. 2019 Jun 5;4(7):671–679. doi: 10.1001/jamacardio.2019.1651

Table 3. Difference-in-Differences Analysis by Change in Number of Residents in Low-Income Strata With Health Insurance.

Increase in Number of Residents With Health Insurance^a	Mean (95% CI)
	Cardiovascular Deaths per 100 000 Residents per y, Unadjusted		Difference-in-Differences Estimate
	Period Before Medicaid Expansion	Period After Medicaid Expansion	Unadjusted	P Value	Adjusted^b	P Value
Counties in Medicaid expansion states in top 50th percentile of increase^c	142.3 (129.0-155.6)	142.2 (127.8-156.7)	−5.3 (−8.1 to −2.4)	.001	−4.8 (−7.5 to −2.2)	.001
All counties in Medicaid nonexpansion states	176.2 (154.1-198.4)	181.4 (158.4-204.4)	−5.3 (−8.1 to −2.4)	.001	−4.8 (−7.5 to −2.2)	.001
Counties in Medicaid expansion states in bottom 50th percentile of increase^d	162.8 (143.2-182.4)	165.8 (147.2-184.5)	0.3 (−2.3 to 2.9)	.81	−1.3 (−4.0 to 1.4)	.34
All counties in Medicaid nonexpansion states	176.7 (153.9-199.5)	179.5 (155.7-203.3)	0.3 (−2.3 to 2.9)	.81	−1.3 (−4.0 to 1.4)	.34
All counties in Medicaid expansion states^e	146.4 (132.3-160.4)	146.2 (131.6-160.7)	−3.4 (−6.1 to −0.6)	.02	−3.2 (−5.7 to −0.8)	.01
Counties in Medicaid nonexpansion states in top 50th percentile of increase^e	165.4 (144.1-186.6)	168.5 (146.6-190.4)	−3.4 (−6.1 to −0.6)	.02	−3.2 (−5.7 to −0.8)	.01
All counties in Medicaid expansion states^f	147.3 (133.1-161.6)	147.0 (132.4-161.7)	−13.8 (−17.4 to −10.2)	.001	−12.2 (−16.0 to −8.4)	.001
Counties in Medicaid nonexpansion states in bottom 50th percentile of increase^f	223.0 (197.7-248.3)	236.4 (210.1-262.8)	−13.8 (−17.4 to −10.2)	.001	−12.2 (−16.0 to −8.4)	.001

^{^a}

Change in number of residents with health insurance refers to change in the number of residents aged 40 to 64 years with health insurance with an income less than 138% of the federal poverty limit between 2010 and 2016.

^{^b}

Adjusted for 2013 National Center for Health Statistics Urban-Rural Classification designation (metropolitan vs nonmetropolitan county), percentage of residents living in poverty, percentage of adults unemployed, inflation-adjusted median household income, percentage of residents aged 40 to 64 years who were female, percentage of residents aged 40 to 64 years who were black, percentage of residents aged 40 to 64 years who were Hispanic, percentage of adult residents with diabetes in 2010, percentage of adult residents with obesity in 2010, percentage of adult residents who smoke in 2010, number of primary care professionals per 100 000 residents, number of cardiologists per 100 000 residents, and percentage of residents aged 40 to 64 years with income less than 138% of the federal poverty limit with health insurance in 2010.

^{^c}

Expansion counties with a change in the number of residents with health insurance greater than 483 residents.

^{^d}

Expansion counties with a change in the number of residents with health insurance fewer than 483 residents.

^{^e}

Nonexpansion counties with a change in the number of residents with health insurance greater than 232 residents.

^{^f}

Nonexpansion counties with a change in the number of residents with health insurance fewer than 232 residents.