Ten-year trends in prevalence of asthma in adults in southern Brazil: comparison of two population-based studies.

There are discrepancies in the literature regarding time trends in the occurrence of asthma in adults. This study compared asthma prevalence in two cross-sectional studies with a ten-year interval in Pelotas, Rio Grande do Sul State, Brazil. The first, in 2000, included 1,968 individuals, and the second, in 2010, 2,466 adults (20-69 years). Prevalence of wheezing and shortness of breath in the prior 12 months remained the same after ten years (6% and 6.1%, respectively). In both studies, asthma was more frequent among females and people with low family income. Physician-diagnosed asthma increased by 35.6%, and lifetime incidence of asthma, by 32.2%. There was no percentage change in current asthma symptoms or current asthma. Local socioeconomic improvement between the two studies was consistent with the increase in medical diagnosis, but did not reflect better management of asthma symptoms, underlining the need for investment regarding other determinants of the disease.