Claims-based frailty, dual eligibility, and potential unmet home-health needs in older breast cancer survivors

Abstract Background Older breast cancer survivors often need home-based functional support, yet whether Medicare’s restricted home health (HH) benefit leaves frailty-related need unmet at the population level is not quantified because measurement is lacking. Methods Using linked Surveillance, Epidemiology, and End Results-Medicare-OASIS data, we studied 347 953 survivor-years during 2017-2020 from 134 410 women with invasive breast cancer 2-10 years post-diagnosis. We derived a claims-based predicted deficit-accumulation frailty index (DAFI), calibrated by penalized elastic-net to the observed OASIS Start-of-Care DAFI, the HH-need benchmark. Outcomes were any Medicare HH use and potential unmet need, defined as no HH use among high-need survivor-years (predicted DAFI ≥ 0.25). Logistic models estimated the marginal effects of DAFI on any Medicare HH use by frailty and dual eligibility, and disparities in potential unmet need. Results The claims-based DAFI was closely calibrated to observed OASIS DAFI (area under the curve = 0.715; slope = 1.111). Any HH use rose with frailty (+1.10 percentage points [pp] per +0.01 DAFI; 95% CI = 1.05 to 1.15), most steeply among never-dual survivors (+1.21 pp; 95% CI = 1.16 to 1.26) and less steeply among always-dual survivors (+0.41 pp; 95% CI = 0.30 to 0.53). Among high-need survivor years, 59.6% had no Medicare HH use. Long-term survivors had similar DAFI to 2-5-year survivors (0.216 vs 0.215) and lower HH use, but potential unmet need did not differ. Conclusions A claims-based frailty proxy reveals potential frailty-related needs that Medicare HH does not reach. Expanding Medicare HH to better cover personal care and other home- and community-based services may help address frailty-related needs.