Table 2.

Assessment of Risk of Bias

Study	Year	Random Sequence Generation	Allocation Concealment	Masking of Participants and Personnel	Masking of Outcome Assessments	Incomplete Outcome Data	Selective Reporting
Ada et al17	2013	Low risk	Low risk	High risk	Low risk	Low risk	Low risk
Chumbler et al18	2012	Low risk	Low risk	High risk	Low risk	Low risk	Low risk
Clemson et al19	2012	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk
Daniel20	2012	Unclear risk	Unclear risk	High risk	Unclear risk	Low risk	Unclear risk
Day et al21	2012	Low risk	Low risk	Low risk	Low risk	Low risk	Unclear risk
Fairhall et al22	2012	Low risk	Low risk	High risk	Low risk	Low risk	Low risk
Foster et al23	2013	Unclear risk	Unclear risk	High risk	Low risk	Low risk	Low risk
Green et al24	2002	Low risk	Low risk	High risk	Low risk	Low risk	Unclear risk
Haines et al25	2009	Unclear risk	Low risk	High risk	Low risk	Low risk	Unclear risk
Harrington et al26	2010	Low risk	Low risk	High risk	Low risk	Low risk	Unclear risk
Korpelainen et al27	2010	Low risk	Low risk	High risk	Low risk	Low risk	Unclear risk
Mayo et al28	2015	Low risk	Low risk	High risk	Low risk	Low risk	Unclear risk
Morey et al29	2009	Low risk	Low risk	High risk	Low risk	Low risk	Unclear risk
O’Shea et al30	2007	Unclear risk	Low risk	High risk	Low risk	Low risk	Unclear risk
Ouellette et al31	2004	Unclear risk	Unclear risk	Low risk	Unclear risk	Low risk	Unclear risk
Roaldsen et al32	2014	Unclear risk	Low risk	High risk	High risk	Low risk	Unclear risk
Winters-Stone et al15	2012	Low risk	Low risk	Low risk	Low risk	Unclear risk	Unclear risk
Winters-Stone et al33	2015	Unclear risk	Unclear risk	Unclear risk	Low risk	Low risk	Unclear risk