Koc 2005.

Methods	Randomised clinical trial.
Participants	Country: Turkey. Number randomly assigned: 53. Postrandomisation dropouts: three (5.7%). Revised sample size: 50. Mean age: 47 years. Females: 41 (82%). Inclusion criteria: 1. Elective laparoscopic cholecystectomy for symptomatic gall stones. 2. ASA I to III. Exclusion criteria: 1. Acute cholecystitis or acute pancreatitis. 2. Common bile duct exploration or another surgical procedure. 3. Treatment with drugs that influence neurohormonal parameters.
Interventions	Participants were randomly assigned to different pressures of pneumoperitoneum. Group 1: low pressure 10 mm Hg (n = 25). Group 2: standard pressure 15 mm Hg (n = 25).
Outcomes	The outcome reported was operating time.
Notes	Reason for postrandomisation dropout: conversion to open cholecystectomy (group not stated). Attempts to contact the trial authors in February 2008 were unsuccessful.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Comment: This information was not available.
Allocation concealment (selection bias)	Low risk	Quote: "...patients were randomized to low‐ or high‐pressure pneumoperitoneum groups by closed envelope method in the operating room prior to surgery."
Blinding (performance bias and detection bias) All outcomes	High risk	Quote: "...a short‐form MGQ (SF‐MGQ) was obtained from all patients by a research assistant who was blind to the group allocation of the patients." Comment: Assessor blinding of primary outcomes was not performed, and so the blinding is inadequate in this trial.
Incomplete outcome data (attrition bias) All outcomes	High risk	Comment: Three postrandomisation dropouts were due to conversion to open cholecystectomy.
Selective reporting (reporting bias)	High risk	Comment: Important outcomes such as mortality and morbidity were not reported.
For‐profit bias?	Unclear risk	Comment: This information was not available.