maratoolAPACHE II vs SOFA
A side-by-side comparison of APACHE II Score and SOFA Score.
APACHE II (Acute Physiology and Chronic Health Evaluation, 1985) and SOFA (Sequential Organ Failure Assessment, 1996) both quantify ICU severity but answer different questions. APACHE II is a one-time admission score predicting hospital mortality from the worst 24-hour physiology. SOFA is a daily/dynamic score that tracks organ dysfunction over time and meets the Sepsis-3 diagnostic criterion when acutely increased by ≥ 2.
When to use APACHE II Score
Use APACHE II at ICU admission for prognosis and case-mix adjustment. It is widely used in clinical trials, ICU benchmarking, and resource allocation discussions. The score captures both acute physiology and chronic health status.
When to use SOFA Score
Use SOFA daily for organ dysfunction tracking during the ICU stay. Acute SOFA increase of ≥ 2 from baseline in a patient with suspected infection meets Sepsis-3 sepsis criteria. SOFA is also used in some research as a continuous severity measure.
Side-by-side comparison
| APACHE II | SOFA | |
|---|---|---|
| Year introduced | 1985 | 1996 |
| Purpose | Admission prognosis | Dynamic organ dysfunction tracking |
| When calculated | Once, on ICU admission | Daily (or per shift) |
| Inputs | 12 acute physiology + age + chronic health | 6 organ systems |
| Score range | 0–71 | 0–24 |
| Predicts | In-hospital mortality | Organ dysfunction progression, Sepsis-3 criterion |
| Includes age? | Yes (weighted 0–6) | No |
| Includes chronic health? | Yes | No |
| Used in Sepsis-3? | No | Yes (≥ 2 acute increase = sepsis) |
Bottom line
APACHE II is the snapshot at admission; SOFA is the movie that follows. They are complementary — most ICU dashboards show both.
Frequently asked questions
Has APACHE II been replaced?
APACHE IV (2006) is the most recent version and is statistically more accurate, but APACHE II remains widely cited in literature and used in many institutional protocols due to its simpler calculation. SAPS II is a common European alternative.
Can SOFA replace APACHE II for prognosis?
Admission-day SOFA correlates with mortality but was not designed for prognosis the way APACHE II was. APACHE II adjusts for age and chronic health status; SOFA does not.
What is "baseline" SOFA for Sepsis-3?
In a previously healthy patient, baseline SOFA is assumed = 0. In a patient with chronic organ dysfunction (e.g., known CKD), baseline reflects their stable state — an acute increase is what defines sepsis.
Do these scores include neurological assessment?
Both include the Glasgow Coma Scale. APACHE II uses 15 − GCS as one of its physiology variables; SOFA scores CNS dysfunction by GCS bands (0 = 15, 4 = < 6).