frailty in middle and old age.

Methods: A cross-sectional design was used. Six hundred and ninety participants (age ≥ 50 years) from an on-going national survey were included in the study.

Depressive symptoms and proinflammatory cytokines across the perinatal period in African American women.

Background: Comparatively few studies have examined the biological mechanisms that may underlie the reported racial disparities in antenatal and postpartum depression.

Objective: To examine the associations among race, depressive symptoms and the proinflammatory cytokines interleukin (IL)-6 and tumor necrosis factor (TNF)-α across the perinatal period in a diverse sample of healthy pregnant women at elevated psychosocial risk.

Methods: 171 subjects were enrolled.

Disordered eating behaviors in young adult Mexican American women: prevalence and associations with health risks.

Recent research has shown that disordered eating behaviors are as prevalent in heterogenous samples of Latinas living in the U.S. as in non-Hispanic white women, yet less is known about the prevalence in women of Mexican origin.

Frequency of mentally stimulating activities modifies the relationship between cardiovascular reactivity and executive function in old age.

Objectives: Recent evidence suggests that younger and middle-age adults who show greater cardiovascular reactivity (CVR) to acute mental stress demonstrate better reasoning and memory skills. The purpose of this study was to examine whether older adults would exhibit a similar positive association between CVR and executive function and whether regular engagement in mentally stimulating activities (MSA) would moderate this association.

Design: Secondary cross-sectional analysis.

Weighted least-squares method for right-censored data in accelerated failure time model.

The classical accelerated failure time (AFT) model has been extensively investigated due to its direct interpretation of the covariate effects on the mean survival time in survival analysis. However, this classical AFT model and its associated methodologies are built on the fundamental assumption of data homoscedasticity. Consequently, when the homoscedasticity assumption is violated as often seen in the real applications, the estimators lose efficiency and the associated inference is not reliable.

A randomized clinical trial of an identity intervention programme for women with eating disorders.

Objective: Findings of a randomized trial of an identity intervention programme (IIP) designed to build new positive self-schemas that are separate from other conceptions of the self in memory as the means to promote improved health in women diagnosed with eating disorders are reported.

Method: After baseline data collection, women with anorexia nervosa or bulimia nervosa were randomly assigned to IIP (n = 34) or supportive psychotherapy (SPI) (n = 35) and followed at 1, 6, and 12 months post-intervention.

Results: The IIP and supportive psychotherapy were equally effective in reducing eating disorder symptoms at 1 month post-intervention, and changes were stable through the 12-month follow-up period.

Trajectories of combined laboratory- and real world-based speed of processing in community-dwelling older adults.

Objectives: To characterize the trajectories of laboratory- and real world-based speed of processing (SOP) over 5 years using finite latent growth mixture modeling, and to explore associated baseline individual-level predictors and functional outcomes in 2,802 community-dwelling older adults from the Advanced Cognitive Training for Independent and Vital Elderly cohort.

Method: Laboratory- and real world-based SOP and functional outcomes were assessed over 5 years, and candidate individual-level predictors were collected at baseline.

Results: After controlling for intervention assignment and demographic information, 4 distinct trajectories were identified: 4.

Effect of leisure activities on inflammation and cognitive function in an aging sample.

Cardiovascular disease risk factors (CVDRFs) increase the risk of dementia. The purpose of this study was to examine whether leisure activities (mental, physical, and social activities) modified the effect of CVDRFs on inflammatory markers and cognitive function in middle and old age. A secondary-data analysis study was conducted using data from 405 middle-age participants (40-59 years) and 342 old-age participants (60-84 years) who participated in the Survey of Midlife Development in the United States (MIDUS).