3.3. Risk of Bias
Bias assessment of RCTs is demonstrated in Table 2. There were some concerns about the risk of bias in the two single-center trials22,23 (allocation concealment, postoperative use of antiarrhythmics and anticoagulants), while CTSN trial had low risk of bias (Table 2.) 13,21. In respect to baseline and intraoperative characteristics, PVI (total N=127) and Cox-Maze patients (total N=126) appeared reasonably balanced within individual trial. Bias assessment of NRSIs is demonstrated in Table 3. Out of 3 NRSIs, one had a serious risk of bias (Table 3) 24.