Lee 2014.

Study characteristics
Methods	Randomised clinical trial
Participants	Country: South Korea Number randomised: 63 Postrandomisation dropouts: not stated Revised sample size: 63 Average age: not stated Females: not stated Cirrhosis: not stated Very early HCC: 0 (0%) Portal hypertension: not stated Viral aetiology: not stated Immunotherapy/antiviral adjuvant therapy: not stated Average follow‐up period in months (for all groups): not stated Criteria for early or very early HCC and other inclusion criteria: Single nodule 2 to 4 cm
Interventions	Participants were randomly assigned to 2 groups: Group 1: surgery (n = 29). Further details: not stated whether surgery was open or laparoscopic resection. Group 2: radiofrequency ablation (n = 34). Further details not available.
Outcomes	The outcomes reported were: mortality, adverse events, HCC recurrence.
Notes	Reasons for postrandomisation dropouts: not stated
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Comment: this information was not available.
Allocation concealment (selection bias)	Unclear risk	Comment: this information was not available.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Comment: this information was not available.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Comment: this information was not available.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Comment: this information was not available.
Selective reporting (reporting bias)	Low risk	Comment: important clinical outcomes were reported.
For‐profit bias	High risk	Comment: grant/research support: Green Cross, Chong Kun Dang Pharm, Novartis, SK Chemicals
Other bias	Low risk	Comment: no other bias noted.