Cause-Specific Adult Mortality: Evidence From Community-Based Surveillance — Selected Sites, Tanzania, 1992-1998

Morbidity and Mortality Weekly Report, May 19, 2000

Mortality data are a standard information resource to guide public health action. Because Tanzania did not have a representative mortality surveillance system, in 1992 the Adult Morbidity and Mortality Project (AMMP)* was established by the Muhimbili University College of Health Sciences, the Ministry of Health of Tanzania (MOH), and the University of Newcastle upon Tyne, United Kingdom. The purpose of the surveillance system is to provide cause-specific death rates among adults in three areas of Tanzania and to link community-based mortality surveillance to evidence-based planning for health care. This report describes the results of AMMP surveillance during 1992-1998, which indicated that human immunodeficiency virus infection/acquired immunodeficiency syndrome (HIV/AIDS) was the leading cause of death reported by decedents' relatives and caretakers for adults of both sexes in all study areas, and suggests that a range of other causes of death exist across the three surveillance sites.

The AMMP surveillance project was conducted in a low-income and in a middle-income section of the city of Dar es Salaam, which is part of a region ranked by the Tanzanian government among the 50% most deprived in Tanzania (i.e., Morogoro Rural District in Morogoro Region), and in part of a region ranked as one of the 15% feast deprived (i.e., Hai District in Kilimanjaro Region) (1). These areas were selected to compare urban with rural conditions and high-income with low-income conditions. Population denominators were determined by semi-annual census rounds in Dar es Salaam and annual census rounds in Morogoro Rural and Hai. Mortality monitoring was conducted by trained volunteers who reported deaths to a team of supervisors. Supervisors then conducted "verbal autopsy" interviews with the decedents' relatives and caretakers to determine the cause of death (2). Family and caretakers were used as sources to determine cause of death because up to 80% of deaths occur outside health facilities and most deaths are not medically certified (3). The interviews usually occurred within a month of a supervisors receipt of the death report (4). The completed interview forms were coded by three physicians using the International Classification of Diseases and Related Health Problems, 10th Revision (3-5).

During 1992-1998, 10,517 persons aged 15-59 years died in the three locations; a cause of death was assigned by AMMP in 95% of cases. Death rates per 100,000 population were calculated for persons aged 15-59 years and for men and women by study area. Cause-specific death rates were calculated for persons aged 15-59, 15-29, 30-44, and 45-59 years, by sex, and by study area; probability of death by age 60 years at age 15 years was calculated by sex and study area. Death rates were standardized to World Health Organization standard populations (6). The probability of death by age 60 years at age 15 years was 45% for women and 42% for men in Dar es Salaam, 43% for women and 51% for men in Morogoro Rural, and 26% for women and 37% for men in Hai.

In addition to indicating 6-year total death rates and death rates from the 10 leading causes of death for men and women (Table 1), the data reflected large variations in cause-specific death by sex and geographic area and are ranked according to an age adjusted death rate for each district; no causes of death were excluded from ranking. HIV/AIDS, tuberculosis (TB), malaria, and diarrhea were major causes of death. HIV/AIDS and TB were particularly high in Dares Salaam, especially among women aged 15-29 years (325 and 62 per 100,000, respectively) and men aged 30-59 years (1199 and 426, respectively). The HIV/AIDS death rate was 608 among men aged 30-44 years in Dar es Salaam, and the TB death rate was 232. HIV/AIDS was the leading cause of death among persons of both sexes aged 15-59 years; the rate ranged from 246 among men in Morogoro Rural to 534 among women in Dares Salaam. However, stroke and TB death rates were 3.0 and 6.7 times higher, respectively, among women in Dar es Salaam than among women in th e other areas, and anemia death rates in Morogoro Rural were 3.0 times higher than in the other districts. In Morogoro Rural, the rate of maternal mortality was 114, with a maternal mortality ratio of 1183 per 100,000 live births, more than eight times the official regional estimate (AMMP, unpublished data, 2000). Among men, malaria, acute diarrheal disease, and anemia death rates were 3.0, 4.3, and 21.7 times higher, respectively, in Morogoro Rural than in the other two districts. Stroke and cancer death rates for both sexes were higher in Dares Salaam and Hai than in Morogoro Rural. Among men, injury was a substantial cause of death, and injury rates for both sexes were higher in rural than urban areas.

Reported by: PW Setel, PhD, N Unwin, MFPHM, KGMM Alberti, DPhil, Univ of Newcastle upon Tyne, Newcastle upon Tyne, United Kingdom. Y Hemed, MBChB, Ministry of Health, Adult Morbidity and Mortality Project Team. Adult Morbidity and Mortality Project Team, Dar es Salaam, Tanzania.