Hospice enrollment and evaluation of its causal effect on hospitalization of dying nursing home patients

OBJECTIVE: To examine the patient, nursing home (NH), hospice provider, and local market factors associated with the selection of the Medicare hospice benefit by eligible NH residents, and evaluate the causal effect of hospice on end-of-life hospitalization rates. DATA SOURCES/STUDY SETTING: Secondary data for 1995-1997 for NH residents. STUDY DESIGN: This retrospective cohort study includes NH residents in five states (Kansa, Maine, New York, Ohio, South Dakota) who died in the years 1995-1997. Medicare claims identified hospice enrollment and hospitalizations. Geocoding of NHs, hospice providers, and hospitals was used to identify local markets. The two outcome measures are hospice enrollment and hospitalization of NH residents in their last 30 days of life. DATA COLLECTION/EXTRACTION METHOD: A file was constructed linking MDS assessments to Medicare claims and denominator files, NH provider files (OSCAR), hospice provider of service files, and the area resource file. PRINCIPAL FINDINGS: Twenty-six percent of hospice and 44 percent of nonhospice residents were hospitalized in their last 30 days of life (odds ratio [OR] 0.45; 95 percent confidence interval [CI]: 0.42-0.48). Adjusting for confounders, hospice patients were less likely than nonhospice residents to be hospitalized (OR 0.47; 95 percent CI: 0.45-0.50). Adding inverse propensity score weighting, hospice patients were still less likely than nonhospice residents to be hospitalized (OR 0.56; 95 percent CI: 0.53-0.61). CONCLUSIONS: Hospice selection introduces some bias in the evaluation of the causal effect of hospice on end-of-life hospitalization rates. However, even after adjusting for selection bias, hospice does have a powerful effect in reducing end-of-life hospitalization rates.