Tag Archives: evidence

04 Apr

The science of birthplace

My work now includes talking to parents-to-be about where they choose to give birth, and so this subject is of increasing interest, particularly since the skeptics I hang out with suck their teeth a little when we get on to the subject. To be quite frank, I suck my own teeth. It’s very hard to weigh up the pros and cons of a subject in which even the most scientifically minded get rather emotionally invested. I will conclude, perhaps, that we all give different weight to different outcomes, and that’s parenting for you, which means that I am as usual chasing my tail and asking “why can’t we all just get along?”

This is a complex and emotive topic, and few people seem able to write about it without their passion leaking through. So let’s state upfront that my passion is to support parents to make their own informed decisions, decisions they will have to live through, and live with, about an event that is in many cases earthshattering in the experience itself, and in its ramifications. Giving birth is a very big deal. Yes, it’s a normal physiological process and women’s bodies are well-adapted to perform it; but let’s bear in mind two very important provisos here:

  • It’s 2014. We give birth in very different conditions than those to which our bodies are adapted; and
  • Birth is safer in England than it has ever been, and this is down to a range of factors including modern techonology and hygiene.

But giving birth is not simply a physiological process. It is a profound life event affecting our bodies and our view of our bodies, affecting our families and other relationships, affecting us in social, financial and psychological ways that cannot possibly be accounted for in a simple birthplace study. Therefore birthplace studies tend to base their conclusions on measurable outcomes, usually neonatal death, injury, or oxygen deprivation to the baby. Some studies also consider some physical outcomes for the mothers, such as whether she experienced medical interventions or whether she went on to breastfeed. Very few studies consider birth trauma as an outcome.

Which? Birth Choice has a very clear set of tables comparing outcomes for hospital obstetric units, midwife-led birth centres, and homebirth. This is based on the 2011 study Perinatal and maternal outcomes by planned place of birth for healthy women with low risk pregnancies: the Birthplace in England national prospective cohort study BMJ 2011;343:d7400. If you click through to the tables in the report you find risks for ALL births reported as 4.3 adverse outcomes per 1000 births. This is then broken down to show the differences for first births (5.3/1000) compared with second or subsequent births (3.1/1000), and broken down still further to show risks according to place of birth. As has been reported, the risk of an adverse outcome at a planned homebirth for a first baby shoots up to 9.3/1000. As has not been reported, the risk of an adverse outcome at a planned homebirth for second or subsequent baby drops to 2.3/1000. The study concludes that “The incidence of adverse perinatal outcomes was low in all settings.” The headlines, meanwhile, focus on the relative risk: 9.3/1000 is more than twice as high as 4.3/1000, therefore homebirth is twice as dangerous as hospital birth.

Parents need to be given these numbers along with a little bit of information about how to make sense of them, which is where the Which? page is useful. But they also need the opportunity to consider what other outcomes are important to them, given that the absolute risk of adverse outcomes is so low. The Which? page gives information about the likelihood of intervention in various settings, and parents may want to consider this as a factor in their decision making.

Meanwhile, all this pitting of hospital birth against homebirth results in Birth Centres being overlooked. Birth Centres are intended to offer a home-like setting, with midwife-led care. They are often located within hospital settings, so the obstetric facilities are on hand. Our birthplace study referenced above shows that the risk of adverse outcomes is comparable to an obstetric unit, while the likelihood of intervention such as instrumental birth or caesarean birth is lower. A 2012 Cochrane Review of Home-like versus conventional institutional settings for birth by Hodnett et al supports this:

Home-like institutional birth settings reduce the chances of medical interventions and increase maternal satisfaction, but it is important to watch for signs of complications.

One thing that is important to beware of is using data originating in the US, since the model of midwifery care in the US is very different to the UK. This perhaps is a subject for a later post, and probably not by me.

Finally I want to come back to the definition of an adverse outcome, where once again women are reduced to the precious vessels, solely charged with but not entirely trusted to bring this baby to the world unharmed and perfect in every way. What about outcomes for mothers? I have heard Sheila Kitzinger speak on the subject and read some harrowing accounts of childbirth:

one reason why many women have low self-esteem and cannot enjoy their babies is that care in childbirth often denies them honest information, the possibility of choice, and simple human respect…..

