BACKGROUND: The integration of leprosy control programs into the basic health system led to the updating of norms in legislation regarding control of the disease. The operational classification adopted for allocating patients for an appropriate multidrug therapy is the one recommended by the World Health Organization (WHO); it is essentially clinical, based on the number of skin lesions. Cases with up to 5 skin lesions are considered paucibacillary (PB) and with more than 5 skin lesions are multibacillary (MB). OBJETIVES: The results of skin smears were correlated to the number of skin lesions, with the objective of evaluating the clinical method of classification. METHODS: The source of information was the data bank where detailed epidemiological, clinical and laboratory information on patients is kept. Data referring to the skin smears of 837 cases from 1986 to 1999 were collected. The criteria were to analyze, using the standard reference method, the number of lesions compared to the results of the skin smear exams. From this comparison, a calculation was made of the relative sensitivity and specificity as well as the positive and negative predictive values using the criterion of cutaneous lesions to evaluate the agreement between the number of lesions and the skin smear calculated by means of the kappa index (k). RESULTS: Of the 837 cases evaluated, 652 presented positive skin smears and 185 negative. Thirty (16.0%) of the patients with negative skin smears presented more than 5 skin lesions. Among the 652 patients with positive skin smears, 68 (11.4%) presented less than 5 skin lesions. Regarding sensitivity and specificity of the clinical method, we found the negative predictive value was 69.5% while the positive predictive value was 95.1%. CONCLUSION: The clinical method based on the number of skin lesions presents limitations that do not invalidate its usefulness, although there is a need for new criteria that allow more accuracy in the allocation of patients to multidrug regimens.
classification; leprosy
