What is the SAPS II Score?

SAPS II (Simplified Acute Physiology Score II) is an illness severity scoring system for ICU patients aged 18 and above, published by Le Gall et al. in 1993 based on a European/North American multicenter study. The score sums points from 12 physiologic variables (worst values during the first 24 hours of ICU care), age points, chronic disease points (metastatic cancer, hematologic malignancy, or AIDS), and admission type points (scheduled surgical, medical, or unscheduled surgical), for a total of 0–163. The higher the score, the more severe the patient condition at the population level.

How is the SAPS II Score calculated?

Sum points from 15 components: age (<40 years = 0, 40–59 = 7, 60–69 = 12, 70–74 = 15, 75–79 = 16, ≥80 = 18); heart rate; systolic blood pressure; temperature (≥39°C = 3); PaO2/FiO2 ratio if ventilated; urine output; BUN/urea; white blood cells; potassium; sodium; bicarbonate; bilirubin; GCS (<6 = 26, 6–8 = 13, 9–10 = 7, 11–13 = 5, 14–15 = 0); chronic disease (none = 0, metastatic cancer = 9, hematologic malignancy = 10, AIDS = 17); and admission type (scheduled surgical = 0, medical = 6, unscheduled surgical = 8). This calculator shows a transparent per-component point breakdown.

How is SAPS II converted into a mortality estimate?

SAPS II uses the logistic regression equation from its original publication: logit = −7.7631 + 0.0737 × SAPS II + 0.9971 × ln(SAPS II + 1), then probability = e^logit / (1 + e^logit). As a guide: score 29 ≈ 10%, score 40 ≈ 25%, score 52 ≈ 50%, score 64 ≈ 75%, and score 77 ≈ 90% hospital mortality. These are population statistics from the original study, not predictions for individual patients.

Which value is used: average or worst?

For each physiologic variable, SAPS II uses the value farthest from normal (worst) during the first 24 hours after ICU admission — not the average. For example, temperature uses the highest value, bicarbonate the lowest, and GCS the lowest (if the patient is sedated, estimate pre-sedation GCS). If heart rate showed both cardiac arrest (11 points) and extreme tachycardia (7 points), take 11 points. If the patient was treated for less than 24 hours, extrapolate urine output to 24 hours.

When is the PaO2/FiO2 ratio scored in SAPS II?

The PaO2/FiO2 ratio is only scored if the patient is on mechanical ventilation or CPAP — use the lowest ratio value in 24 hours (<100 = 11 points, 100–199 = 9 points, ≥200 = 6 points). If the patient was not ventilated or not on CPAP in the last 24 hours, this component scores 0 points.

What is the difference between SAPS II and SAPS III?

SAPS III (Moreno et al., 2005) is the next generation: it uses first-1-hour data (not 24 hours), covers more variables such as admission reason and pre-ICU location, with a 0–217 score range and a different mortality equation. SAPS II remains widely used in Europe for ICU quality benchmarking. This calculator computes SAPS II per the Le Gall 1993 publication.

What is the difference between SAPS II and APACHE II?

Both are adult ICU severity scores, but: APACHE II (Knaus, 1985) sums 12 physiologic variables + age + chronic disease for a total of 0–71 and uses a discrete mortality table; SAPS II (Le Gall, 1993) sums 15 components (including admission type and more specific chronic diseases) for a total of 0–163 and converts the score into a mortality estimate via a continuous logistic equation. Both are population statistics, not individual predictions.

Can this SAPS II calculator be used for clinical decisions?

No. This calculator is an educational tool for understanding how SAPS II scoring works. Its mortality estimate is a population statistic from the 1993 study and must not be used to determine individual patient prognosis, triage decisions, or withdrawal of therapy. All clinical decisions must be made by the ICU team caring for the patient, considering the complete clinical picture.

MEDICAL CALCULATOR · EDUCATIONAL

SAPS II Score Calculator

Q: How is SAPS II converted into a mortality estimate?

SAPS II uses the logistic regression equation from its original publication: logit = −7.7631 + 0.0737 × SAPS II + 0.9971 × ln(SAPS II + 1), then probability = e^logit / (1 + e^logit). As a guide: score 29 ≈ 10%, score 40 ≈ 25%, score 52 ≈ 50%, score 64 ≈ 75%, and score 77 ≈ 90% hospital mortality. These are population statistics from the original study, not predictions for individual patients.

Q: Which value is used: average or worst?

For each physiologic variable, SAPS II uses the value farthest from normal (worst) during the first 24 hours after ICU admission — not the average. For example, temperature uses the highest value, bicarbonate the lowest, and GCS the lowest (if the patient is sedated, estimate pre-sedation GCS). If heart rate showed both cardiac arrest (11 points) and extreme tachycardia (7 points), take 11 points. If the patient was treated for less than 24 hours, extrapolate urine output to 24 hours.

Q: When is the PaO2/FiO2 ratio scored in SAPS II?

The PaO2/FiO2 ratio is only scored if the patient is on mechanical ventilation or CPAP — use the lowest ratio value in 24 hours (<100 = 11 points, 100–199 = 9 points, ≥200 = 6 points). If the patient was not ventilated or not on CPAP in the last 24 hours, this component scores 0 points.

