Making chronic pain count: empirical support for the ICD-11 classification of chronic pain

Purpose of reviewThe purpose is to review the evidence that has been collected with regard to the new classification of chronic pain. In 2022, the World Health Assembly endorsed the 11th revision of the International Classification of Diseases and Related Health Problems (ICD-11), and with it a new classification of chronic pain.Recent findingsThe evidence from the formative field testing indicated that the categories were clearly delineated and the coverage of chronic pain excellent (<3% in remainder categories). Official WHO field tests showed that the classification works well within the technical parameters WHO classifications must conform to and outperformed the ICD-10 diagnoses in all respects. International field tests, in which clinicians diagnosed consecutive patients in settings of medium and high resources, showed substantial interrater reliability (? = 0.596 to ? = 0.783) for the diagnoses and the clinicians rated their clinical utility as very high. Studies using complete hospital records demonstrated that with the information they contain, retrospective coding of the new diagnoses is possible and provides much more meaningful information than the ICD-10 diagnoses.SummaryThe evidence supports the use of the new classification and highlights its informational gains - using it will contribute to making chronic pain count in many contexts.