2.2 Inclusion criteria
The eligibility criteria included the following:
(1) Cohort studies (prospective or retrospective) or randomized control
trials reporting MAE after the diagnosis of BrS including SCD, sudden
cardiac arrest, VF, sustained ventricular tachycardia, and appropriate
shock in BrS patients diagnosed from drug challenge test by sodium
channel blocker (SCB) and spontaneous Type-1 electrocardiogram (ECG).
(2) Adjusted or unadjusted relative risk, Odds ratio (OR), hazard ratio
with 95% confidence interval (CI), or sufficient raw data for the
calculation were provided. Patients with spontaneous Type-1 ECG were
used as controls.
Study eligibility was independently determined by two investigators (CK
and NP) and differences were resolved by mutual consensus. The
Newcastle-Ottawa quality assessment scale (NOS) was used to assess each
study’s quality in three domains, recruitment and selection of the
participants, similarity and comparability between the groups, and
ascertainment of the outcome of interest among cohort and case-control
studies (7).
2.3 Data extraction A standardized data collection form was used to obtain the following
information from each study: title of study, name of first author, year
of publication, study design, country of origin, number, gender and age
of the participants, Brugada ECG pattern, incidence of MAE, available
MAE outcome, follow-up duration, and confounders that were adjusted in
the multivariable analysis, if available.
Two investigators (JK and PM) independently performed this data
extraction process to ensure accurate data extraction. Any data
discrepancy was resolved by referring back to the original articles.