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Abstract
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BACKGROUND: Fracture risk assessment is still far from perfect within the geriatric population. The overall aim of this study is to better identify older women at risk for fractures, using a quantitative measure of frailty in conjunction with the web-based Fracture Risk Assessment Tool (FRAX®).
METHODS: This study was performed in the Osteoporosis Risk Assessment (OPRA) cohort of n = 1023, 75-year-old women followed for 10-years. A frailty index (FI) of 'deficits in health' was created, and FRAX 10-year probability for major osteoporotic and hip fractures 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. 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 been recommended for pharmacological treatment (non-treatment group) was identified, categorized by frailty status and for relative risk analysis, hazard ratios (HR) and 95% confidence intervals were calculated 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 higher 10y hip fracture risk (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 as an index of bone density to define fracture risk. Among n = 678 non-osteoporotic women, frailty added to the 10-year fracture risk (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 are needed to formally test potential benefit.
Language: en |