Screening for women with increased risk of fragility fractures in a general female population using digital X-ray radiogrammetry (DXR)

Abstract

Objective: To evaluate the predictive ability of digital X-ray radiogrammetry (DXR) for fracture in women attending general mammography screening.

Study design: In a nested case-control study, women aged between 40 and 75 years, who attended the regional mammography screening program, had their bone mass assessed with DXR and provided information regarding clinical risk factors for osteoporosis. Follow-up was done through cross-referencing with National Patient Registers. Associations between DXR, clinical risk factors and fracture risk were examined. Receiver operating characteristics curves for DXR T-score and different fracture types were plotted, and their respective AUC calculated.

Main outcome measures: Fractures (hip, major osteoporotic and any clinical facture). Fracture diagnoses were retrieved from National Patient Registers.

Results: 14,841 women had their bone mass examined in conjunction with mammography. Of these women, 10,967 returned fully completed questionnaires regarding clinical risk factors. In total 605 fractures (including 355 major osteoporotic fractures and 18 hip fractures) occurred during the follow-up period (median follow-up time was 3.3 years). Women with fractures were older and had lower DXR T-score compared with those without. DXR T-score correlated with fracture risk. HR/SD T-score decrease was 2.15 (CI 1.55-3.00) for hip, 1.47 (CI 1.36-1.59) for major osteoporotic and 1.33 (CI 1.26-1.42) for any clinical fracture. The AUCs for the different fracture types were 0.79 (hip), 0.69 (major osteoporotic) and 0.65 (any clinical).

Conclusions: DXR T-score is negatively correlated with risk of fracture in a general female population. This indicates a potential use of DXR in population-based screening for osteoporosis.

Keywords: Bone mass; Bone mineral density; Digital X-ray radiogrammetry; Mammography; Osteoporosis; Screening.