Concordance of endotoxemia with gram-negative bacteremia. A meta-analysis using receiver operating characteristic curves.

OBJECTIVE: To apply meta-analysis to compare the concordance between the results of 2 types of limulus amebocyte lysate (LAL) assay, gelation (GLAL) and chromogenic (CLAL), with the detection of gram-negative bacteremia in patients with suspected bacteremia. DESIGN: Meta-analysis using receiver operating characteristic-based analytical method. DATA SOURCES: MEDLINE literature search and manual reviews of article bibliographies together with direct approaches to authors of potentially eligible studies. STUDY SELECTION: The studies that were selected had all included at least 10 patients, of whom at least 2 patients were diagnosed with gram-negative bacteremia, and all had data available for extraction into a contingency table format. RESULTS: Fifty-six studies (28 GLAL and 28 CLAL studies) met the inclusion criteria. Studies were stratified by type of test (GLAL vs CLAL). Each analysis was repeated with smaller studies excluded. There was no difference between the 2 types of LAL assays. Among the CLAL studies, there was no difference between studies that did versus those that did not use the sepsis syndrome criteria as a basis for patient inclusion. Among 45 studies for which data on the proportion of non-Enterobacteriaceae were available, there was a trend toward higher concordance as this proportion increased. CONCLUSIONS: The concordance between the LAL test and the detection of gram-negative bacteremia in patients with suspected bacteremia is no higher with the CLAL assay than with the original GLAL version. However, the concordance is higher among studies with a higher proportion of non-Enterobacteriaceae among the gram-negative bacteremia isolates.