COHORT PROFILE Cohort Profile: Geelong Osteoporosis Study

The Geelong Osteoporosis Study (GOS) began as a population-based study designed to investigate the epidemiology of osteoporosis in Australia. Osteoporosis is a systemic skeletal disease characterized by low bone mineral density (BMD) and micro-architectural deterioration of bone tissue, with a consequent increase in susceptibility to fracture. Fragility fractures at the spine, hip, wrist and other sites are a major public health problem in both sexes because these fractures are responsible for considerable morbidity and mortality. Fractures cost the Australian community an estimated $7 billion annually and this is expected to increase in absolute terms because of the ageing population. The cohort was recruited to address the need for definitive data on the prevalence of osteoporosis, to describe age-related changes in BMD and to characterize the risks for osteoporosis and fracture. Initially the GOS comprised only women; men were recruited later. In addition to the cohort study, the GOS has developed a comprehensive fracture register for the study region and has also conducted case–control studies to investigate risk factors for fracture. Only the cohort study will be described here.