Understanding Your Fracture Risk: FRAX and Canadian Osteoporosis Guidelines

A bone density T-score tells you how your bone mass compares to a young adult average. But it doesn't tell you the number your doctor actually needs to make treatment decisions: your 10-year probability of a fracture. That's where the FRAX tool comes in.

What Is FRAX?

FRAX (Fracture Risk Assessment Tool) was developed by the World Health Organization and is now used by doctors worldwide — including in Canada — to estimate an individual's probability of suffering a major osteoporotic fracture (hip, spine, wrist, or shoulder) or a hip fracture specifically over the next 10 years.

Unlike a T-score alone, FRAX incorporates multiple risk factors beyond bone density, giving a more complete picture of fracture risk. It's calculated by your doctor, or you can estimate it yourself at frax.shef.ac.uk (select Canada as the country).

What Information Does FRAX Use?

The Canadian version of FRAX incorporates:

• Age and sex
• Body mass index (BMI)
• Prior fragility fracture history
• Family history of hip fracture (parent)
• Current smoking status
• Alcohol use (3 or more units per day)
• Rheumatoid arthritis diagnosis
• Secondary osteoporosis (other conditions causing bone loss)
• Current glucocorticoid (corticosteroid) use
• Femoral neck bone mineral density (from DEXA scan, if available)

FRAX can be calculated with or without a DEXA scan — using BMI instead of measured bone density when a scan isn't available. However, using actual DEXA results gives a more precise estimate.

Interpreting Your FRAX Score: Canadian Thresholds

The key output from FRAX is two percentages:

• 10-year probability of a major osteoporotic fracture (MOF) — includes hip, spine, wrist, shoulder
• 10-year probability of a hip fracture specifically

Osteoporosis Canada uses these scores to classify fracture risk:

For hip fracture specifically, a 10-year probability of 3% or more is generally considered high risk.

When Does a Fracture Risk Score Trigger Treatment?

Under Canadian guidelines, treatment is generally recommended when:

• 10-year major osteoporotic fracture probability is ≥20%
• 10-year hip fracture probability is ≥3%
• There has been a prior fragility fracture (regardless of FRAX score)
• T-score is ≤ −2.5 (osteoporosis range)
• Patient is on long-term corticosteroids (separate guidelines apply)

In the moderate-risk zone (10–20%), treatment decisions are individualized. Some factors that push toward treatment: very low T-score, recent fall, rapid bone loss between DEXA scans, or conditions like rheumatoid arthritis that add extra risk beyond what FRAX captures.

Limitations of FRAX

FRAX is a useful tool, but it has known limitations that both patients and clinicians should understand:

• It doesn't capture fall risk — falling is the most proximate cause of most fractures, but FRAX doesn't ask about balance, gait speed, or previous falls. Someone who falls frequently may have higher real-world risk than FRAX suggests
• Corticosteroid dose isn't captured — it only records "yes/no" for glucocorticoid use, not dose or duration. High-dose or long-term use carries substantially higher risk
• Prior fracture is binary — it doesn't distinguish between one fracture and five, or between minor and major fractures
• Trabecular bone score (TBS) not included — TBS is a newer measurement from DEXA scans that assesses bone quality (microarchitecture). Some Canadian centres offer TBS and it can be integrated with FRAX for a more refined estimate
• Designed for untreated patients — FRAX is validated for people not currently on osteoporosis treatment

What Happens After a FRAX Score?

Your FRAX result is a starting point for conversation — not a final verdict. Here's how a typical decision pathway works:

1. Low risk (<10%): No medication needed. Focus on lifestyle (calcium, vitamin D, exercise). Retest in 3–5 years, or sooner if risk factors change.
2. Moderate risk (10–20%): Clinical discussion. Your doctor may order additional testing (like TBS, or a repeat DEXA if one was done 1–2 years ago). Medication decision individualized.
3. High risk (>20%) or prior fracture: Medication recommended. Discuss options — see our guide to osteoporosis medications in Canada.

Talking to Your Doctor About Fracture Risk

If you've had a DEXA scan and received a T-score but no FRAX score, you can ask: "What is my 10-year fracture probability based on FRAX?" This is a reasonable request. Some general practitioners don't routinely calculate FRAX — particularly for men — so asking explicitly makes a difference.

Questions to bring to your appointment:

• "What is my FRAX score, and does it suggest treatment?"
• "How does my score compare to the Osteoporosis Canada treatment thresholds?"
• "What can I do about my modifiable risk factors (smoking, alcohol, fall risk)?"
• "Should I have my vitamin D level checked?"
• "When should I have a repeat DEXA scan?"

Canadian Guidelines: The Osteoporosis Canada Framework

Canada's clinical practice guidelines for osteoporosis, developed by Osteoporosis Canada and last updated in 2023, use a combination of FRAX, DEXA T-scores, and clinical judgment to stratify fracture risk and guide treatment. The guidelines are freely available at osteoporosis.ca and are designed for both clinicians and patients.

The Canadian framework is consistent with international guidelines but is calibrated specifically to Canadian fracture rates, which vary by region and ethnicity. Osteoporosis Canada also provides a patient-facing fracture risk tool that uses the same underlying FRAX model.

Next Steps

If you haven't had a DEXA scan, start there — see our guide to bone density tests in Canada. If you have a score and want to understand your treatment options, read our osteoporosis medications guide. And regardless of your risk level, optimizing calcium, vitamin D, and weight-bearing exercise is never wrong.