title: The choice of normative pediatric reference database changes spine bone mineral density Z-scores but not the relationship between bone mineral density and prevalent vertebral fractures.
abstract: OBJECTIVE
  Our objectives were to assess the magnitude of the disparity in lumbar spine bone mineral density (LSBMD) Z-scores generated by different reference databases and to evaluate whether the relationship between LSBMD Z-scores and vertebral fractures (VF) varies by choice of database.
  
  
  METHODS
  Children with leukemia underwent LSBMD by cross-calibrated dual-energy x-ray absorptiometry, with Z-scores generated according to Hologic and Lunar databases. VF were assessed by the Genant method on spine radiographs. Logistic regression was used to assess the association between fractures and LSBMD Z-scores. Net reclassification improvement and area under the receiver operating characteristic curve were calculated to assess the predictive accuracy of LSBMD Z-scores for VF.
  
  
  RESULTS
  For the 186 children from 0 to 18 years of age, 6 different age ranges were studied. The Z-scores generated for the 0 to 18 group were highly correlated (r ≥ 0.90), but the proportion of children with LSBMD Z-scores ≤-2.0 among those with VF varied substantially (from 38-66%). Odds ratios (OR) for the association between LSBMD Z-score and VF were similar regardless of database (OR = 1.92, 95% confidence interval 1.44, 2.56 to OR = 2.70, 95% confidence interval 1.70, 4.28). Area under the receiver operating characteristic curve and net reclassification improvement ranged from 0.71 to 0.75 and -0.15 to 0.07, respectively.
  
  
  CONCLUSIONS
  Although the use of a LSBMD Z-score threshold as part of the definition of osteoporosis in a child with VF does not appear valid, the study of relationships between BMD and VF is valid regardless of the BMD database that is used.
authors.affiliation: Children's Hospital of Eastern Ontario Research Institute (J.M., M.S.), Ottawa, ON; University of Alberta (K.S., R.C.), Edmonton, AB; Université de Montréal (N.A.), Montréal, QC; University of Ottawa (J.H., M.M., N.S., L.M.W.), Ottawa, ON; University of Calgary (J.H.), Calgary, AB; University of British Columbia (B.L., D.A.C.), Vancouver, BC; McMaster University (S.A., R.B.), Hamilton, ON; Dalhousie University (E.A.C., C.V.F.), Halifax, NS; University of Toronto (R.M.G.), Toronto, ON; University of Manitoba (C.R.), Winnipeg, MB; McGill University (A.M.S., F.R.), Montréal, QC.
authors.forename: Jinhui
authors.initials: J
authors.lastname: Ma
authors.forename: Kerry
authors.initials: K
authors.lastname: Siminoski
authors.forename: Nathalie
authors.initials: N
authors.lastname: Alos
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Halton
authors.forename: Josephine
authors.initials: J
authors.lastname: Ho
authors.forename: Brian
authors.initials: B
authors.lastname: Lentle
authors.forename: MaryAnn
authors.initials: M
authors.lastname: Matzinger
authors.forename: Nazih
authors.initials: N
authors.lastname: Shenouda
authors.forename: Stephanie
authors.initials: S
authors.lastname: Atkinson
authors.forename: Ronald
authors.initials: R
authors.lastname: Barr
authors.forename: David A
authors.initials: DA
authors.lastname: Cabral
authors.forename: Robert
authors.initials: R
authors.lastname: Couch
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Cummings
authors.forename: Conrad V
authors.initials: CV
authors.lastname: Fernandez
authors.forename: Ronald M
authors.initials: RM
authors.lastname: Grant
authors.forename: Celia
authors.initials: C
authors.lastname: Rodd
authors.forename: Anne Marie
authors.initials: AM
authors.lastname: Sbrocchi
authors.forename: Maya
authors.initials: M
authors.lastname: Scharke
authors.forename: Frank
authors.initials: F
authors.lastname: Rauch
authors.forename: Leanne M
authors.initials: LM
authors.lastname: Ward
mesh_terms: D015502:Absorptiometry, Photon / Q000592:standards*; D000293:Adolescent; D015519:Bone Density; D002648:Child; D002675:Child, Preschool; D002755:Choice Behavior; D016208:Databases, Factual; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000293:injuries; D008297:Male; D015995:Prevalence; D012372:ROC Curve; D012016:Reference Values; D012107:Research Design; D016103:Spinal Fractures / Q000000981:diagnostic imaging / Q000453:epidemiology*