Prospective multicentre study on the evaluation of antituberculosis treatment results in Italy: Comparison of the culture- versus the smear- based methods

Cohort analysis of treatment outcomes is the most informative technique to evaluate the tuberculosis (TB) control programme. The aim of the study was to assess treatment outcomes comparing the smear- versus the culture-based methods, using data on TB patients treated under programme conditions in Italy. This was a prospective monitoring study based on the standardized collection of forms from a representative sample of Italian TB Units. The forms, with individual data, were reviewed and analysed on a quarterly basis according to the principles of cohort analysis, using both the smear- and culture-based methods. The complete bacteriological profile of patients was analysed at diagnosis and at completion of treatment. Nine hundred and ninety-two TB cases were notified. Among 681 pulmonary cases, 368 cases were culture-confirmed at diagnosis (333 new and 35 retreatment cases, 293 being sputum smear positive, 79.6%). At the end of treatment, out of the 333 new culture-confirmed cases, 136 (40.8%) were defined cured using the culture- based method and 108 (32.4%) using the smear-based method (p2 test). The culture-based method is the recommended tool to evaluate pulmonary tuberculosis treatment results. Culture allows a more precise definition of a 'cured' patient in both sputum smear positive and negative tuberculosis cases.