Pain interference impacts response to treatment for anxiety disorders.
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.
Teh
Carrie Farmer
CF
Department of Psychiatry, University of Pittsburgh, Pittsburgh, Pennsylvania, USA. tehc@upmc.edu
Morone
Natalia E
NE
Karp
Jordan F
JF
Belnap
Bea Herbeck
BH
Zhu
Fang
F
Weiner
Debra K
DK
Rollman
Bruce L
BL
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
D000701:Analgesics, Opioid; D000893:Anti-Inflammatory Agents; D000928:Antidepressive Agents