Recruitment of older participants in frailty/injury prevention studies.

Despite the lifelong health benefits of physical activity, frailer older adults have typically been excluded from studies promoting more active lifestyles. This study documents the recruitment process and costs from a multisite study to identify effective strategies for recruiting older adults in frailty/injury prevention research. Randomized controlled clinical trials were conducted at 7 sites; an 8th site was a compliance study. Interventions reflected center- and home-based health promotion programs. Site objectives, eligibility criteria, and contact and screening methods were obtained from manuals of operation. Recruitment results (number screened, eligibility rates, randomized to screened ratios) were ascertained from recruitment data. Sites furnished estimated recruitment costs (nonlabor expenses, investigator and staff time, fringe benefits) up to signing the consent form. The sites targeted diverse populations and sample sizes. The majority revised recruitment methods to meet their recruitment goals. Most sites estimated costs of recruitment at over $300 per participant randomized. Recruitment costs were affected by staff time spent alleviating concerns about participants' health, essential interactions with family members, and arranging for transportation. Neither frailty nor intervention intensity was found to be a major predictor of recruitment outcomes. Recruitment expense was associated with selection criteria and frailty status of the target population. Older people can be successfully recruited into beneficial health promotion programs, but it is often challenging. In planning health promotion studies, investigators need to be aware of the numbers of older people they may need to screen and different strategies for increasing recruitment success.