Tan 2015.
| Study characteristics | |||
| Patient sampling | Patients with suspected appendicitis were referred for CT. The decision on inclusion and CT was made by the attending surgeon during the initial assessment No exclusion criteria were stated Recruitment period: August 2013 to March 2014 |
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| Patient characteristics and setting | Age range (median): 15 to 82 years (33). 62% women General Surgery and Radiology Department in Singapore. Single‐centre study Disease spectrum: mainly patients with intermediate suspicion of appendicitis | ||
| Index tests | 256‐slice CT of the entire abdomen with intravenous contrast enhancement (iCT 256, Philips Healthcare). Slice thickness: 0,625 mm. Slice interval: not stated. Voltage: 120 kV. mAs product: up to 1000 mAs | ||
| 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. Follow‐up consisted of checking for readmission within 2 weeks after discharge | ||
| Flow and timing | 450 patients with suspected appendicitis were eligible for inclusion. Of these, 350 were included and all had CT. 168 patients had surgery, 155 had appendicitis confirmed histologically, and 182 had follow‐up | ||
| Comparative | |||
| Criteria for CT diagnosis of appendicitis | Appendix diameter, any involvement of base, any gas pockets to suggest perforation, any fat stranding or periappendicular abscess | ||
| Assessors of the CT‐scan | Radiologist on duty | ||
| Notes | Information about the CT‐scanner and radiological criteria for appendicitis were provided by the corresponding author | ||
| 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? | Unclear | ||
| 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 | ||
| Unclear | 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? | 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 | |||