Intended for healthcare professionals

Rapid response to:

Dr Foster's Case Notes

Social class and elective caesareans in the English NHS

BMJ 2004; 328 doi: (Published 10 June 2004) Cite this as: BMJ 2004;328:1399

Rapid Response:

Authors' reply

We are grateful for the letter from
Macfarlane in correctly pointing out that in our paper on elective
caesareans, we do not describe an analysis by social class. The title
was changed at the last minute in the editorial process without the authors’
consent and is indeed misleading. In fact, as explained in the text, we examine
elective caesareans by area level deprivation using electoral ward of
residence, using the index of multiple deprivation 2000. We agree with the
point made, that residents of all geographical areas,
particularly at ward level are not socially homogenous and acknowledge this in
the text. Further to this however, we would argue that any heterogeneity would
be likely to dilute an association with area deprivation and suggest that our
findings are still valid. We already acknowledge in the text that we are not
able to adjust for provider factors such as teaching status and suggest this as
a possible confounder.


Grant et al. suggest that we show
our ignorance of obstetrics in implying that elective caesarean section means a
caesarean section performed solely at the request of the pregnant woman. We
would argue strongly that nowhere in our paper do we imply this, and that in
fact we are quite explicit in saying maternal request is only reported to be
the fifth most common reason given for performing a caesarean section. We also
clearly state in the text that we were unable to adjust for key confounders
such as obstetric complications, antenatal care and previous caesareans. It was
never our intention to imply that elective caesareans are down to maternal
choice alone.


Grant et al. also suggest that
our findings are explained by maternal age, despite the fact that we have
adjusted for maternal age (amongst several other factors). Whilst we agree that
there may be some residual confounding, the suggestion that this would account
for our findings is unlikely and at odds with the pattern for emergency
caesarean, which do not appear to vary by socio-economic deprivation when fully
adjusted for the same factors (including age). Because of the short format of
case notes we were unable to include this table, but we provide them below.


*Adjusted Odds Ratios with 95% CIs for elective and emergency caesarean section by
Quintile of Index of Multiple Deprivation, compared to the most affluent
quintile - Hospital Episode Statistics 2001/2







1 (Least deprived)




1.00 (0.96-1.04)

1.01 (0.96-1.05)


0.99 (0.95-1.03)

1.01 (0.97-1.05)


0.97 (0.93-1.01)

1.08 (1.04-1.12)

5 (Most deprived)

0.86 (0.82-0.89)

1.00 (0.97-1.04)

*Adjusted for maternal age, birth weight, ethnicity, multiple births,
parity and stillbirths


Finally, Newburn
suggests that the Case Notes bypass a peer review process. All our case notes
are peer reviewed and we as authors try to take onboard all of the referees’
comments within the constraints of the format. This restricts us to just a few
hundred words and a graph or two and limits the extent to which we can fully
describe our methods and results. A more detailed description of our
methodology, and in some cases further results, are
provided in the BMJ online. She also wrongly suggests that we are funded by the
Department of Health, and accuses us of not checking our analyses. Firstly, the
unit at
ImperialCollege is funded by a grant from Dr Foster Ltd, an independent
research and publishing organisation, and secondly, where possible our analyses
are checked against published findings and other reports referenced online.
Interestingly, where comparable, our findings on the relationship of caesarean
section with key variables such as maternal age, birth weight, stillbirth,
parity etc. do agree with published findings including the NHS
Maternity Statistics,
England: 2001-02.[1] It is part of the academic process that published work
is challenged and we are pleased to have stimulated some debate. We stand by
our paper in highlighting a relationship between socio-economic deprivation and
elective caesarean section within routinely collected data while explicitly
acknowledging the inherent limitations of that data. To quote Richard Smith’s
editorial, “Much of what the BMJ publishesarises from experimental
studies, particularly randomised controlledtrials. DrFoster case notes will
provide an opportunity tosee what happens in the real, messy world
of practice.”[2]


[1] NHS Maternity Statistics,
England: 2001-02. Government Statistical Service,
May 2003. (accessed 4 Jun 2004).


[2] Clark J, Smith R. Dr Foster
case notes. BMJ 2004;328:362


Competing interests:
None declared

Competing interests: No competing interests

28 June 2004
Paul Aylin
Clinical Senior Lecturer in Epidemiology
Alex Bottle, Brian Jarman, and Katherine Barley.
Imperial College, Norfolk Place, W2 1PG