Chiropractic + Naturopathic Doctor

Using patient-based outcome assessment instruments

By Dawn Armstrong DC   

Features Clinical Patient Care

What are patient-based outcome assessment instruments, and when should they be used?


While we are familiar with Practitioner Based Outcomes Assessments (objective measurements of strength or posture or active ranges of motion, useful to document a patient’s baseline physical facts and how they change over time), are we familiar with the patient’s subjective experience? How a patient feels and how they are functioning is becoming an equally important measure of a treatment’s success.

Practitioner based tools such as dynamometres, goniometres and plumb lines have been long regarded as the gold standard of evidence of benefit from treatment because (ideally) objective physical assessment is consistent from one visit to the next and one practitioner to another. The use of instruments to measure (quantify) a patient’s status has been, and still is, valued because objectivity is an important goal.  

But there’s a way to objectively measure the subjective experience of a patient, collectively known as patient-based outcome assessment instruments (PBOAIs).


PBOAIs are special intake forms for certain patients – people with chronic/severe pain and people who have been injured at work or in a motor vehicle accident. They can also be used with everyone who seeks out your care because they are simply questionnaires that give patients an opportunity to answer questions like “how are you feeling?” and “how are you doing?”

PBOAIs give us a way to make the subjective objective. How can we objectively measure a patient’s experience of pain or disability?

  • Have them give it a number and rank it, relative to other experiences
  • Have them put it into words; choose statements that best reflect their opinion
  • Have them make a picture of it.

These are all strategies that are used to “measure” and document the facts of a patient’s experience. Tools that let us objectively quantify subjective parameters are now being utilized in a variety of healthcare research settings (including pharmacy and physical rehabilitation).

Patient-based assessment forms come with many names. You will have heard of the McGill pain questionnaire, or the Vernon-Mior neck disability index or Roland-Morris and Oswestry disability questionnaires. There are nearly 30 different ones being used currently and no doubt more will come. We can use these tools to assess both a patient’s pain and their functional abilities, which are often inextricably linked.

There are dozens of valid questionnaires available for use in your office. You will want to ensure that the one(s) you choose will be responsive to the effects of treatment. It should also be valid (it measures what it is supposed to and includes all necessary areas of inquiry) and reliable (can be reproduced and isn’t influenced by the person administering the test).

One of the simplest PBOAIs is the Global Wellbeing Scale, which is a modified visual analog scale. This easy-to-use “tool” lets us objectively document a patient’s subjective response to care:

  • Draw a line across the page
  • At the far left end of the line, place a small vertical line and label it as “Worst you could possibly feel”
  • At the other end of the line, mark it as “Best you could possibly feel”
  • Patients are asked to make a vertical line along the scale to indicate how they feel today. You will take a ruler and note how far along the horizontal line they have marked. Write this number down along with the date and whether this is a pre- or post-treatment assessment.

There is only one rule when it comes to using these special intake forms. The questionnaire must first be administered before any treatment is given. It is then repeated after a course of care is completed and the results are compared. Well-constructed subjective assessment forms have sufficient scale width. This allows for meaningful change to be detected.

These forms objectively demonstrate the benefits of what you do. Your patients and interested third parties (insurance companies, lawyers, etc.) all want to know that your particular type of treatment actually helps, and so do you.

Patient-based assessment questionnaires are an important tool for hands-on health-care professionals who want to document the effectiveness of the treatment they provide and they give patients a chance to accurately communicate their suffering to us.

DR. DAWN ARMSTRONG is a graduate of CMCC and has been in practice for over 30 years. She is currently focused on promoting life-long learning and professional development and has created a continuing education course – Clinical Record Keeping: A Hands-On Approach. Learn more at

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