Determinants of smoke-free homes adoption among Spanish adults who smoke: A prospective cohort study from the 2016–2021 International Tobacco Control (ITC) EUREST-PLUS Spain Surveys

Abstract

Objective: To assess the prevalence and associated factors of smoke-free homes (SFHs) among Spanish adults who smoke across three cohort waves, and to identify determinants of SFH adoption during follow-up (2016-2021). Methods: The International Tobacco Control EUREST-PLUS Spain Survey is a nationally representative cohort of similar to 1000 adults (>= 18 years) who smoke surveyed in 2016, 2018, and 2021. First, we conducted repeated cross-sectional analysis to estimate the prevalence of SFHs at each wave. Second, we estimated incidence and risk ratios (RR) with 95 % confidence intervals (CI) for SFH adoption during the follow-up using adjusted generalised linear models. Independent variables included sociodemographics, smoking characteristics, and beliefs about second-hand smoke harms. Results: SFH prevalence was 13.1 % in 2016, 19.0 % in 2018, and 31.5 % in 2021 (p trend <0.001). Quitting smoking (RR = 2.66; 95 % CI: 2.10, 3.36), remaining in any stage other than precontemplation (RR = 1.76; 1.13, 2.73) and progressing beyond precontemplation stage (RR = 2.59; 1.99, 3.37) were determinants of SFH adoption. Maintaining moderate or high nicotine dependence (RR = 0.46; 0.30, 0.69) was inversely associated with SFH adoption. Conclusions: SFH prevalence among Spanish adults who smoke increased in 2016-2021. Initiatives promoting SFHs should encourage progression through the stages of change towards cessation and provide tailored support for individuals with high nicotine dependence.