Lifestyle interventions and independence for elders study: recruitment and baseline characteristics

Recruitment of older adults into long-term clinical trials involving behavioral interventions is a significant challenge. The Lifestyle Interventions and Independence for Elders (LIFE) Study is a Phase 3 multicenter randomized controlled multisite trial, designed to compare the effects of a moderate-intensity physical activity program with a successful aging health education program on the incidence of major mobility disability (the inability to walk 400 m) in sedentary adults aged 70-89 years, who were at high risk for mobility disability (scoring ≤ 9 on the Short Physical Performance Battery) at baseline.

Recruitment methods, yields, efficiency, and costs are described together with a summary of participant baseline characteristics. Yields were examined across levels of sex, race and ethnicity, and Short Physical Performance Battery, as well as by site.

The 21-month recruiting period resulted in 14,812 telephone screens; 1,635 participants were randomized (67.2% women, 21.0% minorities, 44.7% with Short Physical Performance Battery scores ≤ 7). Of the telephone-screened participants, 37.6% were excluded primarily because of regular participation in physical activity, health exclusions, or self-reported mobility disability. Direct mailing was the most productive recruitment strategy (59.5% of randomized participants). Recruitment costs were $840 per randomized participant. Yields differed by sex and Short Physical Performance Battery. We accrued 11% more participant follow-up time than expected during the recruitment period as a result of the accelerated recruitment rate.

The LIFE Study achieved all recruitment benchmarks. Bulk mailing is an efficient method for recruiting high-risk community-dwelling older persons (including minorities), from diverse geographic areas for this long-term behavioral trial.