How well do radiographic absorptiometry and quantitative ultrasound predict osteoporosis at spine or hip? A cost-effectiveness analysis.
Dual energy X-ray absorptiometry (DXA) is widely accepted as the reference method for diagnosis and monitoring of osteoporosis and for assessment of fracture risk, especially at hip. However, axial-DXA is not suitable for mass screening, because it is usually confined to specialized centers. We propose a two-step diagnostic approach to postmenopausal osteoporosis: the first step, using an inexpensive, widely available screening technique, aims at risk stratification in postmenopausal women; the second step, DXA of spine and hip is applied only to potentially osteoporotic women preselected on the basis of the screening measurement. In a group of 110 healthy postmenopausal woman, the capability of various peripheral bone measurement techniques to predict osteoporosis at spine and/or hip (T-score < -2.5SD using DXA) was tested using receiver operating characteristic (ROC) curves: radiographic absorptiometry of phalanges (RA), ultrasonometry at calcaneus (QUS. CALC), tibia (SOS.TIB), and phalanges (SOS.PHAL). Thirty-three women had osteoporosis at spine and/or hip with DXA. Areas under the ROC curves were 0.84 for RA, 0.83 for QUS.CALC, 0.77 for SOS.PHAL (p < 0.04 vs RA) and 0.74 for SOS.TIB (p < 0.02 vs RA and p = 0.05 vs QUS.CALC). For levels of sensitivity of 90%, the respective specificities were 67% (RA), 64% (QUS.CALC), 48% (SOS.PHAL), and 39% (SOS.TIB). In a cost-effective two-step, the price of the first step should not exceed 54% (RA), 51% (QUS.CALC), 42% (SOS.PHAL), and 25% (SOS.TIB). In conclusion, RA, QUS.CALC, SOS.PHAL, and SOS.TIB may be useful to preselect postmenopausal women in whom axial DXA is indicated to confirm/exclude osteoporosis at spine or hip.
Lippuner
K
K
Osteoporosis Unit, University Hospital of Berne, Switzerland. kurt.lippuner@insel.ch
Fuchs
G
G
Ruetsche
A G
AG
Perrelet
R
R
Casez
J P
JP
Neto
I
I
D015502:Absorptiometry, Photon; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015519:Bone Density; D002111:Calcaneus / Q000000981:diagnostic imaging; D016009:Chi-Square Distribution; D003362:Cost-Benefit Analysis; D005260:Female; D005385:Fingers / Q000000981:diagnostic imaging; D006615:Hip / Q000000981:diagnostic imaging; D006801:Humans; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000000981:diagnostic imaging*; D011237:Predictive Value of Tests; D012372:ROC Curve; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D013131:Spine / Q000000981:diagnostic imaging; D013977:Tibia / Q000000981:diagnostic imaging; D014463:Ultrasonography