Jo 2010.

Study characteristics
Patient sampling	Consecutive patients presented to the Emergency Department with pain in the right lower quadrant of the abdomen. Patients younger than 15 years and patients referred from other hospitals with confirmed diagnoses of appendicitis were excluded
Patient characteristics and setting	Mean age: 37.3 years, 54% women. Patients younger than 15 years, pregnant women, patients with renal insufficiency, and patients with allergy to contrast medium were excluded Emergency Department in Seoul, Korea Disease spectrum: any suspicion of appendicitis
Index tests	CT of the entire abdomen with intravenous contrast enhancement (Brilliance, Philips Medical Systems). No further information about the CT‐scanner and the CT‐protocol
Target condition and reference standard(s)	Appendicitis. Histological examination was performed in patients who had an appendectomy; follow‐up was provided for patients who did not have surgery (telephone calls with structured interview 3 months after CT)
Flow and timing	278 patients were included; 91 were withdrawn (see notes). Of the remaining 187 patients, 120 had surgery and 67 had follow‐up. 111 patients had appendicitis
Comparative
Criteria for CT diagnosis of appendicitis	Not reported. Radiologists' confidence in the diagnosis was scored on a 5‐point scale, with 1 indicating normal appendix and 5 indicating definite appendicitis
Assessors of the CT‐scan	3 board certified body imaging radiologists
Notes	This study compares the accuracy of 3 index tests: CT and clinical assessments made by surgical and emergency medicine residents. The reason for withdrawal of 87 of 91 patients was lack of evaluation by the surgical resident
Methodological quality
Item	Authors' judgement	Risk of bias	Applicability concerns
DOMAIN 1: Patient Selection
Was a consecutive or random sample of patients enrolled?	Yes
Did the study avoid inappropriate exclusions?	Yes
Does the study population represent an unselected sample of adults with suspected appendicitis?	No
		Low	High
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?	No
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?	Yes
		High	High
DOMAIN 3: Reference Standard
Is the reference standards likely to correctly classify the target condition?	No
Were the reference standard results interpreted without knowledge of the results of the index tests?	Unclear
		High	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?	Unclear
Did all patients with a negative CT‐scan have clinical follow‐up?	Unclear
Was the choice of reference standard independent of the result of the index test?	No
Were all patients included in the analyses?	No
		High