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Evidence summaries

C-Reactive Protein in the Diagnosis of Acute Appendicitis

CRP appears to be a test of medium accuracy and a little inferior to the total leukocyte count in the diagnosis of acute appendicitis. Level of evidence: "B"

A systematic review 1 including 22 studies with a total of 3 436 subjects was abstracted in DARE. The cut-off value for CRP varied from 5 to 25 mg/L. Mean sensitivity was 0.70, ranging from 40% to 0.99, and mean specificity was 0.62, ranging from 0.27 to 0.90. Pooling of studies gave overall sensitivity of 0.62 and overall specificity of 0.66. Regression line of D on S: D = 0.428S + 1.467, where S is the test threshold and D represents how well the test discriminates between the well and diseased populations. Comparison of diagnostic accuracy of leukocyte count (13 studies) with CRP showed statistically significantly better diagnostic accuracy of leukocyte count: mean leukocytes D = 2.008 vs mean for CRP D = 1.529, p=0.04.

    References

    • Hallan S, Asberg A. The accuracy of C-reactive protein in diagnosing acute appendicitis--a meta-analysis. Scand J Clin Lab Invest 1997 Aug;57(5):373-80. [PubMed][DARE]

Primary/Secondary Keywords