2.3 Data extraction and quality assessment
A standardized data collection form was extracted by two investigators
independently to obtain the following data from each study including
name of the first author, year of publication, country of origin, study
population, inclusion and exclusion criteria, demographic data of
participants, ablation procedure details. Disagreements were arbitrated
by a third person in re-review. The original author was contacted by
mail for access if the full text could be obtained. For literature in
which the same study populations were reported many times or repeatedly
published, only one with the most complete data was included. The
quality of these studies was evaluated by two investigators (Shuyu Jin
and Yumei Xue) using NewCastle Ottawa scale (NOS) for observational
studies and the Cochrane Collaboration tool for assessing risk of bias
of randomized controlled studies (RCTs). The NOS system consisted of
eight questions with nine possible points. Higher scores represent
higher study quality11,12.