A pragmatic randomised controlled trial of screening for osteoporosis in older women

Osteoporosis is a common disease affecting around 20% of women aged over 50 years. The condition causes a ?thinning? of the bones making a sufferer prone to fractures. These fractures, particularly hip fractures, can lead to disability, a loss of independent living and even death. Current treatment for osteoporosis can reduce the risk of fracture by around 35% to 50%. However, predicting which women are at high risk of fracture and therefore would most likely benefit from treatment has so far not been conducted in a comprehensive and systematic manner. This study sets out to trial a method of screening all women aged between 70 and 85 for risk of fracture. Women in that age group recruited to the study will either be screened or managed as usual. Those screened and considered at high risk will be offered treatment by their GPs. All women will be followed for 5 years and, at the end of that period, a comparison of the fractures in the screened group will be made with those in the non-screened group. It is hoped that screening will reduce the number of fractures by around 20%.

The proposed randomised controlled trial aims to evaluate the effectiveness and cost-effectiveness of a community based screening program for osteoporosis in women aged 70 to 85. Those women randomised to the screening arm of the trial will provide information on clinical risk factors followed by bone mineral density (BMD) measurements where this information would be deemed useful. Based upon this information, a 10-year absolute risk for fracture will be calculated. This information will be given to study subjects? GPs with an indication of whether this risk exceeds a pre-determined treatment threshold or not. Those women in the control arm will be treated ?as usual?. The primary effiacy outcome, to be ascertained from hospital records will be fracture at any site. The follow up period will be 5 years and a sample size of 11 500 women will be sufficient to provided 90% power to detect a 18% relative reduction in fractures.