Longitudinal changes in prevalence of chronic bronchitis in rural people

Abstract

Background: Smoking, obesity, socioeconomic status, family history of lung diseases and airborne pollutants have been significantly associated with the prevalence of chronic bronchitis (CB). Our objective was to evaluate changes in the prevalence of CB and associated risk factors within a rural population. Methods: The Saskatchewan Rural Health Study is a prospective study of the lung health of rural dwellers. The baseline survey was conducted in 2010. We obtained completed questionnaires from 4624 households (8261 individuals) in baseline and 2797 households (4867 individuals) in follow-up (2014). The questionnaire collected information on individual and contextual determinants. Clustering effects within household and due to repeated observations were accounted for appropriately. Results: Incidence of CB was estimated as 4.3% over 4 years. The prevalence was 6.4% and 5.3 % (baseline) and 12.1% and 9.2% (follow-up) in non-farm and farm residents, respectively. The prevalence of CB was associated with the following factors (odds ratio (95% confidence interval)): being female-1.58 (1.25, 2.0), being obese-1.32 (1.04, 1.66), father9s history of lung disease -1.61 (1.27, 2.04), mother smoked during pregnancy-1.52 (1.17, 1.99), allergies to cats-1.85 (1.42, 2.40) and allergies to pollen -1.92 (1.53, 2.40), dose-response relationship was observed with household income adequacy where there was an increased risk associated with lower income group. Exposure to stubble smoke interacted with exposure to wood dust and mother9s history of lung disease was interacted with educational level. Conclusion: High prevalence of CB in rural people appears related to a complex mix of personal and contextual factors.