At what 10-year risk percentage of hip fracture and major osteoporotic fracture is it recommended to start osteoporosis medication?

When to Start Osteoporosis Medication: Risk-Based Treatment Thresholds

Osteoporosis medication should be initiated when the 10-year risk of major osteoporotic fracture is ≥20% or hip fracture risk is ≥3% as calculated by FRAX, or in patients with a T-score ≤-2.5, or those with a prior osteoporotic fracture. 1

Risk Assessment Categories

The decision to start osteoporosis medication is based on fracture risk stratification:

High Risk (Treatment Strongly Recommended)

• Prior osteoporotic fracture(s)
• T-score ≤-2.5 at hip or spine
• FRAX 10-year risk of major osteoporotic fracture ≥20%
• FRAX 10-year risk of hip fracture ≥3%
• Very low T-score (less than -3.0) 2

Moderate Risk (Treatment Conditionally Recommended)

• FRAX 10-year risk of major osteoporotic fracture 10-19%
• FRAX 10-year risk of hip fracture >1% and <3% 2, 1

Low Risk (No Pharmacologic Treatment)

• FRAX 10-year risk of major osteoporotic fracture <10%
• FRAX 10-year risk of hip fracture ≤1% 2

Organization-Specific Thresholds

Different organizations have slightly different thresholds for treatment:

• American College of Physicians/American College of Rheumatology: Recommends treatment at 10-year hip fracture risk ≥3% or major osteoporotic fracture risk ≥20% 1

• International Osteoporosis Foundation/ESCEO: Recommends treatment at 10-year hip fracture risk ≥3% or major osteoporotic fracture risk ≥20% 2

• Society of Obstetricians and Gynaecologists of Canada: Defines high risk as MOF risk >30% or hip fracture risk >4.5%, and intermediate risk as MOF risk ≥20% or hip fracture risk ≥3% 2

• American Association of Clinical Endocrinology: Defines very high risk as MOF >30% or hip fracture >4.5% 2

Special Considerations

Very High Risk Patients

For patients at very high fracture risk, treatment should be initiated promptly:

• Recent fracture (within past 12 months)
• Multiple fractures
• Fractures while on osteoporosis therapy
• Very low T-score (<-3.0)
• High fall risk or history of injurious falls 2, 1

FRAX Adjustment for Glucocorticoid Use

When calculating fracture risk for patients on glucocorticoids:

• If prednisone dose is >7.5 mg/day, multiply the 10-year risk of major osteoporotic fracture by 1.15 and hip fracture risk by 1.2 2

Treatment Algorithm

1. Assess fracture risk using FRAX calculator and BMD testing
2. Categorize patient into risk category (low, moderate, high, or very high)
3. For high or very high risk: Start pharmacologic therapy (bisphosphonate first-line)
4. For moderate risk: Consider pharmacologic therapy based on individual factors
5. For low risk: No pharmacologic therapy; focus on lifestyle modifications and calcium/vitamin D

Common Pitfalls to Avoid

• Undertreatment of high-risk patients: Studies show that only 12-24% of hip fracture patients receive appropriate osteoporosis evaluation, and only 7-37% receive treatment 3

• Overreliance on T-scores alone: FRAX provides a more comprehensive assessment by incorporating clinical risk factors beyond BMD 4

• Failure to recognize very high-risk patients: Those with recent fractures have imminent risk for subsequent fractures and require prompt intervention 2

• Patient preference discordance: Patient decisions to accept treatment may not align perfectly with guideline thresholds, with personal values and prior fracture experience strongly influencing treatment acceptance 5

• Not adjusting FRAX for glucocorticoid use: This can lead to underestimation of fracture risk in patients on steroids 2

By following these evidence-based thresholds for initiating osteoporosis medication, clinicians can appropriately target therapy to patients most likely to benefit from fracture risk reduction.