FRAX predicts fracture risk in kidney transplant recipients

Transplantation. 2014 May 15;97(9):940-5. doi: 10.1097/01.TP.0000438200.84154.1a.


Background: The World Health Organization Fracture Risk Assessment Tool (FRAX) estimates the 10-year fracture probability. We assessed the prognostic value of FRAX in kidney transplant recipients, as its utility in recipients is unknown.

Methods: We considered 458 individuals (mean age 45 years, 64% men) who received a kidney transplant in the province of Manitoba, Canada at the time of their first bone mineral density (BMD) test posttransplant (mean 1.1 years posttransplant; transplant years 1996-2011). FRAX probabilities were calculated from baseline information (age, sex, clinical risk factors, with or without BMD). Recipients were followed a mean of 6.4 years (interquartile range 3.0-10.0 years) after cohort entry for an incident major osteoporotic fracture.

Results: In follow-up, 21 (4.6%) recipients experienced a major osteoporotic fracture. The observed 10-year major osteoporotic fracture risk of 6.3% (95% CI, 3.4-9.2%) was concordant with FRAX predictions (5.0% with BMD, 5.6% without BMD). Major osteoporotic fracture scores showed significant fracture prediction (hazard ratio per standard deviation, FRAX without BMD 1.66, 95% CI, 1.10-2.50; FRAX with BMD 1.64, 95% CI, 1.07-2.51). Area under the curve (AUC) for incident major osteoporotic fracture discrimination (AUC: FRAX with BMD 0.62, 95% CI, 0.50-0.74) was similar to the general population.

Conclusions: FRAX scores categorized most kidney transplant recipients as a low-risk fracture group, and the low observed fracture rates were consistent with the 10-year fracture predictions. FRAX showed modest fracture prediction and discrimination similar to the general population. Independent validation is needed before clinicians can routinely use FRAX in kidney transplant recipients.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Area Under Curve
  • Bone Density
  • Calibration
  • Cohort Studies
  • Female
  • Follow-Up Studies
  • Humans
  • Kidney Transplantation*
  • Male
  • Manitoba
  • Middle Aged
  • Osteoporotic Fractures / diagnosis*
  • Osteoporotic Fractures / etiology
  • Probability
  • Prognosis
  • Proportional Hazards Models
  • Renal Insufficiency / therapy*
  • Risk Assessment*
  • Risk Factors
  • World Health Organization