The Benefits of Using a Graded Chronic Pain Scale (GCPS)

October 1, 2023
By Lisa Germain, DDS, MScD

Have you ever rendered exceptional treatment for a patient’s painful condition only to have them return reporting no change in symptoms? I have. Yet upon questioning them further,  I often discover that they have improved significantly, yet symptoms of a different etiology come to the forefront of their attention.  As we know, pain is a subjective, patient specific experience. I decided to figure out whether there was a way to measure it in a less subjective way.

In medicine, Graded Chronic Pain Scale’s (GCPS) are widely used to assess chronic pain and differentiate it from acute pain syndromes.  Since orofacial pain can present as both acute and/or chronic, I set out to adapt a pain scale as a tool to use in my clinical practice in an attempt to demonstrate improvement of a patients condition.

Upon first glance I came upon the Wong-Baker scale with the smiley/frowny faces which goes from doesn’t hurt to hurts a lot.  This was not what I was looking for, but after doing a deeper dive, I found other more sophisticated and useful tools to work with.  I needed something that would address the heterogeneity of pain in its duration, anatomical presentation, etiology, intensity, and pathophysiology.  The tool I chose is  the Graded Chronic Pain Scale Revised[1].  Its unique value is that it differentiates pain from disability from the pain.  Based on a small number of test items which can be added up and given a numerical score, it provides a valuable, dimensional measure of chronic pain severity (meaning pain intensity and impact on life activities). This brief, easy to score scale has provided me with a tool that not only helps me to assess a patient’s pain, but also makes them a participant in the assessement.  It can help increase their awareness of possible pain etiologies and be motivational in managing it to help improve their quality of life.

Pain Classification

The simplest categorization of pain is determining whether it is acute or chronic. Table 9-1 provides an abridged taxonomy for pain . Acute pain often comes on suddenly, is the result of tissue injury, is shorter in duration and ordinarily resolves once the source is discovered and treated. Chronic pain comes on gradually and is perceived over a longer period (often arbitrarily set at 3 to 6 months). It is frequently difficult to diagnose and treat and is accompanied by a gradual loss of function. [2-5] 

Table 9-1:  Abridged taxonomy for pain

While differentiating between acute and chronic pain primarily addresses duration, it hints at the pain mechanism as well. Acute pain is primarily nociceptive pain and chronic pain is a complex mix of pathologies occurring along neural pathways hence can be nociceptive, neuropathic and or nociplastic. Nociceptive pain, such as a toothache, is caused by ongoing inflammation and damage of tissues. Neuropathic pain, such as trigeminal neuralgia, is caused by nerve damage. However, the mechanism for nociplastic pain, such as TMD’s and headaches, is not as well understood. Nociplastic pain symptoms appear more widespread and intense than the identifiable tissue or nerve damage seem to warrant.  It is often multifocal and can be accompanied by other central nervous system symptoms such as fatigue, depression, sleep and airway problems, memory loss and mood disorders. Table 9-2 divides some of the most common chronic pain syndromes by the origin of their physiological mechanism.  However, this is further complicated by the prevalence of comorbidity associated with chronic pain where multiple factors potentially exacerbate or mask the primary mechanism of the pain [6,7].

Table 9-2:  Classification of common chronic pain syndromes by physiologic mechanism

Adapting the Graded Chronic Pain Scale

In the dental office, when the acute pain is relieved, patients often can not differentiate it from the chronic pain that still lingers. It is therefore important to assess them for chronic pain syndromes as well prior to treatment.  Making them aware of any comorbid etiology in advance is helpful when re-evaluating them for further management.  This is where a pain scale can be used to create a standardized way to assess a patient’s pain experience before treatment. The same forms can then be used during follow-up appointments to measure improvement.

The lack of standardized testing for each variable makes uncovering the primary pain source uniquely challenging.  It is not just difficult for the patient to describe what they’re feeling; It is tricky for the clinician to assess the symptoms described and then use the information to uncover the etiology and formulate a treatment plan.   Chart 9-1 shows my adaption of an intake form for head, neck, and facial pain.  Establishing the onset, duration, intensity, and type of pain is crucial in the formulation of a differential diagnosis.  It can help direct the focus of your examination and discussion with the patient regarding the history of their current illness as well as help you focus on the most likely etiology for the primary pain source.  In addition, the pain descriptors can be used to identify neuropathic pain.  If the patient describes their pain as lancinating, electric, burning, tingling, shocking, stabbing, pins and needles, numb, or extremely sensitive to the lightest touch, referral to a neurologist for further evaluation and treatment is indicated.  This form is a place to start; it does not replace obtaining a detailed verbal history and thorough examination.

