Doctors Can't Read the Test Results
Ever had an X-ray taken? Or one of those fancy scans or lab tests? Did the process strike you as professional and trustworthy? Sure it did -- it's science.
In reality, though, all those scans and tests and results are basically Rorschach tests for doctors. For instance, a study done on one type of test (coronary angiograms) discovered that if you give two different doctors a copy of the same test, they'll disagree up to half of the time. In fact, if you give the same doctor the same angiogram twice, he will disagree with himself up to one-third of the time.
"Still a better rate than my marriage choices ... "
Yet another study found that a group of physicians simply couldn't agree on whether any given patient was showing physical signs of goddamn heart failure. Man, we're not medical professionals, but we've always assumed that the bare minimum qualification is knowing if the patient's heart is working.
What's Going on Here?
As high tech as hospital equipment is, they have no Star Trek scanners that pop out easy diagnoses when swiped over patients. All scans, tests, and even standard lists of symptoms must be interpreted by humans. That means you're always relying on one part accurate science, one part unpredictable humanity, and the results can be seriously affected by that particular doctor's training, his knowledge, and how hard he is thinking about the taco he's going to have for lunch. Hell, he could have just smoked a bunch of meth, we don't know your doctor.
Like what's with all those weird black light posters all the time?
But new techniques are surely fixing the situation, even if slowly, right? Nope! These days, many hospitals use teleradiology, a fancy term for outsourcing the interpretation of your scans and tests to workers (who may or may not have medical training) outside the hospital, anywhere from the next state over to India. This is especially popular in emergency medicine, because smaller hospitals don't want to keep a radiologist in their payroll just for the times Cousin Ronnie stumbles in with a cow-tipping injury.