Andrew McAfee imagines how computerized medicine will improve diagnostics:

When I went to Dr. Watson as a patient, I’d contribute my own data: the contents of my personal health record, any recent test results, and a description of my symptoms. Current speech recognition and natural language processing technologies are so good that I could give this description over the phone.

Dr. Watson would then go to work. It would approach the problem (“What condition(s) does Andy have?”) from many directions at once, turning loose an army of algorithms. Each of them would examine the data I’d supplied, compare it to previous cases and patterns detectable in the accumulated body of medical knowledge, and reach a diagnosis. To oversimplify a bit, the supercomputer would give my case to a host of non-identical virtual diagnosticians, each of which would return with its answer about what was wrong with me. The real-world equivalent of this would be to give my case to hundreds of differently-trained and -oriented doctors, then collect all their answers.

If a large majority of these answers were consistent — if most of the doctors thought I had the same condition — I’d have pretty high confidence in this consensus diagnosis. In just the same way, if most of Dr. Watson’s algorithms converge to the same answer, the computer has high confidence that it knows what’s wrong with me. As those of us who watched the Jeopardy! competition learned, when Watson was confident it was usually also correct.

In certain important ways, this will be less pleasant than the status quo. Dr. Watson won’t ask you if you’re scared or assure you that everything will be all right or talk you through the procedure. There’ll be no human touch, unless you want to pay extra for one. But in certain ways, it’ll be better than the status quo. For one thing, there’ll be no waiting times. Dr. Watson can see a lot of patients at once. And here are a few other advantages McAfee sees:

l  It’s based on all available medical knowledge. Human doctors can’t possibly hold this much information in their heads, or keep up it as it changes over time. Dr. Watson knows it all and never overlooks or forgets anything.

l  It’s accurate. If Dr. Watson is as good at medical questions as the current Watson is at game show questions, it will be an excellent diagnostician indeed.

l  It’s consistent. Given the same inputs, Dr. Watson will always output the same diagnosis. Inconsistency is a surprisingly large and common flaw among human medical professionals, even experienced ones. And Dr. Watson is always available and never annoyed, sick, nervous, hungover, upset, in the middle of a divorce, sleep-deprived, and so on.

l  It has very low marginal cost. It’ll be very expensive to build and train Dr. Watson, but once it’s up and running the cost of doing one more diagnosis with it is essentially zero, unless it orders tests.

l  It can be offered anywhere in the world. If a person has access to a computer or mobile phone, Dr. Watson is on call for them.

What’s more, Dr. Watson knows what it knows, and what it doesn’t know. If a case has it stumped — if it doesn’t have high confidence in its own diagnosis — it can call in the humans to take over. No pride or ego will get in the way of its doing so.