Attrition and retention in clinical trials by ethnic origin

ContextCommon perceptions exist within the medical community that retention of Hispanics in clinical trials is difficult, albeit little data is available to support this conviction.MethodsA total of 541 randomly selected charts from closed clinical trials between 2000 and 2006 were reviewed. Records were from participating institutions in Texas Medical Center, Houston, and targeted diseases of high prevalence, specifically, breast cancer, prostate cancer, and chronic obstructive pulmonary disease (COPD)/asthma.FindingsOverall, 259 participants (48%) completed the trial they were enrolled in (44% whites, 69% Hispanics, 51% blacks; p < .05). Within pediatric trials, whom all were pulmonary patients, retention rates were higher among Hispanics than whites (adjusted odds ratio [OR] = 7.49, 95% confidence interval [CI] = 1.15–58.03, p = .04). Among adults, patient's ethnicity was unrelated to study completion. All associations were adjusted for possible confounders. Reasons for not completing a trial varied by ethnicity: “patient withdrawing consent” was more common among whites (51.4%) than Hispanics (21.7%) or blacks (26.2%) (p < .05). Hispanics were more inclined to be withdrawn from the trial by the investigator (43.5%) than were whites (24%, p = .04), mostly due to non-compliance with the study protocol.ConclusionsHispanic parents of children with COPD may be more likely to complete a trial than parents of non-Hispanic whites. Among adults, Hispanics had similar completion rates as compared to whites. Culturally sensitive, multi-factorial approaches maybe imperative to increasing patient engagement in clinical trials.