Adult deaths and the future: a cause-specific analysis of adult deaths from a longitudinal study in rural Tanzania 2003-2007

Objectives: To determine patterns and risk factors for cause-specific adult mortality in rural southern Tanzania.

Methods: The study was a longitudinal open cohort and focused on adults aged 15-59 years between 2003 and 2007. Causes of deaths were ascertained by verbal autopsy (VA). Cox proportion hazards regression model was used to determine factors associated with cause-specific mortality over the 5-year period.

Results: Thousand three hundred and fifty-two of 65 548 adults died, representing a crude adult mortality rate (AMR) of 7.3 per 1000 person years of observation (PYO). VA was performed for 1132 (84%) deaths. HIV/AIDS [231 (20.4%)] was the leading cause of death followed by malaria [150 (13.2%)]. AMR for communicable disease (CD) causes was 2.49 per 1000 PYO, 1.21 per 1000 PYO for non-communicable diseases (NCD) and 0.53 per 1000 PYO for accidents/injury causes. NCD deaths increased from 16% in 2003 to 24% in 2007. High level of education was associated with a reduction in the risk of dying from NCDs. Those with primary education (HR = 0.67, 95% CI: 0.49, 0.92) and with education beyond primary school (HR = 0.11, 95% CI: 0.02, 0.40) had lower mortality than those who had no formal education. Compared with local residents, in-migrants were 1.7 (95% CI: 1.37, 2.11) times more likely to die from communicable disease causes.

Conclusion: NCDs are increasing as a result of demographic and epidemiological transitions taking place in most African countries including Tanzania and require attention to prevent increased triple disease burden of CD, NCD and accident/injuries.