Studies from 2003 and 2004 found that up to 6% of women show full PTSD symptoms following an experience of birth where they felt scared, helpless and vulnerable. While all the focus is on outcomes for the baby, women’s lived experience is belittled and ignored as a decision-making factor. This is why parents need to be given all the information, and not frightened into seeing hospital birth as the only safe choice for their babies, regardless of how it will feel for them; and the information given needs to include more than just the risk of adverse outcomes for the baby.

04 Feb

Evidence is overrated!

As a confirmed skeptic, my title is deliberately provocative, but reflects the tail-chasing propensity I have to apply skepticism to skepticism. I absolutely have to be evidence-based in my work, and I’ve completed a BA module in understanding and using research, but I still worry that I’m as guilty as the next person of cherry-picking it to suit my own views.

When it comes to birth and parenting, the quality of evidence available is not great. Much of the subject matter is undefined or too complex to boil down to a testable hypothesis, and RCTs on babies are ethically difficult. On top of that, parents being such a super marketing demographic, there are an awful lot of vested interests.

Most people working in this area are emotionally invested in some way, and not all the organisations supporting parents have a rigorous reflective practice and supervision structure, allowing them to debrief to the extent that they don’t carry any value judgement at all into their work.

This muddies our use of evidence.
There is some research on how hard it is to adopt new learning, when prior knowledge is deeply embedded. Hence out of date practices and misinformation propagated through on the job learning. If new evidence is not a good fit with what we already ‘know’, it is difficult to re-align oneself. We see this with adherents to scientifically implausible theories for example within alternative therapies, where belief is very much stronger than evidence.

There is also research [pdf] suggesting that GPs often base their breastfeeding advice on their own experience or that of their partners. In fact this rule applies to most people: if it worked for you, you may well suggest it to someone else, especially since the urge to problem-solve may be overwhelming. One GP spoke to me at length about something that she called “yeast mastitis.” A yeast infection of the breast (thrush) and mastitis are two entirely separate conditions, with different (but sometimes related) causes and different treatments. This is fairly basic stuff.

Parents are certainly titled to evidence-based information, and there are some good sources such as NHS and NCT websites; but this should include information about the limitations of the evidence, and where professionals supporting parents are unsure, untrained, or inexperienced, they should be clear about their boundaries and limitations. More damage is done by the supportive making up of answers than by handing over a reputable helpline number.

Evidence can be used as a stick to beat parents with (perfect example: “breast is best”), and then on the other hand it really is overrated as a decision-making factor compared with pressing lifestyle issues and social influences. Science journalist Linda Geddes, a busy parent of two who knows the evidence behind exclusive breastfeeding to six months, still chooses formula milk for her four month old when it is more convenient to do so. She weighs the risk, according to the evidence, but also in the balance are the fact that her two children are “simultaneously clamouring for their dinner and I don’t have time to sit and breastfeed.”

This is not a value judgement, but an excellent illustration of the way evidence is balanced and sometimes negated by parents’ lifestyle and needs, when making decisions. For me, it’s the evidence about sending a six month old to daycare that makes uncomfortable reading.

Working with parents is about providing evidenced information and decision making tools and confidence in themselves as parents. Evidence does not make something right or wrong when it comes to parenting, and we absolutely cannot use it either to dictate or to judge what parents do.

24 Apr

Regression to the mean

Most weeks, someone will tell me they ‘swear by’ some remedy for one of the many woes of early parenting, and assure me that it has worked wonders. And then they will turn and tell the mum sitting next to them, who [unless healthily sceptical] will unquestioningly accept the recommendation without asking two very important questions:
1. Is there any evidence that it works?
2. Is there any evidence that it does harm?

Infacol is a prime example of a medication recommended widely and unscientifically by mums everywhere, but more worryingly, by GPs and Health Visitors, who must surely know that there is no evidence that it works. Breastfeeding Network has a useful paper [pdf] on colic which discusses Infacol and other remedies, concluding the research is a bit thin on the ground and there are various things you can try; and particularly for the breastfed baby, getting some support with breastfeeding may be key.

Here’s another one: Lansinoh prevents nipple pain. It doesn’t. Its only function is to heal damaged tissue. Nipple pain is almost always prevented (and resolved) by good attachment, and no amount of lanolin cream will facilitate good attachment. In fact, large amounts of it, making the breast slippery, will make it harder for the baby to stay comfortably latched on. In addition, the heavy marketing of Lansinoh reinforces mums’ certainty that breastfeeding will hurt, and is therefore a barrier to doing it at all.

