The Impact of Tobacco and Occupational Exposure on Chronic Obstructive Pulmonary Disease in a 70 and over Jamaican Cohort from the Burden of Obstructive Lung Disease (Jamaica) Study

Background: Chronic obstructive pulmonary disease (COPD) is a chronic respiratory disease predominantly affecting the older population. Not well known, COPD is often confused with asthma. Tobacco smoking is widely acknowledged as the most important risk factor for COPD. but occupational exposures from irritant dust, fumes and, biomass exposures from burning wood and coal indoors, also contribute to COPD prevalence. This paper looks at COPD prevalence and occupational exposures in adults aged 70(+) using data from the United Kingdom-based Burden of Obstructive Lung Disease (BOLD) study in Jamaica (www.boldstudy.org). Subject and Method: Jamaica followed a strict BOLD protocol of face to face standardized questionnaire administration and spirometry testing on participants aged >= 40 years. Questions included sociodemographic characteristics, smoking practices, respiratory symptoms and occupational exposures. The Occupational questionnaire enquired about time spent in thirteen different occupations including farming. construction, firefighting, domestic and industrial cleaning, welding, coal mining, flour, feed or grain milling to mention a few. Spirometry was performed according to American Thoracic Society (ATS) standards. An island-wide multi-stage random sample of non-institutionalized individuals was selected for recruitment with the assistance of the Statistical Institute of Jamaica (STATIN). All questionnaires and spirometry data from consenting participants were submitted electronically to the United Kingdom Coordinating Centre for data cleaning, quality checks and preliminary analysis. Final data were returned to the local research team for further analysis. Result: Total sample selected for recruitment (and response rate) was 883 (91.4%) for persons aged >= 40 years and 190 (87.2%) for persons aged 70(+) years. Of the 164 responders in the 70(+) group, 91 (55.5%) had usable spirometry. Prevalence of ever-smoking by age and gender in this 70(+) cohort was 38.4%. Farming, construction and household cleaning were the most frequently reported occupations (58.8%). Years working in these three occupations ranged from 1-70 (farming and construction) and 1-78 (cleaning). Most were now retired (120 of 164 overall). Weighted estimated population prevalence of Global Initiative for Chronic Obstructive Lung Disease (GOLD) Stage 1 (Post-BD FEV1/FVC < 70%; FEV1 >= 80% predicted) was 12.1% overall for persons aged 40(+), but was highest at 37.8% in the 70(+) age group. Estimated prevalence of GOLD Stage 2 (50 <= FEV1 < 80% predicted) was 9.6% in the 40(+), again highest at 31.3% in the 70(+) age group. Conclusion: Overall prevalence of COPD in the 40(+) age group whether Stage 1 (mild COPD), or Stage 2 (moderate COPD), while it appears low, was still highest in the 70(+) age group. The local data revealed that whilst the prevalence of current smoking had declined by age 70(+), the estimated prevalence of GOLD Stage 1 and Stage 2 COPD was highest in this age group. The contribution of occupational exposures to the development of COPD, requires further analysis to look at the occupational exposures across all participants aged 40(+) as well as the prevalence of COPD among non-smokers. Progression of Stage 1 to Stage 2 disease and its effect on morbidity and quality of life is likely without patient education regarding complications of tobacco smoke and workplace exposures to the development of COPD.