Fracture Risk (FRISK) Score: Geelong Osteoporosis Study

Abstract

Purpose: To develop and evaluate a fracture risk (FRISK) score based on multiple-site bone mineral density (BMD) measurements and other risk factors, to enable prediction of future fracture occurrence.

Materials and methods: All participants gave written informed consent, and the study was approved by the Barwon Health Research and Ethics Advisory Committee. BMD was measured at the femoral neck and spine in two concurrently recruited groups: women 60 years of age or older who had sustained a low-trauma fracture of the hip, spine, humerus or distal forearm during a 2-year ascertainment period (n = 231; mean age, 74 years +/- 7 [standard deviation]) and a population-based random sample of women who had not sustained a fracture during the recruitment period (n = 448; mean age, 72 years +/- 8). Falls in the previous year and the number of self-reported fractures in adult life were recorded. Coefficients of a multiple logistic regression model were used as weightings for a combined model. A longitudinal population-based sample was used to assess the fracture risk equation (n = 600; median age, 74 years; interquartile range, 67-82 years).

Results: The FRISK score was obtained from the following equation: 9.304 - 4.735BMD(SP) - 4.530BMD(FN) + 1.127FS + 0.344NPF + 0.037W, where BMD(SP) is spinal BMD (in grams per square centimeter), BMD(FN) is femoral neck BMD, FS is falls score, NPF is number of previous fractures, and W is weight (in kilograms). The FRISK score successfully predicted 75% of fractures 2 years after baseline measurements in subjects in the longitudinal study with 68% specificity.

Conclusion: This study resulted in the derivation of a fracture risk score that successfully predicted 75% of fractures 2 years after baseline.