2.1 Characteristics of Included Studies.
We identified 332 potentially eligible articles. A total of 127
duplicates were excluded, and 150 unrelated records were also excluded
by reading their abstracts. After reading 55 full-text articles, 38
records were excluded for reasons such as not a RCT, insufficiency of
data and inconsistence of interventions or outcomes. Eventually, 17
RCTs[10-26] were included in the systematic review
and 15 were included in the meta- analysis[10-11,13-25], all of which were published in Chinese. The
study flow diagram is shown in Figure 1.
In this meta-analysis, a total of 2574 parturient women were selected,
including 1288 cases in treatment groups and 1286 cases in control
groups. The controls of all selected trials received obstetric care
routine, such as psychological comfort and Doula delivery; the
intervention measures in treatment groups included auricular acupressure
(16 trials) and auricular acupuncture (1 trial). The main outcome
measures were WHO pain level (5 trials) [15-16,19, 22-23], VAS score (4
trials)[10, 14,21, 24] and maternal satisfaction
(3 trials)[10, 14,24]; the secondary outcome measures included
duration of three stages of labour (1st 9
trials[10-11, 13-14,18-19, 21-24],
2nd 6 trials[13,16, 19, 22-23,25], 3rd 4
trials[13, 19,22-23]), postpartum blood loss (2
trials)[15, 25], neonatal Apgar
score (4 trials)[10, 14,18, 24], number of spontaneous
delivery cases (4 trials)[15-17,25] and number of caesarean section cases (3
trials)[15, 17,25]. Table 1 shows the main characteristics of the
studies.
2.2 Methodological Quality of Included Studies.
Out of all the 17 randomized controlled trials, only 6 of them reported
details about random sequence generation, 3 studies with a random number
table tool and 3 studies with date. No studies mentioned any details
related to allocation concealment. As for blinding, although 2 studies
claimed they were single-blind trials, since the materials and
manipulations used in the treatment were totally different in the test
and control groups, it’s difficult to avoid performance bias. However,
at least the outcome assessors should have been blinded, the detection
bias of all studies was therefore classified as unclear. Most of the
articles showed a low risk of incomplete outcome bias and selective
reporting bias.