Study	Reason for exclusion
Brodsky 1996	Outcomes: Blood loss for adenoidectomy not separated from tonsillectomy
Choy 1992	Allocation: Inadequate randomisation Patient acted as own control
Flint 1980	Allocation: Inadequate randomisation (hospital number) Patient acted as own control
Haddow 2006	Outcomes: No blinding of patient or outcome assessors
Haraldsson 2007	Allocation: Patient acted as own control
Kousha 2007	Allocation: Patient acted as own control
Lassaletta 1997	Allocation: Inadequate randomisation (alternating)
Leach 1993	Allocation: Unclear randomisation Patient acted as own control
Linden 1990	Allocation: High risk of performance bias No information on intraoperative bleeding Assessment of bleeding not blinded
MacGregor 1994	Allocation: No randomisation
Mann 1984	Allocation: Inadequate randomisation (social security number) Patient acted as own control
Pang 1995	Allocation: Unclear randomisation (there was also no blinding for pain/bleeding assessment)
Papangelou 1972	Allocation: Not randomised
Phillipps 1989	Allocation: Inadequate randomisation (alternating patients)
Pizzuto 2000	Outcomes: Pain data not reported Multiple outcome measures
Roy 1976	Allocation: Non‐randomised, non‐blinded
Salam 1992	Allocation: Inadequate randomisation (pack of cards)
Sengupta 1984	Allocation: Inadequate randomisation (alternating cases) Patient acted as own control
Tay 1995	Allocation: Patient acted as own control
Tay 1996	Allocation: Patient acted as own control
Watson 1993	Outcomes: No intraoperative bleeding assessment Assessment of postoperative bleeding not blinded
Weimert 1990	Allocation: Unclear randomisation Patient acted as own control
Wexler 1996	Allocation: Inadequate randomisation (alternating patients)