title: Baseline age and time to major fracture in younger postmenopausal women.
abstract: OBJECTIVE
  This study aims to estimate the incidence of first hip or clinical vertebral fracture or major osteoporotic (hip, clinical vertebral, proximal humerus, or wrist) fracture in postmenopausal women undergoing their first bone mineral density (BMD) test before age 65 years.
  
  
  METHODS
  We studied 4,068 postmenopausal women, aged 50 to 64 years without hip or clinical vertebral fracture or antifracture treatment at baseline, who were participating in the Women's Health Initiative BMD cohort study. BMD tests were performed between October 1993 and April 2005, with fracture follow-up through 2012. Outcomes were the time for 1% of women to sustain a hip or clinical vertebral fracture and the time for 3% of women to sustain a major osteoporotic fracture before initiating treatment, adjusting for clinical risk factors and accounting for competing risks. Women without osteoporosis and women with osteoporosis on their first BMD test were analyzed separately.
  
  
  RESULTS
  During a maximum of 11.2 years of concurrent BMD and fracture follow-up, the adjusted estimated time for 1% of women to have a hip or clinical vertebral fracture was 12.8 years (95% CI, 8.0-20.4) for women aged 50 to 54 years without baseline osteoporosis, 7.6 years (95% CI, 4.8-12.1) for women aged 60 to 64 years without baseline osteoporosis, and 3.0 years (95% CI, 1.3-7.1) for all women aged 50 to 64 years with baseline osteoporosis. Results for major osteoporotic fracture were similar.
  
  
  CONCLUSIONS
  Because of very low rates of major osteoporotic fracture, postmenopausal women aged 50 to 64 years without osteoporosis on their first BMD test are unlikely to benefit from frequent rescreening before age 65 years.
authors.affiliation: From the 1Department of Family Medicine, University of North Carolina, Chapel Hill, NC; 2Division of Pharmaceutical Outcomes and Policy, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC; 3Department of Biostatistics, University of North Carolina, Chapel Hill, NC; 4Department of Medicine, VA Medical Center, Minneapolis, MN; 5Department of Medicine, University of California Los Angeles, Los Angeles, CA; 6The North American Menopause Society, Mayfield Heights, OH; 7University of California at Davis, Sacramento, CA; 8University of Tennessee Health Science Center, Memphis, TN; 9Center for Health Research, Kaiser Permanente Northwest, Portland, OR;10Division of Health Policy and Management, University of Minnesota, Minneapolis, MN; and 11Fred Hutchinson Cancer Research Center, Seattle, WA.
authors.forename: Margaret Lee
authors.initials: ML
authors.lastname: Gourlay
authors.forename: Robert A
authors.initials: RA
authors.lastname: Overman
authors.forename: Jason P
authors.initials: JP
authors.lastname: Fine
authors.forename: Kristine E
authors.initials: KE
authors.lastname: Ensrud
authors.forename: Carolyn J
authors.initials: CJ
authors.lastname: Crandall
authors.forename: Margery L
authors.initials: ML
authors.lastname: Gass
authors.forename: John
authors.initials: J
authors.lastname: Robbins
authors.forename: Karen C
authors.initials: KC
authors.lastname: Johnson
authors.forename: Erin S
authors.initials: ES
authors.lastname: LeBlanc
authors.forename: Catherine R
authors.initials: CR
authors.lastname: Womack
authors.forename: John T
authors.initials: JT
authors.lastname: Schousboe
authors.forename: Andrea Z
authors.initials: AZ
authors.lastname: LaCroix
mesh_terms: D000367:Age Factors; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D050723:Fractures, Bone / Q000453:epidemiology; D006801:Humans; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000453:epidemiology* / Q000517:prevention & control; D058866:Osteoporotic Fractures / Q000453:epidemiology* / Q000517:prevention & control; D017698:Postmenopause; D018570:Risk Assessment; D012307:Risk Factors; D014481:United States / Q000453:epidemiology; D016387:Women's Health