Would you ever buy a car because the press release from Ford said it was a pleasure to drive, has incredible gas mileage and never needs repairs?
Then you shouldn’t accept the claim of a scientific researcher based on a press release that said it was awesome, ground breaking and relevant to current medical practice.
Mainstream media and natural childbirth advocates are trumpeting a press release from a poster presented by two medical students at the American Society of Anesthesiologists (ASA) 2015 annual conference.
[pullquote align=”right” color=”#d24623″]Since a policy of fasting in labor was instituted, deaths from aspiration have dropped dramatically.[/pullquote]
Most healthy women can skip the fasting and, in fact, would benefit from eating a light meal during labor, suggests research being presented at the ANESTHESIOLOGY® 2015 annual meeting. Improvements in anesthesia care have made pain control during labor safer, reducing risks related to eating, researchers note.
Women traditionally have been told to avoid eating or drinking during labor due to concerns they may aspirate, or inhale liquid or food into their lungs, which can cause pneumonia. But advances in anesthesia care means most healthy women are highly unlikely to have this problem today and when researchers reviewed the literature of hundreds of studies on the topic, they determined that withholding food and liquids may be unnecessary for many women in labor.
Really? How did two medical students reach that determination? It’s not easy to tell since there is virtually nothing available for other physicians to read and analyze.
Here’s what they said in their poster presentation:
Declining rates of parturient aspiration mortality have been indicated in the UK with no reported cases from 2000-2005 when compared with rates of 1.499 per 1000 parturients during the 1940s
Wait, let me get this straight: Since a policy of fasting in labor was instituted, deaths from aspiration have dropped dramatically?
And that’s supposed to mean that aspiration is no longer a risk.
But a dramatic drop in the incidence of maternal aspiration doesn’t mean that the risk has disappeared. There’s also been very few cases of polio in the UK since 1990 (because of vaccination). That doesn’t mean that polio has disappeared.
Here’s what the authors of the the poster say it means:
This review suggests that in low-risk patients with no risk factors, fasting does not appear warranted.
Here’s what it is more likely to mean:
Fasting in labor prevents aspiration deaths.
Why did the ASA issue a press release on the findings of two medical students? For the same reason any scientific organization issues a press release, to garner media attention.
What is the impact of such press releases?
According to a 2014 BMJ paper, The association between exaggeration in health related science news and academic press releases: retrospective observational study:
The framing of health related information in the national and international media, and the way in which audiences decode it, has complex and potentially powerful impacts on healthcare utilisation and other health related behaviour in many countries. The media also demonstrably influences the behaviour of scientists and doctors.3 4 Such impacts may often be beneficial, but misleading messages can have adverse effects (even if these effects may be difficult to predict and prove because the responses of audiences are complex and multiply determined).6 This problem is not restricted to rare dramatic cases such as vaccination scares7 8; the cumulative effect of everyday misreporting can confuse and erode public trust in science and medicine, with detrimental consequences.
How accurate are such press releases?
For our analysis of advice we found that 40% of the press releases contained more direct or explicit advice than did the journal article (bootstrapped 95% confidence interval 33% to 46%). For our analysis of statements based on correlational results (cross sectional or longitudinal) we found that 33% of primary claims in press releases were more strongly deterministic than those present in the associated journal article (bootstrapped 95% confidence interval 26% to 40%).
That’s precisely what has happened here. The medical students noted a finding, maternal aspiration now occurs rarely compared to more frequent incidents of aspiration in the 1940’s. This correlated with the development of anesthesia techniques designed to minimize aspiration. They concluded (with no evidence to support that conclusion) that the new anesthesia techniques prevent nearly all cases of aspiration.
But there was one anesthesia “technique” that seems to have escaped their notice, the strict enforcement of fasting during labor.
It is very likely that the fasting in labor is a major factor in the decrease in aspiration deaths. Certainly the authors presented no data to indicate otherwise.
Anesthesia colleagues, help me out here:
Have UK hospitals been allowing women to eat in labor since the 1940’s or did they have a strict fasting policy?
Is there something that I am missing that allowed the researchers to isolate the impact of new anesthesia techniques from the impact of fasting itself?
If not, then the authors drew a conclusion from the data that is not supported by existing scientific evidence.
If not, then the authors are advocating stopping the fasting policy that was responsible for the decrease in deaths.
If not, then the ASA has issued a thoroughly irresponsible press release that contains advice that isn’t merely unsupported by the evidence, but advice that could be deadly.
