Pain Measurement in Chronic Pain Patients

Pain measurement is vital to the evaluation of treatment techniques. Without adequate methods of measurement, pain treatments will continue to be adopted for use without proper scientific evaluation.

Cost effectiveness is becoming more important in pain rehabilitation, and scientifically established and proven assessment techniques are vital in determining the treatment techniques that are the least invasive, least extensive, and least expensive.

Measurement of induced acute pain is easier than measurement of chronic pain. In laboratory-induced acute pain, there are minimal emotional or cognitive factors, and the quantity of pain stimulus is easily controlled.

In the measurement and assessment of chronic pain, unfortunately, there is no generally accepted laboratory model. A clear linear relationship between the quantity of noxious input and the intensity of pain experience is not apparent in chronic pain.

It is difficult to capture what is a personal and private sensory experience. Many times all the doctor's have are the patients' words, their recollections of the experience, and the behavior exhibited when they have the pain experience.

Measuring Pain objectively is very difficult. A pain scale should meet a few basic criteria, including ease of administration and scoring, potential for accurate use by a variety of healthcare professionals, high reliability, and validity.

Pain is a complex experience, and evidence confirming its presence involves several dimensions that depend on changing states and that are continuously influenced by a multitude of stimuli.

There are four main components of pain: Nociception, sensation, suffering, and behavioral reactions.

There are also 3 components of chronic pain measurements. These are the subjective, the physiological, and the behavioral.

The interaction between these components is dynamic and involves a balanced appraisal of sensory input and the degree to which this is modulated by psychological factors.

The subjective component of chronic pain measurement is reflected in rating scales, questionnaires, and dairy cards. The common tools used are categorical and visual analogue scales. The visual analog scale (1-10) is the most frequently used rating scale.

Categorical scales use words to describe the intensity of the pain. They were the earliest pain measure. The patient selects the most appropriate word. Most research groups use four words (none, mild, moderate and severe). Scales to guage pain relief were developed later. The most common one used is the five category scale (none, slight, moderate, good or lots, and complete).

Questionnaires have gained wide acceptance, with the McGill Pain Questionnaires being the most popular.

For more information on Chronic Pain and Pain Management, please visit the author's site PainsWeb.com.