EFFECTS OF INTERVENTION ATTRITION AND RESEARCH ATTRITION ON THE EVALUATION OF AN HIV PREVENTION PROGRAM

Attrition impacts the effectiveness of preventive interventions as wel l as the external validity of efficacy analyses, This paper examines a ttrition from the intervention and from the research data collection i n an HIV prevention program for out-of-treatment drug users. Of the 1, 115 respondents, 87% completed the two-session HIV prevention interven tion and of these 69% completed the 6-month data collection, Factors r elated to completing the intervention were different from those relate d to completing the 6-month interview, Completing the intervention was associated with HIV risk behaviors and with having a negative result on the project's HIV test, whereas research completion was related to indicators of a stable lifestyle, individuals at highest risk were les s likely to complete the data collection and so were under-represented in the assessment of intervention efficacy. These results have implic ations for program planners and evaluators.