Frailty has been proposed as a measure of biological (as opposed to chronological) aging. In this study the investigators plan to: (1) measure frailty in a cohort of older HIV-infected individuals in Hong Kong, and its association with mortality and quality of life; (2) identify risk factors predictive of development of frailty in HIV-infected individuals in Hong Kong; and (3) determine the outcomes of HIV-infected individuals in Hong Kong with and without frailty. The following assessment will be done: 1. Physical examination including measuring height, weight, hip and waist circumference. 2. Grip strength, chair stand test, gait speed test, balance tests, and neurocognitive tests 3. Geriatric syndromes, screening for depression, disability and quality of life. 4. Blood tests during fasting state to measure metabolic parameters. This is a prospective longitudinal observational study that lasts for 10 years.