Serum procalcitonin levels as a diagnostic marker for septic arthritis: A meta-analysis.

Background: The aim of this study was to assess the value of serum procalcitonin (PCT) levels as a diagnostic marker for septic arthritis (SA) via meta-analysis.

Methods: We searched PubMed, Embase and the Cochrane Library, as well as the reference lists of relevant articles, for studies published up to May 21, 2015 and did not impose language restrictions. We selected original studies reporting the usefulness of PCT or C-reactive protein (CRP) as a diagnostic marker for SA. We summarized test performance characteristics with the use of forest plots, hierarchical summary receiver operating characteristic curves, and bivariate random effects models. Prespecified subgroup analyses and meta-regression analyses were also performed.

Results: This meta-analysis comprised 10 studies including 838 patients. The overall sensitivity of serum PCT levels for the diagnosis of SA in these studies was 0.54 (95% CI, 0.41-0.66), and the specificity of PCT was 0.95 (95% CI, 0.87-0.98). The positive likelihood ratio (LR) was 10.97 (95% CI, 4.65-25.89); the negative LR was 0.49 (95% CI, 0.38-0.62); and the area under ROC curve (AUROC) was 0.82 (95% CI, 0.78-0.85). Six studies also examined the usefulness of CRP levels as a marker for the diagnosis of SA. The sensitivity and specificity of CRP were 0.45 (95% CI, 0.35-0.55) and 0.079 (95% CI, 0.0.021-0.25), respectively, and the positive LR, negative LR and AUROC curve were 0.48 (95% CI, 0.39-0.61), 6.79 (95% CI, 2.04-23.81), and 0.30 (95% CI, 0.26-0.34), respectively.

Conclusion: PCT is more valuable than CRP for distinguishing SA from non-SA.