Often times, a chronic pain patient is asked to rate his or her pain on a scale of 1 to 10, with 10 being the worst pain. However, using a numerical scale alone can have a couple of drawbacks. For one thing, different patients have different pain tolerances; one person’s 3 could be another person’s 7. The other problem is that a chronic pain patient might report a sizable reduction in pain and at the same time be bedridden, which is obviously not a success.
A function-based treatment strategy measures a patient's progress not in pain relief, but in his or her ability to function better in life. Functional goals would include sleeping, walking, going to work, and connecting with friends. A functional scale would start with only one or two activities affected on the low end and finish with a number of activities affected at the high end. For example, in the sample scale shown below, the scale starts with just one function adversely affected-enjoyment-and then adds one more function with each step up the scale, ending with seven functions adversely affected as pain worsens: enjoyment, work, mood, activity, sleep, walking, and relationships.
Activities Limited by Pain
Source: Adapted from Responsible Opioid Prescribing: A Physician’s Guide by Scott M. Fishman.
With the function-based paradigm, a chronic pain patient may not report pain reduction; but, if he or she has started walking, sleeping normally, and engaging in daily activities, then progress has clearly been made.
It is important to understand that progress in pain reduction and a return to activities is slow, lasting months or years. Gains are incremental, literally step by step. Sometimes, the patient hits a plateau.
Fishman, MD, Scott M. Responsible Opioid Prescribing: A Physician’s Guide. Washington, DC: Waterford Life Sciences, 2007. pp. 34–42.