Psychometric Evaluation of the GAD-7 and PHQ-9 in Caregivers of Patients With Coronary Heart Disease

Background: Caregivers of patients hospitalized for coronary heart disease (CHD) are at risk of psychological distress, yet validated instruments for assessing anxiety and depression in this population during the acute phase are lacking. Objective: In this study, we aimed to evaluate the psychometric properties of the Generalized Anxiety Disorder-7 (GAD-7) and Patient Health Questionnaire-9 (PHQ-9) in caregivers of hospitalized CHD patients. Methods: This secondary analysis used data from 136 informal caregivers enrolled in the Self-Care in Coronary Heart Disease Patient and Caregiver Dyads study. Participants completed the GAD-7, PHQ-9, along with other self-report measures, during patient hospitalization. Item analysis, confirmatory factor analysis (CFA), internal consistency (McDonald's ω and Cronbach's α), convergent validity, and known-groups validity were examined. Results: Mean scores indicated mild anxiety (GAD-7: 6.71, standard deviation [SD] = 6.58) and mild depressive symptoms (PHQ-9: 5.20, SD = 5.68). CFA supported a 2-factor structure (cognitive and somatic symptoms) for both scales, with good model fit and high factor loadings (>0.60). Internal consistency was satisfactory (GAD-7: ω = 0.93, α = 0.92; PHQ-9: ω = 0.89, α = 0.89). Convergent validity was supported by a strong correlation between GAD-7 and PHQ-9 scores (r = 0.72, large effect) and by associations between higher anxiety/depression and lower self-care self-efficacy scores. Known-groups validity was confirmed, with small-to-moderate correlations between female gender and both anxiety and depression. Conclusions: The GAD-7 and PHQ-9 demonstrated robust psychometric properties in caregivers of hospitalized CHD patients. Both instruments appear suitable for identifying caregivers at risk of anxiety and depression during the acute phase, supporting timely interventions in clinical practice.