Blogger Scepticon takes a look at amber teething beads and basically demolishes them as a remedy for the pain of teething. Teething is a tough time for parents as well as babies, and parents may feel helpless to alleviate the pain and misery, so it’s no wonder there’s such a market in remedies that are only anecdotally effective.

And when we are talking about our babies’ health, anecdotal is just not good enough. There is an ethical obligation on health professionals not to recommend something just because they have no other answers, but the fact is that few health professionals have the time to sit with an anxious parent and help her to work through her worries and gain confidence in what she is doing. Hence the quick fix: a formula top-up, controlled crying, dummies, all of which can be shown to cause harm.

But the anecdotes of one mum to another seem to carry even more weight at this vulnerable time, and is an inevitable result of the peer-support that we encourage. It’s hard to take that away from new parents, but it’s equally important to encourage them to ask those questions rather than accept at face value the claim that something works.

Regression fallacy.

28 Sep

Where’s the evidence?

Louise Timlin is a Health Economist and mother of two.

When I was pregnant with my first child I was often asked about baby-brain. A colleague or friend would smile indulgently and share a story about how they left their laptop on the train, or their wife put their socks in the fridge while pregnant. I smiled politely whilst I thought to myself, of course no non-pregnant person has ever made such a mistake. One day at work, when I was about 6 months pregnant I inadvertently sent out two invites for the same meeting to the same colleagues but for different days. Oops, I thought and shared my error with my boss who was one of the invitees. He laughed heartily and jokingly referred to my “baby-brain”. On my return to my desk I noticed that everyone invited had accepted both meetings without question, yet none of them were pregnant.

I am sure that baby-brain is simply another example of finding evidence for something if you look hard enough. For example I believe that some people are labelled “forgetful” who are probably no more forgetful than anyone else but every time they make a small mistake it is pounced on as evidence of their intractable forgetfulness.

And apparently I am right, according to a study conducted by Dr Helena Christensen from the Centre for Mental Health Research at the Australian National University. The study, published in the British Journal of Psychiatry, followed a representative cohort of women and measured cognition before, during and after pregnancy. No significant differences in cognition were found, leading to the conclusion that previous studies were flawed or biased.

Dr Helena Christensen said, “Part of the problem is that pregnancy manuals tell women they are likely to experience memory and concentration problems, so women and their partners are primed to attribute any memory lapse to the ‘hard to miss’ physical sign of pregnancy. Not so long ago, pregnancy was ‘confinement’ and motherhood meant the end of career aspirations.”

It may be that pregnancy shifts a woman’s focus away from work, and who wouldn’t forget where they’d left the remote control whilst chronically sleep deprived from looking after a new-born baby. But come on girls, give yourselves a break, you are not cognitively deficient and don’t let anyone tell you otherwise.

Having spent 12 years working in the highly regulated field of clinical research I am not a big fan of “alternative therapies”. Don’t get me wrong, I am a big fan of the placebo effect, just don’t kid yourself it is anything else. If it’s not backed up by evidence from a series of well designed, placebo controlled, regulatory and ethically approved clinical trials then you would do well to be sceptical.

The 1023 group concur. They staged a demonstration at 10.23am on 30th January in which more than 400 homeopathy sceptics took a “homeopathic overdose” in protest at Boots continued endorsement and sale of homeopathic remedies. Homeopathic remedies are hugely diluted substances. They are commonly sold at strengths labelled 6C. This means there is 0.0000000001% of the active substance in them.

There are people who are certain that homeopathy works for them. This is why the most rigorous clinical trials are placebo controlled. In clinical trials for antidepressants, up to 40% of patients taking placebo report a beneficial effect. A paper published in the Lancet in 2005 and the Cochrane Collaboration concluded that homeopathy is nothing more than a placebo effect. Proponents will claim that at worst it does no harm. However even this claim should be treated with scepticism. If patients delay seeking proper expert medical advice whilst using homeopathy to treat their condition, they could risk their condition degenerating. By all means go ahead and try it, but don’t forget, we have medicines that have actually been proven to work; why not give them a go at the same time?

Originally written for the Wokingham NCT Newsletter
Views expressed here are my own, and do not represent the views of NCT.