title: A systematic review of psychological factors as predictors of chronicity/disability in prospective cohorts of low back pain.
abstract: METHODS
  A systematic review of prospective cohort studies in low back pain.
  
  
  OBJECTIVE
  To evaluate the evidence implicating psychological factors in the development of chronicity in low back pain.
  
  
  BACKGROUND
  The biopsychosocial model is gaining acceptance in low back pain, and has provided a basis for screening measurements, guidelines and interventions; however, to date, the unique contribution of psychological factors in the transition from an acute presentation to chronicity has not been rigorously assessed.
  
  
  METHODS
  A systematic literature search was followed by the application of three sets of criteria to each study: methodologic quality, quality of measurement of psychological factors, and quality of statistical analysis. Two reviewers blindly coded each study, followed by independent assessment by a statistician. Studies were divided into three environments: primary care settings, pain clinics, and workplace.
  
  
  RESULTS
  Twenty-five publications (18 cohorts) included psychological factors at baseline. Six of these met acceptability criteria for methodology, psychological measurement, and statistical analysis. Increased risk of chronicity (persisting symptoms and/or disability) from psychological distress/depressive mood and, to a lesser extent, somatization emerged as the main findings. Acceptable evidence generally was not found for other psychological factors, although weak support emerged for the role of catastrophizing as a coping strategy.
  
  
  CONCLUSIONS
  Psychological factors (notably distress, depressive mood, and somatization) are implicated in the transition to chronic low back pain. The development and testing of clinical interventions specifically targeting these factors is indicated. In view of the importance attributed to other psychological factors (particularly coping strategies and fear avoidance) there is a need to clarify their role in back-related disability through rigorous prospective studies.
authors.affiliation: Department of Psychology, Royal Holloway, University of London, London, UK.
authors.forename: Tamar
authors.initials: T
authors.lastname: Pincus
authors.forename: A Kim
authors.initials: AK
authors.lastname: Burton
authors.forename: Steve
authors.initials: S
authors.lastname: Vogel
authors.forename: Andy P
authors.initials: AP
authors.lastname: Field
mesh_terms: D000223:Adaptation, Psychological; D002908:Chronic Disease; D015331:Cohort Studies; D015986:Confounding Factors, Epidemiologic; D003863:Depression / Q000150:complications; D004185:Disability Evaluation; D005239:Fear; D006801:Humans; D017116:Low Back Pain / Q000150:complications / Q000175:diagnosis / Q000523:psychology*; D011446:Prospective Studies; D011584:Psychology; D012307:Risk Factors; D013001:Somatoform Disorders / Q000150:complications