Influence of baseline deformity definition on subsequent vertebral fracture risk in postmenopausal women.
BACKGROUND
Approaches for recognizing vertebral fractures remain controversial.


METHODS
An age-stratified population sample of 512 postmenopausal women was followed with serial radiographs for up to 12 years (4455 person-years).


RESULTS
112 women experienced a new vertebral fracture (20% reduction in any vertebral height from baseline) within this study period, for an annual age-adjusted (to US white women > or =50 years of age in 2000) incidence of 23 per 1000. Depending on the morphometric definition used, the prevalence of vertebral deformities at baseline ranged from 3 to 90%. A recent method to standardize vertebral heights produced the best agreement with a qualitative clinical reading of the films [kappa (kappa), 0.53]. Almost all of the different baseline definitions predicted future vertebral fractures, but most of the predictive power was attributable to the severe (e.g., 4 SD) deformities included within more generous (e.g., 3 SD) classifications. Whereas the generous definitions were more sensitive, and the restrictive ones more specific, their overall abilities to predict a new vertebral fracture were roughly comparable as evaluated by the c-index (analogous to the area under an ROC curve).


CONCLUSIONS
This result suggests that the choice of a morphometry definition depends on the particular application and, in particular, on whether it is more important to maximize sensitivity or specificity.
Melton
L J
LJ
Division of Epidemiology, Department of Health Sciences Research, Mayo Clinic, 200 First Street S.W., Rochester, MN 55905, USA. melton.j@mayo.edu
Wenger
D E
DE
Atkinson
E J
EJ
Achenbach
S J
SJ
Berquist
T H
TH
Riggs
B L
BL
Jiang
G
G
Eastell
R
R
D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008875:Middle Aged; D017698:Postmenopause; D011859:Radiography; D012307:Risk Factors; D016103:Spinal Fractures / Q000209:etiology*; D013131:Spine / Q000000981:diagnostic imaging / Q000473:pathology*