Rather than relying solely on the results of a bone mineral density (BMD) test to make treatment decisions for osteoporosis, Osteoporosis Canada recommends combining the results of BMD testing with some very important clinical risk factors. This leads to a much better and more accurate method of predicting a person’s risk of fracture.
As a result, the treatment of osteoporosis has now shifted from just treating BMD test results to treating people with a high fracture risk.
Comprehensive Fracture Risk Assessment Tools
Osteoporosis Canada focuses on estimating an individual’s 10-year absolute fracture risk; that is, the probability of experiencing a fracture over the next 10 years. Although the BMD test is a very important component of the fracture risk assessment, it is not the only aspect that needs to be considered.
Canada has two different tools, both of which provide very accurate estimates of fracture risk. They divide patients into 10-year LOW, MODERATE and HIGH fracture risk categories. Having two tools allows flexibility for Canadian doctors to use the tool that works best in their own work environment.
In 2005, Osteoporosis Canada, in association with the Canadian Association of Radiologists, launched the 10-year absolute fracture risk assessment – CAROC.
In addition to BMD (lowest T-score of hip and lumbar spine), age, gender, fracture history and steroid use are taken into consideration to determine an individual’s 10-year risk of fracture.
The presence of both a fragility fracture and steroid use puts the patient at high fracture risk regardless of BMD result.
Version 2, now available for Canadian physicians, uses only femoral neck (hip) BMD rather than the lowest of hip and lumbar spine.
In addition to femoral neck (hip) BMD, age, gender, fracture history and steroid use, FRAX also takes into account other clinical risk factors to calculate the absolute 10-year risk of a hip fracture or other major osteoporotic fracture (spine, forearm, upper arm). These factors include:
- BMI (weight to height ratio calculation)
- Parental hip fracture
- Rheumatoid arthritis
- Other secondary conditions that contribute to bone loss
- Current smoking
- Alcohol intake (three or more drinks per day)
CAROC vs. FRAX
The FRAX system is based upon a more complete set of clinical risk factors and it can be used without BMD results; but it requires access to FRAX software, website or paper chart.
CAROC is less complete but captures the major risk factors for fracture and is easy to use.
For the majority of people, the results are the same regardless of which of these tools is used. Therefore the choice of FRAX or CAROC by the clinician is a matter of personal preference and convenience.