In Europe, a case-finding strategy for osteoporosis is recommended above widespread population-based screening. However, no universally accepted policy currently exists. In 2005, the Dutch College of General Practitioners published guidelines for GPs to select patients for dual energy X-ray absorptiometry (DXA).
AimTo evaluate the sensitivity, specificity, and predictive value of the Dutch guidelines to select participants with osteoporosis for DXA.
Design of studyCross-sectional.
SettingA total of 345 females aged over 50 years (mean age = 62 years, standard deviation [SD] = 8.3) and 99 males over 65 years of age (mean age = 72 years, SD = 5.2) of a Dutch general practice.
MethodCalculation of sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the Dutch case-finding instrument for selecting patients with osteoporosis for DXA measurement.
ResultsSensitivity was 19.5%, specificity 85.6%, PPV 18.6%, and NPV 86.6%.
ConclusionThe Dutch guidelines are unreliable in detecting people at risk for osteoporosis.
KeywordsDEXA scan; osteoporosis; practice guideline; predictive value of tests; sensitivity and specificity.
INTRODUCTIONOsteoporosis is a major public health issue: osteoporotic fractures affect one in two women and one in five men aged >50 years.1 In 2000, the number of osteoporotic fractures in the European Union was estimated at 3.8 million, equalling a financial burden €31.7 billion. It is expected that by 2050, the direct cost of fractures in Europe will exceed €75 billion.
2The annual incidence of fractures in the UK is estimated at 310 000 with costs of €2.4 billion. 3 In the Netherlands over 430 000 patients have osteoporosis 4 and about 83 000 people aged >55 years have a fragility fracture each year.
5Considering the growing incidence, fracture prevention and thus early diagnosis of osteoporosis are of great importance, especially since pharmacological treatment of osteoporosis has been shown to be cost-effective, irrespective of age.
6Diagnosis of osteoporosis is currently based on bone densitometry, usually by dual energy X-ray absorptiometry (DXA). Bone mineral density is widely recognised as a major predictor for fractures. 7 However, case-finding strategy has been shown to be more cost-effective than population-based NA Verdijk, MSc, PhD candidate; VJ Pop, professor of primary care, the