RESUMO
Through a series of life table analyses, this paper describes the natural history of tuberculosis mortality in a Mexican-origin community over five decades (1935-84) during which the disease underwent a transition from a major underlying cause of death to a disease conditioned mentioned more often on death certificates as contributing to death than causing death. The decline in death rates from 1940 to 1950 was especially remarkable. Successive birth cohorts of Mexican Americans, separated by as little as five years of age, experienced distinctly lower risk of death from tuberculosis as they entered young adulthood. There was a rapid convergence in age-specific patterns of tuberculosis death rates in Mexican Americans toward those of non-Hispanic whites, so that by 1960 tuberculosis was primarily a cause of death in old age rather than young adulthood. The impact of changing environment, both through improvements of conditions within neighborhoods and through residential mobility, on birth cohorts at risk of tuberculosis needs to be examined in further research.
PIP: This study examines the history of tuberculosis mortality during 1935-84 among a Mexican-origin community in Bexar County, Texas. Data were obtained from death records of the San Antonio Metropolitan Health District. Data coding accounted for the shift in 1949 in formatting underlying cause and primary cause of death. Deaths are estimated from multiple decrement life tables for deaths by age and underlying cause in a hypothetical cohort of 100,000 newborns followed to their deaths. Cause-eliminated life tables show the distributions of deaths if tuberculosis were eliminated. Findings indicate that life expectancy of Mexican-origin people in Bexar County during 1938-42 was about 47 years for males and females. Life expectancy for Anglos was higher but still lower than the national average. By 1980, differences in life expectancies by ethnic group converged. The rapid increases in life expectancy occurred during the 1940s: 12.7 years for Mexican-origin women and 10.3 years for Mexican-origin men. The 1940 risk of tuberculosis death among Mexican-origin people was 5-7 times that of Anglos. Among the 1940s Mexican-origin population, tuberculosis caused heavy fatalities in early adulthood between the ages of 15 and 35 years. By 1960, it was a cause only in old age, as it was among Anglos. Cohort comparisons reveal that the cohort reaching the age of 15 years in 1945 had a mortality probability that was only half as great to age 20 in 1950. The mortality probability declined to near zero by age 25 in 1955. The life table proportion of deaths due to tuberculosis declined linearly and added to life expectancy until 1980. Tuberculosis was the underlying cause of death among 96% of Mexican-origin people in 1938-42 and 41% in 1983-85. Tuberculosis morbidity declined during the 1940s and 1950s due to major housing renewal, slum clearance, code enforcement, and residential mobility.