Validation of the Generalized Anxiety Disorder-7 in patients with COPD: a cross-sectional study

Abstract

Background: Patients with chronic obstructive pulmonary disease (COPD) often have comorbid generalized anxiety disorder (GAD), which requires early screening in respiratory clinics. The Generalized Anxiety Disorder-7 (GAD-7) questionnaire is a brief and commonly used screening tool for GAD but has not been validated among patients with COPD in China.

Methods: Stable patients with COPD from a cross-sectional observational study were assessed using the GAD-7 questionnaire and then assessed by a senior psychiatrist to confirm a diagnosis of GAD according to the criteria of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. Demographic characteristics, spirometry, and patient-reported outcomes were collected. Cronbach's α coefficient was calculated, and receiver operating curve (ROC) analysis was performed to validate the GAD-7.

Results: A total of 226 patients with COPD were enrolled, and 50 (22.1%) of these patients were diagnosed with GAD. The Cronbach's α coefficient for the GAD-7 was 0.869, which indicated good internal consistency. ROC curve analysis showed that the GAD-7 had an area under the curve (AUC) value of 0.829 (95% CI: 0.774-0.876) for identifying GAD. The optimal cut-off score was ≥ 4, with a sensitivity of 66.0% and a specificity of 89.2%. Higher GAD-7 scores were significantly associated with health-related quality of life and the symptom burden of COPD. The discriminatory power of GAD-7 did not differ statistically when stratified by COPD severity.

Conclusions: The GAD-7 was shown to be a reliable and valid screening tool for patients with COPD in China, and its screening performance for GAD was not influenced by disease severity.

Keywords: Chronic obstructive pulmonary disease; GAD-7; Generalized anxiety disorder; Screening; Validation.

Fig. 1

Receiver operating characteristic curve of the GAD-7 for identifying generalized anxiety disorder in patients with chronic obstructive pulmonary disease

Fig. 2

Impact of demographics and clinical factors on the area under the curve (AUC) for the GAD-7; * Significant between-group difference (P < 0.05); other between-group differences without this notation were all nonsignificant (P > 0.05)