title: The bidirectional relationship between sleep complaints and pain: Analysis of data from a randomized trial.
abstract: OBJECTIVE
  The goal of this study was to examine the bidirectional relationship of sleep and pain to determine whether changes in sleep complaints over the course of a chronic pain treatment trial predict pain outcomes and vice versa, controlling for changes in depression and anxiety.
  
  
  METHODS
  Data were analyzed from a 12-month randomized, controlled trial that tested the effectiveness of a collaborative care intervention for veterans with chronic musculoskeletal pain. Participants were 250 veterans from 5 primary care clinics in a Veteran Affairs (VA) medical center. Measures of pain, sleep, and depression/anxiety symptoms were collected at baseline, 3 months, and 12 months. Factor analysis was used to clarify the boundaries of these domains, and structural equation modeling was used to examine whether changes in sleep complaints and depression/anxiety during the trial predicted pain at the end of the trial, controlling for covariates. An alternative model was also tested in which changes in pain predicted sleep complaints.
  
  
  RESULTS
  Changes in sleep complaints at 3 months significantly predicted changes in pain at 12 months (standardized path coefficient = .29, p < .001). To a lesser extent, changes in pain predicted changes in sleep (standardized path coefficient = .15, p < .05). Changes in depression/anxiety did not significantly predict changes in pain or sleep. There was also evidence of differential relations of specific sleep complaints with pain.
  
  
  CONCLUSIONS
  This work helps to further disentangle the complex relationship between pain and sleep. This bidirectional relationship may need to be considered to improve pain outcomes.
authors.affiliation: Center for Chronic Disease Outcomes Research, Minneapolis VA Health Care System.
authors.forename: Erin
authors.initials: E
authors.lastname: Koffel
authors.affiliation: VA HSR&D Center for Health Information and Communication, Roudebush VA Medical Center.
authors.forename: Kurt
authors.initials: K
authors.lastname: Kroenke
authors.affiliation: VA HSR&D Center for Health Information and Communication, Roudebush VA Medical Center.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Bair
authors.affiliation: Minneapolis VA Health Care System.
authors.forename: David
authors.initials: D
authors.lastname: Leverty
authors.affiliation: Center for Chronic Disease Outcomes Research, Minneapolis VA Health Care System.
authors.forename: Melissa A
authors.initials: MA
authors.lastname: Polusny
authors.affiliation: Center for Chronic Disease Outcomes Research, Minneapolis VA Health Care System.
authors.forename: Erin E
authors.initials: EE
authors.lastname: Krebs
mesh_terms: D001007:Anxiety / Q000523:psychology; D059350:Chronic Pain / Q000150:complications* / Q000523:psychology / Q000628:therapy*; D003299:Cooperative Behavior; D003863:Depression / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D059352:Musculoskeletal Pain / Q000150:complications* / Q000523:psychology / Q000628:therapy*; D012893:Sleep Wake Disorders / Q000150:complications* / Q000523:psychology; D016896:Treatment Outcome; D014728:Veterans / Q000523:psychology* / Q000706:statistics & numerical data