Investigating the effects of comprehensive smoke-free legislation on neonatal and infant mortality in Thailand using the synthetic control method

Abstract

Background Almost all of the evidence on the benefits of smoke-free legislation on child health comes from evaluations in high-income countries. We investigated the effects of Thailand's 2010 comprehensive smoke-free legislation on neonatal and infant mortality. Methods To overcome some of the methodological issues inherent to traditional quasi-experimental methods, we applied the novel synthetic control approach. Using 2001–2017 country-level panel data from the World Bank and Penn World datasets, we estimated the effects of smoke-free legislation as the difference between the outcome trends in Thailand versus those in a synthetic control country. The synthetic control country was composed of ‘control’ middle-income countries without comprehensive smoke-free legislation to recreate trends in Thailand in the 2001–2009 pre-legislation outcomes and covariates. We compared the legislation effects to ‘placebo effects’ obtained for each control country by fictitiously assuming that comprehensive smoke-free legislation was introduced there in 2010, similar to Thailand. Findings Neonatal and infant mortality decreased by 2.9% and 2.8%/year respectively following smoke-free legislation, with an estimated 7463 infant deaths (including 4623 neonatal deaths) having been averted over eight years. The results were robust to different specifications of the control countries. Comparison with placebo effects indicated that the findings were unlikely to be attributable to factors other than the smoke-free legislation. Interpretation Expanding comprehensive smoke-free policies to middle-income countries can support national efforts to achieve Sustainable Development Goal 3.2 for reducing preventable early-life deaths. Funding Netherlands Lung Foundation, HDRUK, Asthma UK center for Applied Research and NIHR Global Respiratory Health Unit (RESPIRE).

Cigarette taxation and neonatal and infant mortality: A longitudinal analysis of 159 countries

“…Future research could build on our findings by assessing the impacts of the other MPO-WER measures across multiple countries. Previous evidence is limited by the fact that it is based on country or regional level case studies, limiting external validity [10,31,43,44]. While our current study did include information about other MPOWER policies as covariates, these should not be interpreted causally since the choice of models and covariates was driven by the need to adjust for potential confounders associated with taxation and child survival outcomes specifically.…”

“…Covariates were selected based on their previously demonstrated impact on the outcomes and exposure variables [13,31]. All models were adjusted for Gross Domestic Product (GDP) per capita, fertility rate, and MPOWER tobacco control measures (excluding 'Raise taxes', as we analysed detailed taxation data, and scores for 'Monitoring of tobacco use', as this measure is not expected to have an impact on the outcomes).…”

Effect of comprehensive smoke-free legislation on neonatal mortality and infant mortality across 106 middle-income countries: a synthetic control study

“…12 Evidence also suggests that implementing comprehensive smokefree legislation is associated with reduced neonatal mortality and infant mortality. [12][13][14][15] Previous evidence is, however, predominantly derived from studies in HICs and cannot be directly generalised to lowincome and middleincome countries (LMICs), because of their different economic, social, and environmental backgrounds, higher rates of neonatal and infant deaths, and often weaker implementation of smokefree legislation. 12,16 The influence of the tobacco industry and the awareness of the TSErelated harms is considerably less favourable in LMICs than in HICs, which might hinder the success of tobaccocontrol policies.…”

“…22,25 Three studies have evaluated the effects of smokefree legislation on child health outcomes in middleincome countries (MICs), in Brazil, Peru, and Thailand. 14,15,26 Although these studies also showed the positive effects of smokefree legislation, they were conducted in countries known to be tobaccocontrol leaders and with a higher gross domestic product (GDP) per capita than many other MICs. 11 Thus, it is unclear whether the child health benefits of comprehensive smokefree legislation identified in these studies are generalisable to all 106 World Bank MICs.…”

The short‐term impact of a malaria elimination initiative in Southern Mozambique: Application of the synthetic control method to routine surveillance data

“…The only application of SCM relating to malaria is by Barofsky et al (2015) who evaluate the long-term economic consequences (schooling and employment) of the 1959-1960 malaria eradication campaign in Uganda. We are aware of only two applications of SCM in public health; an evaluation of a smoke free legislation in Thailand on neonatal and infant mortality (Radó et al, 2020) and the impact of a decline in country democratic traits on universal health coverage (Wigley et al, 2020).…”