NOT PEER REVIEWED We welcome the timely review published by Hill et al. [1], and agree that more research is needed to assess the equity impacts of tobacco control interventions. The results of the review indicated that "increases in tobacco price have a pro-equity effect on socioeconomic disparities in smoking", but that "evidence on the equity impact of other interventions was inconclusive [...]". The inconclusiveness of findings with regard to smoking ban policies may be partly due to date limitations for the database searches, which included evidence from January 2006 through November 2010. It may also be partly due to the assessment of equity in outcomes that related only to active smoking. Although a benefit of smoking ban policy implementation may be a reduction in active smoking, this outcome is dependent upon an individual's personal response to the intervention. However, the primary purpose for implementing comprehensive smoking ban policies is to reduce secondhand smoke exposure among the population through environmental change. It is therefore important to assess whether the successful implementation of smoking ban policies has pro-equity health effects.

Our previous research indicated that the national smoking ban policy in the Republic of Ireland was associated with immediate reductions in all -cause and cause-specific cardiovascular, cerebrovascular, and respiratory mortality, and that these mortality reductions were primarily due to reductions in population exposure to secondhand smoke [2]. Our subsequent assessment of the socioeconomic differentials of these mortality reductions in the Republic of Ireland suggested that inequalities in smoking-related mortality were immediately reduced following smoking ban implementation [3]. Furthermore, given the higher rates of smoking-related mortality in the most deprived group, even equitable reductions across socioeconomic groups resulted in decreased inequalities in mortality [3].

Partial smoking ban policies do not fully protect health [4], and are likely to yield negative equity effects as a result of policy exclusions for workplaces and hospitality venues located in more deprived areas [5]. In contrast, comprehensive smoking ban policies provide equal protection for all against secondhand smoke exposure. Indeed, previous studies have indicated that comprehensive smoking ban policies are effective public health interventions for reducing both exposure to secondhand smoke and other indoor air pollutants [6-11], the benefits of which are experienced by all employees and patrons of restaurants, bars, and other public places, regardless of individual socioeconomic group. Therefore, we wish to highlight that the evidence for pro-equity effects of comprehensive smoking ban policies may be more conclusive when additional health-related outcomes are considered.

References

1. Hill S, Amos A, Clifford D, Platt S (2014) Impact of tobacco control interventions on socioeconomic inequalities in smoking: review of the evidence. Tob Control 23: e89-e97.

2. Stallings-Smith S, Zeka A, Goodman P, Kabir Z, Clancy L (2013) Reductions in cardiovascular, cerebrovascular, and respiratory mortality following the national irish smoking ban: interrupted time-series analysis. PLoS One 8: e62063.

3. Stallings-Smith S, Goodman P, Kabir Z, Clancy L, Zeka A (2014) Socioeconomic differentials in the immediate mortality effects of the national Irish smoking ban. PLoS One 9: e98617.

4. Tan CE, Glantz SA (2012) Association between smoke-free legislation and hospitalizations for cardiac, cerebrovascular, and respiratory diseases: a meta-analysis. Circulation 126: 2177-2183.

5. Lewis GH, Osborne DC, Crayford TJ, Brown AC (2006) Partial smoking ban would worsen health inequalities. Bmj 332: 362.

6. Fong GT, Hyland A, Borland R, Hammond D, Hastings G, et al. (2006) Reductions in tobacco smoke pollution and increases in support for smoke- free public places following the implementation of comprehensive smoke- free workplace legislation in the Republic of Ireland: findings from the ITC Ireland/UK Survey. Tob Control 15 Suppl 3: iii51-58.

7. Connolly GN, Carpenter CM, Travers MJ, Cummings KM, Hyland A, et al. (2009) How smoke-free laws improve air quality: a global study of Irish pubs. Nicotine Tob Res 11: 600-605.

8. Goodman P, Agnew M, McCaffrey M, Paul G, Clancy L (2007) Effects of the Irish smoking ban on respiratory health of bar workers and air quality in Dublin pubs. Am J Respir Crit Care Med 175: 840-845.

9. Mulcahy M, Evans DS, Hammond SK, Repace JL, Byrne M (2005) Secondhand smoke exposure and risk following the Irish smoking ban: an assessment of salivary cotinine concentrations in hotel workers and air nicotine levels in bars. Tob Control 14: 384-388.

10. Valente P, Forastiere F, Bacosi A, Cattani G, Di Carlo S, et al. (2007) Exposure to fine and ultrafine particles from secondhand smoke in public places before and after the smoking ban, Italy 2005. Tob Control 16: 312-317.

11. Eisner MD, Smith AK, Blanc PD (1998) Bartenders' respiratory health after establishment of smoke-free bars and taverns. JAMA 280: 1909- 1914.

Conflict of Interest:

None declared