Hekimoglu 2011.

Study characteristics
Patient sampling	Patients presented with acute, non‐traumatic abdominal pain clinically suspected to be secondary to acute appendicitis. Patients with possible contrast allergy, pregnant women, and patients with abdominal trauma were excluded Recruitment period: March 2008 to October 2010 Patients were randomly allocated to receive either CT with intravenous contrast enhancement or CT with intravenous and oral contrast enhancement
Patient characteristics and setting	Intravenous contrast group: age range (mean): 20 to 66 years (42); 38% women Intravenous and oral contrast group: age range (mean): 18 to 74 years (38); 42% women Pregnant women and patients with possible contrast allergy were excluded Emergency Department in Ankara, Turkey. Single‐centre study Disease spectrum: unclear
Index tests	16‐slice CT of the entire abdomen with intravenous contrast enhancement (Sensation 16, Siemens Medical Solutions). Multi‐planar reconstructions were used Slice thickness: 5 mm. Slice interval: not stated. Voltage: 120 kV. mAs product: not stated Patients were randomly allocated to receive either CT with intravenous contrast enhancement or CT with intravenous and oral contrast enhancement
Target condition and reference standard(s)	Appendicitis. Histological examination was performed in patients who had an appendectomy and follow‐up was provided for patients who did not have surgery (review of medical records and telephone interviews 1 day and 1 week after discharge)
Flow and timing	Intravenous contrast group: 100 patients were included. All had CT; 26 had appendicitis confirmed histologically Intravenous and oral contrast group: 100 patients were included. All had CT; 32 had appendicitis confirmed histologically The number who had surgery and the number receiving follow‐up are not reported for any of the groups
Comparative
Criteria for CT diagnosis of appendicitis	Appendix diameter > 6 mm, thickened appendix wall, appendix wall hyperenhancement, periappendiceal fat stranding. In patients who had oral contrast enhancement, the absence of contrast filling of the appendix was considered an additional criterion in favour of appendicitis Radiologists used a 5‐point Likert scale to rate their confidence in the radiological diagnosis of appendicitis (1: definitely absent, 2: probably absent, 3: intermediate, 4: probably present, 5: definitely present) Patients rated 1 or 2 were considered CT negative; patients rated 4 or 5 were considered CT‐positive. Patients rated 3 were counted as CT negative when appendicitis was confirmed, and as CT‐positive when appendicitis was not confirmed (worst‐case scenario)
Assessors of the CT‐scan	All CT‐scans were evaluated by 2 radiologists with over 5 years' experience in interpreting abdominal CT‐scans Sensitivity and specificity were reported for each of the 2 radiologists. No consensus evaluation is available. Rounded mean numbers of true‐positives, false‐positives, false‐negatives, and true negatives were used in meta‐analyses
Notes	Patients were recruited for a randomised trial comparing CT with intravenous contrast enhancement vs CT with oral and intravenous contrast enhancement. The 2 groups are considered as individual studies in the meta‐analyses
Methodological quality
Item	Authors' judgement	Risk of bias	Applicability concerns
DOMAIN 1: Patient Selection
Was a consecutive or random sample of patients enrolled?	No
Did the study avoid inappropriate exclusions?	Yes
Does the study population represent an unselected sample of adults with suspected appendicitis?	No
		High	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?	Yes
Is the index test described in sufficient detail to permit its replication?	Yes
Was the analysis based on the initial evaluation of the CT‐scan by the radiologist on call?	Unclear
		Low	Unclear
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?	Unclear
Did all patients with a negative CT‐scan have clinical follow‐up?	No
Was the choice of reference standard independent of the result of the index test?	No
Were all patients included in the analyses?	Yes
		High