FRAX- vs. T-score-based intervention thresholds for osteoporosis

Area of Science:

• Osteoporosis management
• Geriatric medicine
• Public health

Background:

• Current osteoporosis guidelines, including in Kuwait, rely on Bone Mineral Density (BMD) T-score thresholds for fracture risk assessment.
• There is a need to evaluate the effectiveness of these fixed thresholds against newer, age-dependent fracture probability tools.

Purpose of the Study:

• To compare Kuwaiti osteoporosis guidelines, based on BMD T-scores, with FRAX (Fracture Risk Assessment Tool)-based age-dependent intervention thresholds.
• To assess how these different thresholds identify individuals at higher fracture risk, particularly women.

Main Methods:

• Age-specific fracture probabilities from FRAX (equivalent to women with no risk factors and a prior fragility fracture) were compared with probabilities associated with femoral neck T-scores of -2.5 and -1.5 SD.
• FRAX was also used to explore upper and lower assessment thresholds for BMD testing.

Main Results:

• FRAX-based thresholds identified higher fracture probabilities than fixed T-score thresholds, especially in older women.
• A BMD T-score of -2.5 SD identified lower fracture risk than age-matched controls in women aged 83+, and -1.5 SD in women aged 66+.
• FRAX-based intervention thresholds consistently identified women at increased risk across all ages.

Conclusions:

• BMD T-score thresholds alone do not optimally target individuals at higher fracture risk, particularly the elderly.
• FRAX-based intervention thresholds, reflecting a 'fracture threshold', consistently identify higher-risk individuals regardless of age, suggesting a more effective approach to osteoporosis assessment.