About

Osteoporotic fractures constitute a major health burden in aging populations. This clinical estimator predicts the 10-year probability of a hip fracture or a major osteoporotic fracture (spine, forearm, hip, or shoulder). It incorporates critical weighting for age, BMI, and clinical history (glucocorticoid use, rheumatoid arthritis).

Risk models are highly sensitive to geography due to variations in life expectancy and genetic bone density profiles. This tool applies adjustment factors derived from major epidemiological studies to align the baseline risk with the selected population (US, UK, Northern Europe, or Asia). The output assists in the decision-making process for initiating bisphosphonate therapy or DEXA scanning.

Formulas

The probability P is calculated using an exponential survival function:

P = 1 − exp−∑(RiskHazard × DeathHazard)

This simplified estimator uses a weighted score model for approximation:

LogOdds = Base + β_age + β_bmi + ∑(β_risk)

Reference Data

Risk Factor	Relative Risk (Hip)	Mechanism of Action
Previous Fracture	1.8 - 2.0	Structural bone weakness and altered biomechanics.
Glucocorticoids	2.3	Impairs osteoblast function and calcium absorption.
Smoker (Current)	1.5 - 1.8	Reduces blood supply and estrogen efficacy.
RA (Rheumatoid Arthritis)	1.7	Systemic inflammation and immobility.
Parental Hip Fracture	2.3	Strong genetic component to bone geometry.
Alcohol (>3 units/day)	1.7	Toxic to osteoblasts; increases fall risk.

Frequently Asked Questions

Low Body Mass Index (BMI) is a significant risk factor for osteoporosis. Less padding over the trochanter (hip bone) increases the force of impact during a fall, and lower weight often correlates with lower bone mineral density.

Fracture rates vary up to 10-fold between countries. For example, hip fracture rates are significantly higher in Scandinavian countries compared to parts of Asia. This tool adjusts the "Base Hazard" variable according to the region selected to prevent over- or under-estimation.

This category includes disorders strongly associated with osteoporosis, such as Type 1 Diabetes, Osteogenesis Imperfecta in adults, untreated long-standing hyperthyroidism, hypogonadism, or chronic liver disease.

No. This tool is designed to assess clinical risk to determine IF a DEXA scan or treatment is needed. However, including Femoral Neck BMD (T-score) significantly improves predictive accuracy.