title: Predictors of participation and attrition in a health promotion study involving psychiatric outpatients.
abstract: Participant selection biases can reduce the generalizability of research findings and lead to misestimates of intervention effectiveness. The authors examined factors associated with study participation and attrition among psychiatric outpatients recruited for the initial phase of a health promotion trial. Medical records were reviewed to obtain HIV-risk and substance abuse data, as well as psychiatric and demographic characteristics of potential participants. Of 895 eligible outpatients, 67% (n = 601) consented to participate, among whom 69% (n = 415) completed all baseline appointments. Compared with nonconsenters, consenters were more likely to be at risk for drug problems and to receive care from clinics serving more impaired patients. Study completion was associated with older age, a psychiatric diagnosis other than adjustment disorder, and a recent sexually transmitted disease diagnosis. These findings suggest that patients who could most benefit from risk reduction interventions are more likely to participate.
authors.affiliation: Center for Health and Behavior and Department of Psychology, Syracuse University, New York 13244-2340, USA. pvanable@syr.edu
authors.forename: Peter A
authors.initials: PA
authors.lastname: Vanable
authors.forename: Michael P
authors.initials: MP
authors.lastname: Carey
authors.forename: Kate B
authors.initials: KB
authors.lastname: Carey
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Maisto
mesh_terms: D000328:Adult; D005260:Female; D015658:HIV Infections / Q000517:prevention & control*; D007722:Health Knowledge, Attitudes, Practice; D006293:Health Promotion / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D001523:Mental Disorders / Q000453:epidemiology* / Q000523:psychology; D008875:Middle Aged; D009518:New York; D010342:Patient Acceptance of Health Care / Q000523:psychology / Q000706:statistics & numerical data*; D010352:Patient Dropouts / Q000523:psychology / Q000706:statistics & numerical data*; D012309:Risk-Taking; D015983:Selection Bias; D019966:Substance-Related Disorders / Q000453:epidemiology / Q000523:psychology