SOCESP 1999.

Methods	RCT Open‐label Loss to follow‐up reported: yes
Participants	AF lasting < 6 months. Type: recent onset 61%, persistent 39% (mean duration: NS). n = 121 Men: 59% Age (mean): 54 (SD 13) years Structural heart disease: 54%. LAD: 39 mm. LVEF: 68%
Interventions	Quinidine 700 mg/day vs sotalol 240 mg/day Method of AF cardioversion: both pharmacological and electrical, % NS Warfarin discretionary
Outcomes	At 6 months: Mortality Proarrhythmia Adverse effects AF recurrence
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Method of randomisation not described.
Allocation concealment (selection bias)	Unclear risk	Method of allocation not detailed.
Blinding (performance bias and detection bias) All outcomes	High risk	Open‐label study.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Withdrawals were well detailed but unclear whether there were other participants lost to follow‐up.
Selective reporting (reporting bias)	Low risk	All prespecified outcomes and expected outcomes of interest were well reported.
Other bias	Low risk	No other bias apparent.