Bias	Authors’ Judgement	Support for Judgement
Random sequence generation (selection bias)	Unclear risk	Note: The author mentioned that participants were randomly assigned to receive treatment, but we do not know how it was done, because we had access only the abstract.
Allocation concealment (selection bias)	Unclear risk	Note: The authors indicated only that participants were randomly assigned to receive treatment, but we do not know how it was done, because we had access only the abstract. It was not described in the abstract.
Blinding of participants and personnel (performance bias)	Unclear risk	Note: The authors did not mention any details about the blinding of participants and personnel in the abstract.
Blinding of outcome assessment (detection bias)	Unclear risk	Note: The authors did not mention any details about the blinding of outcome assessment in the abstract.
Incomplete outcome data (attrition bias)	Unclear risk	Quote: “123 patients completed 1-year follow up.” Note: 16.89% did not completed 1-year follow up. However, the proportion of dropout is low, the authors did not state any dropout reason.
Selective reporting (reporting bias)	High risk	Quote: “At 3, 6, 12 months post - therapy, the incidence of PHN was still significantly lower in the gabapentin group than in the standard group” Note: The authors reported incomplete outcome results.
Other bias	Unclear risk	Note: We cannot assess other bias because we did not have enough data from the abstract.