Table 3.

Cochrane Risk of Bias for Randomized Controlled Trials Tool for the study selected [31].

	Risk of Bias	Observations
Random sequence generation (selection bias)	Low
Allocation concealment (selection bias)	High	The authors did not provide details about the method of allocation concealment and in the baseline variables there were apparent imbalance between the CBD and placebo groups in the following variables: Gender, previous CBD use, Vibratory Sensation, and NPS domains of Intense, Sharp, Itchy, Deep, Surface. Such imbalance could be due to deficiencies in the randomization process due to insufficient concealment
Blinding of participants and personnel (performance bias)	Unclear	The study had an open label phase, and it is not clear how much this influenced some of the statistical analyses
Blinding of outcomes assessment (detection bias)	Unclear	The study had an open label phase, and it is not clear how much this influenced some of the statistical analyses
Incomplete outcome data (attrition bias)	High	The lost to follow-up rate was high, about 20% (3 subjects in each arm)
Selective outcome reporting (reporting bias)	High	When other common methods to assess the intervention effectivity, like the change of NPS scores from baseline to week 4 (end of RCT blinded phase) are performed to the study data the benefits of the intervention are not confirmed and the protocol of the study was not published before its beginning