Study designs of evaluations included in the review
All study designs were eligible for inclusion. The included studies were all prospective.
Specific interventions included in the review
Studies in which serum PCT was used to determine the severity of AP were eligible for inclusion. In the included studies, PCT was measured by BRAHMS immunoluminometric assay, PCT-Q immunoassay strip or radioimmunoassay. The time at which PCT was measured varied from on admission to 14 days post-diagnosis. The cut-off value for PCT varied from 0.252 to 2.0 ng/mL.
Reference standard test against which the new test was compared
Studies had to report some method of severity stratification to be included in the review. The reference standard was any method of determining the severity of AP other than serum PCT. All of the included studies involved computed tomography. Other methods used in the included studies were symptoms, amylase, lipase, ultrasound, fine-needle aspiration, Altanta criteria and multiple organ dysfunction score. Severity of AP was stratified either in terms of distinguishing mild from severe AP or sterile necrotising pancreatitis from infected necrotising pancreatitis.
Participants included in the review
Studies involving participants with a confirmed diagnosis of AP were eligible for inclusion. In the included studies, the age of the patients (where stated) ranged from 22 to 97 years and the proportion of male patients from 45 to 75%. All of the included studies involved patients with alcoholic or biliary AP; some studies also included other aetiologies.
Outcomes assessed in the review
For inclusion in the review, studies had to report sufficient data to enable the calculation of sensitivity and specificity. The primary outcomes were sensitivity and specificity; diagnostic odds ratios (DORs) and the area under the curve (AUC) of the receiver operator characteristic (ROC) curve were also reported.
How were decisions on the relevance of primary studies made?
The authors did not state how the papers were selected for the review, or how many reviewers performed the selection.