playing science telephone
Hi folks. Let's play a fun game today called "unravelling bad science communication back to its source."
Saw a comment going around on a tumblr thread that "sometimes the life expectancy of autism is cited in the 30s"
That number seemed..... strange. The commenter DID go on to say that that was "situational on people being awful and not… anything autism actually does", but you know what? Still a strange number. I feel compelled to fact check.
Quick Google "autism life expectancy" pulls up quite a few websites bandying around the number 39. Which is ~technically~ within the 30s, but already higher than the tumblr factoid would suggest. But, guess what. This number still sounds strange to me.
Most of the websites presenting this factoid present themselves as official autism resources and organizations (for parents, etc), and most of them vaguely wave towards "studies."
Ex: "Above And Beyond Therapy" has a whole article on "Does Autism Affect Life Expectancy" and states:
The link implies that it will take you to the "research studies" being referenced, but it in fact takes you to another random autism resource group called.... Songbird Care?
And on that website we find the factoid again:
Ooh, look. Now they've added the word "some". The average lifespan for SOME autistic people. Which the next group erased from the fact. The message shifts further.
And we have slightly more information about the study! (Which has also shifted from "studies" to a singular "study"). And we have another link!
Wonderfully, this link actually takes us to the actual peer-reviewed 2020 study being discussed. [x]
And here, just by reading the abstract, we find the most important information of all.
This study followed a cohort of adolescent and adult autistic people across a 20 year time period. Within that time period, 6.4% of the cohort died. Within that 6.4%, the average age of death was 39 years.
So this number is VERY MUCH not the average age of death for autistic people, or even the average age of death for the cohort of autistic people in that study. It is the average age of death IF you died young and within the 20 year period of the study (n=26), and also we don't even know the average starting age of participants without digging into earlier papers, except that it was 10 or older. (If you're curious, the researchers in the study suggested reduced self-sufficiency to be among the biggest risk factors for the early mortality group.)
But the number in the study has been removed from it's context, gradually modified and spread around the web, and modified some more, until it is pretty much a nonsense number that everyone is citing from everyone else.
There ARE two other numbers that pop up semi-frequently:
One cites the life expectancy at 58. I will leave finding the context for that number as an exercise for the audience, since none of the places I saw it gave a direct citation for where they were getting it.
And then, probably the best and most relevant number floating around out there (and the least frequently cited) draws from a 2023 study of over 17,000 UK people with an autism diagnosis, across 30 years. [x] This study estimated life expectancies between 70 and 77 years, varying with sex and presence/absence of a learning disability. (As compared to the UK 80-83 average for the population as a whole.)
This is a set of numbers that makes way more sense and is backed by way better data, but isn't quite as snappy a soundbite to pass around the internet. I'm gonna pass it around anyway, because I feel bad about how many scared internet people I stumbled across while doing this search.
People on quora like "I'm autistic, can I live past 38"-- honey, YES. omg.
tl;dr, when someone gives you a number out of context, consider that the context is probably important
also, make an amateur fact checker's life easier and CITE YOUR SOURCES