Language and geographical location influences the incidence of chronic cough in the Canadian Longitudinal Study on Aging (CLSA)

Abstract

The prevalence of chronic cough in the Canadian Longitudinal Study on Ageing (CLSA) is 16%, but is lower in Quebec(10%) than in Ontario(16%). We investigated whether language (English vs French) or geographical location (provinces) influences the incidence of chronic cough independent of age, sex, smoking, body max index (BMI), province, respiratory diseases and self-perceived general health. The CLSA is a prospective, random sample of adults aged 45-85 at baseline recruited between 2011-2015 and followed-up 3 years later. Chronic cough was defined a daily cough >12 months. Incidental chronic cough was defined as those participants who reported new-onset chronic cough between baseline and follow-up 1. Overall, 2506(11%) participants reported chronic cough at follow-up, of whom 2,131 (11.9%) were English speaking and 375(8%) French speaking. In English speaking participants, the risk of incident chronic cough was lower in Quebec [RR 0.59 (95% C.I. 0.42-0.83)], Nova Scotia [0.66(0.56-0.78)], Newfoundland and Labrador [0.80 (0.68-0.94)], and British Columbia [0.87(0.77-0.97)] compared with Ontario. In French speaking participants, there was no difference in the risk of incident chronic cough living in Quebec compared with Ontario. These findings implicate the role of language, phonation, culture, social norms, genetics, air pollution and weather as potentially influencing chronic cough.