Journal of Environmental and Public Health are generally negative, zeroing them out results in higher predicted rates of AMI and stroke hospitalizations compared to the base case. The diﬀerence between the base case and the counterfactual case is the amount that hospitalization rates were reduced by the implementation of comprehensive smoke-free air laws. We converted the rates into number of age-adjusted events by multiplying the estimated rate by the population of adults aged 35 or older in the given county and time period. We estimated 95% conﬁdence intervals for the number of hospitalizations averted using the bootstrap command in Stata 11 [10]. 3. Results Regression results for AMI hospitalization rates are reported in Table 1. The main eﬀect for comprehensive smoke-free laws was statistically signiﬁcant in New York (b = −1.483, P < 0.05) and marginally signiﬁcant at the 10% level in Florida (b = −4.377, P < 0.10). The interaction between the comprehensive smoke-free air law and time is signiﬁcant for Florida (b = −2.514, P < 0.01) and New York (b = −0.251, P < 0.01), suggesting that hospitalization rates for AMI decrease steadily over time after implementation of a comprehensive smoke-free air law. Moderate smoke-free laws were in eﬀect in communities in New York and Oregon before comprehensive laws were enacted in those states. The moderate law main eﬀect was not signiﬁcant in New York, but it was signiﬁcant and positive in Oregon (b = 3.846, P < 0.05). The interaction between moderate laws and time was negative and signiﬁcant in New York (b = −0.124, P < 0.05) and Oregon (b = −0.242, P < 0.01). Results for stroke hospitalization rates are reported in Table 2. Florida’s statewide comprehensive smoke-free air law is associated with a signiﬁcant reduction in stroke hospital- ization rates, both immediately at the time of implementa- tion (main eﬀect b = −16.194, P < 0.01) and over time (interaction eﬀect b = −2.105, P < 0.01). In New York, local moderate smoke-free laws are associated with a signiﬁcant increase in stroke hospitalization rates for both the main eﬀect (b = 1.848, P < 0.01) and the interaction with the monthly time trend (b = 0.098, P < 0.01). In Oregon, moderate smoke-free laws are signiﬁcantly associated with a decrease in stroke hospitalization rates over time (b = −0.122, P < 0.01). Results from the counterfactual analysis are presented in Table 3. In Florida, the statewide law restricting smoking in all workplaces and restaurants is associated with reductions in AMI hospitalizations of 18.4% (95% CI: 8.8–28.0%) and stroke hospitalizations by 18.1% (95% CI: 9.3–30.0%) over the time period from Quarter 3 2003 through Quarter 4 2006, a span of just over 3 years. On an age-adjusted basis, this is equivalent to approximately 32,425 (95% CI, 15,478–49,373) averted AMI cases and 44,485 (95% CI: 22,745–66,224) averted stroke cases. Annually, this is a decline of approximately 5.3% for AMI and 5.2% for stroke hospitalizations in Florida. New York’s comprehensive statewide smoke-free air law lowered AMI hospitalizations by 15.5% (95% CI: 11.0– 20.1%) between March 2003 and December 2006, an average 3 annual reduction of 4.4%. This is equivalent to 28,649 (95% CI: 20,292–37,006) averted hospitalizations on an age-adjusted basis. Other eﬀects were not associated with signiﬁcant reductions in hospitalizations. 4. Discussion This paper updates a previous estimate of the impact of New York’s comprehensive statewide smoke-free air law on AMI and stroke hospitalization rates [9] and examines the impact of similar laws in Florida and Oregon. More than 3 years after the comprehensive smoke-free laws went into eﬀect, rates of hospitalization for AMI were signiﬁcantly reduced by 18.4% in Florida and 15.5% in New York, and stroke hospitalization rates in Florida were reduced by 18.1%. Failure to detect a signiﬁcant eﬀect of comprehensive smoke-free laws in Oregon derives from the fact that only a few communities in Oregon had such laws during the period of this study. The 24 months of additional data from New York used in this study have strengthened the results for AMI hos- pitalizations reported previously for New York [9]. In the earlier paper, the point estimate for the main eﬀect of comprehensive smoke-free laws was equal to −0.80 and not statistically signiﬁcant. In this study, the main eﬀect for comprehensive smoke-free laws is −1.483 and statistically signiﬁcant. This suggests that the AMI hospitalization rate was immediately reduced after New York’s comprehensive smoke-free laws went into eﬀect, in addition to the gradual reduction over time suggested by the statistically signiﬁcant interaction of comprehensive smoke-free laws with time, which is a similar magnitude (−0.32 versus −0.25) in both studies. Large and signiﬁcant reductions were found in Florida for stroke hospitalizations, whereas none were detected in New York. One explanation is that the burden of stroke is greater in Florida than New York, providing a greater potential for improvement. Florida has a stroke prevalence rate of 2.7%, compared with 2.0% for New York, and a higher rate of mortality from cerebrovascular disease at 51.4 per 100,000 compared with 42.5 per 100,000 in New York [11]. It is also possible that population diﬀerences in age and race/ ethnicity between New York and Florida contributed to these results. Nationally, the cerebrovascular disease mortality rate, which includes stroke, of non-Hispanics is approximately three times that of Hispanics (47.0 versus 14.6 deaths per 100,000, resp.), while Whites and African Americans have roughly equal cerebrovascular mortality rates (44.0 versus 38.7 deaths per 100,000, resp.) [12]. In 2010, 13.5% of New York’s population was age 65 and older, 15.9% were African-American, and 17.6% were Hispanic (http://quick- facts.census.gov/qfd/states/36000.html). In Florida, 17.3% were age 65 and older, 16.0% were African-American, and 22.5% were Hispanic (http://quickfacts.census.gov/qfd/ states/12000.html). Use of age-adjusted hospitalization rates will have ameliorated the eﬀect of age diﬀerences across states, and the diﬀerence in race/ethnicity is not that great. Still, the diﬀerence in results for stroke between the two states is striking and remains unexplained. Perhaps the results in New York are capturing an increase in some causal