Recommendations vs. Guidelines

by Scott AlexanderSSC4 min read13th Apr 201817 comments


MedicineMechanism DesignPlanning & Decision-Making

Medicine loves guidelines. But everywhere else, guidelines are still underappreciated.

Consider a recommendation, like “Try Lexapro!” Even if Lexapro is a good medication, it might not be a good medication for your situation. And even if it’s a good medication for your situation, it might fail for unpredictable reasons involving genetics and individual variability.

So medicine uses guidelines – algorithms that eventually result in a recommendation. A typical guideline for treating depression might look like this (this is a very over-simplified version for an example only, NOT MEDICAL ADVICE):

1. Ask the patient if they have symptoms of bipolar disorder. If so, ignore everything else on here and move to the bipolar guideline.

2. If the depression seems more anxious, try Lexapro. Or if the depression seems more anergic, try Wellbutrin.

3. Wait one month. If it works perfectly, declare victory. If it works a little but not enough, increase the dose. If it doesn’t work at all, stop it and move on to the next step.

4. Try Zoloft, Remeron, or Effexor. Repeat Step 3.

5. Cycle through steps 3 and 4 until you either find something that works, or you and your patient agree that you don’t have enough time and patience to continue cycling through this tier of options and you want to try another tier with more risks in exchange for more potential benefits.

6. If the depression seems more melancholic, try Anafranil. Or if the depression seems more atypical, try Nardil. Or if your patient is on an earlier-tier medication that almost but not quite works, try augmenting with Abilify. Repeat Step 3.

7. Try electroconvulsive therapy.

The end result might be the recommendation “try Lexapro!”, but you know where to go if that doesn’t work. A psychiatrist armed with this guideline can do much better work than one who just happens to know that Lexapro is the best antidepressant, even if Lexapro really is the best antidepressant. Whenever I’m hopelessly confused about what to do with a difficult patient, I find it really reassuring that I can go back to a guideline like this, put together by top psychiatrists working off the best evidence available.

This makes it even more infuriating that there’s nothing like this for other areas I care about.

Take dieting. Everybody has recommendations for what the best diet is. But no matter what diet you’re recommending, there are going to be thousands of people who tried it and failed. How come I’ve never seen a diet guideline? Why hasn’t someone written something like:

1. Try cutting carbs by X amount. If you lose Y pounds per week, the diet is working. If not, you’re probably resistant to cutting carbs because [two hours of mumbling about insulin] and you should move on to the next tier.

2. Try cutting fat by X amount. If you lose Y pounds per week, the diet is working. If not, you’re probably resistant to cutting fat because [two hours of mumbling about leptin], and you should move on to the next tier.

And so on until Step 7 is “get a gastric bypass”.

I agree nobody can ever make a perfect algorithm that works for all eventualities. But still. Surely we can do better than “Try the Paleo diet! I hear it’s great!”

What information do guidelines carry beyond a recommendation?

First, they have more than one recommendation. It may be that the Paleo diet is the best, but the guidelines will also include which is the second-best, third-best, et cetera.

Second, because they have more than one recommendation, they can tailor their recommendation to your specific circumstances. The person with depression and comorbid anxiety may want to start with Lexapro; the person whose main symptom is tiredness may want to start with Wellbutrin. Since I love bread, does that mean I should avoid carb-cutting diets? Does that mean it’s extra-important that I cut carbs? Does it not matter, and really it depends on whether I have a family history of diabetes or not?

Third, they acknowledge that some people might need more than one recommendation. If you hear “try the Paleo diet”, and then you try it, and it doesn’t work, you might believe you’re just a bad dieter, or that all diets are scams, or something like that. Guidelines implicitly admit that everyone is different in confusing ways, that something that’s expected to work for many people might not work for you, and that you should expect to have to try many things before you find the right one.

Fourth, because they admit you may need to try more than one thing, they contain (or at least nod at) explicit criteria for success or failure. How long should you try the Paleo diet before you decide it doesn’t work? How much weight do you need to lose before it qualifies as “working”? If it’s been three months and I’ve lost four pounds, should you stick with it or not?

Fifth, they potentially contain information about which things are correlated or anticorrelated. The depression guidelines make it clear that if you’ve already tried Lexapro and Zoloft and they’ve both failed, you should stop trying SSRIs and move on to something with a different mechanism of action. If I’ve tried five carb-cutting diets, should I try a fat-cutting diet next? If I hate both Mexican food and Chinese food, is there some other category of food which is suitably distant from both of those that I might like it? Guidelines have to worry about these kinds of questions.

My impression is that once you understand a field really well, you have something like a Guideline in your mind. I think if nobody had ever written a guideline for treating depression, I could invent a decent one myself out of everything I’ve pieced together from word-of-mouth and common-sense and personal experience. In fact, I think I do have some personal guidelines, similar to but not exactly the same as the official ones, that I’m working off of without ever really being explicit about it. Part of the confusion of questions like “What diet should I do?” is sorting through the field of nutrition until you can sort of imagine what a guideline would look like.

So why don’t people who have more knowledge of nutrition make these kinds of guidelines? Maybe some do. I can’t be sure I haven’t read dieting guidelines, and if I did I probably ignored them because lots of people say lots of stuff.

But I think that’s a big part of it – making guidelines seems like a really strong claim to knowledge and authority, in a way that a recommendation isn’t. Some idiot is going to follow the guidelines exactly, screw up, and sue you. I just realized that my simplified-made-up depression guidelines above didn’t have “if the patient experiences terrible side effects on the antidepressant, stop it”. Maybe someone will follow those guidelines exactly (contra my plea not to), have something horrible happen to them, and sue me. Unless you’re the American Psychiatric Association Task Force or someone else suitably impressive, your “guidelines” are always going to be pretty vague stuff that you came up with from having an intuitive feel for a certain area. I don’t know if people really want to take that risk.

Still, there are a lot of fields where I find it really annoying how few guidelines there are.

What about nootropics? I keep seeing people come into the nootropics community and ask “Hey, I feel bad, what nootropic should I use?” And sure, eventually after doing lots of research and trying to separate the fact from the lies, they might come up with enough of a vague map of the area to have some ideas. But this is an area where “Well, the first three things you should try for anxiety are…” could be really helpful. And I don’t know of anything like that – let alone something that tells you how long to try before giving up, what to look for, etc.

Or let’s get even broader – what about self-help in general? I don’t really believe in it much, but I would love to be proven wrong. If there were a book called “You Are Willing To Devote 100 Hours Of Your Life To Seeing If Self-Help Really Works, Here’s The Best Way For You To Do It”, which contained a smart person’s guidelines on what self-help things to try and how to go about them, I would absolutely buy it.