Magnitude of social determinants in high risk areas of leprosy in a hyperendemic city of northeastern Brazil: An ecological study

Objective: To investigate the association of certain social determinants with areas at high-risk for leprosy in a hyperendemic city in northeastern Brazil. Methods: An ecological study was carried out in Imperatriz, a hyperendemic municipality of northeastern Brazil. The units of analysis were urban census tracts, in which variables related to the number of dwellers per domicile, literacy and per capita monthly income were selected for the construction of the social determinants dimensions, by means of the Principal Components Analysis (PCA) technique. Spatial scan statistics were applied to identify areas of elevated leprosy risk and binary logistic regression was performed, considering the high-risk areas as the dependent variable and the social determinants dimensions as the independent variable. The Odds Ratios (ORs) were calculated with its 95% Confidence Intervals (CIs). The Receiver Operating Characteristic (ROC) Curve was applied to verify the discriminative power of the model. Type I error was set at 5% (p < 0.05). Results: 2,552 leprosy cases were georeferenced and the scan statistic identified high-risk areas. The logistic model showed that social determinants were associated with high-risk areas (OR = 1.25, 95% CI = 1.07–1.49, p = 0.006). The area under the ROC curve value confirmed the discriminatory capacity for the model at 65%, which was considered sufficient. Conclusions: The high-risk areas for leprosy are associated with social determinants of low household per capita income, low educational levels and high numbers of residents per household.