Table 2.

Hypertension and diabetes diagnosis rates, IRRs and difference-in-difference post-ACA versus pre-ACA by Medicaid expansion status

	Hypertension diagnosis		Diabetes diagnosis
	Pre-ACA	PostA-ACA	Pre-ACA	Post -ACA
Non-expansion states
Unadjusted rate per 100 patients per year	7.0	5.5	0.8	0.9
Adjusted rate* per 100 patients per year	5.5	5.2	0.6	0.7
Post-ACA versus pre-ACA IRR 95% CI		0.94 (0.91 to 0.97)†		1.28 (1.18 to 1.38) †
Expansion states
Unadjusted rate per 100 patients per year	4.7	4.4	0.6	0.7
Adjusted rate* per 100 patients per year	4.6	4.9	0.7	0.8
Post-ACAt versus pre-ACA IRR 95% CI		1.07 (1.03 to 1.10)†		1.25 (1.16 to 1.34) †
Difference in difference (DID)
Expansion versus non-expansion, DID 95% (CI)		1.14 (1.11 to 1.18)†		0.98 (0.91 to 1.05)

*Generalised estimating equation Poisson models adjusted for year and primary community health centre patient population demographics (ie, clinic-level distributions of race/ethnicity, sex, age, most frequent insurance coverage and % federal poverty level).

†Statistically significant p<0.05.

‡Incidence rate was defined as number of new diagnoses at a clinic over person-time at risk.

ACA, Affordable Care Act; CI, confidence interval; IRR, incidence rate ratio.