Ninety percent of drivers think they’re above-average drivers, ninety percent of professors think they’re above-average professors etc. The relevant studies are paywalled, so I don’t know if I should trust them. Our recent discussion of therapy books would make more sense if ninety percent of therapists believed they were above-average therapists. I don’t know about that one either.

But I am pretty sure ninety percent of doctors believe they’re above-average doctors. Here are some traps I’ve noticed myself falling into that might help explain why:

1. Your patients’ last doctor was worse than you. Think about it; if somebody has a good doctor, they’ll stay with them, and you will never see that patient. If somebody has a bad doctor, they’ll go see another doctor instead. That other doctor might be you. So your current patients’ last doctor will be worse than average. But this is where most of your chance to compare yourself with other doctors comes from: “my patient’s last doctor misdiagnosed them, but I got it right” or “my patient hated their last doctor but says I’m much better”. See also You Are Not Hiring The Top 1%.

2. Your patients love you. Similar to the above: if your patients love you, they will stick with you. If your patients hate you, they’ll leave. So over time, your practice will consist of patients who are very happy with your style of practicing medicine. Suppose some patients like very practical/efficient doctors, and others like very touchy-feely doctors. A practical/efficient doctor will collect a set of patients who prefer practical/efficient doctors and who praise them for how focused and sensible they are. A touchy-feely doctor will collect a set of patients who prefer touchy-feely doctors and praise them for how caring and personable they are. It will be obvious to the practical/efficient doctor that they’re satisfying their patients’ preferences much better than the touchy-feely doctor down the road would, and vice versa.

3. Patients often come to you, but never leave you. When a patient transfers to me, I have to review the case, confirm that this is an appropriate case for me, talk to the patient about why they left their last doctor and what we can do differently, and then keep seeing that patient. When a patient leaves me, I usually have no idea. It usually looks like the patient saying “I’ll make an appointment for next month”, and then not making that appointment. If I’m not careful, I never notice this; it’s a dog that doesn’t bark. Even if I do notice, patients stop coming all the time for all sorts of reasons. Sometimes they forget. Sometimes they feel better and decide they don’t need you. Sometimes they move out of state and don’t tell you. Sometimes they lose insurance and can’t afford you, or change insurances to one that doesn’t cover you. If you’re really on top of things you try to call these people and ask what’s going on, but sometimes they don’t answer and sometimes they lie (it’s really awkward to tell a doctor that you’ve fired them). So it naively feels to me like patients switch from the doctor down the road to me all the time, but nobody ever switches from me to the doctor down the road. I’m sure it’s not true, but that’s how it feels.

4. You’ve probably successfully treated most of your patients. Now pull all of the above together. Suppose a patient has a chronic disease like depression or diabetes. If you treat it successfully, they will love you and stay with you; if you fail, they will switch to another doctor (and you will never hear about it). Ten years later, you wake up and notice that most of your patients are success stories. But your patients usually describe their previous doctor as a miserable failure. Selection bias is a heck of a drug.

5. You know what you know, but you don’t know what you don’t know. Suppose each doctor makes errors at the same rate, but about different things. I will often catch other doctors’ errors. But by definition I don’t notice my own errors; if I did, I would stop making them! By “errors” I don’t mean stupid mistakes like writing the wrong date on a prescription, I mean fundamentally misunderstanding how to use a certain treatment or address a certain disease. Every doctor has studied some topics in more or less depth than others. When I’ve studied a topic in depth, it’s obvious to me where the average doctor is doing things slightly sub-optimally out of ignorance. But the topics I haven’t studied in depth, I assume I’m doing everything basically okay. If you go through your life constantly noticing places where other doctors are wrong, it’s easy to think you’re better than them.

6. Your victories belong to you, your failures belong to Nature. Sometimes I get a really difficult case, something nobody else has been able to figure out – and I absolutely nail it. I ride the high for days. I feel like a miracle-worker. Other times I get a difficult case nobody else has been able to figure out, and I can’t figure it out either. I don’t worry too much about it – some things are beyond the ken of modern medicine; obviously nobody can treat untreatable stuff. This is especially true in psychiatry. There are so many things we don’t understand, so many cases that are just inherently unresponsive to any kind of treatment we know about – that it’s hard to beat yourself up over any given failure. When you fail, you just say “I guess that was one of those treatment-resistant cases”. Maybe if I was a slightly better doctor I would have been able to figure out a way to treat it – but I will never know, and that’s not a natural way to think.

7. You do a good job satisfying your own values. Everybody wants to make people healthy and save lives, but there are other values that differ between practitioners. How much do you care about pain control? How much do you worry about addiction and misuse? How hard do you try to avoid polypharmacy? How do you balance patient autonomy with making sure they get the right treatment? How do you balance harms and benefits of a treatment that helps the patient’s annoying symptom today but raises heart attack risk 2% in twenty years? All of these trade off against each other: someone who tries too hard to minimize use of addictive drugs may have a harder time controlling their patients’ pain. Someone who cares a lot about patient autonomy might have a harder time keeping their medication load reasonable. If you make the set of tradeoffs that feel right to you, your patients will do better on the metrics you care about than other doctors’ patients (they’ll do better on the metrics the other doctors care about, but worse on yours). Your patients doing better on the metrics you care about feels a lot like you being a better doctor.

Some of these seem to generalize; do other jobs where customers select someone to work with have the same problems?