Determinants of sustained smoking among individuals with chronic respiratory diseases and effects on all-cause mortality: a population-based study.

INTRODUCTION

Although smoking cessation is essential in the management of chronic respiratory diseases, smoking rates remain high in this population. This study aims to identify factors associated with continued smoking among individuals with chronic respiratory diseases and to estimate its impact on all-cause mortality.

METHODS

A prospective population-based study was conducted including 65,990 individuals aged ≥15 years. Data came from three National and European Health Surveys in Spain (2011-2017) linked with mortality records through December 2023. Participants were grouped by a history of active asthma or chronic obstructive pulmonary disease. Tobacco use, sociodemographic characteristics, and lifestyle factors were collected. Data were analyzed using multivariate logistic and Poisson regression.

RESULTS

The prevalence of active asthma and chronic obstructive pulmonary disease was 4.4% and 6.0%, respectively. The prevalence of current smoking was 21.3% in the asthma group and 21.8% in the chronic obstructive pulmonary disease group. Continued smoking (vs. former smoking) was more likely among women, younger individuals, those with lower educational level (asthma group), and sedentary individuals. It was less likely among overweight and obese, married individuals, and those with greater Mediterranean diet adherence. A higher all-cause mortality risk was observed among current smokers with asthma (RR = 1.70, 95% CI: 1.16; 2.51, p = 0.007) or chronic obstructive pulmonary disease (RR = 1.34, 95% CI: 1.07; 1.67, p = 0.014) than former smokers.

CONCLUSIONS

Continued smoking remains highly prevalent among individuals with chronic respiratory disease and is associated with a higher all-cause mortality risk than quitting smoking. Effective smoking cessation interventions targeting high risk groups are needed.