Difference Between Evidence & Opinions


Last week, I asked if you have ever asked your doctor for evidence. For example, when your doctor prescribed a medication for you, did you ask how many patients, like yourself, have taken this drug and what percentage had a good or bad outcome? Did you ask your surgeon how many patients like yourself did he/she operate on and what percentage of those patients were cured of their problem or ended up with a post-operative complication?

Or did you just rely on their “opinions” because you liked their bedside manner or “heard good things about the doctor” and/or “your instincts felt right”?

I am guessing that most of you have never asked your doctor for evidence.   Too scared? Believe your doctor uses all the relevant evidence? Don’t think you can understand evidence? The ironic thing is that most of you have asked for or used evidence when buying a car or a house or a mutual fund or a book or an appliance.

So what is the difference between evidence and opinions?  

Here is the bottom line: Opinions tell you what MIGHT happen. Evidence tells you what actually DID happen. This line should be a bumper sticker!

Opinions will include terms/phrases including but not limited to: “I believe, I recommend, the evidence shows, this is the best drug, he is the best surgeon.” Opinions are famous for not including any data/numbers.

Evidence (which comes from either published or unpublished studies) is chock full of interesting numbers and facts:

  • The number of patients who were given the therapy (i.e. 100 patients were given the vaccine compared to 100 patients who were given no vaccine)
  • How long the patients were followed to see if the medication was effective and safe (i.e. patients were followed for 6 months)
  • The percentage of the patients that are just like you (i.e. 100% of the patients in the study were female, age 65 and older and had stage 1 breast cancer with triple negative hormone status)
  • The actual number and percentage of patients who had good or bad outcomes of interest (i.e. 700/1000 or 70% of the patients survived, 50/500 or 10% of the patients experienced acute kidney failure)

So what is the ideal recipe for making an informed decision as a patient? Here is what has been proven to work most effectively:

Review of the Evidence with your doctor + personal preferences of patient = Best Healthcare.

The next time your doctor recommends taking a drug for the rest of your life or having a surgery, you should say “Show Me The Evidence,” then review that data with your doctor. Based on your personal preferences (geography, insurance status, feelings about risks and benefits, etc) choose the treatment that is best suited for your unique medical situation.  It’s just like picking the right car, house, stereo or book.

Next week we will start presenting cases of real patients who used evidence to make informed decisions. Inside every patient there is a doctor, IF they have evidence.


About Show Me The Evidence

SMTE’s mission is to expose America’s dependence on “expert” opinions, empower patients to ask questions and be their own advocate, and to help make medical evidence fun and easy to understand. We strongly believe that if people begin to demand evidence, many of the burdens of our current health care system can be lifted.

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