Principles & Practice of Pain Medicine > Part II. Pain: General Principles and Evaluation > Chapter 6. Evaluating the Patient with Chronic Pain Jeremy Goodwin and Zahid H. Bajwa

Pain Measurement Tools

"No single tool or instrument can measure pain fully and objectively in a clinical setting. But several measurement instruments have been developed to assess the most clinically relevant aspects of pain and ways in which it affects the patient's life. These tools are either easily used but limited in what they measure (unidimensional scales) or require time to apply and psychological expertise to interpret (multidimensional scales).In clinical practice, unidimensional and self-report scales offer a simple, useful, and valid method for assessment and monitoring of a patient's pain. Unidimensional scales measure only the intensity of pain.This is the simplest and most commonly used scale to evaluate pain. On a scale of 0 to 10, where 0 represents "no pain" and 10 the "worst imaginable pain," the patient chooses a number to describe the pain intensity. Advantages of this scale are that it is simple and reproducible, it is easily understood by most patients, and small changes in pain can be measured. Its major disadvantage is its inability to reflect anything more than the intensity of pain. Ramifications of pain on mood (or vice versa) are not so easily measured.This instrument is a long and complex questionnaire that requires caution in interpretation (its scales are based on the general population, not a chronic pain patient population). A number of scales are generated, which may lead to a false sense of confidence in the ability of the test to assess pain. The ability to predict..."