2.3 Data extraction
Information was collected for each study including the following
aspects: (1) name of the first author; (2) publication year; (3) study
type; (4) continent where the study was conducted; (5) mean age or
range; (6) outcome of the diseases; (7) ovaries status (hysterectomy
with ovarian preservation; hysterectomy with unilateral oophorectomy;
hysterectomy with bilateral oophorectomy; hysterectomy with
oophorectomy); (8) age at operation; (9) OR , RR orHR with 95% CI including accompanying oophorectomy or not
and age at operation; (10) case number and sample size; (11) adjusted
covariates. If more than one RRs provided, we extracted RRs
(95% CI) which controlled the influential confounding factors to the
greatest extent. Two investigators (Z.W. and X.L.) independently
extracted data and any disagreements were resolved by discussing with
the third investigator (D.Z.).