Poor Dr. Klein; the evidence does not support his claims about epidurals

The last year has been pretty tough for Canadian family practice professor Dr. Michael Klein.

Dr. Klein is a darling of the natural childbirth establishment because, among other things, he opposes epidurals. He is sure with every fiber of his being that epidurals interfere with labor. Too bad that the scientific evidence shows the opposite. Now Dr. Klein has concluded it's time to thrown out the scientific evidence.

You may recall that Dr. Klein routinely delegitimizes women's need to relieve the agonizing pain of labor. In a 1200 word post about epidurals on the increasingly irrelevant Lamaze blog Science and Sensibility, Dr. Klein utterly failedto mention the excruciating pain of childbirth.

In a subsequent post Dr. Klein asked if epidurals change labor. He acknowledged that the scientific evidence suggests they do not. Then he tells us what he personally found in his research on epidurals and why he believes that and chooses to ignore the Cochrane Review that showed epidurals have no impact on the C-section rate.

In fact, Dr. Klein is pretty disgusted with women in general, not simply for their choice of epidurals, but because they reject the entire shaky edifice of natural childbirth philosophy. Dr. Klein falls back on the usual NCB excuse. Those women are uneducated about childbirth decisions. What worse, they accept medical advice from their own obstetricians!

For his troubles, Dr. Klein was publicly chastised by the Society of Obstetricians and Gynecologists of Canada (SOGC), an organization with which he has worked closely. In an unusual step, the SOGC issued a position paper condemning Klein personally for his shoddy and irresponsible conclusions.

But Dr. Klein does not quit. As the mounting evidence produced by meta-analyses and randomized controlled trials shows epidurals, even early epidurals, do not increase the rate of C-sections, Dr. Klein has decided to attack the very notion of evidence based practice.

In a paper entitled The Tyranny of Meta-analysis and the Misuse of Randomized Controlled Trials in Maternity Care published (where else?) in the journal Birth, Klein expresses his peevishness.

Here's the abstract:

Recent meta-analyses of key areas in maternity care have covered home birth and epidural analgesia. In each of these cases serious issues have arisen from the use of subjective inclusion and exclusion criteria, heterogeneity of included studies, and inclusion of studies that were conducted in settings that were not representative of usual maternity care. This latter flaw is especially notable for early epidural analgesia, where study environments with very low cesarean section rates are included. Such study settings lack external validity and have raised concerns about the political uses of meta-analysis...

Why is Dr. Klein upset? He doesn't like a recent study published in the British Journal of Obstetrics and Gynecology entitled Early versus late epidural analgesia and risk of instrumental delivery in nulliparous women: a systematic review by Wassen et al. The study comes from the Netherlands. As the authors note:

... The introduction of a national guideline in the Netherlands in 2008 on the management of labour pain resulted not only in an increase in EA [epidural analgesia] requests, but also those requests being made at an earlier stage in the course of labour. Therefore we are interested in the effect of early EA strictly defined as 3 cm or less in the latent phase on the mode of delivery.

The main objective of this report was to review recent literature on the influence of this stricter definition of early EA (including combined-spinal epidural) compared with late EA in nulliparous women at 36 weeks or more of gestation, on the rate of caesarean deliveries or instrumental vaginal deliveries.

They are not the first to explore the issue:

... Results of randomised controlled trials (RCTs) and systematic reviews published
between 2002 and 2004 did not demonstrate any difference in the rate of caesarean deliveries between women who had received EA and women who only received intravenous analgesia. A Cochrane review, published, in 2005, showed that EA was associated with an increased risk of instrumental vaginal birth (pooled risk ratio [RR] 1.38, 95% CI 1.24–1.53) compared with deliveries with nonepidural analgesia or no analgesia.

A landmark study by Wong et al., published in 2005, provided evidence that early epidurals in comparison with late epidurals do not cause an increased rate of caesarean deliveries and instrumental vaginal deliveries in nulliparous women with spontaneous labour...

