Variation in response to a home intervention to support daily function by age, race, sex, and education

Background. Functional difficulty is associated with increased frailty and poor life quality, with the oldest old, women, African Americans, and less educated persons at greatest risk of disablement. This study examines whether these at-risk groups benefit differentially from an in-home intervention previously found to effectively reduce functional difficulties. Methods. Three hundred nineteen community-living, functionally vulnerable adults 70 years old or older were randomized to usual care or an intervention involving occupational and physical therapy home instruction in problem solving, device use, energy conservation, safety, fall recovery, balance, and muscle strengthening. Outcome measures at 6 and 12 months included difficulty level in ambulation, instrumental (IADLs) and activities of daily living (ADLs), self-efficacy, and fear of falling. Results. At 6 months, for ADLs, individuals >= 80 years (p = .022), women (p = .036), and less educated persons (p = .028) improved compared to their control group counterparts. For mobility, women (p = .048) and the oldest participants (p = .001) improved relative to their counterparts. For self-efficacy, women (p = .036) benefited more than men. For fear of falling, less educated persons improved more than their counterparts (p = .001). A similar pattern was found at 12 months. For IADLs, whites improved more than non-whites at 12 months. Conclusions. Treatment benefits varied by specific participant characteristics, with individuals at greatest disability risk being most responsive to the intervention. Both white and minority participants benefited similarly except in IADL functioning. Future research should control for participant characteristics, identify underlying mechanisms for variation in treatment effects, and tailor treatment to patient characteristics and desired outcomes.