CALCA and Sepsis: Tan M et al reported in their meta analysis that PCT in terms of diagnostic accuracy has AUC of 0.85 (95% CI, 0.82-0.88), with a sensitivity and specificity of 0.80 (95% CI, 0.69-0.87) and 0.77 (95% CI, 0.60-0.88) respectively for diagnosis of sepsis.19 Ahmed S et al reported 93.8% sensitivity and 43.5% specificity at cut off of 0.5ng/ml.