"Physical therapy is not a subspecialty of the medical profession and physical therapists are not medical doctors; we are a separate profession that provides a unique service that physicians are unable and untrained to provide."

Letter to the AMA from the APTA, Dec 2009

Friday, April 10, 2009

Do Physical Therapists Make Decisions Like Doctors?

Anchoring, Availability and Attribution.

One medical student calls these the "3-A Mistakes" so she wont forget how doctors make mistakes.

In How Doctors Think Jerome Groopman, MD describes common cognitive errors that busy doctors make in diagnosing their patients.

Do physical therapists make these same mistakes?

Perhaps I should be more circumspect but I'll follow Dr. Groopman's lead and share with you how at least one physical therapist committed cognitive errors in the diagnosis of a physical therapy patient.

I'm that physical therapist.


First, I'll define the terms Anchoring, Availability and Attribution - types of cognitive errors made by all professional decision makers and not unique to medical doctors or physical therapists.

Anchoring - is seizing upon an initial presenting symptom and making a snap judgment about the diagnosis.

My patient was a middle-aged African-American female with leg pain radiating to, but not past, the knee. Many of my patients with radicular leg pain, past the knee, have been successfully treated with lumbar traction.

My anchoring error occurred when I lumped my poor patient into a traction classification based on what I thought was radicular leg pain which I did not investigate thoroughly enough to find that the radiation stopped just above her knee - referred, but not always radicular pain.

I 'anchored' my decision to use traction based on her leg pain, assigning a high probability that she would improve after the treatment,

Availability - is estimating the probability of a diagnosis based on how easily an example of a recent patient can be brought to mind.

As I've said, many of my patients got better with spinal traction - their successes were fresh in my mind. Many on my patients with referred leg pain had initially presented with pain all the way to the foot and, with treatment, their pain had worked its way back up the leg - occasionally presenting as 'leg pain to the knee'.

My cognitive error was simply because I had many other patients who responded well to traction that my poor patient would also respond well to traction.

Because my experiences were mentally 'available' I was able to quickly decide based on a vivid memory rather than actual statistical probability.

Attribution- is similar to Confirmation bias, where information that confirms one's beliefs is highlighted and information that contradicts prior beliefs is ignored.

Since my poor patient had a referral from her orthopedic surgeon that said 'consider traction for lumbar degenerative disc disease' I easily fell into the Attribution bias trap.

I didn't examine every patient characteristic that I normally do and I 'attributed' her leg pain to a pathologic diagnosis based on a reputable source.

I should have known better.

My Poor Patient

Needless to say, my poor patient didn't get better with lumbar spinal traction - she got worse. She could barely stand up when she got off of the table and it took her ten minutes to walk out of the traction room.

What did she have?

She was in a stabilization classification.

Upon further examination, my poor patient had a mild 'instability catch' and a positive prone instability test. See the full classification criteria here (Childs et al, JOSPT, 2007 June).

She is still seeing me and doing well with a stabilization program.

So, now you know my cognitive errors.

Anyone willing to share theirs?

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Tim Richardson, PT owns a private practice at Medical Arts Rehabilitation, Inc in Palmetto, Florida. The clinic website is at MedicalArtsRehab.com.

Bulletproof Expert Systems: Clinical Decision Support for Physical Therapists in the Outpatient Setting is a manager's workbook with stories, checklists, charts, graphs, tables, and templates describing how you can use paper-based or computerized tools to improve your clinic's Medicare compliance, process adherence and patient outcomes.

Tim has implemented a computerized Clinical Decision Support (CDS) system in his clinic since 2006 that serves as a Reminder, Alerting, Prompting and Predicting CDS using evidence-based tests and measures.

Tim can be reached at
TimRichPT@BulletproofPT.com .

"Make Decisions like Doctors"

Copyright 2007-2010 by Tim Richardson, PT.
No reproduction without authorization.

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