Studies need to be Randomized controlled trials (RCT) other study
designs were excluded.
Population: patients known to have atrial fibrillation w/o history of
antiarrhythmic drug treatment or surgery.
Intervention and Comparison: Cryoablation and AAD respectively
Outcome: Recurrence of arrhythmia or any other related morbidity
Studies that did not meet these criteria were excluded. Two
investigators used a standardized spreadsheet, based on the inclusion
and exclusion criteria, in order to select studies to be included in the
review.