Objective: Assessing sleep in later life is essential for diagnosing and treating sleep problems and their consequences. We aimed to test a short questionnaire specifically designed to assess the subjective sleep quality in older people, the Geriatric Sleep Questionnaire (GSQ) Method: The GSQ was validated in a Portuguese sample of older people (N = 443; 65-100 years; M = 80.02; SD = 6.95). We analyzed reliabil...