A Clinical Description of Chronic Pain in a General Population Using ICD-10 and ICD-11 (The HUNT Pain Examination Study)

●Clinical examinations confirm a high prevalence of chronic pain found by questionnaires.●Most individuals with chronic pain have more than one chronic pain condition.●Most chronic pain conditions cannot be explained by known diseases.●Most individuals with chronic pain have chronic musculoskeletal pain. The purpose was to present a total description, distribution, and ranking of chronic pain conditions in the general population. This was based on structured clinical examinations of a random sample from a population-based survey (HUNT3) with a calculated oversampling of participants with chronic pain. Supplemented with access to hospital reports, the examination was performed by experienced physicians and psychologists using a consistent definition of chronic pain as well as ICD-10- and the new ICD-11-classification. The main findings were that a higher proportion of the 551 participants had chronic pain assessed by clinical examination (399) than by self-report in a survey the same day (337). Among those with examination-verified chronic pain estimated from HUNT3 to represent 27.9% of the general population, 63% had chronic primary pain, 81% musculoskeletal pain, and 77% more than one chronic pain condition. When separating chronic primary from chronic secondary pain according to ICD-11, the weighted prevalence was 17.7% for chronic pain conditions of unknown and 10.2% of known cause. When all the participants’ conditions were accounted for, the most prevalent was nonspecific low back (10.8%) and neck pain (7.6%). Participants with chronic primary pain did not have significantly more psychopathology than those with chronic secondary pain: 14.5% versus 12.5%. Since this study confirms the high prevalence in self-report surveys and indicates that two thirds of chronic pain conditions cannot be explained by underlying diseases, this huge health and societal problem should be solved primarily on a public health level directed toward prevention and rehabilitation.