Brief Literature Review of Pain Assessment
In his literature review of pain research, Bill Noble elaborates on the methods used to test effectiveness of analgesics between 1945 and 2000. His research outlines three different approaches: (1) psychophysics, (2) standardized words on questionnaires, and (3) verbal rating scales. Psychophysics is the oldest method of the three and it uses a stimulus to evoke pain (Hardy & Goodwell, 1940). The stimulus needed to elicit pain is quantified (pain threshold) and then subtracted from the maximum amount of stimulus that the subject is able to handle (pain tolerance) to get the difference (pain interval). The second method has a more clinical use as it is a survey format that asks patients to describe their pain using a set a standardized questions. The first of these surveys was the McGill Questionnaire, which Scarry also references in her analysis of how the assessment of physical pain in a clinical setting has changed. The third method of measuring pain Noble addresses is a verbal scale where patients express their pain on a numerical scale (Figure 1). All three methods have a place in modern medicine. (Noble)
Fig 1. Numerical scale used to quantify pain in people 3 years of age and older (Wong & Baker, 2001)
In their essay, Resnik and Rehm dissect why clinicians do not adequately address pain and what steps need to be taken in order to fix this issue. He points out that clinicians are firstly not given enough training on pain management. Secondly, they are often hesitant to prescribe analgesics because of possible side effects. Medical regulations also prohibit excess or unnecessary prescriptions of narcotics as they can lead to abuse of medication. Along with improper treatment of pain by the physician, inadequate communication of pain by the patient also contributes to the problem at hand. Patients sometimes hold back from expressing pain for various reasons (insurance does not always cover pain medication, pain can mean their illness is progressing, etc.) Resnik and Rehm suggest that retraining medical professionals in pain management would help to overcome this communication gap between physicians and patients. This encompasses using subjective descriptions of pain by patients for diagnosis, alternative methods of treatment pain outside of commercial medicine, and more conversation regarding pain between the physicians and patient to normalize the subject. (Resnik & Rehm, 2001)
Evidently, research has shown that pain is difficult to expressive because of its subjectivity. However, in clinical medicine, standardized questionnaires and scales are used to quantify pain and diagnose patients. These diagnoses are sometimes inaccurate because of confounding variables such as legal pressures against prescribing analgesics and the communication gap between physicians and their patients.
The sources examined in this literature review examine pain assessment from a clinical perspective. While this is a large application of pain assessment, there is little research about the cultural differences that come into play when looking at how pain is perceived and treated. Additionally, there seem to be several standard measures of pain assessment in modern medicine. Having several standards is the equivalent of having no standard. Another area of research that is currently not well studied is the existence of a universal standard to assess pain. Further research should evaluate current models of pain assessment to establish the strengths and weaknesses of each established method used in medicine today.
Citations:
Hardy, J. D., Wolff, H. G., & Goodell, H. (1940). Studies on pain. A new method for measuring pain threshold: observations on spatial summation of pain. Journal of Clinical Investigation, 19(4), 649.
Noble, B., Clark, D., Meldrum, M., ten Have, H., Seymour, J., Winslow, M., & Paz, S. (2005). The measurement of pain, 1945–2000. Journal of pain and symptom management, 29(1), 14-21.
Resnik, D. B., & Rehm, M. (2001). The undertreatment of pain: scientific, clinical, cultural, and philosophical factors. Medicine, Health Care and Philosophy, 4(3), 277-288.
Scarry, E. (1985). The body in pain: The making and unmaking of the world. Oxford University Press, USA.
Wong, D. L., & Baker, C. M. (2001). Smiling face as anchor for pain intensity scales. Pain, 89(2-3), 295-297.
