Precarious employment and its impact on chronic obstructive pulmonary disease in the Swedish working population - a longitudinal register-based study.

Abstract

Chronic obstructive pulmonary disease (COPD) is a respiratory disorder, and - after tobacco smoking - occupational exposures are among the most important risk factors. Precarious employment (PE) has been linked to a range of adverse mental and physical health outcomes; however, evidence regarding its potential association with COPD remains limited. PE may contribute to COPD risk through both greater exposure to occupational hazards and health-related behaviors, particularly smoking. This study aimed to examine whether PE is associated with COPD in the Swedish working population and assess whether these associations differ by gender. A nationwide register-based cohort of 1 984 081 working-age individuals in Sweden was followed for 14 years (2003-2017). PE was operationalized multidimensionally: contractual employment insecurity, temporariness, multiple jobholding, income level, and coverage by collective bargaining agreements. Cumulative incidence of COPD (2004-2017) was identified through register-based diagnoses. Risk ratios (RR) were estimated using generalized linear models with a log link function, adjusting for sociodemographic factors, occupational exposures, and smoking where available. PE was associated with a graded increase in COPD risk, ranging from substandard employment [adjusted RR (RR_adj) 1.18, 95% confidence interval (CI) 1.14-1.22] to PE (RR_adj 1.39, 95% CI 1.31-1.47). Among the dimensions of PE, low income was the strongest contributor (RR 1.44, 95% CI 1.39-1.50), while unstable employment had a modest effect (RR 1.16, 95% CI 1.12-1.20). PE is associated with elevated risk of COPD in the Swedish workforce. These findings emphasize the role of employment conditions as a social determinant of respiratory health.