Explaining pain is a big part of how we treat patients with chronic pain. Through education, we try to change those inaccurate pain beliefs that contribute to the maintenance of pain. However, explaining pain clearly is not always easy, and for patients, learning new concepts that contradict with strong existing beliefs can be challenging too. Therefore it makes sense to regularly assess our patients to ensure our message is getting through.
The patient-version of the Neurophysiology of Pain Questionnaire (NPQ)  has been used extensively to assess pain biology knowledge in patients. Prior to education, it can help identify inaccurate beliefs, such as ‘chronic pain means that an injury hasn’t healed properly’. After education, it can be used to assess knowledge change and identify gaps in knowledge. Yet, despite its widespread use, the English version of the NPQ had never been formally assessed.
To test the NPQ, we analysed the responses of a random sample of 345 chronic spinal pain patients . We used Rasch analysis, a fancy statistical process, to help answer the following questions:
- Are the NPQ questions too easy or too hard?
- Does the difficulty of the questions target the ability of patients?
- Can the NPQ questions be summed to provide an overall score of ‘pain biology knowledge’?
- Do any of the questions duplicate the content of others?
We also assessed whether the NPQ was reliable by reassessing as group of patients a week later.
We found the NPQ effectively targets the ability of chronic spinal pain patients and is sensitive enough to distinguish between high and low performers. The NPQ had acceptable test-retest reliability and could be validly summed to provide a score of pain biology knowledge. However, some questions functioned erratically or duplicated others and preliminary analysis suggested the tool could be improved with the removal of some questions.
Our teaching can result in the knowledge uptake which can facilitate a reconceptualisation of pain and in turn reduce pain . Despite some limitations, the patient-version of the NPQ is a useful tool for briefly assessing a patient’s beliefs regarding pain prior to education and for ensuring our Explain Pain message is understood.
Mark Catley is a PhD candidate in the Body in Mind Research Group (at University of South Australia) in Adelaide. When he is not busy researching, Mark works as a physiotherapist in a rehabilitation hospital. He is interested in the brain’s involvement in the transition from acute pain to chronic pain, and is currently investigating the relationship between cognitive variables, mood and sensory function in people with back pain.
He also has a very particular approach to cooking rice. For perfectly cooked rice: 2/3 cup rice, double that in COLD water, and then 8mins in microwave uncovered. Actually, he has a particular approach to many things – including windows. He is the only BiM team member you should ever get to clean a window.
 Butler DS, Moseley GL. Explain pain. Adelaide, S. Aust: Noigroup Publications, 2003.
 Moseley L (2003). Unraveling the barriers to reconceptualization of the problem in chronic pain: the actual and perceived ability of patients and health professionals to understand the neurophysiology. Journal of pain, 4 (4), 184-9 PMID: 14622702