Trends in asthma mortality in young people in southern Brazil

Background: Mortality from asthma increased and is now declining in some co untries, but little is known about these trends in South America. Objective: We aimed to assess trends in mortality from asthma in southern B razil in children and young adults. Methods: Death certificates of 425 people in the state of Rio Grande do Sul aged between 5 and 39 years in whom asthma was reported to be the underlyi ng cause of death during the period 1970 to 1992 were reviewed. Population data were available in 10-year age groups. Testing for trends in mortality rates was conducted using linear and log-linear regression procedures. Results: Asthma mortality rates in the age groups 5 to 19 and 20 to 39 year s ranged between 0.04 and 0.39/100,000 and 0.28 to 0.75/100,000, respective ly, and were nonuniformly distributed over the study period. The mean annua l increase in rate in 5- to 19-year olds was +0.01 (95% CI 0.003 to 0.016), an average annual percentage increase of +6.8% (95% CI 3% to 11%), with a total increase of 352% between 1970 and 1992. This increase was not due to a shift in labeling from bronchitis to asthma. In the 20 to 39-year age gro up, asthma and bronchitis mortality rates showed no trend to increase or de crease. Conclusions: Asthma mortality in southern Brazil is low, but rose significa ntly between 1970 and 1992 in the 5 to 19-year age group. This trend differ s from that found in other states of Brazil and several other Latin America n countries. Reasons for this difference remain unclear.