How to read statistics accurately

January 5, 2017 4:01 PM

I know the risk of SIDS is quite low. I can't figure out just how low given that some of the factors are preventable.

My baby is at the prime age for SIDS and I've googled it more than I should. The most widely held theory is that a possibly genetic cause is triggered by an environmental factor. What I want to know is what the risk would therefore be if I control every preventable factor.

So for instance Google says it is 1 in 1500 babies. Risk factors which make babies more susceptible include parents who smoke or drink (we do not), are very young (we are not), co-sleep (we do not), put baby to sleep on his tummy (I don't), have loose blankets or toys in the crib (we do not) or use loose blankets, crib bumpers etc. We do none of these things. I am very careful about this. He sleeps in an empty crib with a fitted sheet and nothing else, in a crib beside my bed. If he falls asleep elsewhere (eg a baby swing) I move him to the crib as soon as it's feasible.

So what I want to know but cannot figure out is how to adjust the statistic. Even if you follow every guideline scrupulously, I assume some babies would still be at risk from the sheet randomness of fate. But I assume that number is not 1 in 150,000. So how can I figure out what it is?

posted by JoannaC to Health & Fitness (8 answers total)

This isn't an answer to your question, but I am the mother of a 3 month old and spent one sleepless, anxious night trying to answer this very question. As far as I know, there hasn't been a study of SIDS incidence in mid to upper class, educated people that follow all the guidelines. It would be difficult to do such a study because it's such a rare event in that population.

What I eventually came to terms with was that yes, it's possible my baby might die in his sleep, even if I do everything right. If I'm following all the recommendations and it happens anyway, by definition there's nothing I could have done to prevent it. It would have just been extreme bad luck, like a shark attack or getting struck by lightning. The risk is very low though, just like these other events.

And if it's really stressing you out, there are monitors like Snuza that check your baby's breathing and alert you if it stops, for greater peace of mind.
posted by permiechickie at 4:33 PM on January 5, 2017

Well, on some further searching, for white college graduates, SIDS risk is less than 0.25 per 1000 (figure 1) after doctors started telling people to put babies to sleep on their backs

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1449471/#!po=31.6092
posted by permiechickie at 4:38 PM on January 5, 2017

Since the intrinsic risks for SIDS are shared with intrinsic risks for other causes of infant deaths, I don't think there's a reliable answer to your question. Furthermore, don't confuse "per 1000 births" measures with any kind of predictive power for a specific individual. Missing data from health records and confounding factors masking other risk factors make it nearly impossible to give a meaningful number.
posted by demiurge at 4:50 PM on January 5, 2017

I've seen a study that discusses which fraction of SIDS babies had zero, one, two etc risk factors. Most cases had multiple risk factors (3ish?) Some of the factors were preventable, some were demographic, some were non-preventable (like recent upper respiratory infection.) Babies with zero or one risk factors had very significantly lower overall rates. I read this study when I was doing just what you are now, when my baby was the same age as yours, for the exact same reasons. I'm on my phone now (nursing said baby, now a toddler), but I'll see if I can't find you a link in a bit.
posted by wyzewoman at 5:48 PM on January 5, 2017

Ok, found the link. (Memail if you need help getting the full text.) "Concurrent Risks in Sudden Infant Death Syndrome" by Ostfeld et al.
posted by wyzewoman at 6:12 PM on January 5, 2017

But do keep demiurge's point in mind!
posted by wyzewoman at 6:20 PM on January 5, 2017

My understanding is your risk is about 1 in 10000 of you follow the guidelines. I am a light sleeper and coslept and wasn't at all concerned.

Tidbit: My child had ~1 in 100 chance in dying from a endocrine issues as a baby. The doctors said just don't worry about. SIDs is way, way less likely. So follow the guidelines mostly and enjoy this time. It is over soooo fast.
posted by Kalmya at 6:28 PM on January 5, 2017

I don't remember where it was but I read an article a few months ago about how sometimes medical examiners list SIDS as the cause of death when the ME works closely with the community to spare the parents some grief. Listing suffocation as the cause of death makes parents feel like it's their fault but SIDS just happens sometimes, so the thinking goes. So that likely skews the statistics as well.
posted by kat518 at 10:11 PM on January 5, 2017