Evaluation of claims-based frailty measurements in older patients with cancer: a retrospective cohort study.

Background: Frailty is associated with poor outcomes in older adults with cancer. Several efforts have been made to assess frailty using the administrative claims data based on the number of clinical diagnosis codes, yet the literature reporting on this is scarce. This study aimed to evaluate the impact of frailty measures using administrative databases in Japan.

Design: A retrospective cohort study.

Setting and participants: 5176 patients with cancer aged ≥65 years who underwent cancer treatment in hospitals.

Methods: The Electronic Frailty Index (eFI) and Veterans Affairs Frailty Index (VA-FI), based on diagnostic codes recorded were calculated. We plotted Kaplan-Meier survival curves and calculated hazard ratios (HR) using Cox regression analyses. The primary outcome was mortality, whereas the composite secondary outcome included a decline in care-need level, admission to a long-term care facility (LTCF) or mortality.

Results: The Kaplan-Meier survival curve demonstrated a significant association between the eFI and VA-FI and each research outcome. Compared to the lowest frailty group, the highest frailty group exhibited an HR of 2.59 [95% confidence interval (CI), 1.66-4.06] for eFI and 2.45 (95%CI, 1.02-5.91) for VA-FI in relation to a decline in care-need level, an LTCF admission and mortality. The trend test indicated a significant increase in the rate of each outcome with higher frailty levels.

Conclusions: Higher frailty levels are associated with an increased risk of composite outcomes in older adults with cancer. This study suggests the potential application of frailty measurements in oncology care settings.