Some popular screening tools to help guide when to order a bone density test. FRAX is the most popular, but may not be the most sensitive. PREVENTION of osteoporosis is always better than treatment of osteoporosis. See my other posts that relate to this: here and here.
"Osteoporosis screening guidelines from the US Preventive Services Task Force (USPSTF) miss three-quarters of women 50 to 64 years of age with osteoporosis, and are only "slightly better than chance alone" at discriminating between women with and without the condition, a new study has found.
"The USPSTF guidelines on osteoporosis screening call for routine screening — most commonly with dual-energy x-ray absorptiometry (DXA) and quantitative ultrasonography — for women 65 years and older and for younger women who have a fracture risk equivalent to a 65-year-old white woman with no additional risk factors but who have a 10-year risk of 9.3% or higher as measured with the FRAX assessment tool.
Not Much Better Than Chance
Dr Jiang and colleagues recruited 445 postmenopausal women 50 to 64 years of age who presented for DXA screening from January 2007 to March 2009. They were asked about traits assessed with the FRAX tool, including age, weight, height, race, personal and parental history of fracture, steroid use, smoking status, and history of rheumatoid arthritis.
Of the 38 women found to have osteoporosis on DXA, just nine would have been identified with the USPSTF strategy alone. "In other words, 76% were missed by USPSTF," Dr Jiang reported.
Conversely, of the 77 women who met the USPSTF criteria for high risk, 68 (88%) were found to not have osteoporosis on DXA.
The sensitivity of USPSTF was 24%, specificity was 83%, positive-predictive value was 12%, negative-predictive value was 92%, and area under the curve was 0.62, or "just slightly better than chance alone," Dr Jiang said. The number needed to scan to detect one case of osteoporosis was nine.
In contrast, sensitivity for four other screening modalities ranged from 66% for risk-factor-based screening (one or more) to 95% for a body mass index (BMI) below 28 kg/m². For the other two modalities — the Osteoporosis Self-assessment Tool and the Simple Calculated Osteoporosis Risk Estimation — the numbers needed to scan to detect one case were seven and eight, respectively.
Changing the FRAX cutoff from 9.3% to 4.7% improved the sensitivity to 92%, but increased the number needed to scan to detect one case to 10. "It may be time to revisit and redefine this FRAX-based threshold," Dr Jiang said.
Overall, BMI alone, with a cutoff of 28 kg/m², performed best, with a sensitivity of 95%, specificity of 38%, positive-predictive value of 13%, area under the curve of 0.73, and eight scans needed to detect one case. (Dr Jiang presented data on BMI as a potential osteoporosis predictor in a separate presentation at the meeting.)
Who Should Be Screened?
"I believe the best screening approach is yet to be defined," Dr Jiang told Medscape Medical News. "Body mass index greater than 28 kg/m² alone seems to have the highest sensitivity and area under the curve of all modalities, but is still far from ideal."
Dr Nachtigall said she uses a risk-factor-based approach. "Menopause is such a risk factor. Being female, older than 50, and white, particularly, are three risk factors. Automatically I think those people should be screened at menopause to get a baseline, and 2 years later to see what their loss is. That's a guideline I follow. It's much simpler," she told Medscape Medical News.
An audience member said she has been penalized by payers when she screens women younger than 65 years who don't meet the USPSTF criteria."