A cohort of individuals who enrolled at the 18 Elderly Health Centers from January 1, 2000, to December 31, 2003, was retrospectively assembled. The date of enrollment, name, sex, age, identity card number, smoking status, passive exposure to tobacco smoke in the same household, alcohol use, language spoken, education level, marital status, housing situation, working status, public means–tested financial assistance status, body mass index, coexisting medical conditions, hospital admission within 1 year, recent weight loss of 5% or more within 6 months, and activity of daily living scores (possible range, 7-21, from total independence to total dependence) were retrieved from the baseline health assessment database of the Elderly Health Service. Only women younger than 75 years who were married but not widowed, separated, or divorced at baseline were included in the present analysis. All persons with active TB, a suspected malignant neoplasm, or a significant weight loss of 5% or more in the past 6 months at baseline were excluded. The database was then cross-matched prospectively with the TB notification registry and the death registry using the identity card number as identifier, supplemented by name and age, from enrollment to December 31, 2008. The duration of follow-up was defined as the period from enrollment to the date of notification of TB, death, or December 31, 2008, whichever came first. Information on date of TB notification and bacteriological status was retrieved from the TB registry. The diagnosis and clinical information of all identified TB cases, including contact with other TB cases in the same household, were verified by reviewing the medical records retrieved from the chest clinics and other relevant sources as well as the public health records of the Tuberculosis and Chest Service.