Tuberculosis is one of the major infectious diseases in developing countries, and the length of time for which the chain of transmission is maintained has been implicated as a major factor in the perpetuation of the disease. In this context, regulatory agencies in such countries have approved new diagnostic tools, which have been almost immediately incorporated into the national tuberculosis control programs. Health interventions have been increasingly investigated in clinical trials, including explanatory trials (in order to evaluate the beneficial effects of such interventions) and pragmatic trials (in order to aid in the decision-making process). We argue that the evaluation of new diagnostic techniques for the detection of tuberculosis should not escape this same logic of evaluation.

Keywords: Tuberculosis/diagnosis; Tuberculosis/prevention & control; Controlled clinical trial as topic.

Objective: To estimate the total time elapsed between symptom onset and diagnosis of pulmonary tuberculosis (patient delay plus health care system delay), analyzing the factors associated with delayed diagnosis in the state of Rio de Janeiro, Brazil. Methods: We conducted a questionnaire-based survey involving 218 pulmonary tuberculosis patients treated for two months at 20 health care clinics and 3 hospitals in eight cities within the state of Rio de Janeiro. We collected socioeconomic and demographic data, as well as data regarding the health care system and the medical history of the patients. Results: The median time elapsed from the onset of symptoms to diagnosis was 68 days (interquartile range [IQR]: 35-119 days). The median patient delay (time from symptom onset to initial medical visit) was 30 days (IQR: 15-60 days), and the median health care system delay (time from initial medical visit to diagnosis) was 21 days (IQR: 8-47 days). A cut-off point of 21 days was adopted. The factors independently associated with patient delay were female gender, cough, and unemployment [adjusted OR (95% CI) = 2.7 (1.3-5.6); 11.6 (2.3-58.8); and 2.0 (1.0-3.8), respectively], whereas only female gender was independently associated with health care system delay (OR= 3.2; 95% CI: 1.7-6.0). Conclusions: Delayed diagnosis of pulmonary tuberculosis remains a problem in Rio de Janeiro, increasing the risk of transmission and mortality, that risk being greater for women and the socioeconomically disadvantaged. Patients might not recognize the significance of chronic cough as a health problem. Tuberculosis education programs targeting women might improve this situation.

Keywords: Lung neoplasms; Neoplasm metastasis; Antineoplastic combined chemotherapy protocols; Radiotherapy, computer-assisted.