Dual-energy X-ray absorptiometry diagnostic discordance between Z-scores and T-scores in young adults.
AuthorsCarey, John J
Delaney, Miriam F
Love, Thomas E
Cromer, Barbara A
Miller, Paul D
Richmond, Bradford J
Lewis, Steven A
Thomas, Charles L
Licata, Angelo A
AffiliationDepartment of Rheumatology, Merlin Park University Hospital, Galway, Ireland. John.firstname.lastname@example.org
Reproducibility of Results
Sensitivity and Specificity
MetadataShow full item record
CitationDual-energy X-ray absorptiometry diagnostic discordance between Z-scores and T-scores in young adults., 12 (1):11-6 J Clin Densitom
PublisherJournal of clinical densitometry : the official journal of the International Society for Clinical Densitometry
JournalJournal of clinical densitometry : the official journal of the International Society for Clinical Densitometry
AbstractDiagnostic criteria for postmenopausal osteoporosis using central dual-energy X-ray absorptiometry (DXA) T-scores have been widely accepted. The validity of these criteria for other populations, including premenopausal women and young men, has not been established. The International Society for Clinical Densitometry (ISCD) recommends using DXA Z-scores, not T-scores, for diagnosis in premenopausal women and men aged 20-49 yr, though studies supporting this position have not been published. We examined diagnostic agreement between DXA-generated T-scores and Z-scores in a cohort of men and women aged 20-49 yr, using 1994 World Health Organization and 2005 ISCD DXA criteria. Four thousand two hundred and seventy-five unique subjects were available for analysis. The agreement between DXA T-scores and Z-scores was moderate (Cohen's kappa: 0.53-0.75). The use of Z-scores resulted in significantly fewer (McNemar's p<0.001) subjects diagnosed with "osteopenia," "low bone mass for age," or "osteoporosis." Thirty-nine percent of Hologic (Hologic, Inc., Bedford, MA) subjects and 30% of Lunar (GE Lunar, GE Madison, WI) subjects diagnosed with "osteoporosis" by T-score were reclassified as either "normal" or "osteopenia" when their Z-score was used. Substitution of DXA Z-scores for T-scores results in significant diagnostic disagreement and significantly fewer persons being diagnosed with low bone mineral density.
- DXA-generated Z-scores and T-scores may differ substantially and significantly in young adults.
- Authors: Carey JJ, Delaney MF, Love TE, Richmond BJ, Cromer BA, Miller PD, Manilla-McIntosh M, Lewis SA, Thomas CL, Licata AA
- Issue date: 2007 Oct-Dec
- Recalculation of the NHANES database SD improves T-score agreement and reduces osteoporosis prevalence.
- Authors: Binkley N, Kiebzak GM, Lewiecki EM, Krueger D, Gangnon RE, Miller PD, Shepherd JA, Drezner MK
- Issue date: 2005 Feb
- A prospective study of discordance in diagnosis of osteoporosis using spine and proximal femur bone densitometry.
- Authors: O'Gradaigh D, Debiram I, Love S, Richards HK, Compston JE
- Issue date: 2003 Jan
- Use of a Swedish T-score reference population for women causes a two-fold increase in the amount of postmenopausal Swedish patients that fulfill the WHO criteria for osteoporosis.
- Authors: Ribom EL, Ljunggren O, Mallmin H
- Issue date: 2008 Jul-Sep
- [Bone mineral density in postmenopausal women with proximal femoral fractures--comparative study between quantitative ultrasonometry and gold standard DXA].
- Authors: Schnabel M, Eser G, Ziller V, Mann D, Mann E, Hadji P
- Issue date: 2005 Oct