Validity of British Thoracic Society guidance (the CRB-65 rule) for predicting the severity of pneumonia in general practice: systematic review and meta-analysis

Abstract

The CRB-65 score is a clinical prediction rule that grades the severity of community-acquired pneumonia in terms of 30-day mortality. AimThe study sought to validate CRB-65 and assess its clinical value in community and hospital settings. Design of studySystematic review and meta-analysis of validation studies of CRB-65. Medline (1966 to June 2009), Embase (1988 to November 2008, British Nursing Index (BNI) and PsychINFO were searched, using a diagnostic accuracy search filter combined with subject-specific terms. The derived (index) rule was used as a predictive model and applied to all validation studies. Comparison was made between the observed and predicted number of deaths stratified by risk group (low, intermediate, and high) and setting of care (community or hospital). Pooled results are presented as risk ratios (RRs) in terms of over-prediction (RR>1) or under-prediction (RR<1) of 30-day mortality. Method ResultsFourteen validation studies totalling 397 875 patients are included. CRB-65 performs well in hospitalised patients, particularly in those classified as intermediate (RR 0.91, 95% confidence interval [CI] = 0.71 to 1.17) or high risk (RR 1.01, 95% CI = 0.87 to 1.16). In community settings, CRB-65 over-predicts the probability of 30-day mortality across all strata of predicted risk, low (RR 9.41, 95% CI = 1.75 to 50.66), intermediate (RR 4.84, 95% CI = 2.61 to 8.69), and high (RR 1.58, 95% CI = 0.59 to 4.19). ConclusionCRB-65 performs well in stratifying severity of pneumonia and resultant 30-day mortality in hospital settings. In community settings, CRB-65 appears to over-predict the probability of 30-day mortality across all strata of predicted risk. Caution is needed when applying CRB-65 to patients in general practice. Keywordsgeneral practice; meta-analysis; pneumonia; prognosis; severity of illness index. INTRODUCTIONCommunity-acquired pneumonia (CAP) has an annual incidence of 5-11 per 1000, accounting for 5-12% of all cases of adult lower respiratory tract infection managed by GPs.1 Appropriate management for patients with suspected CAP must be determined by GPs at initial presentation, particularly with regard to whether or not to manage a patient in the community or refer them to hospital.2 The proportion of adults with CAP who require hospital admission in the UK varies between 22% and 42%.1 This proportion varies in other countries, possibly due to differing structures of primary and secondary healthcare systems.

Syncope Risk Stratification in the Emergency Department

“…Moreover, there is no consensus about risk thresholds, and different groups consider different thresholds to be acceptable. 10,25 …”

Severity assessment for lower respiratory tract infections: potential use and validity of the CRB-65 in primary care

“…There have been three recent systematic reviews of evidence for using severity assessment rules in the management of CAP. [10][11][12] Two of these excluded patients who had not had a chest x-ray. 10,11 This limited the applicability of the findings as an x-ray is not performed for most patients with LRTI managed in the community.…”

“…The third review compared the use of the CRB-65 to predict 30-day mortality in hospital and community settings, and found that the rule over-predicted the probability of mortality in community settings. 12 However, while studies have evaluated the use of CRB-65 in outpatient clinics, emergency departments, and private specialist clinics, [13][14][15][16] only one study has evaluated its use in primary care, and this study was limited to older patients (aged >65 years) with an empirical diagnosis of pneumonia. 17 No study has yet assessed the extent to which primary care clinicians routinely assess the features that make up the CRB-65 score, the value of the CRB-65 in all adults presenting with LRTI in primary care, or whether the tool can be used to predict more severe or prolonged illness in the community.…”

CURB‐65 Performance Among Admitted and Discharged Emergency Department Patients With Community‐acquired Pneumonia

“…CURB-65 has fewer variables than the Pneumonia Severity Index (PSI), which requires 20 separate patient characteristics and does not require obtaining an arterial blood gas, yet has demonstrated similar accuracy in predicting 30-day mortality in studies of patients who have been hospitalized. [11][12][13][18][19][20][21][22][23][24][25] Patients who were kept in the hospital under observation status were included among patients admitted to the hospital. CURB-65 scores were calculated based on the established severity scoring system 19 for each adult ED pneumonia encounter, using elements from the electronic health record.…”