       Document 0283
 DOCN  M9630283
 TI    Demographic and behavioral differences among participants,
       nonparticipants, and dropouts in a cohort study of men who have sex with
       men.
 DT    9603
 AU    Campsmith ML; Goldbaum GM; Wood RW; Department of Health Services,
       University of Washington, Seattle,; USA.
 SO    Sex Transm Dis. 1995 Sep-Oct;22(5):312-6. Unique Identifier : AIDSLINE
       MED/96100870
 AB    BACKGROUND AND OBJECTIVES: Results of prospective cohort studies can be
       biased when subjects selectively refuse to participate or be included in
       follow-up. GOAL OF THIS STUDY: To assess the potential for bias in a
       longitudinal study of sexual risk behavior among men who have sex with
       men. STUDY DESIGN: This was a cross-sectional comparison of clinical
       data regarding men who have sex with men attending an urban human
       immunodeficiency virus testing clinic. RESULTS: Of 3,390 men who have
       sex with men invited to participate, 2,063 refused, 589 dropped out
       after completing an initial study questionnaire, and 738 participated in
       follow-up at 6 months. There were no significant differences in the
       same-gender sexual behaviors of participants, dropouts, and
       nonparticipants, with one exception: Nonparticipants were more likely to
       abstain from receptive oral sex (27%) compared with participants (18%)
       or dropouts (21%). CONCLUSION: The similarities in reported activities
       among participants, dropouts, and nonparticipants suggest that selection
       bias may have limited impact on cohort studies of sexual behavior.
 DE    Adolescence  Adult  Aged  Cohort Studies  Cross-Sectional Studies
       Homosexuality, Male/*STATISTICS & NUMER DATA  Human  HIV
       Infections/*EPIDEMIOLOGY  Longitudinal Studies  Male  Middle Age
       Prospective Studies  Risk Factors  Selection Bias  Sex Behavior  JOURNAL
       ARTICLE

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).

