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The form uses a responsive 3-column, 2-column, and 1-column grid depending on screen size.
Formula used
This page combines validated screening formulas with a transparent educational index.
1) BMI
BMI = weight (kg) ÷ [height (m)]²
2) OST score
OST = (weight in kg − age in years) × 0.2
A score below 2 is often used as a flag for increased osteoporosis risk in simple screening.
3) ORAI score
For women, ORAI adds points from age, weight, and current estrogen use:
- Age 45–54 = 0, 55–64 = 5, 65–74 = 9, 75+ = 15
- Weight under 60 kg = 9, 60–69 kg = 3, 70+ kg = 0
- No current estrogen use = 2
An ORAI score of 9 or more is often used to support further screening.
4) Composite screening index
This index is an educational summary, not a diagnostic probability and not a substitute for FRAX.
It adds points for age, sex, postmenopause, low BMI, prior fragility fracture, parental hip fracture, smoking, glucocorticoids, rheumatoid arthritis, secondary osteoporosis causes, higher alcohol intake, inactivity, low calcium or vitamin D intake, falls, and an optional T-score.
How to use this calculator
- Enter age, sex, weight, and height first.
- Mark menopause status, fracture history, smoking, alcohol, steroid use, and related conditions.
- Add a T-score only if you have a recent DXA result.
- Press Calculate Risk to show the result above the form.
- Review the OST score, ORAI score, composite index, and recommendation together.
- Use CSV or PDF export if you want a saved copy.
- Take the result to a clinician if you have fractures, a low T-score, or multiple risk flags.
Example data table
| Example | Age | Sex | Weight | Height | Key factors | Sample interpretation |
|---|---|---|---|---|---|---|
| Example A | 67 | Female | 56 kg | 158 cm | Postmenopause, smoking, parent hip fracture | High screening concern and screening commonly recommended |
| Example B | 58 | Female | 63 kg | 164 cm | Postmenopause, glucocorticoids, inactive lifestyle | Moderate screening concern and formal assessment may be reasonable |
| Example C | 61 | Male | 72 kg | 173 cm | Previous fracture, alcohol 3+ units, T-score -2.6 | Very high screening concern and prompt clinical follow-up suggested |
FAQs
What does this calculator estimate?
It estimates screening concern for osteoporosis using recognized risk factors, simple screening formulas, and optional bone density input. It does not diagnose disease.
Is this the same as FRAX?
No. FRAX estimates 10-year fracture probability with country-specific modeling. This page uses FRAX-style clinical factors plus OST, ORAI, BMI, and optional T-score.
When is screening commonly recommended?
Women age 65 or older are commonly screened. Postmenopausal women under 65 may also need screening when important risk factors are present.
What if I do not know my T-score?
Leave the T-score blank. The calculator still works using age, body size, menopause, fracture history, and other clinical factors.
What does an OST score below 2 mean?
It is a simple flag often used to identify people who may benefit from additional osteoporosis evaluation or bone density testing.
What does an ORAI score of 9 or more mean?
In women, that threshold is often used to support further screening. It is a screening aid, not a final diagnosis.
What T-score suggests osteoporosis?
A T-score of -2.5 or lower is in the osteoporosis range. Scores between -1.0 and -2.5 suggest low bone mass.
Can men use this calculator?
Yes, but routine screening evidence in men is less certain. Results in men should be interpreted with clinician judgment, especially when risk factors cluster.