Session Type: Abstract Submissions (ACR)
In the over 75s the diagnosis of osteoporosis may be assumed following a fracture, making the need for a dual energy absorptiometry scan (DEXA) optional 1. In those presenting without fracture, it has been suggested that referral for a DEXA scan in the over 75s should require the presence of 2 risk factors for osteoporotic fracture2. However, the strength of these risk factors for predicting fractures in this specific age range has not been properly assessed. This study aims to assess the sensitivity of the risk factors in predicting fractures in patients aged 75 and over.
Using a nested case-control approach, a cohort of patients aged over 75 and referred between 2004 and 2011 to a DEXA scanner were indentified. The patients were divided into two cohorts depending on their fracture history. The risk factors assessed were hip and spine BMD, family history of fragility fracture, smoking, alcohol excess, steroid use, body mass index (BMI) and rheumatoid arthritis. Logistic models were fitted predicting fractures in the group, adjusting for age and gender.
4,663 patients over the age of 75 were identified; the median age of the cohort was 79.2 years (SD 3.1 years), with 3732 (80%) females. Fracture was the presenting feature in 1830 (39.25%) of the subjects. The only risk factors which were significantly increased in the fracture group, when adjusted for age and gender, were reduced BMD in the hip (OR: 1.65, CI: 1.21 – 2.42), reduced BMD in the spine (OR: 3.81, CI: 2.81 – 5.16) and rheumatoid arthritis (OR: 6.42 CI: 3.56 – 11.58). The other risk factors of smoking, alcohol excess, family history, steroids and BMI were not significantly associated with fractures when adjusted for age and gender with steroids showing an apparent protective effect (OR 0.74 95%CI 062, 0.87).
Most of the traditional risk factors which predict bone mineral density loss and fracture, such as smoking, alcohol, low BMI and steroid use do not predict fragility fracture in the over 75s, with a curious beneficial effect of steroids. This study has found that the factors which most predict fracture in the elderly are a low BMD in both the hip and spine, and rheumatoid arthritis. This shows that the current clinical advice to not routinely DEXA scan the over 75 year old patients is potentially incorrect; in this age group a patient’s hip and spine BMD can provide useful information for judging fracture risk. Limitations of this study include it’s observational design, but this association should be studied further.
1. The Lancet. 2002;359(9321):1929-36.
2. Excellence NICE. Osteoporosis: assessing the risk of fragility fracture. 2012.
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ACR Meeting Abstracts - https://acrabstracts.org/abstract/factors-predicting-fracture-in-the-over-75s-an-observational-case-control-study/