Light cigarette smoking and all-cause mortality in Spain. A national population-based cohort study

Abstract

Purpose: Regular light cigarette consumption (light smoking) is increasing in many countries; however, few studies have assessed its impact on mortality. The main aim of this study is to estimate the association between the number of cigarettes consumed and all-cause mortality in Spain while focusing on light smoking. Methods: Longitudinal study based on data from 42,902 individuals aged ≥15 years included in the 2011-2012 (Spanish) National Health Survey or the 2014 European Health Survey for Spain. Data were linked with the mortality registry up to December 2020. Multivariate Cox regression models were used to estimate hazard ratios (HR) adjusted for sociodemographic variables, lifestyle factors, and health status indicators. Results: Compared to never smokers, the mortality HR for nondaily smokers was 1.30 (95% CI: 0.81-2.09), increasing to 2.23 (95% CI: 1.25-3.96) among those smoking 1-2 cigarettes/d, and to 1.54 (95%CI: 1.14-2.07) for consumers of 3-5 cigarettes/day. When individuals who reported trying to quit during the previous year were excluded, resulting HRs were 1.31 (95% CI: 0.81-2.10), 1.48 (95% CI: 0.69-3.19) and 1.64 (95% CI: 1.16-2.34), respectively. Conclusions: Compared to never smokers, consumers of small quantities of tobacco, that is, light smoking, had an increased mortality risk. In view of these results, we suggest the need for awareness-raising campaigns regarding how smoking even a small number of cigarettes a day causes serious harm to one´s health.