Decadt 1999.

Methods	Design of RCT: parallel clinical trial                                                        Power calculation: not stated                                                      No blinding used                                                            Follow‐up at six weeks                                                        120 participants recruited, 120 randomly assigned                                                    26 participants refused to enter the trial                                                     Lost from follow‐up: 12 participants in group 1 and 16 participants in group two did not answer the survey about well‐being scores at six weeks of discharge                                                120 participants analysed                                                    Single centre: Department of General Surgery, Norfolk and Norwich NHS Trust Hospital, Norwich, UK                                     Enrolment between November 1995 and October 1998       Source of funding: not stated   Ethical issues: text states only that informed consent was given   Method to establish definitive diagnosis: visual examination of appendix and abdominal cavity and histological examination of the appendix in laparoscopic group. Not clearly stated in conventional group
Participants	Acute abdominal pain of less than seven days' duration; after examination and baseline investigations, diagnosis remained uncertain  Tests: full blood count, measurement of urea, electrolytes, serum amylase, urine culture and pregnancy test in women of reproductive age. Chest and abdominal radiograph if indicated clinically    Exclusion criteria: participants in whom surgery was required even if the exact diagnosis was uncertain                                                   91 women and 29 men included: 43 women and 16 men in laparoscopy group and 48 women and 13 men in second group           Median age in laparoscopy group: 28 years (16 to 84). Median age in conventional group: 29 years (16 to 62)                                                        Median weight: 64 kg (43 to 111) in laparoscopy group; 68 (46 to 134) in conventional group                                                  Median serum white cell count: 11,000 (5300 to 23,100) in laparoscopy group; 10,700 (3300 to 25,600) in conventional group
Interventions	Early laparoscopy performed in first 18 hours versus active observation                                     Laparoscopy performed using an open Hasson technique for the first port placement in the umbilical area with one 5‐mm port in the midline suprapubic area and a third port if necessary When no abnormality identified at laparoscopy, appendicectomy performed                                                   Conventional method: information about this method not provided
Outcomes	Gastrointestinal and general well‐being: assessed on admission and after six weeks of follow‐up by means of combined Gastrointestinal Symptom Rating Scale (GSRS) and Psychological General Well Being Index (PGWB); stated in methods and reported                                                   Final diagnosis: reported.                                                             Duration of hospital stay: reported Radiological examinations: reported Complications: not validated, reported Readmission: reported                                                            Complications: reported                                                    Readmission rate: reported
User defined 1	76% of sample: women
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Randomly assigned by sealed envelopes: no further description about how randomisation was generated
Allocation concealment (selection bias)	Unclear risk	Paper: states only 'sealed opaque envelopes', nothing about whether they were sequentially numbered or when they were opened
Blinding (performance bias and detection bias) All outcomes	High risk	Open RCT
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Not clear whether follow‐up was similar in the two groups. All randomly assigned participants analysed. 28/120 did not answer the survey about well‐being scores at six weeks of discharge
Selective reporting (reporting bias)	Unclear risk	Protocol of the study not available
Free of differential verification bias	Unclear risk	Definitive diagnosis not done with the same reference standard in the two groups
Free of partial verification bias	Unclear risk	Non‐random set of participants not undergoing the reference standard
Free of Incorporation Bias	High risk	Index test incorporated as the reference standard in the laparoscopic group
Other bias	Unclear risk	All baseline characteristics not reported