[Ability of the modified CRB75 severity scale in assessing elderly patients with community acquired pneumonia].

OBJECTIVE: To compare the ability of the classic CRB65 (confusion, respiratory rate, blood pressure and age ≥65 years) vs the modified CRB-75 for the severity assessment of patients 65 years or older with community acquired pneumonia (CAP).

DESIGN: Prospective cohort study.

SETTING: Tarragona Health Region.

PARTICIPANTS: A total of 350 patients ≥65 years with a radiographically confirmed CAP (hospitalized or outpatient) during 2008-2010.

MAIN OUTCOME MEASURES: The CRB-65 score (confusion; respiratory rate ≥30; systolic blood pressure <90 mmHg or diastolic ≤ 60 mmHg; age ≥65 years) and the modified CRB-75 (similar criteria but age ≥75 years) were calculated at the time of diagnosis, and 30-day mortality was considered as the main dependent variable.

RESULTS: The overall 30-day mortality rate was 13.1% (4% in outpatient CAP and 15% in hospitalized CAP). According to CRB-65, mortality was 7,7% with a score of 1, 22.5% with a score of 2, and 50% with a score of 3 (no cases with a score of 4). Mortality also directly increased according to CRB-75, being 3,2% with a score of 0, 9,7% with a score of 1, 30.0% with a score of 2, and 45.5% with a score of 3. The discriminative value of both CRB65 and CRB75 rules to classify risk of short-term mortality among our study population was acceptable, with a better area under receive operating characteristic curve (ROC) for CRB75 than for CRB-65 (0,735 vs 0,681; P<.01).

CONCLUSION: Both CRB-65 and CRB-75 scales are an acceptable tool to classify mortality risk among elderly patients with CAP. However, CRB-75 can be more useful for evaluating patients over 65 years with CAP.