Data extraction, strength of evidence assessment, and bias
assessment
Two reviewers (Mingjie Lin and Wenqiang Han) independently extracted the
designed variables and data, including first author, year, country,
study design, number of patients, age, sex, follow-up time, AF
detection, dementia or cognitive deficit definition,
CHADS2 or CHA2DS2-VASc
Score,history of stroke, observational window, maximum adjusted
covariates, defined OAC use, drugs of OACs, percentage of OACs use,
comparison group, adjusted OR/RR/HR with 95% CIs. The correspondent
authors were contacted by e-mail when overall adjusted OR/RR/HR were
missing. The study was excluded if the authors did not reply. Another
reviewer (Jingquan Zhong) checked the extracted data. Disagreements
regarding any extracted data were resolved by discussion among the three
reviewers.
Two reviewers (Mingjie Lin and Wenqiang Han) independently assessed the
strength of evidence (SOE) and risk of bias. Any disagreements were
resolved through discussion. The SOE was evaluated based on five
domains: study limitations, directness, consistency, precision, and
reporting bias; it was defined as four levels: high, moderate, low,
insufficient.24 Risk of bias assessment was evaluated
with the Cochrane risk of bias tool for RCTs20 and the
Newcastle-Ottawa Scale (NOS) for observational
studies.25 The RCT was classified as low, high, or
unclear risk. The observational study with NOS score ≥ 8 was defined as
high quality.