title: Bone-density testing interval and transition to osteoporosis in older women.
abstract: BACKGROUND
  Although bone mineral density (BMD) testing to screen for osteoporosis (BMD T score, -2.50 or lower) is recommended for women 65 years of age or older, there are few data to guide decisions about the interval between BMD tests.
  
  
  METHODS
  We studied 4957 women, 67 years of age or older, with normal BMD (T score at the femoral neck and total hip, -1.00 or higher) or osteopenia (T score, -1.01 to -2.49) and with no history of hip or clinical vertebral fracture or of treatment for osteoporosis, followed prospectively for up to 15 years. The BMD testing interval was defined as the estimated time for 10% of women to make the transition to osteoporosis before having a hip or clinical vertebral fracture, with adjustment for estrogen use and clinical risk factors. Transitions from normal BMD and from three subgroups of osteopenia (mild, moderate, and advanced) were analyzed with the use of parametric cumulative incidence models. Incident hip and clinical vertebral fractures and initiation of treatment with bisphosphonates, calcitonin, or raloxifene were treated as competing risks.
  
  
  RESULTS
  The estimated BMD testing interval was 16.8 years (95% confidence interval [CI], 11.5 to 24.6) for women with normal BMD, 17.3 years (95% CI, 13.9 to 21.5) for women with mild osteopenia, 4.7 years (95% CI, 4.2 to 5.2) for women with moderate osteopenia, and 1.1 years (95% CI, 1.0 to 1.3) for women with advanced osteopenia.
  
  
  CONCLUSIONS
  Our data indicate that osteoporosis would develop in less than 10% of older, postmenopausal women during rescreening intervals of approximately 15 years for women with normal bone density or mild osteopenia, 5 years for women with moderate osteopenia, and 1 year for women with advanced osteopenia. (Funded by the National Institutes of Health.).
authors.affiliation: Department of Family Medicine, University of North Carolina, Chapel Hill, Chapel Hill, NC 27599-7595, USA. margaret_gourlay@med.unc.edu
authors.forename: Margaret L
authors.initials: ML
authors.lastname: Gourlay
authors.forename: Jason P
authors.initials: JP
authors.lastname: Fine
authors.forename: John S
authors.initials: JS
authors.lastname: Preisser
authors.forename: Ryan C
authors.initials: RC
authors.lastname: May
authors.forename: Chenxi
authors.initials: C
authors.lastname: Li
authors.forename: Li-Yung
authors.initials: LY
authors.lastname: Lui
authors.forename: David F
authors.initials: DF
authors.lastname: Ransohoff
authors.forename: Jane A
authors.initials: JA
authors.lastname: Cauley
authors.forename: Kristine E
authors.initials: KE
authors.lastname: Ensrud
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015519:Bone Density; D001851:Bone Diseases, Metabolic / Q000150:complications / Q000175:diagnosis*; D018450:Disease Progression; D005260:Female; D050723:Fractures, Bone / Q000209:etiology; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D010024:Osteoporosis / Q000150:complications / Q000175:diagnosis* / Q000453:epidemiology; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors