Evidence-based outcomes on diagnostic accuracy of quantitative ultrasound for assessment of pediatric osteoporosis - a systematic review.

BACKGROUND: Dual-energy absorptiometry (DXA) is the current reference standard for assessing pediatric osteoporosis; however due to its areal nature, it has limitations. Thus, quantitative ultrasound (QUS), a modality free of ionizing radiation, has been proposed as a potential surrogate for DXA.

OBJECTIVE: To semi-quantitatively assess the diagnostic accuracy of QUS for evaluating pediatric osteoporosis according to the U.S. Preventive Services Task Force guidelines.

MATERIALS AND METHODS: We retrieved articles on the diagnostic accuracy of quantitative US for assessing abnormal bone quality or quantity in patients of mean age ≤19 years from MEDLINE, EMBASE and Cochrane Library CCTR databases. Evidences were analyzed for reliability, construct and criterion validity, and responsiveness of quantitative US, according to the following questions: (1) How reliable is the acquisition of QUS measurements? (2) Is QUS diagnostically accurate to characterize bone strength and quality in osteoporotic children? (3) Is QUS sensitive to detect changes in bone status over time? (4) Is QUS able to predict future skeletal fractures/degeneration? Three reviewers independently evaluated the quality of reporting and methodological quality using the Standards for Reporting of Diagnostic Accuracy (STARD) and the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tools.

RESULTS: Out of 262 retrieved references (215 unique), we included 28 studies (1,963 patients; 807 reported boys and 761 girls, others unspecified; reported mean age, 0-19 years). The mean quality of reporting score was "excellent" in 24/28 (86%) studies; 11/28 (39%) studies had "adequate" research design quality.

CONCLUSION: There is no evidence of the diagnostic value of QUS at the present time despite the overall excellent and adequate research design quality of primary studies. Although QUS can produce reliable measurements, insufficient evidence has been reported to support other clinimetric properties of this technique.