Medical Errors

One of my Attendings, a senior and respected nephrologist at Massachusetts General Hospital, went through the following calculation the other day with me. I'm paraphrasing:

"How many patient encounters have I had during my career as a physician? Well, let's say I see 25 patients in a day--that's a reasonable number and probably an underestimate. Let's also say I work 300 days a year--which is also a reasonable assumption. Already that's 7,500 patient encounters a year. Over the course of a 25-year career, that calculates out to an astounding 187,500 patient encounters.

"Now let's also say that I'm a competent physician, and I have a low error rate--let's say I only make an error in 0.1% which would be pretty exceptional--over the course of 25 years, that's still nearly 200 patients in which I screwed up."