DETERMINANTS OF RESEARCH FOLLOW-UP PARTICIPATION IN AN ALCOHOL TREATMENT OUTCOME TRIAL

This study examined factors associated with research attrition in a lo ng-term follow-up study (48 months). Researchers attempted to contact all randomized participants, not just those who completed treatment. T he processes by which baseline characteristics, early treatment-resear ch experiences, and short-term outcome affected subsequent participati on were examined using logistic regression. The analyses deal primaril y with refusal, the main reason for attrition. Baseline characteristic s had small effects on likelihood of refusal; research engagement had some impact; but treatment participation had a strong effect. Short-te rm outcome did not predict refusal. These findings, if generalizable, have implications for the conduct and reporting of outcome studies. By directly studying bias, rather than presuming its absence on skimpy e vidence, researchers can achieve a better understanding of the strengt hs and limitations of outcome results.