[Study of inequalities in hospital mortality using the Charlson comorbidity index]

The evaluation of quality and equity in healthcare attendance requires adequate study methods and information systems. Thus, this study was performed with the objective of comparing mortality among elderly patients attended within the private network and within the Brazilian national health system (SUS).

An information system that recorded causes of hospitalization and associated diseases (comorbidity) in relation to public and private hospital admissions was utilized. The hospitalization of 21,695 patients in Ribeirão Preto, State of Sao Paulo, in 1998 and 1999 was studied. These patients had diseases of the circulatory and respiratory systems. Analysis was done via the methodology put forward by Charlson, in which comorbidities are scored to give the Charlson comorbidity index and age over 50 years (per decade) is scored to give the Charlson comorbidity-age index. The patients were stratified according to comorbidity and decade of age over 50 years, with separation of hospitalizations via SUS from those via the private network (non-SUS). The coefficient of hospital mortality was calculated for each stratum.

It was observed that the risk of death increased almost sixfold when the number of associated diseases increased. The risk of death for SUS patients was more than twice the risk for non-SUS patients (relative risk: 2.12). Significant differences between SUS and non-SUS patients were found by associating the patient's comorbidity with decade of age. When the risk of death was very low or very high, there were no statistical differences between SUS and non-SUS patients. In other, intermediate situations, precisely where the attendance might make a difference, the mortality among SUS patients was more than twice as great (relative risk: 2.14).

The difference in mortality between SUS and non-SUS patients, according to Charlson's criteria, is significant among patients of intermediate risk, for whom the care is most important. The Charlson comorbidity index correlates with hospital mortality.