Nanhua Zhang

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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 Although more individuals are sharing their experiences with chronic pain or illness through blogging (writing an Internet web log), research on the psychosocial effects and motivating factors for initiating and maintaining a blog is lacking. OBJECTIVE The objective was to examine via online questionnaire the perceived psychosocial and health(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)
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)
  • LaRon E. Nelson, Leo Wilton, Thomas Agyarko-Poku, Nanhua Zhang, Yuanshu Zou, Marilyn Aluoch +3 others
  • 2015
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)
In longitudinal studies it is often of interest to investigate how a repeatedly measured marker in time is associated with a time to an event of interest. This type of research question has given rise to a rapidly developing field of biostatistics research that deals with the joint modeling of longitudinal and time-to-event data. Normality of model errors(More)
BACKGROUND Preventing smoking initiation among adolescents is crucial to reducing tobacco-caused death and disease. This study focuses on the effectiveness of a Web-based computer-tailored smoking prevention intervention aimed at adolescents. OBJECTIVE The intent of the study was to describe the intervention characteristics and to show the effectiveness(More)
BACKGROUND Seasonal variations in smoking and quitting behaviors have been documented, with many smokers seeking cessation assistance around the start of the New Year. What remains unknown is whether smokers who are recruited to cessation treatment trials during the New Year are as motivated to quit, or as likely to enroll in a research trial, adhere to a(More)