Objectives: The objective was to characterize patients in a chronic pain population by examining whether biopsychosocial characteristics differ among individuals based on morphine equivalent dose (MEQ).
Design: This cross-sectional study recruited individuals from a chronic pain clinic in Ontario, Canada. The following data/outcome measures were collected: sociodemographics, clinical health information (MEQ), Patient Health Questionnaire-9 (PHQ-9), Generalized Anxiety Disorder 7 item (GAD-7), Pain Disability Index (PDI), Brief Pain Inventory short form (BPI), CAGE substance abuse screening tool, Anxiety Sensitivity Index (ASI), and Acceptance and Action Questionnaire (AAQ). Differences between four MEQ groups (0, 1-89, 90-199, > 200) were compared using one-way ANCOVAs for continuous variables and Fisher’s exact tests for nominal data. Bonferroni-corrected post-hoc tests were conducted as necessary.
Results: 218 individuals (140 females) completed the study with a mean age of 52.9±11.9 years and mean time since injury of 14.2±10.3 years. There was no significant difference in age, type of pain, education, living arrangement, use of non-opioid medications or cannabis use between MEQ groups (p >0.05 for all). Time since injury (p< 0.001), gender (p=0.002), employment (p=0.014), and pain severity (p=0.001) differed between groups. While controlling for time since injury and pain severity, the ANCOVAs demonstrated significant differences between groups on the PHQ-9 (p< 0.001), GAD-7 (p=0.006), PDI (p=.026), BPI interference (p=0.001), ASI (p=0.003), and AAQ (p=0.007), but not CAGE (p=0.674). Post hoc t-tests revealed that the MEQ-90-199 and >200 groups had significantly worse scores on all measures compared to the MEQ-0 group (p< 0.05 for all). The MEQ- >200 group was significantly worse on all measures compared to the no and low MEQ groups (p< 0.05 for all).
Conclusions: The data suggest that, compared to individuals using no or low-dose opioids to treat chronic pain, those using high-dose opioids have significantly greater pain disability, depression, and anxiety.
Amanda McIntyre– Research Associate, Parkwood Institute Research, Parkwood Institute
Swati Mehta– Scientist, Parkwood Institute Research, Parkwood Institute
Jerome Iruthayarajah– Research Associate, Parkwood Institute Research, Parkwood Institute
Shannon Janzen– Research Associate, Parkwood Institute Research, Parkwood Institute
Danielle Vanderlaan– Research Associate, Parkwood Institute Research, Parkwood Institute
Eldon Loh– Physiatrist, St. Joseph's Health Care London
Robert Teasell– Physiatrist, Parkwood Institute Research, Parkwood Institute