FRAX score underestimates fracture recurrence

The World Health Organization’s (WHO) Fracture Risk Assessment tool (FRAX) severely underestimates risk of fragility fracture (FF) in certain patients, according to a new study. Published in the Journal of Clinical Endocrinology & Metabolism, the findings are by Canadian investigators.

Both men and women aged older than 50 years at the time of FF were included in the prospective cohort. The objective of the research was to evaluate estimated FRAX probabilities of FF at the time of a FF and to compare them with observed incidence of recurrent FF.

Investigators calculated FRAX scores without bone mineral density (FRAX-body mass index [BMI]) before and after inclusion of FF on 1,399 participants. Recurrent FFs were recorded over a 4-year follow-up period and univariate and multivariate analyses were used to identify determinants associated with recurrent FF.

High-risk FRAX-BMI scores were present in only 42.7% of patients before and 56.4% after the incident FF. Men younger than age 65 or without previous FF-rather than women-comprised the majority of those with low or moderate risk before their initial FF.

At median follow-up of 3 years, 108 patients (2.69 per 100 patient-years) had recurrent FF. The sensitivity of post-FF FRAX in prediction of recurrent FF was 71.3% overall, 63% in those without previous FF at study inclusion, and 13% in patients younger than age 65.

FRAX-BMI scores, the researchers said, were below the Canadian threshold for treatment in more than half the patients at the time of FF and in nearly one-third of those with recurrent FF.

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