title: Comparison of plain vertebral X-ray and dual-energy X-ray absorptiometry for the identification of older women for fracture prevention in primary care.
abstract: BACKGROUND
  Recently, the dual-energy X-ray absorptiometry (DXA) diagnostic cut-off (T-score) for Australian Pharmaceutical Benefits Scheme (PBS) supported primary fracture prevention therapy with alendronate for older women (>70 years) has been changed from -3.0 to -2.5.
  
  
  OBJECTIVE
  To examine the impact of the expanded criteria for PBS-supported fracture prevention therapy in older women on case finding and cost.
  
  
  METHODS
  One thousand, nine hundred and eighty-three women, median age 76 years, not previously known to have low bone mineral density by DXA or a vertebral fracture underwent DXA scanning and a thoracolumbar X-ray. A woman was considered eligible for fracture prevention therapy if she had a T-score ≤-2.5 at the femoral neck and/or the lumbar vertebrae (two to four) or at least one vertebral fracture of ≥20% deformity.
  
  
  RESULTS
  Seven hundred and forty-six women (37.6%) met the new criteria as a case for PBS-subsidised fracture prevention therapy. Four hundred and thirty-one (21.7%) had a T-score ≤-2.5 on DXA compared with 10.6% (n = 210) with a T-score ≤-3.0. Four hundred and eighty-three (24.4%) had at least one vertebral fracture. Only 8.5% (n = 168) had both a T-score ≤-2.5 and a prevalent vertebral fracture. The cost per case found by DXA equated to $460 compared with $398 for screening by thoracolumbar X-ray.
  
  
  CONCLUSIONS
  The use of either DXA or X-ray will identify approximately two-thirds of women aged 70 years and over who would be eligible for fracture prevention. The use of X-ray would identify a marginally larger number of women and at lower financial cost but involve substantially greater radiation exposure.
authors.affiliation: Women's Health Research Program, School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia. penny.robinson@monash.edu
authors.forename: P J
authors.initials: PJ
authors.lastname: Robinson
authors.forename: R J
authors.initials: RJ
authors.lastname: Bell
authors.forename: A
authors.initials: A
authors.lastname: Lanzafame
authors.forename: L
authors.initials: L
authors.lastname: Segal
authors.forename: C
authors.initials: C
authors.lastname: Kirby
authors.forename: L
authors.initials: L
authors.lastname: Piterman
authors.forename: S R
authors.initials: SR
authors.lastname: Davis
mesh_terms: D015502:Absorptiometry, Photon / Q000191:economics; D000368:Aged; D000369:Aged, 80 and over; D019386:Alendronate / Q000627:therapeutic use; D001315:Australia / Q000453:epidemiology; D015519:Bone Density; D050071:Bone Density Conservation Agents / Q000627:therapeutic use; D005260:Female; D005265:Femoral Neck Fractures / Q000517:prevention & control; D005272:Femur Neck / Q000000981:diagnostic imaging; D005598:Fractures, Spontaneous / Q000000981:diagnostic imaging / Q000191:economics / Q000209:etiology / Q000517:prevention & control*; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging* / Q000293:injuries; D008403:Mass Screening; D015663:Osteoporosis, Postmenopausal / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000191:economics / Q000453:epidemiology; D011320:Primary Health Care / Q000379:methods*; D011829:Radiation Dosage; D018570:Risk Assessment; D016103:Spinal Fractures / Q000000981:diagnostic imaging / Q000191:economics / Q000209:etiology / Q000517:prevention & control*; D013904:Thoracic Vertebrae / Q000000981:diagnostic imaging* / Q000293:injuries
chemical_list: D050071:Bone Density Conservation Agents; D019386:Alendronate