TABLE 3—

Utilization of Physician Services in the 3 Years Before and After the January 1, 2014, Implementation of the Affordable Care Act (ACA) According to Target Population Status: United States

		Unadjusted Results				Adjusted Resultsb
	No.a	Before	After	Difference	P	DiD Estimate (95% CI)	P
No. office visits/100 persons
≤ 138% FPL	41 608	350.7	361.1	10.3	.1	12.5 (−0.6, 25.5)	.06
≤ 250% FPL	71 540	334.4	339.9	5.6	.22	11.6 (0.8, 22.4)	.036
≤ 400% FPL	102 089	330.6	333.0	2.4	.53	10.0 (0.0, 20.1)	.05
Not target	100 081	416.0	408.7	−7.3	.06	0 (Ref)
≥ 1 office visits, %
≤ 138% FPL	41 608	69.5	73.0	3.50	< .001	2.7 (1.4, 4.0)	< .001
≤ 250% FPL	71 540	70.2	73.6	3.36	< .001	2.8 (1.8,3.8)	< .001
≤ 400% FPL	102 089	73.1	75.3	2.25	< .001	1.9 (1.0, 2.8)	< .001
Nontarget	100 081	88.4	88.7	0.35	.23	0 (Ref)
No. surgical procedures/100 persons
≤ 138% FPL	41 766	13.2	14.2	1.0	.11	1.7 (0.1, 3.2)	.032
≤ 250% FPL	71 756	12.8	13.5	0.6	.19	1.4 (0.1, 2.7)	.035
≤ 400% FPL	102 343	13.1	13.2	0.1	.77	1.0 (−0.2, 2.2)	.09
Nontarget	100 441	19.4	18.5	−0.9	.08	0 (Ref)

Note. CI = confidence interval; DiD = difference-in-difference; FPL = federal poverty level, based on US Census thresholds from the year an individual was surveyed. Affordable Care Act target population = those aged 18–64 y with family income as a percentage of the FPL below threshold; not-target population = those aged ≥ 65 y of any income or aged 18–64 y with income > 400% FPL.

Source. Authors’ analysis of the 2011–2016 National Health Interview Survey.

^aAnalyses used multiply imputed income data, which resulted in slight variations in the number of observations around the no. shown in the table.

^bAdjusted for age, sex, family size, region, race, marital status, health status, education, pre–post ACA dummy variable, employment status, ACA target population status, and ACA target population status*pre–post ACA dummy variable interaction term. See Appendix notes 8 and 9 for details on treatment of covariates.