Gong 2008.

Methods	Multicentre, randomised, double‐blind, placebo‐controlled, parallel groups. No enrichment or imputation method mentioned Forced titration from 300 mg daily to 1800 mg daily over 8 days, then stable dose to 6 weeks
Participants	PHN N = 231 Mean age 66 years (± 12), 43% women Mean baseline PI: 6.2/10 (± 1.3)
Interventions	Gabapentin 1800 mg daily, n = 109 Placebo, n = 106 Rescue medication: 2 x 100 mg tramadol if required 3 days after reaching maximum dose of gabapentin
Outcomes	≥ 25% and ≥ 50% pain relief PGIC ("mild effective" and "excellent") Sleep Quality of life Adverse events
Notes	Oxford Quality Score: R = 1, DB = 2, W = 0, Total = 4 Unknown funding
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not adequately described. "Patients were randomised to different groups according to their recruitment order", but then refers to "pre‐determined code"
Allocation concealment (selection bias)	Unclear risk	Not adequately described. "Researchers allocated the treatments according to the pre‐determined code"
Blinding (performance bias and detection bias) All outcomes	Low risk	"Identical‐appearing capsules containing placebo were used to blind the patients"
Incomplete outcome data (attrition bias) Efficacy	High risk	Withdrawals (7%) and reasons for withdrawal not given per treatment group. No information about how data from withdrawals contributed to analyses
Size Efficacy	Unclear risk	50‐199 participants per treatment arm (106, 109)