TABLE 2—

Results of Interrupted Time Series Analyses of Mean Monthly Firearm Mortality per 100 000 Population Before and After Implementation of HB 4145: West Virginia and the United States

Region	Estimated Monthly Firearm Deaths per 100 000 Population		Percentage Increase (95% CI)
	January 1999–April 2016	May 2016–December 2021
West Virginia	1.204	1.519	26.2 (19.8, 31.7)
United States	0.913	0.904	−0.9 (−6.2, 4.4)

Note. CI = confidence interval. Rates were calculated via interrupted time series analyses of monthly firearm mortality per 100 000 population; pre–HB 4145 (January 1999–April 2016) values correspond to the model intercept, whereas post–HB 4145 enactment (May 2016–December 2021) values correspond to the model intercept along with the step change value shown in Table A (available as a supplement to the online version of this article at http://www.ajph.org).