Prevention at home in older persons with (pre-)frailty: analysis of participants' recruitment and characteristics of the randomized controlled PromeTheus trial

BACKGROUND: The "PromeTheus" trial is evaluating a home-based, multifactorial, interdisciplinary prevention program for community-dwelling (pre-)frail older adults. These individuals often suffer from reduced participation, which can complicate the recruitment and enrollment in a clinical trial.

AIMS: The aim of this study was to evaluate different recruitment strategies and differences in participant characteristics in relation to these strategies.

METHODS: This cross-sectional study used baseline data from the randomized-controlled PromeTheus trial, in which community-dwelling (pre-)frail older persons (Clinical Frailty Scale [CFS] 4-6 pt., ≥ 70 years) were recruited via general practitioners ("GP recruitment") or flyers, newspaper articles, and personalized letters ("direct recruitment"). Differences in the sociodemographic, clinical, physical, functional, mobility-related, psychological and social characteristics were analyzed in relation to the recruitment strategy.

RESULTS: A total of 385 participants (mean age = 81.2, SD 5.9 years; women: n = 283, 73.5%) were enrolled, of which 60 (16%) were recruited by GPs and 325 (84%) through direct recruitment. Participants recruited via GPs had significantly higher subjective frailty levels (CFS), were more often physically frail (Fried Frailty Phenotype), and showed lower physical capacity (Short Physical Performance Battery), participation (disability component of the short version of the Late-Life Function and Disability Instrument), and life-space mobility (Life-Space Assessment) compared to those recruited via the direct approach (p = 0.002-0.026). Costs per randomized participant were 94€ for the GP recruitment strategy and €213 for the direct recruitment strategy.

CONCLUSION: Different strategies may be required to successfully recruit (pre-)frail home-living older adults into preventive programs. Direct recruitment strategies, in which potential participants are directly informed about the prevention program, seem to be more promising than GP recruitment but may result in enrolment of persons with less functional impairment and higher recruitment costs.

TRIAL REGISTRATION: German Clinical Trials Register, DRKS00024638. Registered on March 11, 2021.