Mortality and Hospitalizations for Dually Enrolled and Nondually Enrolled Medicare Beneficiaries Aged 65 Years or Older, 2004 to 2017

摘要

Importance Medicare beneficiaries who are also enrolled in Medicaid (dually enrolled beneficiaries) have drawn the attention of policy makers because they comprise the poorest subset of the Medicare population; however, it is unclear how their outcomes have changed over time compared with those only enrolled in Medicare (nondually enrolled beneficiaries). Objective To evaluate annual changes in all-cause mortality, hospitalization rates, and hospitalization-related mortality among dually enrolled beneficiaries and nondually enrolled beneficiaries. Design, Setting, and Participants Serial cross-sectional study of Medicare fee-for-service beneficiaries aged 65 years or older between January 2004 and December 2017. The final date of follow-up was September 30, 2018. Exposures Dual vs nondual enrollment status. Main Outcomes and Measures Annual all-cause mortality rates; all-cause hospitalization rates; and in-hospital, 30-day, 1-year hospitalization-related mortality rates. Results There were 71 & x202f;017 & x202f;608 unique Medicare beneficiaries aged 65 years or older (mean age, 75.6 [SD, 9.2] years; 54.9% female) enrolled in Medicare for at least 1 month from 2004 through 2017. Of these beneficiaries, 11 & x202f;697 & x202f;900 (16.5%) were dually enrolled in Medicare and Medicaid for at least 1 month. After adjusting for age, sex, and race, annual all-cause mortality rates declined from 8.5% (95% CI, 8.45%-8.56%) in 2004 to 8.1% (95% CI, 8.05%-8.13%) in 2017 among dually enrolled beneficiaries and from 4.1% (95% CI, 4.08%-4.13%) in 2004 to 3.8% (95% CI, 3.76%-3.79%) in 2017 among nondually enrolled beneficiaries. The difference in annual all-cause mortality between dually and nondually enrolled beneficiaries increased between 2004 (adjusted odds ratio, 2.09 [95% CI, 2.08-2.10]) and 2017 (adjusted odds ratio, 2.22 [95% CI, 2.21-2.23]) (P < .001 for interaction between dual enrollment status and time). All-cause hospitalizations per 100 & x202f;000 beneficiary-years declined from 49 & x202f;888 in 2004 to 41 & x202f;121 in 2017 among dually enrolled beneficiaries (P < .001) and from 29 & x202f;000 in 2004 to 22 & x202f;601 in 2017 among nondually enrolled beneficiaries (P < .001); however, the difference between these groups widened between 2004 (adjusted risk ratio, 1.72 [95% CI, 1.71-1.73]) and 2017 (adjusted risk ratio, 1.83 [95% CI, 1.82-1.83]) (P < .001 for interaction). Among hospitalized beneficiaries, the risk-adjusted 30-day mortality rates declined from 10.3% (95% CI, 10.22%-10.33%) in 2004 to 10.1% (95% CI, 10.02%-10.20%) in 2017 among dually enrolled beneficiaries and from 8.5% (95% CI, 8.50%-8.56%) in 2004 to 8.1% (95% CI, 8.06%-8.13%) in 2017 among nondually enrolled beneficiaries. In contrast, 1-year mortality increased among hospitalized beneficiaries from 23.1% (95% CI, 23.05%-23.20%) in 2004 to 26.7% (95% CI, 26.58%-26.84%) in 2017 among dually enrolled beneficiaries and from 18.1% (95% CI, 18.11%-18.17%) in 2004 to 20.3% (95% CI, 20.21%-20.31%) in 2017 among nondually enrolled beneficiaries. The difference in hospitalization-related outcomes between dually and nondually enrolled beneficiaries persisted during the study period. Conclusions and Relevance Among Medicare fee-for-service beneficiaries aged 65 years or older, dually enrolled beneficiaries had higher annual all-cause mortality, all-cause hospitalizations, and hospitalization-related mortality compared with nondually enrolled beneficiaries. Between 2004 and 2017, these differences did not decrease.