2.2 Study selection
All included studies were reviewed independently by two investigators
(Z.W. and X.L.), and the results were reviewed by the third investigator
(D.Z.). The inclusion criteria were restricted to (1) observational
studies (cohort studies, case-control studies and cross-sectional
studies); (2) the exposure of interest was hysterectomy; (3) the outcome
of interest was CVD or its
subordinate diseases; (4)
hazard ratio (HR ) or odds
ratio (OR ) or risk ratio (RR ) and 95% confidence interval
(95% CI ) were available; (5) the controls were women without
hysterectomy; (6) the most recent and complete article was adopted when
data were duplicated in more than once for the same outcome.