Authors' reply re: OASI Care Bundle
Authors: Martinez Dorian , Thakar Ranee 
Published: October 2021

Sir,
We would like to thank Scamell and colleagues for their letter in
response to our paper describing the results of the Obstetric Anal
Sphincter Injury Care Bundle (OASI-CB) evaluation (1,2). We have
previously addressed most of the points raised in our response to an
earlier critical review of the OASI-CB by two of the signatories of this
letter (3).
First, Scamell and colleagues indicate that they are disappointed in the
quality of the evidence that supports the components of the OASI-CB. We
feel that this criticism is misdirected, because the OASI-CB project was
initiated in response to this lack of high-quality evidence. We
developed a care bundle and we performed a multicentre study, which
produced evidence of its positive effect.
A second criticism expressed by the authors is that the OASI-CB does not
include warm compresses. We have previously acknowledged the evidence
that warm compresses reduce the risk of OASI (3). They were not included
as a standardised component of the OASI-CB partly because of variation
in availability and use (4), and partly because of clinical
practicalities such as the feasibility of safely heating/reheating
compresses. However, we do encourage the more widespread use of warm
compresses because they would further improve the prevention already
provided by the OASI-CB.
A third concern raised by the authors is that the OASI-CB has only a
small effect: a reduction in the OASI rates from 3.3 to 3.0%. As we
explained in our article, this reported reduction is very likely to be
an underestimate of the true effect of the OASI-CB, given that the
OASI-CB also requires a careful check of the perineum following birth
for the immediate detection of OASI. Therefore, we emphatically reject
the suggestion that our results could be explained by ascertainment
bias.
Last, the authors suggest that we did not consider women’s experiences
and the acceptability of the OASI-CB. Women were–and still are–at the
very heart of the development, evaluation and implementation of the care
bundle (2). For example, women told us that they experienced a hands-on
approach protecting the perineum as very positive and that good
communication with the midwife was key to a calm birth (5).
We are now performing the OASI2 study that evaluates the sustainability
of the OASI-CB and its implementation in a wider group of units
(www.rcog.org.uk/oasi2). Based on
multi-stakeholder discussions and lessons learned from the original
OASI-CB project (6), we updated the OASI-CB manual and antenatal
discussion guide and improved our training materials. For example, the
antenatal discussion guide now also includes antenatal perineal massage,
birth position, importance of a slow birth and the use of warm
compresses as discussion points alongside the OASI-CB elements. In
OASI2, we will also explore women’s perspectives further via a
large-scale survey.
We would like to reiterate that women’s health and a positive birth
experience are at the centre of the OASI-CB. Our article presents
evidence of the effectiveness of the OASI-CB. It is this evidence that,
together with our commitment to support women and clinicians, will
empower women to make informed choices about whether or not they want
the OASI-CB as part of their birth plan.