Tucson epidemiologic study of obstructive lung diseases. I: Methodology and prevalence of disease.

Using a multistage stratified cluster sample of Anglo-white Tucson households (based on the 1970 Census block statistics), this longitudinal study enrolled 1655 households. The study sample of 3805 individuals thus selected representatively covered the household structures, including the age and sex subgroupings, of the Tucson Anglo-white population. The estimated prevalence rates had a very low standard error of estimate both overall and in the age- and sex-specific categories, indicating a good selection and sufficient numbers in all age-sex specific subgroups. As anticipated, prevalence rates of diagnosed respiratory and other chronic diseases were higher than those found nationally. Despite much higher rates of diagnosed pulmonary diseases within the age-sex populations over the age of 40, the results of this study are within the ranges of other surveys in terms of prevalence of many common chronic respiratory symptoms. Reasons for this apparent discrepancy are so far undertermined.