Short-term mortality of adult inpatients with community-acquired pneumonia: external validation of a modified CURB-65 score

ABSTRACT

Objective

The management of community-acquired pneumonia (CAP) continues to be a challenge, especially in older people. To enable better risk stratification, a variation of the severity scores CRB-65 and CURB-65, called CURB-age, has been suggested. We compared the association between risk groups as defined by the scores and 30-day mortality for a cohort of mainly older inpatients with CAP.

Methods

We retrospectively analysed data from the CAP database from the years 2005 to 2009 of a single centre in Herne, Germany. Patient characteristics, criteria values within the severity scores CURB-65, CRB-65 and CURB-age, and 30-day mortality were assessed. We compared the association between score points and score-defined risk groups and mortality. Sensitivity and specificity with corresponding 95% CIs were calculated, and receiver operating characteristic (ROC) curve analysis was performed.

Results

Data from 559 patients were analysed (mean age 74.1 years, 55.3% male). Mortality at day 30 was 10.9%. CURB-age included more patients in the low-risk category than CRB-65 (195 vs 89), and the patient group had a lower mortality (2.6% vs 3.4%). When compared with CURB-65, CURB-age included slightly fewer patients (195 vs 214) with lower mortality (2.6% vs 4.2%). CURB-age sorted the most patients who died within 30 days into the high-risk CAP group (CURB-age, 32; CURB-65, 28; CRB-65, 9), which had the highest mortality (CURB-age, 26.4%; CURB-65, 19.4%; CRB-65, 21.4%). Advantages of CURB-age categories were depicted through ROC curve analysis (area under the curve 0.73 (95% CI 0.67 to 0.79) for CURB-age categories, 0.67 (95% CI 0.60 to 0.74) for CURB-65 categories, and 0.59 (95% CI 0.52 to 0.66) for CRB-65 categories).

Conclusions

In comparison with CRB-65 and CURB-65, risk stratification as defined by CURB-age showed the closest association with 30-day mortality in our sample. Further prospective studies are needed to assess the potential of CURB-age for better risk prediction, especially in older patients with CAP.

INFECTIOUS DISEASES, community-acquired pneumonia, risk prediction, CURB-65, CURB-age