During an acute medical problem, older people may lose functional independence. ADL scales are used to assess this loss of independence. The simplest and most convenient ADL scale is the Katz Index, which measures six ADL: bathing, dressing, toileting, transferring, continence, and feeding. A lower ADL score indicates greater loss of functional independence. The ADL score prior to the acute medical problem (baseline) is estimated by questioning the patient or the caregivers, and this score is then compared with that on hospital admission. The ADL score should be monitored from hospital admission until discharge to allow early detection of changes in functional independence. Identifying any loss of functional independence before and during hospitalization provides information to caregivers regarding the risk of short-term mortality risk and complications, and the prognosis after hospitalization.