title: Pain interference impacts response to treatment for anxiety disorders.
abstract: BACKGROUND
  Anxiety disorders and pain are commonly comorbid, though little is known about the effect of pain on the course and treatment of anxiety.
  
  
  METHODS
  This is a secondary analysis of a randomized controlled trial for anxiety treatment in primary care. Participants with panic disorder (PD) and/or generalized anxiety disorder (GAD) (N=191; 81% female, mean age 44) were randomized to either their primary-care physician's usual care or a 12-month course of telephone-based collaborative care. Anxiety severity, pain interference, health-related quality of life, health services use, and employment status were assessed at baseline, and at 2-, 4-, 8-, and 12-month follow-up. We defined response to anxiety treatment as a 40% or greater improvement from baseline on anxiety severity scales at 12-month follow-up.
  
  
  RESULTS
  The 39% who reported high pain interference at baseline had more severe anxiety (mean SIGH-A score: 21.8 versus 18.0, P<.001), greater limitations in activities of daily living, and more work days missed in the previous month (5.8 versus 4.0 days, P=.01) than those with low pain interference. At 12-month follow-up, high pain interference was associated with a lower likelihood of responding to anxiety treatment (OR=.28; 95% CI=.12-.63) and higher health services use (26.1% with >/=1 hospitalization versus 12.0%, P<.001).
  
  
  CONCLUSIONS
  Pain that interferes with daily activities is prevalent among primary care patients with PD/GAD and associated with more severe anxiety, worse daily functioning, higher health services use, and a lower likelihood of responding to treatment for PD/GAD.
authors.affiliation: Department of Psychiatry, University of Pittsburgh, Pittsburgh, Pennsylvania, USA. tehc@upmc.edu
authors.forename: Carrie Farmer
authors.initials: CF
authors.lastname: Teh
authors.forename: Natalia E
authors.initials: NE
authors.lastname: Morone
authors.forename: Jordan F
authors.initials: JF
authors.lastname: Karp
authors.forename: Bea Herbeck
authors.initials: BH
authors.lastname: Belnap
authors.forename: Fang
authors.initials: F
authors.lastname: Zhu
authors.forename: Debra K
authors.initials: DK
authors.lastname: Weiner
authors.forename: Bruce L
authors.initials: BL
authors.lastname: Rollman
mesh_terms: D000203:Activities of Daily Living; D000293:Adolescent; D000328:Adult; D000701:Analgesics, Opioid / Q000627:therapeutic use*; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use*; D000928:Antidepressive Agents / Q000627:therapeutic use*; D001008:Anxiety Disorders / Q000175:diagnosis / Q000188:drug therapy* / Q000453:epidemiology*; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D005500:Follow-Up Studies; D006304:Health Status; D006801:Humans; D008297:Male; D008605:Mental Health Services / Q000706:statistics & numerical data; D008875:Middle Aged; D010146:Pain / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology*; D010147:Pain Measurement; D011320:Primary Health Care / Q000379:methods; D011788:Quality of Life / Q000523:psychology; D012720:Severity of Illness Index; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000701:Analgesics, Opioid; D000893:Anti-Inflammatory Agents; D000928:Antidepressive Agents