title: Estimating the prevalence of chronic pain: validation of recall against longitudinal reporting (the HUNT pain study).
abstract: Methods for classifying chronic pain in population studies are highly variable, and prevalence estimates ranges from 11% to 64%. Limited knowledge about the persistence of pain and the validity of recall questions defining chronic pain make findings difficult to interpret and compare. The primary aim of the current study was to characterize the persistence of pain in the general population and to validate recall measures against longitudinal reporting of pain. A random sample of 6419 participants from a population study (the HUNT 3 study in Norway) was invited to report pain on the SF-8 verbal pain rating scale every 3 months over a 12-month period and to report pain lasting more than 6 months at 12-month follow-up. Complete data were obtained from 3364 participants. Pain reporting was highly stable (intraclass correlation 0.66, 95% confidence interval 0.65 to 0.67), and the prevalence of chronic pain varied considerably according to level of severity and persistence: 31% reported mild pain or more, whereas 2% reported severe pain on 4 of 4 consecutive measurements. When defined as moderate pain or more on at least 3 of 4 consecutive measurements, the prevalence was 26%. Compared with the longitudinal classification, a cross-sectional measure of moderate pain or more during the last week on the SF-8 scale presented a sensitivity of 82% and a specificity of 84%, and a sensitivity of 80% and a specificity of 90% when combined with a 6-month recall question. Thus pain reporting in the general population is stable and cross-sectional measures may give valid prevalence estimates of chronic pain.
authors.affiliation: Department of Cancer Research and Molecular Medicine, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway National Competence Centre for Complex Symptom Disorders, St. Olav's University Hospital, Trondheim, Norway Department of Public Health, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway Department of Circulation and Medical Imaging, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway Department of Anaesthesia and Emergency Medicine, St. Olav's University Hospital, Trondheim, Norway Department of Oncology, St. Olav's University Hospital, Trondheim, Norway.
authors.forename: Tormod
authors.initials: T
authors.lastname: Landmark
authors.forename: Pål
authors.initials: P
authors.lastname: Romundstad
authors.forename: Ola
authors.initials: O
authors.lastname: Dale
authors.forename: Petter C
authors.initials: PC
authors.lastname: Borchgrevink
authors.forename: Stein
authors.initials: S
authors.lastname: Kaasa
mesh_terms: D000328:Adult; D000368:Aged; D059350:Chronic Pain / Q000175:diagnosis* / Q000453:epidemiology*; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D011939:Mental Recall / Q000502:physiology*; D008875:Middle Aged; D009664:Norway / Q000453:epidemiology; D010147:Pain Measurement; D015995:Prevalence; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D055815:Young Adult