Sensitivity and specificity of the decision rule in the derivation and validation populations.

Values are expressed as values or % (95% CI).Discriminative values were compared using a χ2 test for unpaired sample.*Data in the column come from the previously published derivation of the decision rule [34].**Adjusted OR were calculated with the multi-level logistic regression models.†Differences are rounded to the closer integer.Abbreviations: NPV, Negative predictive value; OR, Odd ratio; PCT, Procalcitonin; PPV, Positive predictive value.