Table 3.

Risk of bias assessment for RCTs and pre–post studies

Source	Risk of bias (high, low, unclear)
	Randomisation sequence allocation	Concealment	Performance bias	Ascertainment bias	Incomplete outcome data	Selective reporting
RCTs
Campbell et al 33	Low	Low	Unclear	Unclear	Low	Unclear
Chen et al 39	Unclear	Unclear	Low	Low	Low	Unclear
Cheung et al 29	Low	Low	Low	Low	Low	Unclear
Gleeson et al 25	Low	Low	Unclear	Low	Low	Unclear
Hackney et al 32	High	High	High	Unclear	Low	Unclear
Jeter et al 42	Low	Low	High	Low	Low	High
Kovacs et al 30	Low	Low	Unclear	Low	Low	Unclear
Surakka et al 36	Unclear	Unclear	High	High	Unclear	Unclear
Waterman et al 34	Low	Low	High	Low	Low	Low
Pre–post with no comparison group
Ackley-Holbrook et al 31	–	–	–	–	Low	Unclear
Jeter et al 41	–	–	–	–	High	Unclear
Kingston37	–	–	–	–	Unclear	Unclear
Larsson43	–	–	–	–	Low	Unclear
Miszko et al 40	–	–	–	–	Unclear	Unclear
Ponchillia et al 27	–	–	–	–	Low	Unclear
Salari28	–	–	–	–	Unclear	Unclear
Surakka35	–	–	–	–	Unclear	Unclear

*Not applicable.

RCT, randomised controlled trials.