The Oxford Pain, Activity and Lifestyle (OPAL) study is a large cohort study of community dwelling adults (n=4000) aged 65 years and over. This cohort data will allow the investigators to describe the prevalence, severity, course and prognosis a range of musculoskeletal problems in older people. The initial focus is to evaluate the impact of back pain on important health outcomes for older people (quality of life, mobility, falls and fractures). In order to do this, the investigators will study people with and without back pain at the inception of the cohort. The OPAL cohort will be followed for 5 years in the first instance and the investigators will study a range of factors hypothesised to moderate and mediate the effects of back and other musculoskeletal pain for example, co-morbidities.