Statistical analyses
The included studies with adjusted OR/RR/HR and 95% CIs were
meta-analyses. The RRs were used as the general effect estimates of
studies; HRs were considered comparable to RRs;9 ORs
were transferred to RRs using the published method.26The RRs and corresponding 95% CIs were calculated using the
DerSimonian-Laird random-effects model. Statistical heterogeneity was
tested using Cochran Q test (significance level: 0.1) and
I2 Statistics (>50%: considerable
heterogeneity).27 To explore possible sources of
heterogeneity, subgroup analyses were performed based on study designs
(prospective vs. retrospective studies), a history of stroke (patients
with a prior stroke only vs. patients with and without prior stroke),
observational window (with vs. without); sensitivity analysis was
carried out by the leave-one-out method. Publication bias was explored
with a funnel plot, and statistically evaluated by the Begg’s and
Egger’s tests, and the trim-and-fill method. All analyses were performed
using the STATA 16.0 (StataCorp, College Station, TX, USA), and ap -value of <0.05 indicated a statistically significant
difference.