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 71 017 608 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, 11 697 900 (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 100 000 beneficiary-years declined from 49 888 in 2004 to 41 121 in 2017 among dually enrolled beneficiaries (P < .001) and from 29 000 in 2004 to 22 601 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.

中文翻译：

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2004 年至 2017 年 65 岁或以上双重登记和非双重登记医疗保险受益人的死亡率和住院率

重要的同时参加 Medicaid 的 Medicare 受益人（双重登记的受益人）已经引起了决策者的注意，因为他们是 Medicare 人口中最贫困的一部分；然而，与仅参加 Medicare 的人（非双重登记的受益人）相比，他们的结果如何随时间变化尚不清楚。目的 评估双重登记受益人和非双重登记受益人的全因死亡率、住院率和住院相关死亡率的年度变化。设计、设置和参与者 2004 年 1 月至 2017 年 12 月期间 65 岁或以上的医疗保险按服务收费受益人的连续横断面研究。随访的最终日期为 2018 年 9 月 30 日。暴露双重与非双重参保状态. 主要结果和措施 年全因死亡率；全因住院率；和住院 30 天、1 年住院相关死亡率。结果 从 2004 年到 2017 年，共有 71 017 608 名年龄在 65 岁或以上的独特医疗保险受益人（平均年龄为 75.6 [SD，9.2] 岁；54.9% 为女性）参加医疗保险至少 1 个月。在这些受益人中，有 11 697 90 (16.5%) 同时参加了医疗保险和医疗补助至少 1 个月。调整年龄、性别和种族后，年全因死亡率从 2004 年的 8.5%（95% CI，8.45%-8.56%）下降到 2017 年的 8.1%（95% CI，8.05%-8.13%），其中双重登记的受益人，非双重登记的受益人从 2004 年的 4.1%（95% CI，4.08%-4.13%）到 2017 年的 3.8%（95% CI，3.76%-3.79%）。在 2004 年（调整后的优势比，2.09 [95% CI，2.08-2.10]）和 2017 年（调整后的优势比，2.22 [95% CI，2.21-2.23]）之间，双重登记和非双重登记受益人的年全因死亡率差异有所增加)（对于双重注册状态和时间之间的交互，P < .001）。在双重登记受益人中，每 10 万受益人年的全因住院人数从 2004 年的 49 888 人下降到 2017 年的 41 121 人（P < .001），并从 2004 年的 29 000 人下降到非受益人中的 22 617 人（非受益人中的 22 601 人）。 001); 然而，这些组之间的差异在 2004 年（调整后风险比，1.72 [95% CI，1.71-1.73]）和 2017 年（调整后风险比，1.83 [95% CI，1.82-1.83]）之间扩大（P < .001相互作用）。在住院受益人中，风险调整后的 30 天死亡率从 10.3%（95% CI，10. 2004 年的 22%-10.33%) 到 2017 年的 10.1% (95% CI, 10.02%-10.20%) 在双重登记的受益人中和 2004 年的 8.5% (95% CI, 8.50%-8.56%) (9. % CI, 8.06%-8.13%) 在 2017 年在非双重登记的受益人中。相比之下，住院受益人的 1 年死亡率从 2004 年的 23.1%（95% CI，23.05%-23.20%）增加到 2017 年的 26.7%（95% CI，26.58%-26.84%）。在非双重登记的受益人中，2004 年的 %（95% CI，18.11%-18.17%）到 2017 年的 20.3%（95% CI，20.21%-20.31%）。在研究期间，双重登记和非双重登记受益人之间住院相关结果的差异持续存在。结论和相关性 在 65 岁或以上的 Medicare 按服务收费受益人中，双重登记受益人的年全因死亡率较高，与非双重登记受益人相比，全因住院和住院相关死亡率。从 2004 年到 2017 年，这些差异并没有减少。