Adherence and retention of female injection drug users in a phase III clinical trial in inner city Baltimore.

Adherence and retention of female injection drug users (IDUs) in clinical trials are not well known and were evaluated among 458 female IDUs in a clinical trial in Baltimore. Of all, 62.9% were adherent to visits (attended > or = 80% of visits). Of women with > or = 1 visit after enrollment, 76% were adherent to treatment (took > or = 80% of pills); 27.7% were lost to follow-up (missed > or = 3 consecutive visits). Women nonadherent to visits were younger and less likely to be on methadone. Women lost to follow-up were younger, more often white, not on methadone, and injecting drugs daily. Fair-moderate adherence to visits and treatment occurs among female IDUs in a clinical trial.