Risk factors for diarrhoeal deaths: a case-control study at a diarrhoeal disease hospital in Bangladesh

Abstract

The study of diarrhoeal mortality risk has been limited to descriptive epidemiological investigations. This is the first case-control study in this area, and our results show that certain risk factors are predictive of diarrhoeal deaths. We have compared the disease history, associated complications, signs, symptoms and laboratory values of 346 patients who died on the medical wards of Dhaka Hospital and that for 346 matched controls to identify the risk factors for mortality. Patients presenting with oedema, severe dehydration or convulsion were found to have a risk of mortality two times higher than controls. Several laboratory results were compared by a matched pair analysis, demonstrating that hyponatraemia (less than 130 mmol/L), hypobicarbonaemia (less than 20 mmol/L) and raised anion gap (greater than 14.9 mmol/L) were moderately associated with mortality. However, hypoproteinaemia (less than 50 gm/L) was strongly associated. For children less than 10 years of age, both hyper- and hyponatraemia were found to be associated with mortality, and the nutritional status of the children modified the effect of hypernatraemia on diarrhoeal mortality. The strong association between diarrhoeal death and hypoproteinaemia may be due to the effect of the pre-existing malnutrition of these patients and/or their loss of protein during shigella infection. The various risk factors that we have identified could be used as a prognostic guide by physicians treating such patients