Kepner 2012.

Study characteristics
Patient sampling	Patients 18 years of age or older with clinically suspected appendicitis were referred for CT by Emergency Department (ED) physicians Exclusion criteria included pregnancy, allergy to intravenous or oral contrast material, creatine level ≥ 1.5 (unit not reported), current incarceration, inability to give informed consent, appendicitis not primary concern of the ED physician Included patients were randomised to receive CT of the entire abdomen with either intravenous (IV) contrast material or IV and oral contrast material
Patient characteristics and setting	IV contrast: age quartiles (median): 22 to 40 years (32). 59% women IV and oral contrast: age quartiles (median): 25 to 43 years (32). 55% women Emergency Department in York, Pennsylvania, USA. Single‐centre study Disease spectrum: unclear
Index tests	CT of the entire abdomen and pelvis via a 16‐slice CT‐scanner (Somatom Sensation, Siemens Medical Solutions). Slice thickness: 3 mm. Slice interval, voltage, and mAs product: not stated Included patients were randomised to receive enhancement by either intravenous (IV) contrast material or intravenous and oral contrast material
Target condition and reference standard(s)	Appendicitis. Intraoperative findings were used to confirm appendicitis in patients who were operated on. Patients who did not have surgery were followed up Follow‐up consisted of telephone calls within 1 week to 1 month after discharge. Letters with questionnaires and stamped return envelopes were sent to patients who could not be reached by telephone
Flow and timing	Overall 244 patients were included. 17 patients were excluded, including 3 patients lost to follow‐up. 114 patients were allocated to IV contrast, and 113 were allocated to IV and oral contrast IV contrast: 114 patients had CT. Appendicitis was found in 41 patients IV and oral contrast: 113 patients had CT. Appendicitis was found in 34 patients The number of patients who had surgery and the number who had follow‐up are not reported for any of the groups
Comparative
Criteria for CT diagnosis of appendicitis	Appendix diameter > 5 mm, localised abscess or fluid collection, appendicolith, periappendiceal fat stranding, hyperenhancement of the appendix mucosa, thickened appendix wall (> 2 mm) After evaluating the CT‐scan, the radiologist had the option of 'yes', 'no', or 'possible' for the diagnosis of appendicitis. In the analyses, 'possible' assessments were counted as 'yes'
Assessors of the CT‐scan	All CT‐scans were initially assessed by an attending radiologist. These assessments were not analysed Subsequently, 2 board certified radiologists with 18 years' and 27 years' experience reassessed all CT‐scans independently. These reassessments were used in the analyses. The board certified radiologists were unaware of the initial assessment. It is unclear how the 2 radiologists' assessments were aggregated into the reported single estimates for sensitivity and specificity
Notes
Methodological quality
Item	Authors' judgement	Risk of bias	Applicability concerns
DOMAIN 1: Patient Selection
Was a consecutive or random sample of patients enrolled?	Unclear
Did the study avoid inappropriate exclusions?	Yes
Does the study population represent an unselected sample of adults with suspected appendicitis?	Unclear
		Unclear	Unclear
DOMAIN 2: Index Test All tests
Were the index test results interpreted without knowledge of the results of the reference standard?	Yes
If a threshold was used, was it pre‐specified?	Yes
Is the index test described in sufficient detail to permit its replication?	No
Was the analysis based on the initial evaluation of the CT‐scan by the radiologist on call?	No
		Low	High
DOMAIN 3: Reference Standard
Is the reference standards likely to correctly classify the target condition?	Yes
Were the reference standard results interpreted without knowledge of the results of the index tests?	Unclear
		Unclear	Low
DOMAIN 4: Flow and Timing
Did all patients receive a reference standard?	Yes
Did all patients receive the same reference standard?	No
Did all patients with a positive CT‐scan have surgery?	No
Did all patients with a negative CT‐scan have clinical follow‐up?	Yes
Was the choice of reference standard independent of the result of the index test?	No
Were all patients included in the analyses?	Yes
		High