Study selection
Studies were considered if they provided specific information on younger
vs. Older patients within the main article or subgroup and if they
reported primary endpoints of interest in patients undergoing catheter
ablation of AF. Catheter ablation is a type of endocardial ablation
procedure (including radiofrequency or cryoablation). The following
criteria were used to determine which studies would be included: 1.
studies required to offer accurate information on at least one of the
main endpoints; and (2) endpoints were to be reported as numerical
occurrences rather than just hazard ratios, relative risks, or odds
rates. We made an effort to get in touch with the associated authors to
request further information if pertinent data were not given in the
published studies. Retrieval results were examined by three writers to
confirm that studies met the predetermined inclusion criteria.