7. FUTURE RESEARCH DIRECTIONS
In striving towards a more comprehensive and patient-centered approach to pain assessment, thereby improving pain treatment and fostering improved quality of life and outcomes for individuals with pain and OUD, we set out a brief research agenda for next steps on this topic.
First, validating pain scales tailored specifically to individuals with OUD remains an essential undertaking. Understanding how opioid use impacts pain perception is critical to developing accurate and reliable pain assessment tools that consider the unique characteristics of this population (including opioid-pain phenomena such as hyperalgesia, tolerance, and withdrawal. An additional direction includes the use of the data points obtained from these scales to inform patients and shared decision-making regarding medication changes and dose increases, as well as potentially quantifying the analgesic potential of each drug using multimodal methods.
Validating these assessments would involve evaluating their content validity to ensure they measure key pain domains relevant to this population, and its criterion validity by correlating each tool’s scores against other pain measures. Construct validity would be assessed by correlating scores with related factors like depression and disability. Its responsiveness, or ability to detect changes over time or with treatment, must also be analyzed. Finally, these tools should demonstrate inter-rater reliability, ensuring consistent scores between different raters, and test-retest reliability to assess score consistency upon repeated administrations.
Second, assessing and validating various technologies and tools for the assessment of pain (e.g., QST, EEG, fMRI) and how they may impact clinical outcomes is needed. QST allows for a more precise evaluation of sensory perception and pain responses. Functional MRI and EEG can offer insights into the neural mechanisms underlying pain and chronic opioid effects, and how they intersect in OUD, with varying degrees of spatial and temporal resolution. Future research should investigate the neurobiological mechanisms underlying pain modulation in OUD and explore potential alterations in pain processing pathways, as these could inform objective methods of pain assessment, as well as using these technologies to expand the role of potential non-opioid analgesic strategies207. Integrating these cutting-edge technologies into pain and OUD care may someday allow for mechanistic-based treatment of pain rather than symptom-based management, the current panorama.
Third, we highlight the necessity to advance pain assessment approaches in minoritized populations. Historically biased approaches to pain assessments among these populations have repeatedly resulted in worse clinical outcomes208. Recognizing the impact of social stress and racism on the pain experience is essential to address disparities in treatment outcomes. Future research should delve into the social determinants of pain experiences, considering racism-related stress, cultural factors, social support networks, and stigma. By understanding these dynamics, healthcare professionals can develop culturally sensitive pain interventions that acknowledge and respect the diversity of experiences within these communities. The groundwork and methodological considerations for the elaboration of anti-racist pain research have been thoughtfully described in the three-part work by Morais and colleagues208.
Finally, the expansion of pain assessment education for healthcare professionals and the use of multidisciplinary care for pain and addiction management present promising avenues for future research. Particularly refining the training of the professionals involved in the assessment of pain among patients with OUD is as important as improving the assessments themselves. Multidisciplinary education is necessary to guarantee that the various forms of assessments discussed in this manuscript are correctly and widely used.