Co-sleeping with infants and the NICE guidelines update

The National Institute for Health and Care Excellence (NICE) provide guidelines on a vast range of aspects of health care issues. This week NICE updated their 2006 guidelines on postnatal care (Guideline CG37) which included recommendations on co-sleeping (defined by NICE as parents or carers sleeping on a bed or sofa or chair with an infant) and sudden infant death syndrome (SIDS) up until infants are one year old. The updated guidelines report “an association between co-sleeping and SIDS” but also states that “the evidence does not allow us to say that co‑sleeping causes SIDS”. So what does this mean and how did the media handle this potentially complex message?

SIDS and co-sleeping: Associated but not a causal relationship

The reporting of an association but not a causal relationship between co-sleeping and SIDS is a fairly complex message to those without a scientific background. So they are connected but one doesn’t necessarily cause the other – what exactly does that mean? Even the NICE clinical practice director, Mark Baker, is quoted (from ITV reporting on the story) as saying “its quite a confusing message, it is not clear”.

We at Research the Headlines have previously written about association and cause-and-effect in Part 5 of our How to “Research the Headlines” series. Here we described how the more closely two variables are associated, the larger the correlation between them (i.e. a statistical relationship between them). However, while cause and effect relationships produce correlations, not all correlations are produced by a cause and effect relationship. Just because two measurements fluctuate in tandem does not mean that they are meaningfully related to one another. A frequently used example of a spurious correlation is that ‘pirates cause global warming’ because the higher the number of pirates in an area the hotter it is. There may be other background factors (what we call confounds in research) that cause two items to be associated with one another.

In the case of co-sleeping and SIDS, the NICE guidelines state that the association may be greater when one or other parent/carer smokes and with:

• parental or carer recent alcohol consumption,
• parental or carer drug use,
• or low birth weight or premature infants.

The press release published by NICE on 3rd December in connection with the updated guidelines is headed by “empowering families to make informed choices on co-sleeping with babies”. The guidelines are recommending that parents make an informed choice about sharing a bed with their infant in light of the above factors, rather than advising them not to do so. Within the same guidelines (the 2006 original guidelines) there are a number of recommendations which emphasise the importance of breastfeeding; many mothers co-sleep because they are breastfeeding, making the situation tricky to advise on. But importantly, while the evidence reviewed by NICE suggested that co-sleeping is associated with SIDS, this does NOT mean that co-sleeping in and of itself causes SIDS and the advice has to be couched in this context.

So how did the media handle this?

The media handled reporting about the press release very well in general. For example the Daily Mail ran with the fairly conservative headline ‘Warning over sleeping with babies’. They described the association between co-sleeping and SIDS and described the factors outlined by NICE known to increase the association. The Daily Mail also included statements from health professionals who were involved in updating the guidelines and the opinions of a policy advisor from the National Childbirth Trust. This advisor, Rosemary Dodds, was able to add some additional opinion: she expressed concern that NICE did not distinguish between co-sleeping on sofas or chairs and bed-sharing as she states that there is evidence that it is more dangerous to fall asleep with a baby on a sofa or a chair. This is a good example of accurate and informative reporting using relevant expert opinion.

Not all the media reporting was accurate though. The Mirror showed an image of a baby with the header “Don’t sleep alongside your baby”. The NICE guidelines did not advise stopping the practice of co-sleeping, but to make informed decisions in light of the association between co-sleeping and SIDS and the factors that increase the association instead. The main headline of the Mirror was ‘sleeping alongside your baby could put their lives at risk, warn health chiefs’ which could be deemed sensationalist in the context of the specific guidelines.

A final point

NICE and the media have a working definition of co-sleeping as parents or carers sleeping on a bed or sofa or chair with an infant. Co-sleeping is in practice a broader concept than bed-sharing. Many parents now use ‘co-sleeper cots’ which are in effect 3-sided cots or they adjust a typical cot that can be aligned and adjusted to the same height as the parents/carers bed. It is somewhat surprising that this type of co-sleeping was not referred to/recommedations given in relation to it given its increasing use by parents in the U.K.