I’ve been confused for a while about the controversy over “evidence-based medicine.”  Some doctors think it is correct; others don’t.  We patients take it for granted that there is solid scientific evidence behind the drugs and treatments our doctors prescribe.  So have we been misled there?

The Center for Evidence-Based Medicine (yes, there is one!) describes it as “the conscientious, explicit and judicious use of current best evidence in making decisions about the care of individual patients.”  Well yes, isn’t that how most academics approach their science?

But a light went on the other day while I was reviewing one of the entries for the current MedGadget SciFi Writing Contest.  In a deliciously creepy story on what happens to medicine by the year 2050, the author threw in this dig at current practices: “… surely so meticulous a scholar need not be reminded that the plural of ‘anecdote’ is not ‘evidence.‘”  Correct.

So how DO doctors decide what treatments to prescribe, anyway?

According to this enlightening look at EBM (as it is affectionately nicknamed) from a fellow “e-Patient” (cancer survivor) named Dave, there’s been a lot of “medical superstition” at work: doctors tending to overprescribe certain treatments for no reason other than the individual doctor’s preferences or prejudices.  It appears that EBM is an effort to correct this, by calling for (according to Wikipedia) “the systematic review of evidence for particular treatments, mainly randomized controlled trials.”

Again, kind of shocking that this isn’t what medical decision-makers have been doing all along.

But here’s the rub: We in diabetes know all too well that clinical trials can provide all sorts of contradictory “evidence.”  One week we read that dairy products are good for diabetes, the next week, dairy is taboo.  We read a bunch about how cinnamon lowers blood sugars, and then we learn that it may not. Etc, etc. You know the drill.

To make matters worse, Big Pharma is known for manipulating clinical studies so that they’ll be sure to produce desired results supporting their drug offerings.

So how can your doctor be expected to make any more of sense of all this than we can?  Maybe this is why many choose to rely on their own instincts and experiences within their own clinic.

Also, as Dave points out, the forced reliance on clinical trial evidence can create a bottleneck for new treatments that patients are need of now. The evidence being gathered may simply not be published yet.  You know I am thinking of Continuous Glucose Monitoring (CGM) here: the insurers wouldn’t even look at it without a mound of clinical trial data, which has thankfully been championed by the JDRF.

(Dave suggests we have a look at “the lethal lag time” section in Chapter 5 of the e-Patients White Paper recently published by the Robert Wood Johnson Foundation.)

I read somewhere recently that the US is the only western industrialized country that doesn’t have an independent body of medical experts tasked with evaluating collective study data and setting national standards of medical care — although there’s been a lot of work in this direction for diabetes in particular.  Still, these standards are presented as “goals” and “recommendations,” and I don’t believe the ADA or anyone else has the authority to enforce them.

So it’s all kind of a mess, I guess.  As a nurse-CDE told me while I was researching a story on diabetes education last year: “Some hospitals prefer to put all new type 1 patients on injections of NPH and Regular insulin. Other hospitals start all new patients on insulin pumps right away. It really depends on how advanced the program is. You could get completely different knowledge even in two hospitals across town from each other.”

And now you know why: it depends where doctors get their “evidence.”

Monday, November 24th, 2008 | Permalink | Comments (7)