2.2. Data Extraction and Quality Assessment. Data extraction
was undertaken by TD and CK using a data extraction form
in accordance with the CONSORT statement for reporting
herbal medicinal interventions [27]. The data extracted and
reported included study design; number of participants; age
of participants; herbal compress ingredients; characteristics
of the intervention; and outcome measurement. Outcomes
of interest depended on indication of herbal compress. For
example, outcome measures for studies on pain reduction
were level of pain and difficulties in performing activities.
Time to milk secretion or milk ejection score was outcomes
of interest for studies that investigated the effects of herbal
compress on the induction of lactation. Studies included
in this review were assessed for methodological quality
by TD and CK using the Cochrane risk of bias tool [25]
and Jadad score [28]. The Cochrane risk of bias evaluates
bias in intervention studies based on a number of criteria
including sequence generation; allocation concealment;
blinding; incomplete outcome data; selective reporting; and
other sources of bias. Studies in which baseline characteristics
were different among study groups or not tested for their
differences were considered as high risk for the domain of
“other risks of bias.” The overall risk of bias for each study was
based on the risk of bias of key domains which, in this review,
were “sequence generation” and “other sources of bias”. Each
study was classified as having low risk (low risk of bias for
all key domains), high risk (high risk of bias for one or more
key domains), or unclear risk (unclear risk of bias for one
or more key domains). Disagreements between the reviewers
were settled through discussion and consensus.