Targeted assessment of fracture risk in women at midlife

This study establishes a profile for women at midlife, referred for a dual energy X-ray absorptiometry (DXA), most likely to have osteoporosis, and from this, a pre-DXA screening tool has been developed. These findings inform much needed evidence-based guidelines for targeted and effective screening for osteoporosis and osteoporotic fracture prevention in women at midlife.

There is no consensus as to whether women at midlife should undergo screening dual energy X-ray absorptiometry (DXA) to identify osteoporosis (T-score < -2.5).

We investigated the prevalence of osteoporosis in women, aged 40-65 years, referred to 42 community-based Australian radiology centres, and identified the characteristics that best predict osteoporosis in women having a screening DXA.

One thousand four hundred and two women completed the study questionnaire and had DXA reports available. After excluding women with an established indication for a DXA (58 %), users of bone-specific medication (10.5 %) and cancer (7.6 %), 466 women were classified as having a screening DXA. Forty of these women had osteoporosis at the lumbar spine (n = 32, 6.9 %) or femoral neck (n = 17, 3.6 %). Three predictors of osteoporosis (postmenopausal, nonuse of hormonal therapy and body mass index) were identified and incorporated into the Monash Osteoporosis Risk Score for women at midlife (MORS). In the screened study population, the MORS had a sensitivity of 70 % and specificity of 66 %, with a positive predictive value of 16.2 % and negative predictive value of 95.9 % for osteoporosis.

Very few women referred for a screening DXA scan will be found to have osteoporosis. The MORS, a simple decision tool, would have identified 70 % of the women in our screening DXA study population and would have eliminated over 60 % of the screening DXA studies. Hence, use of the MORS may reduce unnecessary DXA scans and facilitate identification of the majority of cases of osteoporosis in women aged 40 to 65 years.