History of Pain: The Psychosocial Assessment of Pain
Over the past 30 years, we have seen tremendous changes in the diagnosis and treatment of pain—including a better understanding of pain as the 5th vital sign. The prevalence of pain is striking. According to the Institute of Medicine’s survey, an estimated 100 million people in the US experience pain.1 Further, 25% of adult Americans report having an episode of pain during the last month that persisted for more than 1 day.2
Data from the National Health Survey indicated that within the sample, 15% of adults had experienced migraines or severe headache, 15% experienced pain in the neck, 27% in the lower back, and 4% in the jaw.3
According to a recent article by Turk and Melzack, despite improvements in medicine, “pain is not well understood and the severity of the pain may not be adequately managed.”4 They further note that the central problem in providing appropriate treatment of pain continues to be the inherent subjectivity of the pain experience.
In this installment of the History of Pain, we will examine the psychosocial assessment of pain. In the August issue of Practical Pain Management, I introduced the Melzack and Casey model of pain that was published in 1968.5 I still refer to this model today to formulate my assessment approaches. As noted in earlier installments of this series, I use subjective data in forming my clinical impressions and treatment recommendations.6-8
However, health care providers should keep in mind that the assessment process is a 2-way experience because the patient also is assessing the provider based on subjective impressions. If the patient is unhappy with their provider or treatment, it can influence treatment outcome. Both the provider and the patient should keep in mind that pain medicine is not an exact science but is based on a trial and error process.
First Step: Initial Evaluation (Impressions)
The first step in the subjective assessment process begins when the patient arrives for the initial appointment. For example, the completeness of the patient’s initial paperwork, his or her appearance, and how he or she interacts with the provider’s staff create an initial impression that follows the patient throughout the assessment experience. Under usual circumstances, the patient then is evaluated by the primary care provider (PCP), who will have reviewed their initial paperwork and incorporate staff subjective impressions before actually meeting the patient.
After the PCP completes the initial evaluation of the History and Physical (H&P), 2 approaches are possible: treat the patient with pain medicine and conservative treatment (physical therapy) or refer the patient to a specialist for further assessment and recommendations. If the PCP chooses to refer to a specialist, the PCP will forward the initial evaluation that will include subjective impressions.
The specialist may elect to perform additional tests before they forward their response back to the PCP. This evaluation may include additional subjective impressions as well as objective findings. The end result is that as the patient’s medical record expands, it includes accumulating subjective impressions that will greatly influence subsequent treatment recommendations. Each participant in the assessment process plays a specific role. In addition, each provider will determine the outcome of initial assessment recommendations.
At this point in the process, the assessment and initial recommendations become part of the trial and error treatment journey. The patient should be aware that the provider is charting the course of this journey with some of the following goals: formulating a differential diagnosis, understanding the nature of the patient’s pain, evaluating the impact of the pain on the patient’s life, assessing physical strengths and weaknesses, and measuring response to treatment. Finally, the provider should be sensitive to the physical and emotional demands placed on the patient by extended assessments.
How to Measure Pain
The measurement of pain presents a number of challenges. The patient is the only one who can provide information about the intensity of their pain. Throughout the assessment process, patients are asked to rate their pain—usually using a visual analog scale (VAS) from 0-10, ranging from no pain (0) to the worst pain they can imagine (10). In reality, this may be the only measure of pain used in the clinical setting.
There are a number of concerns with this approach. For example, if a patient is asked to recall their pain level over the past week as an indication of pain intensity, the unreliable nature of memory becomes evident. One study found that patients will consistently underestimate or overestimate their pain levels when asked to recall pain.9 Therefore, relying on a single measure of pain intensity (eg, VAS), the provider is omitting critical data that maybe obtained through other assessment tools. In my practice, I use the patient’s VAS rating as a projective measure of psychosocial distress and not a sole measure of sensory perception. The old adage that you cannot tell a book by its cover is relevant to this issue.
Physical Pathology May Not Equate to Pain
There are some clinicians who feel that the only approach to identify the true nature of pain is to demonstrate physical or chemical pathology. For disability claims, including Social Security, only physical findings—imaging and laboratory results—are used to determine whether a claim should be accepted or rejected. The reasoning behind this approach is based on the faulty assumption that physical findings are directly related to the pain experience.
Unfortunately, biomedical research has not been able to confirm that the existence of physical pathology and pain are directly related. In fact, a number of studies have found that significant pathology can exist in individuals who report little or no pain, and conversely, studies have found significant levels of pain with little or no physical pathology.10-12 Turk and Melzack have written that “the association between physical abnormalities and patient’s reports of pain is often ambiguous or weak. In addition, physical pathology has been reported not to be predictive of disability.”5
Despite these findings, there are still many clinicians who feel that if pain is not associated with physical pathology, then by simple deduction, pain must be psychogenic in origin. Again, as I have pointed out previously, there is no creditable empirical research to support this position.