Quasi-experimental study on the impact of local smoke-free policies on smoking among Indonesian adults: Evidence from repeated national health surveys

Background: Smoke-free policies (SFPs) have been effective in reducing smoking prevalence, but evidence remains limited for low- and middle-income countries. Due to decentralized governance in Indonesia, SFPs are adopted in different ways in different locations. This study aims to assess the impact of local smoke-free policies (SFPs) on current smoking among Indonesian adults. Methods: Data from national health surveys conducted in 515 districts and 34 provinces in 2007, 2013, and 2018, involving 1,599,517 adults, were analyzed. A multilevel logistic regression analysis was performed, considering variables such as survey year, SFP adoption in 2007, SFP between 2007 and 2013, SFP between 2013 and 2018, socio-demographic factors, and district characteristics. Results: Moderate (OR:0.94, 95%CI:0.91-0.97) and strong (OR:0.95, 95%CI:0.0.92-0.98) district-level SFPs between 2013 and 2018 were associated with decreased odds of current smoking, compared to no district-level SFP adoption. Similar results were observed for moderate (OR:0.91, 95%CI:0.86-0.96) and strong (OR:0.89, 95%CI:0.85-0.94) district-level SFPs between 2007 and 2013, compared to no district-level SFP. Compared to provinces without SFPs, individuals living in provinces with moderate SFPs between 2007 and 2013 had lower odds of current smoking (OR:0.67; 95% CI:0.63-0.71), while those in districts with moderate SFPs between 2013 and 2018 had higher odds (OR: 1.08, 95% CI: 1.05-1.11). Conclusions: Local SFPs demonstrated a potential in reducing smoking persistence in Indonesia, particularly at the district level. However, the impact of province-level SFPs differed. Tailored SFPs and district-province strategies, focusing on synchronizing the top-down SFP implementation in the Indonesia's decentralized systems, are critical for lowering smoking rates.