title: Effects of medical comorbidity on anxiety treatment outcomes in primary care.
abstract: OBJECTIVE
  To evaluate the effects of medical comorbidity on anxiety treatment outcomes.
  
  
  METHODS
  Data were analyzed from 1004 primary care patients enrolled in a trial of a collaborative care intervention for anxiety. Linear-mixed models accounting for baseline characteristics were used to evaluate the effects of overall medical comorbidity (two or more chronic medical conditions [CMCs] versus fewer than two CMCs) and specific CMCs (migraine, asthma, and gastrointestinal disease) on anxiety treatment outcomes at 6, 12, and 18 months.
  
  
  RESULTS
  At baseline, patients with two or more CMCs (n = 582; 58.0%) reported more severe anxiety symptoms (10.5 [95% confidence interval {CI} = 10.1-10.9] versus 9.5 [95% CI = 9.0-10.0], p = .003) and anxiety-related disability (17.6 [95% CI = 17.0-18.2] versus 16.0 [95% CI = 15.3-16.7], p = .001). However, their clinical improvement was comparable to that of patients with one or zero CMCs (predicted change in anxiety symptoms = -3.9 versus -4.1 at 6 months, -4.6 versus -4.4 at 12 months, -4.9 versus -5.0 at 18 months; predicted change in anxiety-related disability = -6.4 versus -6.9 at 6 months, -6.9 versus -7.3 at 12 months, -7.3 versus -7.5 at 18 months). The only specific CMC with a detrimental effect was migraine, which was associated with less improvement in anxiety symptoms at 18 months (predicted change = -4.1 versus -5.3).
  
  
  CONCLUSIONS
  Effectiveness of the anxiety intervention was not significantly affected by the presence of multiple CMCs; however, patients with migraine displayed less improvement at long-term follow-up. Trial Registration ClinicalTrials.com Identifier: NCT00347269.
authors.affiliation: Department of Psychiatry, University of California, San Diego, 8939 Villa La Jolla Drive, Suite 200, La Jolla, CA 92037. campbell-sills@ucsd.edu.
authors.forename: Laura
authors.initials: L
authors.lastname: Campbell-Sills
authors.forename: Murray B
authors.initials: MB
authors.lastname: Stein
authors.forename: Cathy D
authors.initials: CD
authors.lastname: Sherbourne
authors.forename: Michelle G
authors.initials: MG
authors.lastname: Craske
authors.forename: Greer
authors.initials: G
authors.lastname: Sullivan
authors.forename: Daniela
authors.initials: D
authors.lastname: Golinelli
authors.forename: Ariel J
authors.initials: AJ
authors.lastname: Lang
authors.forename: Denise A
authors.initials: DA
authors.lastname: Chavira
authors.forename: Alexander
authors.initials: A
authors.lastname: Bystritsky
authors.forename: Raphael D
authors.initials: RD
authors.lastname: Rose
authors.forename: Stacy Shaw
authors.initials: SS
authors.lastname: Welch
authors.forename: Gene A
authors.initials: GA
authors.lastname: Kallenberg
authors.forename: Peter
authors.initials: P
authors.lastname: Roy-Byrne
mesh_terms: D000328:Adult; D001008:Anxiety Disorders / Q000453:epidemiology / Q000628:therapy*; D001249:Asthma / Q000453:epidemiology*; D015928:Cognitive Behavioral Therapy / Q000379:methods; D015897:Comorbidity; D003299:Cooperative Behavior; D005260:Female; D005767:Gastrointestinal Diseases / Q000453:epidemiology*; D006801:Humans; D007406:Interview, Psychological; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D008881:Migraine Disorders / Q000453:epidemiology* / Q000523:psychology; D011320:Primary Health Care; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D012720:Severity of Illness Index; D016896:Treatment Outcome
keywords: anxiety; asthma; medical illness; migraine; primary care; randomized controlled trial