Association between reimbursement-based discharge planning and support and days at home for older patients hospitalized for anticancer drug therapy: A retrospective cohort study.

BACKGROUND: Home-based care is vital for older adults with cancer; however, how discharge support intensities influence the proportion of days at home remains uncertain. OBJECTIVE: We examined the association between discharge support intensities and proportion of days at home (claims-based proxy: days not hospitalized) among older patients hospitalized for anticancer drug therapy. Based on the Japanese universal health insurance system, we defined four discharge support levels and identified the patient-, hospital-, and regional-level factors associated with this outcome. METHODS: A retrospective cohort study was conducted using the National Health Insurance Database (Kokuho Database) from 32 municipalities in Shizuoka, Japan (December 2012-September 2017). We included 2865 patients (61.5% male) with various cancers, aged ≥65 years (median: 74). The primary outcome was the proportion of days at home 2-12 months post-therapy, calculated as total survival days minus inpatient days (range: 1-337 calendar days). Discharge interventions were categorized using the Japanese medical fee reimbursement codes: (1) Standard coordination, (2) High-intensity discharge support, (3) Moderate-intensity discharge support, and (4) No additional support (reference). We identified patient-, hospital-, and regional-level factors associated with the proportion of days at home and used multivariable linear regression with robust standard errors (HC3) to examine the association between these fees and the proportion of days at home, compared with no fee. RESULTS: The median proportion of days at home was 0.899. Utilization rates were 6.6%, 3.4%, and 1.1% for Standard coordination and High- and Moderate-intensity discharge support, respectively. After adjustment, High-intensity discharge support showed statistically significant association with a higher proportion of days at home (unstandardized regression coefficient [Β] =0.077, 95% confidence interval: 0.025-0.129, p = 0.003), compared with no fee. Standard and Moderate-intensity support showed no such association. Older age, lung, gastrointestinal, and hematologic cancers, pain, and long-term care were linked to a lower proportion of days at home. Liver cancer and Comprehensive Geriatric Assessment correlated with higher proportion of days at home. CONCLUSIONS: Although this claims-based proxy reflects "days not hospitalized" and may overestimate true days at home, it provides valuable insights for policy evaluation. High-intensity discharge support is significantly associated with a higher proportion of days at home among older patients receiving anticancer drug therapy. These findings suggest that implementing tailored, multidisciplinary discharge support, informed by comprehensive clinical and functional assessments, warrants further evaluation to optimize care for older patients undergoing anticancer drug therapy.