Role of Inflammatory Markers in Diagnosing Diabetic Foot Infection A Meta-Analysis

Background Inflammatory markers including erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and procalcitonin (PCT) are frequently ordered in suspected cases of diabetic foot infection (DFI). We did a meta-analysis to compare diagnostic performance of these inflammatory markers for detecting DFI. Materials and Methods The meta-analysis was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We used bivariate random-effects regression model to pool the sensitivity and specificity of the targeted biomarkers. Results A comprehensive literature search identified 73 studies. Twelve studies met our inclusion criteria. The number of studies reporting data on each individual biomarker was as follows: 11 for ESR, 7 for CRP, and 5 for PCT. For Infectious Diseases Society of America grade I versus grade II, we calculated pooled sensitivity and specificity for ESR to be 0.86 and 0.82, positive likelihood ratio (LR+) of 4.7, negative likelihood ratio (LR-) of 0.17, and area under receiver operating characteristic curve (AUROC) of 0.91. Pooled sensitivity and specificity for CRP were found to be 0.54 and 0.91, LR+ of 6.2, LR- of 0.50, and AUROC of 0.80. Pooled sensitivity and specificity for PCT were 0.72 and 0.96, LR+ of 18.4, LR- of 0.29, and AUROC of 0.84. For Infectious Diseases Society of America grade II versus grade III, we calculated pooled sensitivity and specificity for ESR to be 0.81 and 0.80, LR+ of 4.0, LR- of 0.24, and AUROC of 0.84. Conclusions Erythrocyte sedimentation rate has the highest AUROC of 0.91 followed by PCT (0.84) and CRP (0.80) to diagnose DFI. For osteomyelitis, ESR has a diagnostic accuracy of 0.84. Erythrocyte sedimentation rate could be beneficial in ruling out infection in persons who have low suspicion of disease (lowest -LR). For those who have high suspicion of disease, PCT could be helpful in ruling in infection (highest +LR). All inflammatory markers need standardization of threshold levels for detecting infection.