The Clinical Utility of FRAX to Discriminate Fracture Status in Men and Women with Chronic Kidney Disease

Unlabelled: We assessed the ability of the World Health Organization's fracture risk assessment tool (FRAX), bone mineral density (BMD), and age to discriminate fracture status in adults with pre-dialysis chronic kidney disease (CKD). In adults with CKD, FRAX was able to discriminate fracture status but performed no better than BMD alone.

Introduction: Patients with CKD are at increased risk for fracture but the best method to assess fracture risk is not known.

Methods: We assessed the ability of the World Health Organization's FRAX, compared with BMD at the femoral neck (FN), and age to discriminate fracture status (prevalent clinical nonspine and/or morphometric vertebral) in men and women, 18 years and older with pre-dialysis CKD. Results are presented as area under receiver operator characteristic curves (AUC) with 95% confidence intervals (CI).

Results: We enrolled 353 subjects; mean age was 65 ± 14 years; weight was 79 ± 18 kg, and estimated glomerular filtration rate was 28 ml/min/1.73 m(2). About one third of the subjects had a prevalent clinical nonspine and/or morphometric vertebral fracture. FRAX was able to discriminate among those with prevalent clinical nonspine fractures (AUC, 0.72; 95% CI, 0.65-0.78), morphometric vertebral fractures (AUC, 0.66; 95% CI, 0.59-0.73), and any fracture (AUC, 0.71; 95% CI, 0.65-0.77). The discriminative ability of BMD at the FN alone was similar to FRAX for morphometric vertebral and any fractures; FRAX performed better than BMD for prevalent clinical nonspine fractures (AUC for BMD alone, 0.66; 95% CI, 0.60-0.73). Compared to FRAX, the AUC for age alone was lower for all fracture types.

Conclusions: Among men and women with CKD, FRAX is able to discriminate fracture status but performs no better than BMD alone.