Factors associated with false-negative results from the rapid molecular test for pulmonary tuberculosis in the state of São Paulo, Brazil

Objective To analyze the factors associated with the frequency of false negative results for the RMT-TB test for the diagnosis of pulmonary tuberculosis in the state of São Paulo. Methods Cross-sectional study using pulmonary tuberculosis cases from the state of São Paulo reported in the TB-WEB system between 2014 and 2023. RMT-TB results were compared with sputum smear microscopy, sputum culture, and sensitivity testing. Subsequently, variables with p Results There was a significant increase in the use of RMT-TB over the years, reaching 76% of cases in 2023. Analysis of the test accuracy revealed high agreement with sputum culture (82.6%) and the sensitivity test (98.4%), although it showed lower agreement with sputum smear microscopy (78.5%). The study identified factors associated with false-negative results on the RMT-TB, such as advanced age, female sex, HIV status, imprisoned, and a normal chest X-ray. Logistic regression confirmed that these factors increase the likelihood of false-negative results. Conclusion The RMT-TB is an effective tool for diagnosing pulmonary tuberculosis, but the interpretation of results must consider each patient's specific risk factors, especially in high-risk populations. The study highlights the importance of combining the RMT-TB with other diagnostic methods and clinical evaluation to ensure accurate diagnosis and appropriate treatment.