Chart 9-1:  Non-odontogenic head, neck, and facial pain intake form

Chart 9-2 shows my adaption of the Graded Chronic Pain Scale (GCPS)-revised [1] . Since chronic pain develops over an extended period, it does not usually have a “cure” per se; the goal is to help the patient find ways to manage it.  The efficacy of this particular GCPS  was measured using interview-based research on patients who were suffering from chronic back pain, headache and TMD. Hence, I felt comfortable using it as my model to diagnosis both odontogenic and non-odontogenic head, neck, and facial pain. 

The first question is asked in order to identify the duration of the patient’s chronic pain. Respondents are asked on how many days they had pain during the prior 3 months: never, some days, most days, every day. The second question is used to identify patients with high impact chronic pain. Respondents are asked how often pain limited life or work activities (never, some days, most days, every day) with high impact chronic pain defined by pain limiting life or work activities most or every day in the prior 3 months. Questions 3-5 are added up and are a measure of limitations due to pain + loss of enjoyment + reduction in activity (PEA Score). A sum PEA score of 12 or greater is used to identify those with moderate to severe pain.  Question 6 is not part of the score, however is asked as a final question to confirm if the pain is completely life altering and the patent is disabled.

Chart: 9-2: Chronic graded pain scale for head. Neck, and facial pain

Chart 9-3 details the algorithm used to interpret this data to divide patients into 4 categories based on the severity of pain and how much disability it manifests. These are as follows:

  • Grade I: low disability-low intensity pain
  •  Grade II: low disability-high intensity pain
  • Grade III: high disability-moderately intensity pain
  •  Grade IV: high disability-severe intensity pain

In general, the patients who report low disability, yet high intensity pain tend to have more favorable treatment outcomes than patients who have higher disability with any grade of pain intensity.  This suggests that when a patient reports low disability regardless of the pain intensity,  is a better measure of a favorable prognosis than the intensity of the pain alone.

Chart: 9-3: Algorithm for interpreting the chronic graded pain scale. 

Conclusion

While medicine’s understanding of pain continues to evolve, quantifying pain remains arduous. Since pain thresholds differ widely from patient to patient, this makes it difficult to assess whether a patient’s symptoms are improving from procedures rendered for that purpose.  In addition, since the patient often presents with multiple sources of pain (comorbidity), distinguishing which symptoms are related to which cause can be daunting. Measuring the efficacy of various therapies also presents a unique dilemma. A simple rating system such as a GCPS can also be used in advance, between treatments, after treatment, and for follow-up appointments to quantify the benefits of pain control therapies and measure the benefits of targeted interventions over time.

For copies of the Graded Chronic Pain Scale described in this article, use this link: LINK

  1. Von Korff M, DeBar LL, Krebs EE, Kerns RD, Deyo RA, Keefe FJ. Graded chronic pain scale revised: mild, bothersome, and high-impact chronic pain. Pain. 2020 Mar;161(3):651-661
  2. Merskey, H., & Bogduk, N. (Eds.). (1994). Classification of chronic pain: Descriptions of chronic pain syndromes and definitions of pain terms (2nd ed.). Seattle: IASP Press
  3. Derasari, M. D. (2000). Taxonomy of pain syndromes: Classification of chronic pain syndromes. In P. P. Raj (Ed.), Practical management of pain (3rd ed., pp. 10–16). St.Louis, MO: Mosby.
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  5. Coda, B. A., and Bonica, J. J. (2001). General considerations of acute pain. In J. D. Loeser et al. (Eds.), Bonica’s management of pain (3rd ed., pp. 222–240). Philadelphia: Lippincott/Williams & Wilkins.
  6. Brookoff, D. (2000). Chronic pain: 1. A new disease? Hospital Practice. McGraw-Hill [online]. Available:http: //www.hosppract.com/issues/2000/07/brook.htm.
  7. Fitzcharles, Mary-Ann et al. Nociplastic pain: towards an understanding of prevalent pain conditions The Lancet, Volume 397, Issue 10289, 2098 – 2110