A cohort of clients who enrolled at the 18 health centers for elderly patients from January 1, 2000, to December 31, 2000, was retrospectively assembled as previously reported.9 The date of enrollment, name, sex, age, identity card number, smoking status, alcohol use, language spoken, educational level, marital status, housing situation, work status, public means–tested financial assistance status, coexisting medical conditions, recent weight loss, hospital admissions during the past 12 months, activities of daily living score, cholesterol level, and hemoglobin A1c level were retrieved from the baseline health assessment database of the Elderly Health Service. The baseline database was cross-matched prospectively with the death registry and the tuberculosis notification registry using the identity card number as the identifier, supplemented by name and age, from 3 months (arbitrarily considered 91 days) after enrollment to December 31, 2005. The BMI was classified into the following categories, which are in line with the World Health Organization expert consultation on the appropriate BMI for Asian populations: less than 18.5 (underweight), 18.5 to less than 23 (normal), 23 to less than 25 (at risk), 25 to less than 30 (overweight), and 30 or higher (obese).10 Hypertension and diabetes mellitus were defined as the corresponding physician-diagnosed conditions with or without treatment, and the updated diagnoses after the screening at enrollment were used in the analysis. The hemoglobin A1c level and cholesterol level at enrollment were also included. The duration of follow-up in days was defined as the period from the start of matching (91 days after enrollment) to the date of notification of tuberculosis, the date of death, or December 31, 2005, whichever was the earliest. Information on date of tuberculosis notification, bacteriological status, form of tuberculosis, and previous tuberculosis history was retrieved from the notification registry. The diagnosis and clinical information for all identified tuberculosis cases were verified by reviewing medical records retrieved from chest clinics and other relevant sources as well as the public health records of the Tuberculosis and Chest Service. An active case of tuberculosis was defined as disease proved by isolation of Mycobacterium tuberculosis or, in the absence of bacteriological confirmation, disease diagnosed on clinical, radiological, and/or histological grounds with an appropriate response to antituberculosis treatment.