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. 2017 Sep 26;12(4):1320–1360. doi: 10.1111/crj.12674

Table 3.

Features of common scoring scales for evaluating CAP severity

Scales Indices and calculation Risk ratings Recommendation

CURB‐65

score 64

5 indices in total; 1 pt for each criterion satisfied:

  1. Disturbance of consciousness;

  2. BUN >7 mmol/L;

  3. RR ≥ 30 bpm;

  4. SBP < 90 mm Hg or DBP ≤ 60 mm Hg;

  5. age ≥ 65 yrs.

Mortality risk evaluation:

0–1: low risk;

2: moderate risk;

3–5: high risk

 Simple, highly sensitive, easy for clinical application

CRB‐65

score 64

4 indices in total; 1 pt for each criterion satisfied:

  1. Disturbance of consciousness;

  2. RR ≥ 30 bpm;

  3. SBP < 90 mm Hg or DBP ≤ 60 mm Hg;

  4. age ≥ 65 yrs.

Mortality risk evaluation:

0: low risk, outpatient treatment;

1–2: moderate risk, hospital admission or extramural treatment with close follow‐up is recommended;

≥3: high risk, patient should be hospitalized

 Suitable for medical institutions unable to perform biochemical tests
PSI score 65 Sum of age (female minus 10 pts) and scores for all risk factors:

  1. Residing in a geracomium (+10 pts);

  2. Underlying disease: tumour (+30 pts); hepatic disease (+20 pts); congestive heart failure (+10 pts); cerebrovascular disease (+10 pts); renal disease (+10 pts);

  3. Physical signs: change in state of consciousness (+20 pts); RR ≥ 30 bpm (+20 pts); SBP < 90 mm Hg (+20 pts); body temperature < 35°C or ≥ 40°C (+15 pts); heart rate ≥ 125 bpm (+10 pts);

  4. Laboratory tests: arterial blood pH < 7.35 (+30 pts); BUN ≥30 mg/dL (or 11 mmol/L) (+20 pts); blood sodium < 130 mmol/L (+20 pts); blood glucose ≥ 14 mmol/L (+10 pts); Haematocrit (Hct) < 30% (+10 pts); PaO2 < 60 mm Hg (or fingertip O2 saturation < 90%) (+10 pts);

  5. Chest radiograph: pleural effusion (+10 pts).

Evaluation of mortality risk:

Low risk: Class I (<50 years of age, without underlying diseases);

Class II (≤70 pts);

Class III (71–90 pts);

Moderate risk: Class IV (91–130 pts);

High risk: Class V (>130 pts).

Patients at Classes IV and V need hospitalization

Sensitive measurement for evaluating whether a patient needs hospitalization, highly specific.

Complex scoring system

CURXO

score 66

Major indices:
  1. Arterial blood pH < 7.30;
  2. SBP < 90 mm Hg.
Minor indices:
  1. RR ≥ 30 bpm;
  2. Disturbance of consciousness;
  3. BUN > 11 mmol/L;
  4. PaO2 < 54 mm Hg or oxygenation index < 250 mm Hg;
  5. Age ≥ 80 yrs;
  6. Chest X‐ray showing multiple‐lobe or bilateral pulmonary involvement.
 Patients are diagnosed as severe CAP if any one of the major indices or two of the minor indices are met Simple scoring method used for emergency diagnosis of severe CAP

SMART‐COP

Score 67

Sum of scores for all the following risk factors:

SBP < 90 mm Hg (+2 pts); chest X‐ray showing bilateral pulmonary involvement (+1 pt); serum albumin < 35 g/L (+1 pt); RR ≥ 30 bpm (> 50 yo) or ≥ 25 bpm (≤ 50 yo) (+1 pt); heart rate ≥ 125 bpm (+1 pt); New onset of disturbance of consciousness (+1 pt); hypoxemia (+2 pts): PaO2 < 70 mm Hg, or fingertip O2 saturation ≤ 93%, or oxygenation index < 333 mm Hg (≤ 50 yo); PaO2 < 60 mm Hg, or fingertip O2 saturation ≤ 90%, or oxygenation index < 250 mm Hg (>50 yo); arterial blood pH < 7.35 (+2 pts).

0–2: low risk

3–4: moderate risk

5–6: high risk

7–8: extremely high risk

 A score > 3 indicates the possibility that the patient needs respiratory monitoring or circulatory support therapy