Underlying and proximate determinants of diarrhoea-specific infant mortality rates among municipalities in the State of Ceara, north-east Brazil: An ecological study

This ecological study examines the variations in diarrhoea-specific infant mortality rates among municipalities in the State of Ceara, north-east Braz il, using data from a community health workers' programme. Diarrhoea is the main cause of postneonatal deaths in Ceara, and diarrhoea mortality rates vary substantially among municipalities, from 7 to 50 per thousand live bir ths. To determine the inter-relationships between potential predictors of d iarrhoea-specific infant mortality, eleven variables were classified into p roximate determinants (i.e. adequate weight gain and exclusive breastfeedin g in first 4 months) and underlying determinants (i.e. health services and socioeconomic variables). The health services variables included percent ag e with prenatal care up-to-date, participation in growth monitoring and imm unization up-to-date, while the socioeconomic factors included female illit eracy rate, per capita gross municipality product and percentage of househo lds with low income, percentage of households with inadequate water supply and inadequate sanitation, and urbanization. Using linear regression analys is variables were included from each group to build regression models. The significant determinants of variability in diarrhoea-specific infant mortal ity between municipalities were prevalence of infants exclusively breastfee ding, percentage of infants with adequate weight gain, percentage of pregna nt women with prenatal care up-to-date, female illiteracy rate and inadequa te water supply. These findings suggest that community-based promotion of e xclusive breast-feeding in the first 4 months and care-giving behaviours th at prevent weight faltering, including weaning practices and feeding during and following diarrhoea episodes, may further reduce municipality-level di arrhoea-specific mortality. Primary heath care strategies addressing these two proximate determinants provide only a partial solution to reducing diar rhoeal disease mortality. Improvements in municipal health services (prenat al care) and socioeconomic status variables, including water supply and mat ernal education, can also contribute to reduction of infant mortality due t o diarrhoea. These results may be used by government health officials to se t priorities by considering not only the strength of the association betwee n selected risk factors and diarrhoea mortality rates, but also the prevale nce of the risk factors being considered at the municipality level. Finally , the methods used are applicable to other settings with community-based pr imary health care decentralized to the state or municipal level.