Effects of Italian smoking regulation on rates of hospital admission for acute coronary events: a country-wide study

Abstract

Background: Several studies have reported a reduction in acute coronary events (ACEs) in the general population after the enforcement of smoking regulations, although there is uncertainty concerning the magnitude of the effect of such interventions. We conducted a country-wide evaluation of the health effects of the introduction of a smoking ban in public places, using data on hospital admissions for ACEs from the Italian population after the implementation of a national smoking regulation in January 2005.

Methods and findings: Rates of admission for ACEs in the 20 Italian regions from January 2002 to November 2006 were analysed using mixed-effect regression models that allowed for long-term trends and seasonality. Standard methods for interrupted time-series were adopted to assess the immediate and gradual effects of the smoking ban. Effect modification by age was investigated, with the assumption that exposure to passive smoking in public places would be greater among young people. In total, 936,519 hospital admissions for ACEs occurred in the Italian population during the study period. A 4% reduction in hospital admissions for ACEs among persons aged less than 70 years was evident after the introduction of the ban (Rate Ratio [RR], 0.96; 95% Confidence Interval [CI], 0.95-0.98). No effect was found among persons aged at least 70 years (RR 1.00; 95% CI 0.99-1.02). Effect modification by age was further suggested by analyses using narrower age categories.

Conclusions: Smoke-free policies can constitute a simple and inexpensive intervention for the prevention of cardiovascular diseases and thus should be included in prevention programmes.

Figure 1. Hospital admissions for Acute Coronary Events (ACEs) in Italy during the period 2002–2006.

Observed (circles) and predicted (solid lines) standardised rates among persons under 70 years of age (A) and persons aged at least 70 years (B). The dashed lines represent the deseasonalised trend of ACEs before and after the introduction of the national smoking regulation.

Figure 2. Effect of the smoking ban on different age groups.

Rate ratios and 95% confidence intervals of hospital admissions for acute coronary events during the ban period compared with the pre-ban period by age groups. Results adjusted for long-term trends and seasonality. Italy, 2002–2006.