The Journal of Orthopaedic and Sports Physical Therapy (JOSPT) recently started a series called “Engaging With Research: Linking Evidence With Practice” in which they try to help everyday clinicians become better in their consumption of the research so they can integrate evidence more into their daily practice. In the first write-up, they cover the common biases and limitations that we may encounter.
Below, I have unpacked most of the biases they covered and summarized it in a more digestible way. As I get more years under my belt, I become more aware of my biases. It seems like a lot of times during a treatment, the main conflict I encounter is within myself. It does get frustrating sometimes that I never “let things be,” but the scientist in me knows that my continuous critical analysis only polishes my skills further and helps me continue to grow as a clinician and as a person.
Type: Confirmation Bias
Layman definition:
-Assigning too much value on evidence, ideas, statements that support what you believe in.
-Devaluing information that go against your side
-Skewing information in the middle towards your views
Simple analogy:
You love the color blue
You don’t care much for red
You see purple as blue
Clinical example: Dry needling
-You paid a lot of money and spent a lot of time on these courses. You love its effects and use it frequently in your treatment session.
-You cling to the 2-3 studies and anecdotal evidence that dry needling is beneficial and use them frequently in arguments against systematic reviews and meta-analysis that say otherwise
-You make excuses for the studies with inconclusive results such as “the therapists weren’t as experienced” or “they didn’t look at patients with acute pain” to help justify your side
Tips on how to decrease this bias:
-Constantly challenge yourself and try to prove yourself wrong. If you go into an eval and have settled that your patient has a rotator cuff tear, you’ll go in there performing highly specific tests to rule it in, when in fact he had a Type 2 labral tear and every special test is positive because he was irritable.
-Even if there’s a period of time that all your patients are getting better, was it really because of your interventions? Or was it time? Placebo effect? What separates experts from novices is that experts are constantly reflecting and challenging their confirmation biases.
Type: Recall Bias
Layman definition:
You tend to remember the EXTREMELY GOOD or the EXTREMELY BAD more than the in between
Simple analogy:
-We remember the days when a blizzard or a hurricane hits but forget the ~360 days in between with normal weather
-If you were a running back in the NFL, you remember your 220 yd 4 td game, as well as the 18 yd 0 td 2 fumbles game, but forget that you were consistently doing 100 yd 1td a game during the rest of the season.
Clinical example:
-A patient with “frozen shoulder” improved 90% within the first 4 weeks of therapy. You start to hold every patient with the same diagnosis to the same standard even though the original patient was an anomaly.
-You had a 16 weeks s/p achilles repair patient re-tear their achilles during rehab while doing lunges. It was multifactorial and wasn’t your fault, but you will start being overly cautious with every s/p achilles repair patient you see in the future
-The JOSPT article gives an example about many patients stop showing up to PT and we tend to assume that the reason they stopped coming was because they got better, when in fact they may have gotten worse and seeked other treatments
-Not clinical, but during a standardized exam like the NPTE or the OCS, you tend to remember strongly the 20 questions you missed instead of the 300+ that you answered correctly. This is why we leave the testing facility feeling like we failed. WORST FEELING EVER.
Tips on how to decrease this bias:
-Live by this advice: once you’ve seen a patient with ______ diagnosis, you’ve seen one person with _______ diagnosis
-You are the quarterback of the plan of care. As a quarterback you have to have short term memory. Do you think Tom Brady stews on his Week 13 interception returned for a touchdown against the Bills? Nope, he moves on and learns from the previous experience. Do you think that he has taken the foot off the gas pedal after winning one super bowl? Obviously not! The short term memory applies to the incredibly good and incredibly bad moments! Just go back in the next day and continue crushing it!
-Life is pretty much about the law of averages; same in PT too. The best way to really investigate this is to start tracking your outcomes at discharge. I would recommend the Global Rating of Change (GROC) outcome measure as one of the things you use to track stats.
