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A-DROP Score | Adult Pneumonia Severity

For adults with pneumonia. Septic shock cannot be diagnosed from blood pressure alone. Missing or unknown answers do not count as a negative finding (0 points).

Complete the fields, then select Calculate.

Required fields depend on your selections.

A Age

One point for men aged 70 or older, or women aged 75 or older.

years

D Dehydration

One point for BUN ≥21 mg/dL or clinical dehydration.

Clinical dehydration
mg/dL

BUN may be omitted when dehydration is confirmed. Otherwise, a BUN value may be needed to resolve this criterion.

R Respiration

One point for SpO₂ ≤90% or PaO₂ ≤60 Torr.

Enter the method with its measurement. When available SpO₂ and PaO₂ results conflict, do not rely on a single measure for clinical classification.

O Orientation

One point for altered consciousness.

Altered consciousness

P Pressure

One point for systolic blood pressure ≤90 mmHg.

mmHg

Septic shock exception (not part of the five-point score)

JRS 2024: septic shock with at least one positive criterion classifies as very severe.

Septic shock (clinically assessed separately)

Not calculated: complete the questions and select Classify severity.

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Scoring method, applicability and references

Scoring method

According to the Japanese Respiratory Society Adult Pneumonia Guidelines (2024), A-DROP Table 1 (p. 31), each of the five criteria contributes one point. A score or severity cannot be finalized with essential unknown answers.

0: mild; 1–2: moderate; 3: severe; 4–5: very severe. Septic shock with one or more A-DROP criteria is very severe under the stated exception. Septic shock with zero positive criteria is not covered by that exception and remains unclassified.

Example (hypothetical)

Male, age 70, no dehydration, BUN 20 mg/dL, SpO₂ 91%, no altered consciousness, systolic BP 120 mmHg, no septic shock: age is the only positive criterion; 1 point (moderate). With separately confirmed septic shock the same score is classified as very severe.

Limits

Do not use A-DROP alone to diagnose pneumonia or septic shock, decide treatment setting, or prescribe medication. Oxygen therapy, conflicting SpO₂/PaO₂, missing laboratory tests and hospital-acquired pneumonia require separate clinical consideration.

Evidence and review

JRS 2024 adult pneumonia A-DROP, sources checked 2026-11-10. Underlying numeric checks: implementer-verified.