Anxiety is associated with diminished exercise performance and quality of life in severe emphysema: a cross-sectional study
1 Mental Health Service, VA Ann Arbor Healthcare System, Ann Arbor, MI, USA
2 Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, MI, USA
3 Department of Psychiatry, University of Michigan, Ann Arbor, MI, USA
4 Pulmonary and Critical Care Medicine Section, VA Ann Arbor Healthcare System, Ann Arbor, MI, USA
5 Division of Pulmonary & Critical Care Medicine, University of Washington, Seattle, WA, USA
6 Department of Surgery, St Louis University, St Louis, MO, USA
7 Division of Pulmonary & Critical Care Medicine, Temple University, Philadelphia, PA, USA
8 Division of Pulmonary Sciences and Critical Care Medicine, National Jewish Medical Center and Research Center, University of Colorado, Denver, CO, USA
9 Division of Pulmonary & Critical Care Medicine, Johns Hopkins University, Baltimore, MD, USA
10 Department of Medicine, University of Pennsylvania, Philadelphia, PA, USA
11 Division of Pulmonary & Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA, USA
Respiratory Research 2010, 11:29 doi:10.1186/1465-9921-11-29Published: 9 March 2010
Anxiety in patients with chronic obstructive pulmonary disease (COPD) is associated with self-reported disability. The purpose of this study is to determine whether there is an association between anxiety and functional measures, quality of life and dyspnea.
Data from 1828 patients with moderate to severe emphysema enrolled in the National Emphysema Treatment Trial (NETT), collected prior to rehabilitation and randomization, were used in linear regression models to test the association between anxiety symptoms, measured by the Spielberger State Trait Anxiety Inventory (STAI) and: (a) six-minute walk distance test (6 MWD), (b) cycle ergometry peak workload, (c) St. Georges Respiratory Questionnaire (SRGQ), and (d) UCSD Shortness of Breath Questionnaire (SOBQ), after controlling for potential confounders including age, gender, FEV1 (% predicted), DLCO (% predicted), and the Beck Depression Inventory (BDI).
Anxiety was significantly associated with worse functional capacity [6 MWD (B = -0.944, p < .001), ergometry peak workload (B = -.087, p = .04)], quality of life (B = .172, p < .001) and shortness of breath (B = .180, p < .001). Regression coefficients show that a 10 point increase in anxiety score is associated with a mean decrease in 6 MWD of 9 meters, a 1 Watt decrease in peak exercise workload, and an increase of almost 2 points on both the SGRQ and SOBQ.
In clinically stable patients with moderate to severe emphysema, anxiety is associated with worse exercise performance, quality of life and shortness of breath, after accounting for the influence of demographic and physiologic factors known to affect these outcomes.