1.0 The problem

Osteoporotic fractures are a major public health problem. It has been estimated that in the USA the remaining lifetime fracture risk at the age of 50 years is 40% for white women and 13% for white men,1 the major fracture sites being spine, forearm and hip. This results in considerable morbidity and mortality and rising costs, including acute hospital care and long term care in the home or nursing home. The estimated total annual cost of osteoporotic fractures in England and Wales is £742 million ($464 million).2These costs are likely to increase as the population ages.

2.0 Screening

2.1 BONE MINERAL DENSITY

Osteoporosis can be reliably detected by measurement of bone mineral density (BMD), which can be expressed as the number of SDs above or below either the mean BMD for young adults (T score) or the mean BMD for age matched controls (Z score). A BMD more than 2.5 SD below the mean for a young adult is generally taken to indicate osteoporosis.3 Stratification for fracture risk is possible using BMD. The risk increases roughly twofold for each SD decline in BMD below the population mean.4 5 This compares with a 1.5-fold increase in the risk of death from coronary artery disease with each SD increase in cholesterol concentrations or diastolic pressure.

2.2 RISK FACTORS FOR FRACTURE

It is important to recognise that osteoporosis is but one of a number of factors predisposing to fracture, just as a raised cholesterol and diastolic pressure are each just one of many factors predisposing to coronary artery disease. Awareness of surroundings, mobility, and eyesight collectively contribute to a tendency to fall and all are likely to be important.6 Furthermore, bone strength is largely related to trabecular structure, certainly in the proximal femur, whereas BMD is a composite measurement of both cortical and trabecular bone.7 Although the …