Table 2.
DID Regression Analysis for 51- to 64-Year-Old Low-Education Respondents in Medicaid Expansion Versus Nonexpansion States
| Outcomes | Expansion states | Nonexpansion states | Adjusted DID (95% CI) | DID, p value | ||||
|---|---|---|---|---|---|---|---|---|
| Baseline | Postexpansion | ∆ After expansion | Baseline | Postexpansion | ∆ After expansion | |||
| Coverage | ||||||||
| Any insurance (%) | 80.2 | 89.2 | +9.0 | 75.5 | 87.2 | +11.7 | −2.6 (−8.7 to 3.5) | .40 |
| Medicaid (%) | 10.3 | 20.9 | +10.6 | 8.6 | 11.8 | +3.2 | +7.4 (3.1 to 11.7) | .001 |
| Private insurance (%) | 61.7 | 59.1 | −2.6 | 59.3 | 62.7 | +3.4 | −6.0 (−12.2 to 0.1) | .05 |
| Access | ||||||||
| Usual source of care (%) | 76.5 | 80.5 | +4.0 | 74.4 | 79.7 | +5.3 | −1.2 (−8.0 to 5.7) | .74 |
| Difficulty finding a physician (%) | 4.5 | 6.1 | +1.6 | 4.9 | 3.4 | −1.5 | +3.1 (−0.9 to 7.0) | .13 |
| Foregone care due to cost (%) | 17.6 | 11.5 | −6.1 | 19.6 | 11.2 | −8.4 | +2.3 (−3.4 to 7.9) | .43 |
| Cost-related medication nonadherence (%) | 20.8 | 13.7 | −7.1 | 25.9 | 15.1 | −10.8 | +3.6 (−1.9 to 9.2) | .20 |
| Out-of-pocket costsa ($) | 1,620.6 | 1,425.4 | −195.2 | 1,709.1 | 1,497.4 | −211.7 | +16.5 (−426.8 to 459.8) | .94 |
| Utilization | ||||||||
| Outpatient visitb, in past 2 years (%) | 83.9 | 84.9 | +1.0 | 84.0 | 85.6 | +1.6 | −0.6 (−6.5 to 5.3) | .84 |
| Hospitalization, in past 2 years (%) | 20.7 | 29.9 | +9.2 | 20.2 | 19.1 | −1.1 | +10.4 (3.6 to 17.2) | .003 |
| Health | ||||||||
| Health, excellent or very good (%) | 37.7 | 30.9 | −6.8 | 34.3 | 27.9 | −6.4 | −0.5 (−6.7 to 5.7) | .88 |
| Depressive symptomsc | 1.9 | 1.7 | −0.2 | 2.0 | 1.6 | −0.4 | +0.2 (−0.1 to 0.5) | .21 |
| Health limits paid/house/any work (%) | 37.3 | 40.9 | +3.6 | 35.4 | 46.4 | +11.0 | −7.5 (−12.8 to −2.2) | .006 |
Notes: CI = confidence interval; DID = difference-in-differences. Baseline year is 2010, except for variables introduced in 2012 (usual source of care, difficulty finding a physician, and foregone care due to cost). Generalized estimating equations with Huber–White robust standard errors clustered at the respondent level for longitudinal analyses, adjusting for age, gender, race/ethnicity, wealth, employment, and marital status.
aOut-of-pocket costs were log-transformed to approximate a normal distribution in analyses; estimates were transformed back from the logarithmic scale to present mean dollar amounts and confidence intervals.
bOutpatient visits include visits to the clinic, physician’s office, or emergency room.
cDepressive symptoms were measured using the Center for Epidemiological Studies Depression scale.