Offer of primary care services and detection of tuberculosis incidence in Brazil

OBJECTIVE: To evaluate the association between the health services offered by primary care teams and the detection of new tuberculosis cases in Brazil. METHODS: This was an ecological study covering all Brazilian municipalities that registered at least one new tuberculosis case (diagnosed between 2012 to 2014 and notified in the Information System of Notifiable Diseases) and with at least one primary care team evaluated by the second cycle of the National Program for Improving Access and Quality of Primary Care (PMAQ-AB). The variables of the PMAQ-AB were classified as proximal or distal, according to their relation with the tuberculosis diagnosis. Then, they were tested hierarchically in multiple models (adjusted by States) using negative binomial regression. RESULTS: An increase of 10% in the primary health care coverage was associated with a decrease of 2.24% in the tuberculosis detection rate (95% CI -3.35--1.11). Regarding the proximal variables in relation to diagnosis, in the multiple model, the detection of tuberculosis was associated with the proportion of teams that conduct contact investigation (increase in Incidence Rate Ratio [IRR] = 2.97%, 95% CI 2.41-3.53), carry out tuberculosis active case finding (increase in IRR = 2.17%, 95% CI 1.48-2.87), and request culture for mycobacteria (increase in IRR = 1.87%, 95% CI 0.98-2.76). CONCLUSIONS: The variables related to the search actions were positively associated with the detection of new tuberculosis cases, which suggests a significant contribution to the strengthening of the sensitivity of the surveillance system. On the other hand, primary care coverage was inversely associated with the tuberculosis detection rate, which could represent the overall effect of the primary care on transmission control, probably from the identification and early treatment of cases.