Introduction Osteoporosis is a well-recognised complication of intestinal malabsorption related to Coeliac Disease. It is diagnosed by dual energy x-ray absorptiometry (DXA). While referral for DXA scanning in other conditions is widely based on 10-year fracture risk calculated by the FRAX tool designed by the WHO, the 2007 BSG guidelines advise screening patients with a higher risk of osteoporosis with a DXA scan, irrespective of 10-year fracture risk as calculated by FRAX.
Methods Aim: We aimed to establish whether the FRAX and linked NOGG tool was a good screener to determine the need for DXA scan in patients with coeliac disease who are at risk of osteoporosis.
Methods: We used the Hospital Nuclear Medicine database to retrieve the records of 50 patients with a diagnosis of coeliac disease who had been investigated with a DXA scan to assess osteoporosis. Using their medical records, we then calculated their FRAX score for risk of major osteoporotic fracture and hip fracture, and the corresponding NOGG guidance. A 10-year fracture risk of 10% or the linked NOGG guidance was considered to be significant to have a DXA scan.
Results Of the 50 patients with Coeliac disease who had DXA scans, 10 had osteoporosis and 40 had either a normal result or osteopaenia. Of these 10 cases, 9 would have also been referred on the basis of a calculated FRAX score and only one case would have been falsely reassured. Of the 40 cases with either a normal DXA scan or osteopaenia, 31 would have been referred for DXA on the basis of the FRAX score, resulting in an unnecessary test. We concluded that a positive FRAX score does not accurately predict osteoporosis in Coeliac disease. The positive predictive value of the FRAX tool to detect osteoporosis in Coeliac disease is low at 22.5%; however the negative predictive value is high, 90%.
Conclusion The use of FRAX to identify patients with Coeliac disease at risk of osteoporosis has a high negative predictive value. It therefore has merit as a screening tool but has little value as a diagnostic test. Although the sample size was too small to show statistical significance, we suggest that FRAX tool could potentially be adopted as a screener in the context of celiac disease to prevent unnecessary DXA scanning. A osteoporosis risk of <10% or a NOGG guidance of reassurance is likely to be associated with a normal DXA scan. Further large studies are needed to validate this hypothesis and also to determine cost benefit of a FRAX driven strategy for osteoporosis in Coeliac Disease.
Disclosure of Interest J. Weightman: None Declared, M. Bridges: None Declared, A. Dhar Consultant for: Honoraria for advisory roles ot the Pharmaceutical Industry, Speaker bureau with: Warner Chilcott UK, Falk Pharma UK, Almirall, Ferring Pharma UK, Astellas UK.