Here’s a “tweet” that’s been retweeted (copied and passed on) a lot lately:
Downs Syndrome: 1 in 1000 births, Autism: 1 in 100, Congenital Heart Defects: 1 in 85. Which one have you heard the most about?
Well, first things first, I can tell you that the incidence of Congenital Heart Defects (CHDs) is not 1 in 85. It affects 1 live birth per every 125, and has stayed at that rate for quite a few years. A jump to 1 in 85 would be a 32% increase, Cardiologists would freak out and the news media would be talking about a “Heart Defect Epidemic!” That’s not happening.
But what has happened is the rate of Autism occurrence has changed: from 1 out of 150 children up to about 1 in 91. That’s a huge percentage change, too: 39%. When you see a huge jump in a number such as this, the first thing you do is ask, What’s changed?
What has changed may not really be an increase in the number of cases of Autism, but rather a better understanding of the disease. Autism is an extremely complicated disease probably (it is not certain) caused by changes that occur at the cellular level.
Relatively speaking, Heart Defects are easy to identify: There is only one basic heart design, and any variation can be considered a defect, even if it has no effect on the body. Thirty-five different Congenital Heart Defects have been identified, though it is not unheard of to have more than one. With Autism no one seems to know how it occurs, exactly what occurs to cause it, and it can manifest itself in many different ways.
But researchers have now identified another possible “key” to the Autism puzzle, and the general understanding of how the brain develops is improving.
But that really doesn’t address what is so irritating about that “tweet” that keeps going around. I’d really like to know where that “1 in 85 have a CHD” statistic came from, because it just doesn’t make sense. There has been no trend that shows that kind of increase.
Changing the numbers to highlight “your” cause doesn’t help, and is embarrassing when that fake number bumps into the facts. Both Autism and Heart Defects are debilitating illnesses, and campaigning for more research into either is a worthy cause. Don’t cheapen either one by playing fast and loose with the numbers.