Reducing the Need for Central Dual-Energy X-Ray Absorptiometry in Postmenopausal Women: Efficacy of a Clinical Algorithm Including Peripheral Densitometry
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We evaluated the efficacy of a triage approach based on a combination of osteoporosis risk-assessment tools plus peripheral densitometry to identify low bone density accurately enough to be useful for clinical decision making in postmenopausal women. We conducted a cross-sectional diagnostic study in postmenopausal Caucasian women from primary and tertiary care. All women underwent dual-energy X-ray absorptiometric (DXA) measurement at the hip and lumbar spine and were categorized as osteoporotic or not. Additionally, patients had a nondominant heel densitometry performed with a PIXI densitometer. Four osteoporosis risk scores were tested: SCORE, ORAI, OST, and OSIRIS. All measurements were cross-blinded. We estimated the area under the curve (AUC) to predict the DXA results of 16 combinations of PIXI plus risk scores. A formula including the best combination was derived from a regression model and its predictability estimated. We included 505 women, in whom the prevalence of osteoporosis was 20 %, similar in both settings. The best algorithm was a combination of PIXI + OST + SCORE with an AUC of 0.826 (95 % CI 0.782–0.869). The proposed formula is Risk = (–12) × [PIXI + (−5)] × [OST + (−2)] × SCORE and showed little bias in the estimation (0.0016). If the formula had been implemented and the intermediate risk cutoff set at −5 to 20, the system would have saved €4,606.34 in the study year. The formula proposed, derived from previously validated risk scores plus a peripheral bone density measurement, can be used reliably in primary care to avoid unnecessary central DXA measurements in postmenopausal women.
KeywordsBone density DEXA Osteoporosis Diagnosis
This work was supported by Grants to fund research, development, and innovation (R + D + i) in the biomedical and health sciences from Sistema Sanitario Público de Andalucía (PI-0219; ORDEN June 7, 2005).
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