Is physical activity protective against hip fracture in frail older people?

Background: there is limited evidence of a protective effect of physical activity in preventing hip fractures among older people living in institutions and in those aged 80 or over. Objective: to examine the relationship between physical activity and risk of hip fracture in frail older people. Design: a case-control study. Setting: Auckland, New Zealand. Subjects: a random sample of individuals hospitalized with a fracture of the femoral neck (n=911) and 910 randomly selected age- and sex-matched individuals from the lists of a random sample of general practitioners. Methods: we sought information on physical activity and other potential risk factors for hip fracture from cases and controls, using a standardized interviewer-administered questionnaire. We conducted multivariate analyses, separately for those living in private homes and residential institutions. Results: increasing hours of physical activity per week protected against the risk of hip fracture among individuals living in private homes, including those who are over 80. However, among individuals living in institutions, physical activity levels were extremely low (<15% participated in <greater than or equal to>2 h per week) and there was limited evidence of a protective effect. Conclusions: efforts to prevent hip fractures in individuals living in care homes and institutions should focus on passive interventions which are known to be effective.