Objective: To determine the prevalence of temporary social security benefits due to respiratory disease granted to employees, as well as the number of lost workdays and costs resulting from those in Brazil between 2003 and 2004. Methods: Cross-sectional study using data obtained from the Unified System of Benefits of the Brazilian Institute of Social Security (INSS, Instituto Nacional de Seguro Social) and the Brazilian Social Registry Database. Data regarding gender, age, diagnosis and type of economic activity, as well as type, duration and cost of benefits, were compiled. Results: Respiratory diseases accounted for 1.3% of the total number of temporary social security benefits granted by INSS, with a prevalence rate of 9.92 (per 10,000 employment contracts). Females and individuals older than 50 years of age were the most affected. Non-work-related benefits were more common than were work-related benefits. The most prevalent diseases were pneumonia, asthma and COPD, followed by laryngeal and vocal cord diseases. The most prevalent types of economic activity were auxiliary transportation equipment manufacturing, tobacco product manufacturing and computer-related activities. The mean duration of benefits was 209.68 days, with a mean cost of R$ 4,495.30 per occurrence. Respiratory diseases caused by exogenous agents demanded longer sick leave (mean, 296.72 days) and greater cost (mean, R$ 7,105.74). Conclusions: The most prevalent diseases were airway diseases and pneumonia. Workers from auxiliary transportation equipment manufacturing, tobacco product manufacturing and computer-related activities were the most affected. Diseases caused by exogenous agents demanded longer sick leaves and resulted in greater costs.

Keywords: Respiratory tract diseases; Sick leave; Work; Workers' compensation; Social security.