Malone 1993.

Study characteristics
Patient sampling	Patients with equivocal symptoms and signs of appendicitis were referred to a Radiology Department for an emergency barium enema. No exclusion criteria were stated Recruitment period: May 1991 to not stated
Patient characteristics and setting	Age range (mean): 4 to 91 years (ns). 59% women Radiology Department in Arlington Heights, Illinois, USA. Single‐centre study Disease spectrum: intermediate suspicion of appendicitis
Index tests	Non‐helical CT of the lower abdomen without contrast enhancement (GE 9800 or PACE, General Electric). Slice thickness and interval: 10 mm. Voltage and mAs product: not stated
Target condition and reference standard(s)	Appendicitis. Surgical reports and histopathological reports were provided for patients who had surgery with or without appendectomy. Patients who did not have surgery were followed up clinically for up to 6 months ‐ patients were contacted to determine if symptoms had resolved, and if surgery had been performed elsewhere at a later date
Flow and timing	211 patients were included, 94 had surgery, and 75 had appendicitis. The 117 patients who did not have surgery were followed up, and none had appendicitis
Comparative
Criteria for CT diagnosis of appendicitis	A thickened appendix > 6 mm with associated inflammatory changes in the periappendiceal fat and/or abnormal thickening in the right lateroconal fascia with or without an appendicolith
Assessors of the CT‐scan	Not stated
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?	Unclear
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?	Yes
		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?	Yes
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