Data Extraction:
Two independent reviewers extracted data onto 3 different forms; abstract of relevant data, assess risk of bias, statistical Data.
For the abstract of relevant Data form, extracted data included year of publication, study design, patient entry period, number of patients, population demographics (i.e. age, sex), surgical characteristics (type of cryoablation), drug characteristic (dosage, period and type of AAD), place of intervention and follow up period.
For the assess risk of bias form, we worked according to the Cochrane Collaboration’s tool for assessing risk of bias (Higgins 2011), and extracted data relevant to each risk of bias: (16)
Afterwards, we evaluated each risk as high, low, or unclear, as stated by Higgins 2011. Discrepancies were resolved by discussing every risk of bias until consensus was reached. Since our study has a surgical component, blinding was not possible for ethical and practical reasons. Furthermore, our measurement of outcome should not be affected by unblended participants, since they are all objectively measured, for example; morbidity and mortality.
For the statistical data we extracted, the total number of participants in each leg of each study, % of follow up, number of serious adverse events, number of serious adverse events related to trial, recurrence Atrial Fibrillation, Atrial Tachycardia, Atrial Flutter all the data was reported within 1 year of follow up post treatment.