Q: What is the difference between SAPS II and SAPS III?

SAPS III (Moreno et al., 2005) is the next generation: it uses first-1-hour data (not 24 hours), covers more variables such as admission reason and pre-ICU location, with a 0–217 score range and a different mortality equation. SAPS II remains widely used in Europe for ICU quality benchmarking. This calculator computes SAPS II per the Le Gall 1993 publication.

Q: What is the difference between SAPS II and APACHE II?

Both are adult ICU severity scores, but: APACHE II (Knaus, 1985) sums 12 physiologic variables + age + chronic disease for a total of 0–71 and uses a discrete mortality table; SAPS II (Le Gall, 1993) sums 15 components (including admission type and more specific chronic diseases) for a total of 0–163 and converts the score into a mortality estimate via a continuous logistic equation. Both are population statistics, not individual predictions.

Q: Can this SAPS II calculator be used for clinical decisions?

No. This calculator is an educational tool for understanding how SAPS II scoring works. Its mortality estimate is a population statistic from the 1993 study and must not be used to determine individual patient prognosis, triage decisions, or withdrawal of therapy. All clinical decisions must be made by the ICU team caring for the patient, considering the complete clinical picture.

Calculate the Simplified Acute Physiology Score II (Le Gall et al., JAMA 1993): 12 physiologic variables + age points + chronic disease points + admission type points. Total 0–163, with a transparent per-variable point breakdown and hospital mortality estimate from the original logistic regression equation.

⚠ Important limitations — read first

This calculator is an educational tool. SAPS II is a prognostic score populasi from a 1993 study — it is not a prediction of outcomes for individual patients and must not be used for triage decisions, individual prognosis, or withdrawal of therapy.

All clinical decisions must be made by tim ICU the team caring for the patient. Use the worst values during the first 24 hours of ICU care for each variable, per the original definition.

1 · Physiologic variables (worst first-24-hour values)

2 · Usia, penyakit kronis & tipe admisi

Usia

<40: 0 · 40–59: 7 · 60–69: 12 · 70–74: 15 · 75–79: 16 · ≥80: 18

Patient age (years)

0 points

Chronic disease

select the most severe one (if more than one, take the highest points)

None Kanker metastatik · 9 Keganasan hematologi (limfoma, leukemia akut, mieloma multipel) · 10 AIDS (HIV+ with clinical complications) · 17

0 points

Tipe admisi

definition: scheduled = surgery scheduled ≥24 hours in advance

Scheduled surgical · 0 Medical (no surgery within 1 week before admission) · 6 Unscheduled surgical · 8

0 points

Severe ICU case example / reset:

3 · Results

Total SAPS II Score

rentang 0–163

Estimated hospital mortality: ≈0,0%
Kategori (konteks populasi): low
Logit value: -7,7631

Mortality estimate is calculated from the Le Gall 1993 logistic regression equation and reflects the observed death rate in populasi studi — not an individual patient's probability of death. This is an educational tool, not medical advice.

Breakdown per variabel

Per-component point breakdown (worst first-24-hour values)
Komponen	Input value	Points
Total SAPS II		0

Reference table: mortality estimate vs score (Le Gall 1993 logistic equation)

Hospital mortality estimates at reference score points, calculated from the original equation. Population statistics, not individual predictions.
SAPS II Score	Estimasi mortalitas

Per-variable point table (transparent)

All SAPS II point bands per the Le Gall et al., JAMA 1993 publication. A value exactly at a band's lower bound falls in that band.
Variabel	Value range	Points

Methodology note: each variable uses the terburuk (farthest from normal) value during the first 24 hours of ICU — temperature uses the tertinggi, bicarbonate uses the terendah, GCS uses the terendah (if sedated, estimate pre-sedation GCS). PaO2/FiO2 ratio₂/FiO₂ is only scored if the patient is on mechanical ventilation or CPAP. Chronic disease: if more than one, take only the highest points. Unit conversions: BUN (mg/dL) = urea (mmol/L) × 2,8; bilirubin (mg/dL) = µmol/L ÷ 17,1.

Scope boundary: this tool calculates SAPS II (Le Gall 1993) for adult (≥18 years) ICU patients. It does not cover SAPS III (Moreno 2005, 0–217 range, different equation), APACHE III/IV, pediatric scores (PRISM/PIM), or daily organ dysfunction scores like SOFA — use the appropriate score calculator for your needs. For comparison with APACHE II, see the related calculators below.

Frequently asked questions (FAQ)

Related calculators

APACHE II Score Calculator — Knaus 1985 ICU severity score (12 physiologic variables + age + chronic disease, total 0–71) with a mortality estimate table.

Free tool by NRTechStudio

SAPS II Score Calculator

1 · Physiologic variables (worst first-24-hour values)

2 · Usia, penyakit kronis & tipe admisi

Usia

Chronic disease

Tipe admisi

3 · Results

Breakdown per variabel

Reference table: mortality estimate vs score (Le Gall 1993 logistic equation)

Per-variable point table (transparent)

Frequently asked questions (FAQ)

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