Incidence and Longitudinal Changes in Prevalence of Chronic Bronchitis in Farm and Non-Farm Rural Residents of Saskatchewan.

To assess the predictors associated with incidence and longitudinal changes in the prevalence of chronic bronchitis (CB) among farm and non-farm residents of rural Saskatchewan, Canada.The Saskatchewan Rural Health Study was a prospective study of the lung health of rural dwellers. We obtained information on 4624 households, 8261 individuals (2797 households, 4867 individuals) at baseline (follow-up).Incidence of CB was 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 current smokers; father ever had lung trouble; obesity; mother smoked during pregnancy; allergic reaction to cats and to pollen; household income inadequacy and age.Prevalence and incidence of CB in rural people appear to be a complex mix of personal and contextual factors.