At what Frax (Fracture Risk Assessment) score should osteoporosis be treated with medication?

FRAX Treatment Thresholds for Osteoporosis

Initiate pharmacologic treatment for osteoporosis when FRAX scores reach ≥20% for 10-year major osteoporotic fracture (MOF) risk OR ≥3% for 10-year hip fracture risk. 1, 2

Treatment Thresholds by Risk Category

Adults ≥40 Years of Age

High Fracture Risk (Strong recommendation for treatment):

• FRAX 10-year MOF risk ≥20% 3
• FRAX 10-year hip fracture risk ≥3% 3
• Prior osteoporotic fracture 3
• T-score ≤-2.5 at hip or spine (men ≥50 years, postmenopausal women) 3

Moderate Fracture Risk (Conditional recommendation for treatment):

• FRAX 10-year MOF risk 10-19% 3
• FRAX 10-year hip fracture risk >1% and <3% 3
• T-score between -1.0 and -2.4 3

Low Fracture Risk (No pharmacologic treatment):

• FRAX 10-year MOF risk <10% 3
• FRAX 10-year hip fracture risk ≤1% 3
• T-score >-1.0 3

Critical FRAX Adjustments for Glucocorticoid Users

If the patient is taking prednisone >7.5 mg/day, you must adjust FRAX scores upward:

• Multiply MOF risk by 1.15 3
• Multiply hip fracture risk by 1.2 3

For example, if calculated hip fracture risk is 2.0%, adjust to 2.4% (2.0 × 1.2), which then meets the ≥3% threshold when combined with other risk factors. 3

Very High Fracture Risk in Glucocorticoid Users

These patients warrant immediate aggressive treatment:

• FRAX (GC-adjusted) MOF ≥30% OR hip ≥4.5% 3
• T-score ≤-3.5 3
• High-dose glucocorticoids ≥30 mg/day for >30 days 3
• Cumulative glucocorticoid dose ≥5 g/year 3

Age-Specific Considerations

Adults <40 years: FRAX is not validated in this age group. 3 Treatment decisions should be based on:

• Prior osteoporotic fracture 3
• Z-score <-3 with ongoing glucocorticoid use ≥7.5 mg/day for ≥6 months 3
• Rapid bone loss (≥10% at hip or spine over 1 year) 3

Common Pitfalls to Avoid

Do not use FRAX alone without considering:

• The standard FRAX calculation assumes prednisone 2.5-7.5 mg/day; higher doses require manual adjustment 3
• Prior fragility fractures automatically place patients at high risk regardless of FRAX score 3
• FRAX should not be used to monitor treatment response—it is not sufficiently responsive to medication effects 4

Recognize that treatment decisions are highly personal: Research shows wide overlap in fracture risk between patients who accept versus decline treatment, with only 47% of patients meeting MOF ≥20% threshold actually accepting treatment. 5 However, the evidence-based thresholds remain the clinical standard for initiating treatment discussions.

Treatment Approach by Risk Level

For patients meeting treatment thresholds (≥20% MOF or ≥3% hip):

• First-line: Oral bisphosphonates (alendronate, risedronate) 3
• Alternative: IV bisphosphonates if oral not appropriate 3
• Very high risk: Consider PTH/PTHrP agonists (teriparatide, abaloparatide) over bisphosphonates 3

For patients below treatment thresholds (<10% MOF and <1% hip):

• Optimize calcium (1,000-1,200 mg/day) and vitamin D (600-800 IU/day, target level ≥20 ng/ml) 3, 1
• Weight-bearing exercise, smoking cessation, limit alcohol to 1-2 drinks/day 3, 1
• Repeat DXA in 2 years to monitor progression 1

The number needed to treat is substantially higher in osteopenic patients (NNT >100) compared to those with T-score <-2.5 (NNT 10-20), which is why FRAX thresholds are critical for identifying who truly benefits from pharmacologic intervention. 6