Wassen et al. searched for RCTs, prospective cohort studies and retrospective cohort studies in which the effects of early EA (cervical dilatation <4 cm) on the mode of delivery in nulliparous women have been studied. They found 6 studies comprising 15 399 nulliparous women in spontaneous or induced labor. Risk of caesarean delivery (pooled risk ratio 1.02, 95% CI 0.96–1.08) or instrumental vaginal delivery (pooled risk ratio 0.96, 95% CI 0.89–1.05) was not significantly different between groups. They concluded:

This systematic review of the literature showed no increased risk of caesarean delivery or instrumental vaginal delivery for women receiving early EA compared with late EA. Therefore, a woman’s request for EA early in labour cannot be rejected on the grounds of its presumed adverse influence on the mode of delivery. Consequently, the preference of the labouring women should be leading.

Dr. Klein, of course, disagrees. He shared his disagreement in a letter to the editor of BJOG that was systematically demolished by Wassen et al:

Dr Klein suggests that the meta-analysis is primarily about caesarean section, and that the title is therefore misleading. The primary focus of our meta-analysis was the effect of early epidural analgesia (EA) on the rate of instrumental vaginal delivery or caesarean delivery. Table 3 illustrated the inclusion of six studies (15 399 women) for the rate of instrumental delivery and five studies (14 836 women) for the rate of caesarean delivery. Thus, we disagree with Klein’s conclusion, and consider the title appropriate.

The fact that Luxman’s study was underpowered is irrelevant because the results were pooled with results from other studies. In addition, Klein refers repeatedly to the fact that there is a low caesarean section rate in several studies. He does not argue, however, about what would be the effect of a higher, versus lower, rate of caesarean section on the relative risk...

In Wang’s study, a minimum of 1-cm dilation was required to receive epidural analgesia in the early group, and results were compared with the late group in which dilation was at least 4 cm. We believe that Klein’s comment on the type of comparison in this study was unjustified.

Finally, Dr Klein expressed doubts about the external validity of Wang’s study to women in spontaneous labour. We, however, see no important difference between the outcomes of studies with spontaneous or induced labour.

Now Dr. Klein has taken the argument to the journal Birth where he can be fairly certain that no one will be able to point out the mistakes in his reasoning. He repeats his already discredited assertions and then goes on to editorialize:

... Missing from the discussion of epidural analgesia use in maternity care is the recognition of how this technology has completely transformed childbirth—sometimes for the better and sometimes with unintended negative consequences. Most of the new generation of medical and nursing staff have been educated in, and practice in, high epidural and high cesarean section environments. It is reasonable to assume that in such settings, skills for the support of women, absent epidurals, either atrophy or were never learned. Hence, it is likely that epidural analgesia applied early and on a routine basis, even employing the newer low dose ("walking") epidurals, will contribute to the ever-increasing cesarean section rates --- not as a single factor as randomized controlled trials have attempted to isolate, but as part of an overall technology-dependent approach.

In other words, randomized controlled trials, the gold standard in research, have failed to demonstrate that epidurals lead to an increase in C-sections. But, according to Dr. Klein, it's okay to ignore them.

Klein then references one of his own discredited studies:

The Canadian provider maternity attitudes study demonstrated that the younger generation(<40 yr) of obstetricians were more likely to believe that epidural analgesia did not interfere with the progress of labor or result in more medical interventions when compared with their older colleagues. This finding was probably because the former were educated in the era of high-epidural use, compared with older practitioners, who saw the change that occurred when epidural analgesia was introduced.

No, Dr. Klein, it's because the scientific evidence SHOWS that epidurals do not interfere with the progress of labor.

Comfort with, and dependency on, epidural analgesia by younger obstetricians and their anesthesia colleagues provide a fertile field for the unquestioning acceptance of randomized controlled trials and meta-analyses which appear to show that epidural analgesia, given early, does not increase the cesarean section rate.

So there you have it: Dr. Klein is sure that women who choose epidurals are uneducated and inappropriately influenced by their obstetricians. And he is sure that obstetricians are inappropriately influenced by the actual scientific evidence.

Instead of acknowledging that he is wrong, he has been forced to declare that everyone else in the world (mothers, obstetricians and research scientists) is wrong. At this point, Dr. Klein is simply making a fool of himself.