Study population, 1993–2007.

<p>The figure shows the classification of patients in the study and the inclusion criteria. TB patients included those who were alive at TB diagnosis with culture-positive, pulmonary TB (in both episodes for recurrent TB patients), and, had completed anti-TB therapy. Patients were excluded if initial isoniazid or rifampin drug susceptibility test results were not documented, or, if the date of treatment completion or date of initiation of treatment for a second TB episode was not documented. Percentages were calculated using the previous group (previous box) as the denominator. One hundred forty eight persons in this study population had late recurrent TB, and 23,369 had one episode of TB (see text for details). TB = tuberculosis.