手頃なケア法（ACA）の拡大と外傷ケアのパラドックス：保険適用の改善の中でも死亡率の上昇

The association between insurance status and survival among critically injured patients has been shown to be profound, yet the impact of the Affordable Care Act (ACA) on trauma outcomes remains unclear. We evaluated the association between ACA implementation and changes in insurance status, discharge disposition, and in-hospital mortality among trauma patients.

We conducted a retrospective analysis of adult trauma patients admitted to Level I and II trauma centers in the National Trauma Data Bank. The pre-ACA period was defined as 2007-2013, with 2014 as a washout year and 2015-2019 as post-ACA. Bivariate and multivariable analyses compared insurance status, in-hospital mortality, and discharge disposition.

Among 3,171,236 patients, uninsured rates declined (28.9% to 20.1%, p<0.001) and Medicaid coverage increased (15.4% to 25.4%, p<0.001) post-ACA. Odds of discharge to post-acute care (OR 1.16; 95% CI 1.15-1.17) and home with services were also increased (OR 1.47; 95% CI 1.45-1.49; p<0.001). Although unadjusted mortality decreased slightly (2.7% to 2.6%, p<0.001), adjusted mortality was higher post-ACA (OR 1.13; 95% CI 1.11-1.15, p<0.001). Patients treated at Level II centers (34.0% to 38.2%, p<0.001) and non-teaching centers (9.6% to 12.0%, p<0.001) increased, but transfers to Level I centers (24.5% to 23.9%, p<0.001) decreased post-ACA. Insurance status was independently associated with higher odds of mortality post-ACA (Medicaid OR 1.12; 95% CI 1.09 - 1.16, Uninsured 2.17; 95% CI 2.10 - 2.24 compared to Private insurance).

Despite improved insurance coverage, mortality increased post-ACA. Our findings suggest evolving trauma care patterns in the post-ACA era, including greater reliance on Level II centers and fewer transfers, underscoring the importance of developing a national trauma system under changing policy conditions.