Key Point

The CURB-65 score accurately classifies pneumonia patients according to mortality and other risks and can be used to guide their management.

BIZKAIA, SPAIN—The Pneumonia Severity Index has been useful in assessing community-acquired pneumonia (CAP) and will continue to be. However, two other CAP evaluation tools, the CURB-65 score and its relative the CRB-65 score, were recently validated.¹

CURB-65, as many pulmonologists know, is an acronym for Confusion, Urea (geater than 7 mmol⋅L^-1), Respiratory rate (30⋅min^-1 or greater), low Blood pressure, and an age of 65 or older. "The current study demonstrates a significant correlation between the CURB-65 score and the risk of 30-day mortality, need for mechanical ventilation, and rate of hospital admission," related the authors. "Among hospitalized patients, the CURB-65 score was significantly associated with duration of hospital stay."

The results were similar for the even simpler CRB-65 score, the authors also reported; they pointed out that a urea measurement was omitted from that score. The study’s principal author was Alberto Capelastegui, MD, who is Director of the Service of Pneumology at the Hospital of Galdakao in Bizkaia, Spain.

ACCURATE CLASSIFICATION

The ability of the CURB-65 and CRB-65 scores to stratify CAP patients into different management groups was prospectively evaluated among 1,776 adults diagnosed with CAP in the emergency department during a four-year period. The mean age of the study population was 61.8; about 55% of the patients were 65 or older.

Nearly 62% of the patients were hospitalized and about 38% were managed as outpatients. Forty-five were admitted to the ICU; of this group, 18 required mechanical ventilation and five (11.1%) died within 30 days. Thirty-day mortality was 6.7% overall and 10.7% among inpatients.

Thirty-day mortality, mechanical ventilation, and hospitalization rates were all directly related to the CURB-65 and CRB-65 scores. The 30-day mortality rates for CURB-65 scores of 0 through 5 were 0%, 1.1%, 7.6%, 21%, 41.9%, and 60%, respectively. "The [area under the curve] of the CURB-65 was similar to the CRB-65 and to the [Pneumonia Severity Index] with regard to prediction of pneumonia mortality," the authors said.

Among hospitalized patients, in-hospital and 30-day mortality rose with CURB-65 scores. In this group, significant associations were also observed between CURB-65 scores and the duration of intravenous antibiotic therapy, the risk of being hospitalized for more than three days, and mechanical ventilation. The mechanical ventilation rates for each of the CURB-65 scores ranging from 0 to 5 were 0%, 0.8%, 2.3%, 2%, 4.2%, and 11.1%, respectively.

"We confirmed that the CURB-65 score accurately classifies patients with CAP into different management groups that correlate with key CAP management points," Dr. Capelastegui told Pulmonary Reviews. "The CURB-65 and CRB-65 scores are simple clinical approaches that can be applied in the community setting to augment clinical judgment regarding the need for hospital admission. Likewise, at admission, they can help physicians determine which patients may be candidates for early discharge."

The authors suggested the following mortality risk classifications based on the CURB-65 score.

0: Very low risk; home treatment may be appropriate.

1: Relatively low risk; home treatment may be appropriate, but further assessment of admission criteria is needed.

2: Intermediate risk of mortality; short-stay inpatient treatment should be considered.

> 2: High risk; management for severe pneumonia is necessary.

COMBINE ASSESSMENT SYSTEMS?

In an editorial, Niederman and colleagues recommended using both the CURB-65 score and Pneumonia Severity Index.² The two scoring systems are complementary and neither can stand alone, the authors explained.

They suggested that low-risk patients with a Pneumonia Severity Index of I to III or a CURB-65 score of 0 or 1 be managed at home if serious vital sign abnormalities or comorbidities are absent and if there are no social factors or other illnesses requiring hospitalization. "Moderate risk patients (CURB-65 of 2 or greater or Pneumonia Severity Index classes IV and V) would be admitted," said the authors, "and scoring systems and clinical assessments could be used to separate those who need intensive care from those who are likely to become clinically stable rapidly and who would then require only a short hospital stay."

Ewig and coauthors acknowledged that pneumonia assessment tools such as the CURB-65 score are useful but cautioned that they cannot replace sound clinical judgment.³ "In particular, insurance companies must not be allowed to refuse compensation when a patient with a low risk score has been hospitalized," the authors stressed. "In order to convincingly prevent such deleterious malpractice, physicians should document the severity score together with a brief comment why they feel that this particular patient should be hospitalized despite a low risk score."

—Timothy Begany

Reference
1. Capelastegui A, España PP, Quintana JM, et al. Validation of a predictive rule for the management of community-acquired pneumonia. Eur Respir J. 2006;27:151-157.
2. Niederman MS, Feldman C, Richards GA. Combining information from prognostic scoring tools for CAP: an American view on how to get the best of all worlds. Eur Respir J. 2006;27:9-11.
3. Ewig S, Torres A, Woodhead M. Assessment of pneumonia severity: a European perspective. Eur Respir J. 2006;27:6-8.

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