Type: Treatment effect
Layman definition:
You apply a treatment to a patient’s condition and they get better. You attribute all the credit to the treatment
Simple analogy:
My parents applied Vicks Vaporub to my chest/back/nose every time I had a cold, flu, or fever. My parents think Vicks Vaporub is a miraculous ointment that cures all (even though it was likely time and your immune system that fought the infection)
Clinical example:
-All your acute low back pain patients always get better after a lumbar gap and SIJ manipulation
-Ultrasound decreased the palpable swelling in the Achilles tendon of a patient with Achilles tendinitis
Tips on how to decrease this bias:
-Always take into account the healing time frames
lifecare
-For manual therapy, recheck the asterisk sign after EVERY technique you performed. If you do 4-5 things at once, you don’t know which ones you are getting the most bang for your buck on. This advice seems intuitive, but follow this tip and you could save five figures on avoiding residency and fellowship training
-Try to keep up with the emerging evidence. The clinical practice guidelines from 10 years ago could be completely different today. The beauty of having randomized controlled trials is their effort in trying to minimize as much bias as possible
-Accept that most treatments are multi-modal and require a combination of exercise and education on activity/prolonged positional modification in conjunction with your body’s amazing healing capabilities
-Words matter. Don’t use nocebic language or pictures to the patient that would cause them to rely on other modalities or people to help them feel better. Empower them and give them the tools and understanding to help manage their pain themselves.
Type: Patient politeness
Layman definition:
Patients will over-inflate their response to PT because they don’t want to disappoint their therapist, especially after the strong rapport you two have built.
Simple analogy:
When your spouse or relative cooks a meal that tastes worse than dog food, but you smile and wolf that thing down anyways (pun intended)
Clinical example:
A patient with chronic low back pain has been coming to your clinic for 3 weeks now. He is 6’5, 330 lbs. You perform manual therapy on him for 10 minutes. You’re sweating, your forearms are tired and frankly, the positioning of some of them were awkward because his proportions are bigger than you’re used to.
“Alright, can you hop off that table and let’s see you bend forward again”
*Patient grunts and is all red after bending forward
“Uhhhh…it’s better”
“Sweet. Let’s go do some burpees”
Tips on how to decrease this bias:
-Educate the patient on the purpose of the intervention, and be honest about its evidential backing
-Try to use neutral phrases and general terms
-Quantify your patient reports with objective measures (ie NPRS, ROM, etc)
-Use open ended questions like “how do you feel?” instead of “is it better now?”
Type: Availability heuristic
*Bonus* not included in the JOSPT article
Layman definition:
We make decisions based on the things we can easily remember. We also think that those pieces of information are more important because we are able to remember them so easily
Simple analogy:
You need to go to the store for eggs. Your spouse recites a list to you, “Don’t forget to also grab milk, bagels, and toilet paper.”
While in the store you forget the original reason of why you’re there, but can’t forget that you need milk, bagels, and toilet paper. You start to believe that’s why you went to the store in the first place.
You get home, open the fridge door, and realize why you needed to go to the store…#$%@#$
Clinical example:
-Ever have an exercise of the week? You see a colleague prescribe a creative core stabilizing exercise (ie turkish getups) and during that week, all your patients that need core stability re-education are doing the turkish getup
-This can happen a lot during the patient’s subjective. You patient needs to climb ladders for work, and you get hung up on the fact that he plays soccer “sometimes”. You start rehabbing him with agility and speed drills when this whole time you just remembered he played soccer and assumed that’s what his rehab goal was.
Tips on how to decrease this bias:
-Constantly be reviewing practice guidelines for whatever diagnoses you encounter. You start to have your go-tos but those may be outdated unbeknownst to you
-Try to make plan of cares individualized to each patient; avoid cookie cutter treatments! This is easier said than done and in fact, you may be rolling your eyes already because you do it all the time right? Think of your last two rotator cuff repair patients? What exercises did you give them? Did you know one of them was a supraspinatus tear and the other was infraspinatus tear? You knew one was an electrician and one was a retired sedentary woman! Those statements probably did not apply to you, but it made you think!
-If you’re seeing a patient that you didn’t evaluate, chart review for yourself. When you ask your colleague for a quick summary of the patient, they get struck by the availability heuristic and only tell you what was the easiest for them to recall.
Conclusion
So there it is. All these biases I have presented today are just the tip of the iceberg. You are an amazing therapist (because you read blogs like this) and you don’t need to question your confidence all the time; however, when things are going really well and you start acting like your poop don’t stink, step back and check yourself before you wreck yourself (aka start challenging your biases).
References:
- Kamper SJ. Engaging With Research: Linking Evidence With Practice. J Orthop Sports Phys Ther. 2018;48(6):512-513.
- Tversky, Amos; Kahneman, Daniel (1973). “Availability: A heuristic for judging frequency and probability”. Cognitive Psychology. 5 (2): 207–232.