How can we improve our understanding of pain to help thousands of Canadians who experience chronic pain? The answer to this vital question starts with the development of valid and reliable measurement tools.
Canada Research Chair and Distinguished Research Professor of Psychology Joel Katz led a team of researchers from York University, Toronto General Hospital and the Centre de recherche du Centre hospitalier de l’Université de Montréal in a study that developed and assessed a new tool for measuring how people respond to pain as well as the thoughts and feelings they have when they’re in pain: the Sensitivity to Pain Traumatization Scale (SPTS).
The goal of this work, which was funded by the Canadian Institutes of Health Research (CIHR), the Social Sciences and Humanities Research Council of Canada (SSHRC), York University, and the University of Toronto, was to evaluate the validity and reliability of the SPTS in people with and without ongoing pain.
The SPTS passed with flying colours. Katz’s research team concluded that it is an excellent new resource for assessing people’s reactions to pain, and published their findings in the Journal of Pain Research (2017).
“The SPTS measures the tendency for people to respond to pain in a way that’s similar to how they respond to other traumatic events. So, for some people, pain itself is a traumatic stressor, and living with pain on a daily basis can be traumatizing,” Katz explains. “The SPTS could lead to improved approaches in treatment for people who live with pain on a daily basis,” he concludes.
Katz is one of Canada’s leading researchers in psychological, emotional and biomedical factors involved in acute and chronic pain. He is particularly interested in the processes involved in the transition of acute, time-limited pain to chronic, pathological pain; interventions to minimize acute post-operative pain; and the relationship between PTSD and chronic pain.
Link established between chronic pain and anxiety
For the past two decades, pain research has become increasingly focused on the link between pain and anxiety. This line of inquiry was influenced by the findings of a large American survey of 5,692 individuals in 2005, which revealed that anxiety disorders showed a strong an association with chronic spinal pain as did mood disorders. This research found that chronic spinal pain was very often present with other pain conditions, chronic diseases and mental disorders, and that this played a significant part in role disability associated with chronic spinal pain.
Researchers then started to consider the role of post-traumatic stress disorder (PTSD) and pain. They found core mechanisms that are mutually reinforcing, such as reminders of the trauma, emotional triggers and anxiety related to pain perceptions.
This research, collectively, started to paint a more cohesive picture of pain, anxiety and PTSD. This is what led Katz to develop the SPTS. In the 2017 research article, his team undertook three different studies, each adding a different piece to the puzzle.
116 York undergrads participate in Study 1
The goal of Study 1 was to create the new questionnaire, the SPTS, to accurately measure the possibility that, for some people, pain represents a traumatic stressor. In this study, a group of 116 first-year York students completed a questionnaire about current pain and pain history. The study protocol was reviewed and approved by the research ethics board at York University, the Human Participants Review Subcommittee.
Students provided information about fear and the physical symptoms of anxiety. The severity and impact of a traumatic event were also measured, as were levels of anxiety related to pain.
This study was successful in that the SPTS was shown to be consistent and highly reliable.
Students in Study 2 complete online survey about pain, anxiety
The objective of Study 2 was to evaluate the properties of the SPTS in two groups of York students: those who were pain-free (555 in number), and those who were facing ongoing pain (268). Participants, totalling 823, were recruited between 2009 and 2013. Again, the study protocol was reviewed and approved by the research ethics board at York University.
Participants were asked to complete an online survey that featured nine questionnaires to assess anxiety, traumatic responses, perception of painful experiences and depressive symptoms.
The SPTS was, again, proven to be consistent and highly reliable.
Toronto General Hospital surgery patients participate in Study 3
Study 3 took place at Toronto General Hospital. The study protocol was approved by the University Health Network Research Ethics Board at Toronto General Hospital and by the York University Human Participants Review Subcommittee.
In study 3, the participants, 345 in total with ages ranging from 25 to 90 years, had undergone coronary artery bypass graft surgery ̶ the most common type of heart surgery ̶ a minimum of six months prior to the study.
Using the SPTS, the subjects completed questionnaires involving pain history, anxiety, traumatic responses, perception of painful experiences and depressive symptoms. Patients also rated their average post-surgical chest pain; movement-evoked pain, such as deep breathing; and pain upon gentle touch to the affected areas.
Thirty-seven per cent of participants reported chronic pain, a result of the surgery, with over 80 per cent of these patients reporting pain at the time of assessment. Twenty-seven per cent of participants reported ongoing pain unrelated to the surgery, with over 90 per cent of these patients reporting pain at the time of assessment.
Again, the reliability and validity of the SPTS were deemed excellent.
Sets the stage for future research
Taken together, all three studies (united in one comprehensive research paper) provide key evidence in support of the validity and reliability of the SPTS, and point to the possibility of new improved approaches for treatment for patients in pain based on how they score on the SPTS.
This research also opens the door for future work. Other avenues to explore could involve administering the SPTS at different points after surgery to better monitor pain and possibly predict spikes in pain; or the new tool could be applied in non-pain settings, nonsurgical chronic pain groups and the general population.
The article, “Sensitivity to pain traumatization scale: Development, validation, and preliminary findings,” was published in the Journal of Pain Research (2017). For more information about Katz’s research, visit his faculty profile.
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By Megan Mueller, manager, research communications, Office of the Vice-President Research & Innovation, York University, muellerm@yorku.ca