Can Frailty in Conjunction with FRAX Identify Additional Women at Risk of Fracture - a Longitudinal Cohort Study of Community Dwelling Older Women

Abstract

Abstract Background Fracture risk assessment is still far from perfect within the geriatric population. The overall aim of this study is to better identify elderly women that are at risk for fractures, using a quantitative measure of frailty in conjunction with FRAX. Methods This study was performed in the OPRA cohort of n=1023, 75-year old women followed for 10-years. A frailty index (FI) of ‘deficits in health’ was created, and 10-year probability for major osteoporotic and hip fractures using FRAX was calculated and bone mineral density measured. Incident fractures were continuously registered for 10-years. Receiver Operating Characteristic (ROC) curves were used to compare FI, FRAX and the combination FI+FRAX as instruments for risk prediction of fractures. Discriminative ability was estimated by comparing area under the curve (AUC). In addition, using guidelines from the Swedish Osteoporosis Foundation, a category of low risk women who would not have would have been recommended for pharmacological treatment (non-treatment group) was identified, categorized by frailty status and their fracture risk determined using Cox proportional hazard regressions. Results For hip fracture, FRAX and frailty performed almost equally (HIP AUC 10y: 0.566 vs. 0.567, p=0.015 and p=0.013). Next, FI was used in conjunction with FRAX; proving marginally better than either score alone (AUC 10y: 0.584, p=0.002). Comparable results were observed for osteoporotic fracture. In the non-treatment group (564 women), being frail was associated with a higher 10y risk of hip fracture (HR 2.01 (1.13-3.57)), although failing to reach statistical significance for osteoporotic fracture (HR 1.40 (0.97-2.01). The utility of measuring frailty was also demonstrated when using T-score to define fracture risk. Among n=678 non-osteoporotic women, frailty added to the 10-year risk of fracture (Hip; HR 2.22 (1.35-3.71); Osteoporotic fracture; HR 1.57 (1.15-2.14)) Conclusions While the addition of frailty to FRAX marginally improved fracture prediction, applying a frailty measurement to a group of ‘low risk’ women, identified a set of individuals with high actual hip fracture risk that would not be prioritized for pharmacological treatment. Further cost-benefit analysis studies will be needed to formally test the potential benefit.