Before you use this calculator

Use of this calculator is charged at AUD $1,250.00 per use, plus GST — a total of AUD $1,375.00 (including GST of $125.00). Proceeding to the calculator constitutes your agreement to this fee and to the terms set out below.

This calculator is operated by The Trustee for Victorian Neuro & Ortho Rehab Services Pty Ltd (ABN 49 344 093 742), the practice of Assoc. Prof. Vaidya Bala ("the provider").

Nature and intended use

This calculator produces a statistical estimate of remaining life expectancy following moderate-to-severe traumatic brain injury, based on the peer-reviewed actuarial model published in Bala (2026). It is a decision-support aid intended solely for suitably qualified health, rehabilitation and medico-legal professionals exercising their own independent judgement.

An estimate, not a prediction

Each result is a population mean for a group of people sharing the entered characteristics. It is not a prediction of any individual's lifespan and is not a guarantee. The life expectancy of any particular person may differ substantially from the estimate.

Not advice; no professional relationship

The calculator does not provide medical, clinical, legal or financial advice. Use of it does not create any clinician–patient or practitioner–client relationship, and it is not a substitute for individual clinical assessment or independent expert opinion.

Known limitations

The model does not account for factors including problematic substance use, psychiatric comorbidity or post-injury seizures; it is derived from United States cohorts of inpatient-rehabilitation survivors and predates the COVID-19 pandemic; its functional categories are broad; and the severity (SMR) mode is a screening approximation only. Results must be interpreted in light of these limitations.

User responsibility and discretion

Whether and how to rely on any output is entirely a matter for the user's professional discretion and responsibility. The user is responsible for the accuracy of the inputs entered, for interpreting outputs in their full clinical and evidentiary context, and for compliance with all applicable professional, ethical, evidentiary and regulatory obligations.

No warranty; liability

The calculator is provided "as is", without warranty of any kind as to accuracy, completeness or fitness for a particular purpose. To the maximum extent permitted by law, the provider excludes all liability for any loss or damage arising from use of, or reliance on, the calculator or its outputs. Nothing in these terms excludes, restricts or modifies any right or remedy that cannot lawfully be excluded, including under the Australian Consumer Law.

Intended purpose

The calculator is supplied as a structured actuarial aid to professional judgement. It is not intended to diagnose, treat, cure or prevent any disease or condition.

Intellectual property and governing law

The calculator and underlying model are © 2026 The Trustee for Victorian Neuro & Ortho Rehab Services Pty Ltd (ABN 49 344 093 742). The model is described in Bala (2026), J Brain Neuros Res 10:040. These terms are governed by the laws of New South Wales, Australia.

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Actuarial estimator · moderate-to-severe TBI, 1-year survivors

Remaining life years after traumatic brain injury

Enter a patient's characteristics to estimate expected remaining years of life, with the full step-by-step audit trail the estimate is built from. Implements the four-step disability-graded life-table procedure and the SMR screening fallback described in Bala (2026).

Patient inputs

Four inputs drive the estimate: current age, sex, and either functional category or injury severity.

Current age40 yrs

Sex

Estimation method

Functional category

Estimated remaining life expectancy

25 further years

Projected mean age at death 65 · General-population figure at this age 39 yrs

Reduction vs general population

14 yrs

Relative reduction

36%

Method

Functional

Survival curve from current age This patient General population

Audit trail

Every quantity that produced the estimate, for review and reporting.

Read before use — this is an estimate, not a prediction

The figure is a population mean for a group of similar patients. It is not a guaranteed lifespan for any one person and must be presented as such.
The model omits several known mortality modifiers, including problematic alcohol or drug use, psychiatric comorbidity, and post-injury seizures. Adjust by clinical judgement for the specific case.
Functional categories are broad. The "does not walk, fed by others" group overstates survival in the most extreme neurological states (prolonged disorders of consciousness, gastrostomy dependence); "walks well" is pessimistic for people living wholly independently.
Parameters derive from United States moderate-to-severe TBI cohorts of inpatient-rehabilitation survivors, and predate the COVID-19 pandemic. Extrapolation to other health systems, untreated injury, or uncomplicated mild TBI is uncertain.
The severity (SMR) mode is a screening approximation only, assuming constant relative risk across age. Prefer the functional method where FIM data exist.
Intended as a structured aid to — not a replacement for — individualised clinical judgement. Pair every estimate with its caveats and, where required, a standard error.