Effects of the Affordable Care Act Medicaid Expansion on in‐Hospital Mortality, Access to Rehabilitation, and Readmission Rates Among Young Adult Trauma Patients
Authors: Cooper Jennifer , Asti Lindsey , Metzger Gregory , Xiang Henry , Deans Katherine , Chisolm Deena 
Published: September 2021

Research ObjectiveTrauma is the leading cause of death and disability among young adults. Prior to the implementation of the Affordable Care Act (ACA), more than 30% of young adult trauma patients were uninsured, and uninsured patients had higher in‐hospital mortality rates and worse access to rehabilitation. We aimed to assess the impact of the ACA Medicaid expansion on insurance coverage and rates of in‐hospital mortality, access to rehabilitation, and unplanned readmissions and return emergency department (ED) visits in young adult trauma patients.

Expansion States
Non‐expansion States
Difference‐in‐Differences Estimate (95% CI)
P

2011–2013(N = 56,196)
2014–2017 (N = 62,893)
2011–2013 (N = 104,344)
2014–2017 (N = 143,595)

Uninsured
27.1
9.7
32.7
31.8
−16.50 (−17.08 to −15.93)

<0.001

In‐hospital mortality
2.22
2.03
2.04
1.78
0.07 (−0.34 to 0.47)
0.74

Discharged to inpatient rehabilitation
6.18
8.07
5.91
6.47
1.33 (0.68 to 1.97)

<0.001

Discharged to a skilled nursing facility
1.97
2.24
1.76
1.61
0.42 (0.11 to 0.73)

0.008

Discharged to home healthcare
8.25
7.85
7.77
7.59
−0.22 (−1.51 to 1.07)
0.74

30‐day unplanned readmission
7.47
7.88
8.09
8.20
0.30 (−0.70 to 1.31)
0.55

30‐day return ED visit
18.31
18.96
21.58
22.67
−0.44 (−1.66 to 0.78)
0.48

Risk‐adjusted marginal percentages are shown.

Study DesignWe used the state inpatient databases of 5 states that expanded Medicaid through the ACA (Arkansas, Iowa, Illinois, Kentucky, and Maryland) and 5 states that did not (Florida, Georgia, Kansas, Missouri, North Carolina) to perform a difference‐in‐difference (DD) analysis comparing changes in insurance coverage and risk‐adjusted outcomes in young adults hospitalized for traumatic injuries before (2011–2013) and after (2014–2017) Medicaid expansion and open enrollment.Population StudiedWe included adults aged 19–44 years who were hospitalized for traumatic injury in their state of residence. Patients admitted electively or for burn injuries were excluded.Principal FindingsOf the 367,028 trauma patients included, 26.7% were women and the mean age was 30.8 years. As shown in the table, Medicaid expansion was associated with a more than 16 percentage point decrease in the uninsured rate. This drop increased over time, with the annual DD estimates for 2014–2017 being −11.9, −17.4, −17.8, and − 19.3 percentage points respectively. Medicaid expansion was not associated with decreases in in‐hospital mortality or 30‐day readmission or return ED visit rates. It was associated with increases in access to inpatient rehabilitation, and this access grew over time (annual change in the DD: 0.8 percentage points, p < 0.001).ConclusionsAmong young adult trauma patients, Medicaid expansion increased insurance coverage and access to inpatient rehabilitation, and these increases have grown over time. It has not reduced in‐hospital mortality or readmission rates.Implications for Policy or PracticeMedicaid expansion has enabled more young adults with serious injuries to access inpatient rehabilitative care, likely resulting in improved functional outcomes. However, given the unexpected nature of traumatic injury and the long recovery period that is sometimes required, these benefits may be eliminated if Medicaid waivers adding work requirements or eliminating retroactive Medicaid eligibility go into effect.Primary Funding SourceNational Institutes of Health.