Nanhua Zhang

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OBJECTIVE Many targeted interventions have been developed and tested with African Americans (AA); however, AAs are a highly heterogeneous group. One characteristic that varies across AAs is Ethnic Identity (EI). Little research has been conducted on how to incorporate EI into the design of health messages and programs. DESIGN We tested whether tailoring a(More)
BACKGROUND The Internet provides us with tools (user metrics or paradata) to evaluate how users interact with online interventions. Analysis of these paradata can lead to design improvements. OBJECTIVE The objective was to explore the qualities of online participant engagement in an online intervention. We analyzed the paradata in a randomized controlled(More)
BACKGROUND Evaluation of online health interventions should investigate the function of theoretical mechanisms of behavior change in this new milieu. OBJECTIVES To expand our understanding of how Web-based interventions influence behavior, we examined how changes at 6 months in participants' psychosocial characteristics contributed to improvements at 16(More)
OBJECTIVES We conducted a group randomized trial of 2 South African school-based smoking prevention programs and examined possible sources and implications of why our actual intraclass correlation coefficients (ICCs) were significantly higher than the ICC of 0.02 used to compute initial sample size requirements. METHODS Thirty-six South African high(More)
BACKGROUND The method used to determine choice of standard deviation (SD) is inadequately reported in clinical trials. Underestimations of the population SD may result in underpowered clinical trials. PURPOSE This study demonstrates how using the wrong method to determine population SD can lead to inaccurate sample sizes and underpowered studies, and(More)
Ghanaian men who have sex with men (MSM) have high rates of HIV infection. A first step in designing culturally relevant prevention interventions for MSM in Ghana is to understand the influence that peer social networks have on their attitudes and behaviors. We aimed to examine whether, in a sample of Ghanaian MSM, mean scores on psychosocial variables(More)
African American attitudes toward organ donation differ from other racial and ethnic groups. However, existing measures of organ donation attitudes do not adequately address ethnic identity and cultural factors. We examined the psychometric properties of a new 18-item organ donation scale among 1225 members of 21 African American churches in Southeast(More)
Ghanaian men who have sex with men (MSM) have a high HIV seroprevalence, but despite a critical need to address this public health concern, research evidence has been extremely limited on influences on sexual risk behavior among MSM in Ghana. To investigate associations between HIV/STD knowledge, HIV stigma, and sexual behaviors in a sample of MSM in Ghana,(More)
Medicare Advantage was implemented in 2004 and the Recovery Audit Contractor (RAC) program was implemented in Florida during 2005. Both increase surveillance of medical necessity and deny payments for improper admissions. The purpose of the present study was to determine their potential impact on for-profit (FP) and not-for-profit (NFP) hospital operating(More)
BACKGROUND Web-based computer-tailored approaches have the potential to be successful in supporting smoking cessation. However, the potential effects of such approaches for relapse prevention and the value of incorporating action planning strategies to effectively prevent smoking relapse have not been fully explored. The Stay Quit for You (SQ4U) study(More)