Power analysis for clustered non-continuous responses in multicenter trials

Power analysis for multi-center randomized control trials is quite difficult to perform for non-continuous responses when site differences are modeled by random effects using the generalized linear mixed-effects model (GLMM). First, it is not possible to construct power functions analytically, because of the extreme complexity of the sampling distribution of parameter estimates. Second, Monte Carlo (MC) simulation, a popular option for estimating power for complex models, does not work within the current context because of a lack of methods and software packages that would provide reliable estimates for fitting such GLMMs. For example, even statistical packages from software giants like SAS do not provide reliable estimates at the time of writing. Another major limitation of MC simulation is the lengthy running time, especially for complex models such as GLMM, especially when estimating power for multiple scenarios of interest. We present a new approach to address such limitations. The proposed approach defines a marginal model to approximate the GLMM and estimates power without relying on MC simulation. The approach is illustrated with both real and simulated data, with the simulation study demonstrating good performance of the method.     

Matching in sexual experience for married, cohabitating, and dating couples

The present study examined heterosexual romantic partners' number of intercourse partners prior to the initiation of their relationship to determine if a significant positive correlation (matching) occurred between partners, and if this matching was associated with their level of love, satisfaction with, and commitment to the relationship. One hundred and six couples who were dating, cohabitating, or married participated in this study. Results indicated that, with the exception of cohabitating couples, romantic partners showed a significant level of matching in the prior number of intercourse partners. Further, among the married couples, a higher discrepancy between men's and women's number of previous intercourse partners was related to lower levels of love, satisfaction, and commitment in the relationship.     

Differences by gender, ethnicity, and acculturation in the efficacy of the keepin' it REAL model prevention program

This study examined whether the efficacy of keepin' it REAL, a model program for substance use prevention in schools, was moderated by gender, ethnicity, and acculturation. Gender differences in program efficacy may arise through boys' higher risk of drug use, inadequate attention to girls' developmental issues, or cultural factors like polarized gender expectations. Data came from a randomized trial in 35 Phoenix, Arizona, middle schools involving 4,622 mostly Latino 7th graders. Using multi-level mixed models and multiple imputation missing techniques, results for the total sample showed no gender differences in program effects on recent substance use, but the program was more effective in fostering boys' than girls' anti-drug norms. Subgroup analyses demonstrated several more beneficial program effects for boys than girls (less alcohol and cigarette use and stronger anti-drug norms), but only among less acculturated Latinos. There were no gender differences in program effects among more acculturated Latinos, nor among non-Latino whites.     

Examining the correlates of engagement and disengagement coping among help-seeking battered women

This study examined several potential correlates of engagement and disengagement coping, including abuse-related factors, socioeconomic and social coping resources, and childhood trauma variables among a sample of battered women (N = 388). Relationship abuse frequency, particularly psychological aggression, and peritraumatic dissociation were the strongest positive predictors of the use of disengagement coping. Social coping resources, including tangible support and appraisals of social support and belonging, were associated with higher engagement coping and lower disengagement coping. A positive association was also found between interparental domestic violence and disengagement coping, and negative associations were found between both childhood physical and sexual abuse and engagement coping. Results suggest that coping strategies used by battered women are multidetermined and deserve further exploration.     

A pilot intervention to promote walking and wellness and to improve the health of college faculty and staff

There is a need to investigate novel interventions that promote worksite physical activity and wellness. OBJECTIVE: The authors' purpose in this study was to evaluate the effectiveness of a 12-week walking program supplemented with a pedometer, computer educational program, and weekly e-mails. METHODS: College faculty and staff participated in a one-group pre-posttest study to determine whether the 12-week walking intervention had an effect on body mass index (BMI), blood pressure, blood glucose, and cholesterol. The authors also determined participant-perceived wellness effects. RESULTS: The authors observed differences between baseline and follow-up in BMI (p = .024), blood glucose (p = .06), and total cholesterol (p = .09). The program had a moderate effect on fitness, mood, health awareness, nutrition, and health. CONCLUSIONS: It is incumbent that experts develop innovative worksite physical activity and wellness programs. A pedometer-monitored walking program is one way that a worksite health initiative can improve the health and wellness of its employees and simultaneously reduce health-care costs.     

Pearls and pitfalls in evaluating a Student Assistance Program: a five-year case study

This article presents data from a five-year evaluation-research case study of a large urban schools district's internal Student Assistance Program (SAP). The district employed specially trained and licensed school-based counselors to implement an internal SAP expanded to include tertiary prevention, and modeled after an employee assistance program established for adults. From the population of more than 10,000 students who received some type of program assistance for at-risk behaviors, a stratified random sample of 2,238 cases, over a five year period, were reviewed. Results indicate a statistically significant decline (p < .05) in students' drug use and a significant improvement in internal locus of control occurred each year. While not statistically significant, the average number of student discipline referrals was less than the year prior to program admission; however, there was no significant change in academic performance. A significant correlation between students' drug use and the amount of time in program, the type of assistance received, and the student's custody status was also found.     

Environmental changes to increase physical activity: perceptions of older urban ethnic-minority women

Despite the numerous benefits of physical activity, older adults continue to be more sedentary than their younger counterparts, and sedentary behavior is more prevalent among older racial and ethnic minorities than among Whites. This study used the nominal group technique (NGT) to examine participants' perceptions of what neighborhood environmental changes would encourage greater physical activity for older African American and Hispanic women. Participants age 50-75 years were recruited from 2 urban community health clinics. Nine NGT sessions (45 participants) were conducted. The women were asked what changes in their neighborhood environment would encourage them to become more physically active. Responses to the research question were tabulated, and qualitative analysis was used to identify themes and categories. Major categories were physical environment changes, safety, and activities/social support. Although the physical environment received the greatest number of points, concerns for personal safety cut across categories. Participants indicated the need for more facilities in which to be active.     

A family systems-based model of organizational intervention

Employee assistance professionals are expected to be proficient at intervening in organizations and creating meaningful behavioral change in interpersonal functioning. Because of their training in family systems theories and concepts, marriage and family therapists (MFTs) are well suited to serve organizations as "systems consultants." Unfortunately, the authors were unable to identify any family systems-based models for organizational intervention that have been empirically tested and supported. In this article, the authors present a family systems-based model of intervention that they developed while working in an employee assistance program (EAP). They also present research that was used to refine the model and to provide initial support for its effectiveness.     

A DECISION THEORY EXAMPLE IN FOOTBALL

In the 1967 Harvard-Cornell football game, Harvard was ahead 14–0 late in the game when Cornell scored two touchdowns. On both occasions, Cornell tried and failed on the two-point conversion attempt and lost the game 14–12. Postgame arguments were divided on the merits of Cornell's strategy. For this frequently occurring scenario in college football, we derive a maximum expected utility decision rule for the decision of kicking versus running/passing based on the relative utility of a win, a tie, or a loss and the probabilities of success with a kick as opposed to a run/pass.