A population laboratory for studying disease processes and mortality--the Demographic Surveillance System, Matlab Comilla, Bangladesh

Abstract

Describes the Demograhic Surveillance System (DSS) of the International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B), initiated in 1963. The DSS consists of periodic censuses of the study population with intervening registration of vital events. The surveillance area currently consists of 159 villages, containing an estimated population (1974) of 160 thousand, in Matlab, Comilla district. Immediate objectives are assessment of maternal and child health and family planning services in the area, research related to diarrheal diseases, measurements and determinants of fertility and mortality, and development of a demographic field site for training of people involved in national programs. Data are collected through a 3 tiered system: vital events are recorded by female village workers, whose work is checked by field assistants, then coded and processed in Dacca, and put on computer. Selected results from DSS studies are discussed, focusing on particular aspects of mortality or morbidity and epidemiological studies regarding diarrhea and nutrition, to illustrate the possibilities of a population laboratory in these contexts. The DSS has 7 advantages: 1) enables an accurate count of the population; 2) provides accurate sampling frames; 3) provides precise age data; 4) enables studies of client cooperation with health services; 5) facilitates prospective research designs; 6) collects demographic data which may reflect national statistics; 7) serves as a field training site. However, limitations of expense, data collected on causes of events, error correction, and study design must be considered. Computerization should make it possible to turn the DSS into a registration system. Population laboratories in other parts of the world, with differing focuses, are briefly described, and some of their studies are compared to those of the DSS