To Örebro University

Conclusion: In this population-based study, self-reported diagnosed asthma was independently associated with economic difficulties but not with educational level. Lifestyle factors did not explain the association between economic difficulties and asthma prevalence.These findings apply to both men and women as well as younger and older age groups.

Introduction: Previous studies have reported inconsistent findings about socioeconomic differences in asthma prevalence among adults. The aim of this study was to examine differences in the prevalence of self-reported diagnosed asthma by socioeconomic status and the contribution of lifestyle factors to these differences.

Methods: The study was based on 28,531 persons aged 18 years or older who answered a survey questionnaire sent to a random population sample in Mid-Sweden in 2017. The overall response rate was 44%. Socioeconomic status was measured with educational level and economic difficulties, and lifestyle factors with physical activity, smoking, snuff use, risk-drinking of alcohol and obesity. The associations were analysed using multivariate logistic regression.

Results: The overall asthma prevalence was 9% among women and 7% in men. Asthma was most prevalent in the youngest age group 18-29 years.

Educational level was not independently associated with asthma.

Statistically significant odds ratios for the prevalence of asthma were observed for economic difficulties 1.5 (95% CI: 1.3-1.7), physical inactivity 1.2 (95% CI: 1.1- 1.3) and obesity 1.6 (95% CI: 1.4-1.8).

Persons born outside the Nordic countries had lower prevalence of asthma than persons born in Sweden.

Smoking was not associated with asthma.