OASIS (Oxford Acute Severity of Illness Score)
OASIS Oxford Acute Severity of Illness Score: pre-ICU stay, age, GCS, heart rate, MAP, respiratory rate, temperature, urine output, mechanical ventilation, and elective-surgical status map to a score with predicted in-hospital mortality.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Pre-ICU length of stay
- 2 hours
- Age
- 70 years
- Glasgow Coma Scale
- 10
- Heart rate
- 130 bpm
- Mean arterial pressure
- 55 mmHg
- Respiratory rate
- 28 breaths/min
- Temperature
- 35 °C
- Urine output
- 500 mL/24 h
- On mechanical ventilation
- Yes
Result: OASIS 51 — predicted in-hospital mortality 58.1%.
The tool opens with these values already filled in. Replace them with your own.
What the result means
- Mortality
- Predicted in-hospital mortality via logit = −6.1746 + 0.1275·OASIS. A low-input alternative to APACHE II / SAPS II; a model estimate, not an individual prognosis.
What you enter
- Pre-ICU length of stay
- Age
- Glasgow Coma Scale (3–15)
- Heart rate
- Mean arterial pressure
- Respiratory rate
- Temperature
- Urine output
- On mechanical ventilation (+9)
- Elective surgical admission (leave unchecked for urgent / emergency / medical, +6)
How this is calculated
- Inputs
- Ten banded variables: pre-ICU stay, age, GCS, heart rate, MAP, respiratory rate, temperature, urine output, mechanical ventilation, and elective vs non-elective status (total 0–75).
Johnson AEW, Kramer AA, Clifford GD. A new severity of illness scale using a subset of Acute Physiology and Chronic Health Evaluation data elements shows comparable predictive accuracy. Crit Care Med. 2013;41(7):1711-1718. Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.