Table 2. Quality of RCTs accessed by Cochrane risk of bias assessment.

Study ID	Random sequence generation	Allocation concealment	Blinding of participantsand personnel	Blinding of outcome assessment	Incomplete outcomedata	Selective reporting	Other bias
Chesnut 2012	low risk	unclear risk	unclear risk	unclear risk	low risk	unclear risk	unclear risk
Kostic 2011	high risk	unclear risk	unclear risk	unclear risk	low risk	unclear risk	unclear risk

RCTs: randomized controlled trials.