Risk of asthma in relation to occupation: A hospital-based case-control study

Asthma is a common occupational lung disease and is preventable by removing identifiable allergens.

(1) To assess the relationship between occupation and asthma (2) To determine the agents associated with asthma.

In this hospital-based, case-control study 153 cases from the Asthma Clinic and 306 non-asthmatic controls from Srinagarind Hospital, Thailand were interviewed. Crude odds ratios (COR), 95% confidence intervals (95% CI) and adjusted ORs (AOR) for multiple logistic regression were calculated.

Of the 153 cases, 70.6% were females with median age of 53 (IQR-14). Of the 306 controls, 62.4% were females with median age of 56 (IQR-16). The highest risk of asthma was family history of asthma and history of atopy [AOR 11.68 (95% CI 4.52, 30.24) and AOR 8.03 (95% CI 5.07, 13.60)], respectively. If only occupations were considered, healthcare workers had the highest risk [AOR 4.08 (95% CI 1.35, 12.30)], followed by textile workers [AOR 3.34 (95% CI 1.07, 10.47)] and school workers AOR 2.40 (95% CI 1.31, 4.41). When subgroups of non-atopy were considered, school workers had a significant association with asthma [COR 3.18 (95% CI 1.48, 6.83)]. When no family history of asthma was considered, school and textile workers had the most significant association with asthma [COR 3.10 (95% CI 1.87, 5.13) and COR 3.06 (95% CI 1.15, 8.13), respectively]. Inorganic dust was the agent most significantly associated with asthma COR 1.89 (95% CI 1.25, 2.82).

School, textile and healthcare workers have the greatest risk of asthma. Family history of asthma and being atopic would also promote asthma in relation to occupation.