Friday, April 09, 2004

Your Biology Lecture For The Day: Otters Get Pedantic

[T]he prestigious Institute of Medicine has put a number on just how many people have "limited health literacy" -- a surprising 90 million adults.

They have problems following instructions on drug labels, interpreting hospital consent forms, even understanding a doctor's diagnosis and instructions.
This is not exactly news to me. As a specialist in behavioral medicine, I spend a lot of time translating medical information into - not just plain English, but simple, concrete, and vivid English. A full third of my clients have less than an eighth grade education, and most of them have only the haziest understanding of their disease process.

It's easy to put the blame on doctors for their overreliance on medical jargon. But putting complex medical information into simple terms is a lot harder than it looks. Even professionally produced patient education materials often do a bad job of it. We have all kinds of educational pamphlets and comic books in our clinic, but I rarely use them.

Here's an example of why (warning: PDF file). It's a lovely, glossy, full-color, comic-style brochure that purports to teach basic facts about HIV by using analogies to everyday activities. Analogies are great - I use them all the time. But they're not so easy to come up with, and if you do a superficial job of it, you don't increase explanatory power at all. For example: here's how the brochure explains critical elements of HIV bloodwork:
"Just as this crossing guard directs the traffic at this busy city intersection, the CD4 cell is the part of the immune system that directs others to attack harmful things, like bacteria and germs, that enter the body every day...Just like your body tells you it's time to eat by making your stomach rumble, your viral load tells you and your doctor how well your HIV medication is working."
Hoo, boy. Where to start. A crossing guard keeps traffic moving smoothly and safely, and attempts to prevent collisions. It's only a good analogy for CD4+ cells if you imagine the crossing guard directing cars to run down, say, escaped rabid dogs, or jaywalkers. But at least the second half of the analogy is a valid description of what CD4+ cells do, whereas the description of viral load misses the boat entirely. VL is the amount of HIV in the bloodstream. So, yeah, doctors can indirectly tell how well HIV medicines are working by looking at VL, but what it directly measures is how powerful and widespread HIV is in the body. The analogy implies that VL is irrelevant for patients who aren't on medicine. Worst of all, though, the two analogies don't link CD4+ count and VL together at all, so there's no concrete example of how they relate.

These same concepts - CD4+ count and viral load - are things that I explain several times a week. I also use analogies, although mine haven't been made into a glossy comic book. Here's roughly what I say:
CD4+ cells are like the cops of your immune system. They patrol your blood looking for germs - invaders - and when they find them, they sound the alarm and bring the rest of your immune system in to attack. HIV is like a gang that's trying to hunt those cops down and kill them. Your viral load is a measure of how much HIV is in your system, so, how many gang members are on the hunt.

Now, you know what happens when there aren't very many cops to patrol a neighborhood? The criminals move in. And when you don't have a lot of CD4+ cells to patrol in your blood, the germs move in and take over. That's how people get sick with AIDS: the HIV gang has killed off so many CD4+ cops that there's nothing left to protect against whatever germs come around. But if you're able to knock out some of the gang members, by taking your medicines, the CD4+ cops have time to call up reinforcements, and they can start patrolling again.
I'm not saying this is the world's best analogy either, but at least my clients come away with a concrete picture of what's going on in their blood. And they don't tend to forget which of their lab results represents the "good guys," something most of them aren't sure of when they come to me.

But the point is not to proclaim my superiority over the nice health educators that Agouron Pharmaceuticals hired to produce the analogy brochure, it's to say that patient education is harder than it probably seems to people who don't have to do it. You can have all the right elements - concrete comparisons, high-interest presentation, lots of pictures, links to everyday life - and still come up with something that doesn't much help.