Horton 2000.
| Study characteristics | |||
| Patient sampling | Patients 18 to 65 years old presenting to the Emergency Department with equivocal symptoms and signs of appendicitis Patients with unequivocal symptoms and signs of appendicitis (symptom duration < 48 hours, migration of pain to right lower quadrant, rebound tenderness, anorexia, and white blood cell count > 10,000) were excluded Included patients were randomised to have ultrasonography or unenhanced CT of the abdomen Recruitment period: May 1997 to May 1999 |
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| Patient characteristics and setting | Age range (mean): not stated ‐ inclusion criterion age 18 to 65 years Gender distribution: not stated for the CT group. Overall 54% women Emergency Department in Seattle, Washington, USA. Single‐centre study Disease spectrum: intermediate suspicion of appendicitis |
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| Index tests | Unenhanced CT of the lower abdomen. Model name and manufacturer of the CT‐scanner were not stated. Slice thickness: 5 mm. Slice interval, voltage, and mAs product: not stated | ||
| Target condition and reference standard(s) | Appendicitis. It is unclear whether the reference standard is the intraoperative finding of an inflamed appendix or histological assessment of the removed appendix. Patients who did not have surgery were followed up | ||
| Flow and timing | 106 patients with equivocal signs of appendicitis were included. 17 of these were withdrawn because the admitting surgeon believed that presentation was typical; these patients were admitted for surgery without diagnostic imaging. Of the remaining 89 patients, 49 were randomly allocated to CT. Among these, 38 had appendicitis and 37 had surgery with appendectomy. Follow‐up was uneventful in 9 patients, other diagnoses were made in 2 patients, and 1 patient was treated for appendicitis with antibiotics | ||
| Comparative | |||
| Criteria for CT diagnosis of appendicitis | One or more of the following: appendix diameter > 6 mm, appendicolith, inflamed pericaecal fat, pericaecal free fluid with or without gas bubbles | ||
| 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? | Unclear | ||
| Low | Unclear | ||
| DOMAIN 3: Reference Standard | |||
| Is the reference standards likely to correctly classify the target condition? | Unclear | ||
| 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? | 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 | |||