A core outcome set of measurement instruments for assessing effectiveness and efficacy of perioperative pain management: results of the international IMI-PainCare PROMPT Delphi consensus process

Effective perioperative pain management is crucial to prevent patient suffering, delayed recovery, chronic postsurgical pain, and long-term opioid use. However, the heterogeneous use of outcomes in studies complicates evidence synthesis and might not accurately reflect the experiences of individual patients. We initiated a consensus process to establish a core outcome set (COS) of patient-reported outcome measures (PROMs) in postoperative pain, building upon the earlier consensus on a COS of domains. Potential PROMs were identified via systematic literature searches for the domains pain intensity (with subdomains at rest and during activity), physical function, self-efficacy, and adverse events, followed by appraisal of psychometric properties according to the COnsensus-based Standards for the selection of health Measurement INstruments methodology. Then, a consensus meeting was convened, followed by a Delphi process with an international, multiprofessional panel of stakeholders, including those with lived experience. A conclusive consensus meeting approved the final COS of PROMs. The final COS consists of one unidimensional numerical rating scale for assessing pain intensity on average, worst pain intensity, pain intensity at rest, and procedure-specific pain intensity during activity; one unidimensional scale for pain interfering with activities in bed; one procedure-specific scale for assessing physical function; the IMI-PainCare PROMPT adaptation of the Arthritis Self-Efficacy Scale for assessing self-efficacy; and the IMI-PainCare PROMPT adaptation of the Opioid-Related Symptom Distress Scale for assessing adverse events. Comprehensive use of a core outcome set will help harmonise outcome assessment, facilitate comparisons between studies, promote patient-centred research, and improve postoperative pain care.