2.6. Data extraction and quality assessment

Data were extracted by 2 independent reviewers. Important information such as the adverse cardiovascular and bleeding outcomes which were reported in the original studies, the duration of follow-up, the number of DM participants who were assigned to the DT and TT groups respectively, the type of oral anticoagulants, the comorbidities which were reported, the year of publication, the type of study (randomized trial or observational cohort), the number of events in each outcome category were carefully extracted. Any disagreement was carefully discussed and resolved by consensus.

The methodological quality of the randomized trials was assessed by the recommendations suggested by the Cochrane collaboration^[13] whereas the methodological quality of the observational cohort was assessed by the Newcastle Ottawa Scale (NOS).^[14]