FRAX Score Thresholds for Bisphosphonate Treatment
Bisphosphonates are indicated when the FRAX 10-year risk for major osteoporotic fracture is ≥10% or the 10-year risk for hip fracture is >1% (with glucocorticoid adjustment if applicable). 1
FRAX Thresholds by Clinical Context
General Population
- FRAX 10-year risk for major osteoporotic fracture ≥20% or hip fracture ≥3% indicates treatment according to the National Osteoporosis Foundation 1
- T-score ≤-2.5 at hip or spine is an indication for treatment regardless of FRAX score 1
Glucocorticoid Users
- FRAX 10-year risk for major osteoporotic fracture ≥10% indicates bisphosphonate treatment 1
- FRAX 10-year risk for hip fracture >1% indicates bisphosphonate treatment 1
- Important: For patients on prednisone >7.5 mg/day, increase the calculated FRAX risk by 15% for major osteoporotic fracture and by 20% for hip fracture 1
Risk Stratification and Treatment Algorithm
High Fracture Risk (Strong Indication for Bisphosphonates)
- History of osteoporotic fracture 1
- T-score ≤-2.5 at hip or spine in adults ≥40 years 1
- FRAX 10-year risk for major osteoporotic fracture ≥10% (with glucocorticoid adjustment) 1
- FRAX 10-year risk for hip fracture >1% (with glucocorticoid adjustment) 1
- Very high-dose glucocorticoid treatment (prednisone ≥30 mg/day and cumulative dose >5 gm in past year) 1
Special Populations
- Adults <40 years: Consider bisphosphonates with history of osteoporotic fracture, Z-score <-3, or rapid bone loss (≥10%/year) 1
- Glucocorticoid users: Lower threshold for treatment due to higher fracture risk 1
Important Clinical Considerations
FRAX Calculation Adjustments
- For patients on prednisone >7.5 mg/day, multiply FRAX risk by 1.15 for major osteoporotic fracture and by 1.2 for hip fracture 1
- Example: If calculated hip fracture risk is 2.0%, increase to 2.4% for patients on >7.5 mg prednisone daily 1
Treatment Selection
- Oral bisphosphonates are first-line therapy for most patients 1, 2
- IV bisphosphonates should be considered for patients with adherence concerns or contraindications to oral therapy 2, 3
- Teriparatide is an alternative for high-risk patients when bisphosphonates are contraindicated 1
Monitoring During Treatment
- BMD testing every 1-2 years during treatment 2
- Consider drug holiday after 5 years of oral bisphosphonate or 3 years of IV bisphosphonate in lower-risk patients 4, 5
- Continue treatment for up to 10 years in high-risk patients 4, 5
Common Pitfalls
- Failing to adjust FRAX scores for patients on high-dose glucocorticoids (>7.5 mg/day) 1
- Not recognizing that FRAX can still be used to guide treatment decisions in patients previously treated for osteoporosis 6
- Overlooking the need for adequate calcium (1,000-1,200 mg/day) and vitamin D (600-800 IU/day) supplementation alongside bisphosphonate therapy 1
- Neglecting to consider rare but serious side effects like osteonecrosis of the jaw and atypical femoral fractures in long-term bisphosphonate users 7, 5