Mortality experience of Tsimane amerindians of Bolivia: Regional variation and temporal trends

This paper examines regional and temporal trends in mortality patterns among the Tsimane, a population of small-scale forager-horticulturalists in lowland Bolivia. We compare age-specific mortality in remote forest and riverine regions with that in more acculturated villages and examine mortality changes among all age groups over the past 50 years. Discretetime logistic regression is used to examine impacts of region, period, sex, and age on mortality hazard. Villages in the remote forest and riverine regions show 2-4 times higher mortality rates from infancy until middle adulthood than in the acculturated region. While there was little change in mortality for most of the life course over the period 1950-1989, overall life expectancy at birth improved by 10 years from 45 to 53 after 1990. In both periods, over half of all deaths were due to infectious disease, especially respiratory and gastrointestinal infections. Accidents and violence accounted for a quarter of all deaths. Unlike typical patterns described by epidemiologic transition theory, we find a much larger period reduction of death rates during middle and late adulthood than during infancy or childhood. In the remote villages, infant death rates changed little, whereas death rates among older adults decreased sharply. We hypothesize that this pattern is due to a combination of differential access to medical interventions, a continued lack of public health infrastructure and Tsimane cultural beliefs concerning sickness and dying.