Methods: In accordance with the guidelines, patients were enrolled in this survey according to their chest radiographic findings and microbiologic test results. They were treated with a multi-drug regimen including clarithromycin, rifampicin, and ethambutol (clarithromycin -based regimen) until bacilli negative conversion on continual treatment for 1 year. Data were collected "pre-administration," "on the bacilli negative conversion," and "at 6 months after the end of treatment."