Whipps Cross 1998.

Methods	A randomisation schedule in balanced blocks randomly chosen to be of length 4 or 6. Allocations were placed in consecutive opaque envelopes and the seal broken in the anaesthetic room immediately before surgery.
Participants	403 patients with an inguinal hernia. Exclusion criteria included patients who were unfit for general anaesthesia, had psychological complaints, were under 18 years of age or had a poor understanding of English.
Interventions	Laparoscopic versus open mesh inguinal herniorrhaphy. Laparoscopic group: (n=200) repair performed by the TAPP technique. All patients were given a general anaesthesia, Open group: (n=200) repair performed by the Lichtenstein technique. All patients were given a local anaesthesia.
Outcomes	Included data items: Duration of surgery (minutes) Intraoperative complications Length of hospital stay (% discharged) Postoperative complications Persistent Numbness (1 and 3 months) Persistent pain (1 and 3 months) Hernia recurrence Mortality Other data items: Postoperative pain (day 1) SF36 Costs
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Low risk	A ‐ Adequate