title: Biopsychosocial predictors of pain, disability, health care consumption, and sick leave in first-episode and long-term back pain: a longitudinal study in the general population.
abstract: BACKGROUND
  Long-term outcome in back pain is related mainly to cognitive factors such as pain-related beliefs and expectations. Most research has been performed on patient samples.
  
  
  OBJECTIVE
  This study aimed at investigating changes over time in reported back pain, pain intensity, disability, health care consumption, and sick leave as well as biopsychosocial factors over a 12-month period. A second aim was to identify predictors of reported pain, pain intensity, disability, health care consumption, and sick leave.
  
  
  METHODS
  As parts of a large back pain sample from a general population (n = 1,024), two groups-one with first-episode pain (n = 77) and one with long-term pain (n = 302)-responded twice to a self-administered questionnaire. Among participants reporting pain at both assessments, changes over time were analyzed and predictive models were tested.
  
  
  RESULTS
  Generally, the results demonstrated overall stability in the self-reports over time. However, reported pain decreased in both groups, while pain catastrophizing and pain expectations increased in the first-episode group. Pain intensity and disability were predicted in regression models including four cognitive factors and initially reported levels of pain intensity and disability.
  
  
  CONCLUSIONS
  The significance of pain-related beliefs and expectations both in early and later stages of a back pain condition is pointed out. The results in this study based on a sample from the general population are in line with previous research on patient samples.
authors.affiliation: Department of Public Health and Caring Sciences, Uppsala University, Box 564, 75122 Uppsala, Sweden. ingrid.demmelmaier@pubcare.uu.se
authors.forename: Ingrid
authors.initials: I
authors.lastname: Demmelmaier
authors.forename: Pernilla
authors.initials: P
authors.lastname: Asenlöf
authors.forename: Per
authors.initials: P
authors.lastname: Lindberg
authors.forename: Eva
authors.initials: E
authors.lastname: Denison
mesh_terms: D000208:Acute Disease; D000328:Adult; D001416:Back Pain / Q000523:psychology*; D002908:Chronic Disease; D003071:Cognition; D003695:Delivery of Health Care / Q000706:statistics & numerical data*; D004185:Disability Evaluation; D005239:Fear / Q000523:psychology; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D012042:Registries; D012307:Risk Factors; D012494:Sampling Studies; D012720:Severity of Illness Index; D018582:Sick Leave / Q000706:statistics & numerical data*; D011795:Surveys and Questionnaires; D013997:Time Factors