Table 1. Difference-in-Difference Model for Primary Care Spending and Use Among Adults Eligible for the ACA Marketplace Relative to Adults With Employer-Sponsored Insurance.
| Outcome | Mean (SD) value | Differences-in-differences adjusted estimatea | ||||
|---|---|---|---|---|---|---|
| Intervention (N = 3563) | Control (N = 35 852) | |||||
| Pre-ACA period (2010-2013) | Post-ACA period (2014-2017) | Pre-ACA period (2010-2013) | Post-ACA period (2014-2017) | Estimate (95% CI) | P value | |
| Primary care spending, $ | 225.05 (1099.67) | 263.88 (783.20) | 270.38 (978.73) | 227.86 (1485.10) | 44.96 (−24.21 to 114.14) | .20 |
| OOP spending for primary care visits, $ | 50.35 (128.15) | 45.60 (117.89) | 40.31 (121.52) | 34.13 (126.89) | −2.89 (−13.72 to 7.93) | .60 |
| Any primary care visit, % | 0.49 (0.50) | 0.50 (0.50) | 0.51 (0.49) | 0.45 (0.49) | 0.02 (−0.01 to 0.06) | .24 |
| No. of primary care visits | 0.95 (1.44) | 1.20 (1.89) | 1.15 (1.90) | 0.99 (1.66) | 0.24 (0.11 to 0.38) | <.001 |
Abbreviations: ACA, Affordable Care Act; OOP, out-of-pocket.
a
Differences-in-differences adjusted estimate was estimated from a linear regression model or a linear probability model that controlled for age, sex, marital status, educational level, family income, area of residence, self-reported health status, 10 chronic conditions (asthma, arthritis, diabetes, emphysema, stroke, heart attack, coronary heart disease, other heart disease, angina, and joint pain), and survey year.