Table 1.

Risk of bias within randomized control trials

Source	Randomization	Allocation concealment	Blinding of participants & personnel	Blinding of outcome assessment	Incomplete outcome data	Selective reporting
Bonsignore MR et al. 2008	Low risk	Unclear risk	Low risk	Low risk	Low risk	Unclear risk
Boyd, A. et al. 2011	Low risk	Unclear risk	Low risk	Low risk	Low risk	Unclear risk
Bundgaard A, et al. 1982	Unclear risk	Low risk	Low risk	Low risk	Low risk	Unclear risk
Cochrane LM et al.	Low risk	Low risk	Low risk	Low risk	Low risk	Unclear risk
Emtner, M. et al. 1998	Low risk	Unclear risk	Low risk	Low risk	Low risk	Unclear risk
Fanelli A, et al. 2007	Low risk	Low risk	Low risk	Low risk	Low risk	Unclear risk
Fitch, KD et all, 1986	Unclear risk	Unclear risk	Low risk	Low risk	Low risk	Unclear risk
Gunay, O. et al. 2012	Unclear risk	Low risk	Low risk	Low risk	Low risk	Unclear risk
Henriksen JM, et al. 1983	Unclear risk	Low risk	Low risk	Low risk	Low risk	Unclear risk
Matsumoto I, et al. 1997	Low risk	Unclear risk	Low risk	Low risk	Low risk	Unclear risk
Mendes, et al. 2011	Low risk	Low risk	Low risk	Low risk	Low risk	Unclear risk
Moreira, A et al. 2008	Low risk	Low risk	Low risk	Low risk	Low risk	Unclear risk
Neder JA, et al. 1999	Unclear risk	Low risk	Low risk	Low risk	Low risk	Unclear risk
Onur E, et al. 2011	Unclear risk	Low risk	Low risk	Low risk	Low risk	Unclear risk
Sly RM, et al. 1972	Unclear risk	Unclear risk	Low risk	Low risk	Low risk	Unclear risk
Svenonius E, et al. 1983	Unclear risk	Low risk	Low risk	Low risk	Low risk	Unclear risk