PARTICIPATION IN CLINICAL-TRIALS AND LONG-TERM OUTCOMES IN ALZHEIMERS-DISEASE

The objective of this study was to determine whether participation in clinical trials affects long-term outcomes in Alzheimer's disease (AD) . Participation in clinical trials for persons with dementia is often justified on the grounds that patients benefit from the medical oversi ght typical of trials, even when experimental agents do not demonstrat e short-term benefits. This claim has not been rigorously assessed. Of 215 community-resident subjects enrolled in a prospective study of ou tcomes in AD, 101 participated in randomized clinical trials (RCTs) du ring the first 2 years of follow-up. These subjects were compared with subjects who met eligibility requirements for RCTs but did not partic ipate (N = 57) and with subjects who were ineligible (N = 57), over a total of 3.5 years of follow-up. Survival analyses assessed risk of de ath, nursing home placement, and incident functional deficit end point s, adjusting for baseline differences. Subjects who participated in RC Ts were younger and more highly educated. Mortality, risk of hospitali zation, number of medical examinations conducted by study physicians, and onset of severe functional deficit did not differ between the grou ps, but risk of nursing home admission was significantly lower among R CT participants compared with eligible nonparticipants and ineligible subjects (16.8% versus 36.8% and 31.6%, respectively [p = 0.01]). The difference in risk of nursing home placement may represent a long-term , drug-related benefit to patients, a selection effect (caregivers of patients who participate in RCTs differ from caregivers of patients wh o do not), or a positive effect on caregivers (greater contact with a medical service may be associated with better care-giving outcomes). F urther research is required to assess these effects.