Smoke-free legislation and active smoking, second hand smoke exposure and health outcomes in low- and middle-income countries.

Background: Exposure to tobacco smoke imposes a heavy morbidity and mortality burden and exacerbates health inequalities. Whilst the health and economic benefits of smoke-free legislation (SFL) are evident in high income countries (HICs), there is a lack of evidence from low- and middle-income countries (LMICs) where implementation and monitoring mechanisms are generally weak. Objectives: To examine whether the health benefits of SFL identified in HICs are likely to accrue in LMICs and whether any benefits are evenly distributed between socioeconomic status (SES) groups. Methods: 1) A systematic review was undertaken to examine the impact of SFL on socioeconomic inequalities in tobacco-related health outcomes in adults 2) Secondary analyses of the Global Adult Tobacco Survey (GATS) data from 15 LMICs was undertaken to examine inequalities in second hand smoke (SHS) exposure at work and at home 3) Quasi-experimental difference-in-differences study design was used to examine whether the National Tobacco Control Programme (NTCP) in India was associated with reductions in active smoking. Results: 1) Evidence from LMICs examining the health impacts of SFL was sparse. Comprehensive SFL was associated with pro-equity impacts in smoking associated health outcomes in HICs 2) In LMICs, exposure to SHS at workplaces and at homes was higher among the low SES groups. Being employed in a smoke-free workplace in LMICs was associated with reduced exposure to SHS in the home 3) There was no compelling evidence that NTCP reduced bidi and cigarette consumption over and above the general reduction that occurred in all districts in India. Policy implications: Poor implementation of SFL in LMICs is associated with substantial forgone health benefits, especially in the low SES groups. Strengthening tobacco control is key to improve health outcomes and reduce inequalities in LMICs and attainment of the Sustainable Development Goals for Health.