Identification of micro-regions with under-reported tuberculosis cases in Brazil, 2012-2014

Objective to identify Brazilian micro-regions with under-reported tuberculosis cases, from 2012 to 2014. Methods this was an ecological study using data from the Notifiable Health Conditions Information System (SINAN). The indirect estimator of the proportion of notified cases (EIPCN) was calculated as the mean between the proportion of cases that adhered to treatment and the proportion of those who underwent sputum smear microscopy. Negative Binomial Regression was used to investigate evidence of under-reporting in the micro-regions selected through EIPCN. Results under-reporting was suspected in 89 (17.5%) micro-regions with EIPCN below 83%. The EIPCN rate ratio in the regression model was 0.996 (95%CI 0.988;1.003) considering all the data and equal to 0.987 (95%CI 0.974;0.999) excluding the 89 micro-regions with suspected under-reporting. Conclusion evidence of tuberculosis case under-reporting was found in micro-regions where basic indicators of surveillance system quality had poor performance.