Health‐Related Quality of Life and Depression Among Diabetic and Cardiac Patients at Al‐Thawra Modern General Hospital: A Comparative Cross‐Sectional Study

Background Depression is highly prevalent among individuals with chronic illnesses and is associated with significant impairment in health‐related quality of life (HRQoL). Patients with diabetes mellitus and cardiac diseases are particularly vulnerable, with evidence indicating a bidirectional relationship influenced by genetic, environmental, and psychosocial factors. Aim This study aimed to compare HRQoL and depression levels between patients with diabetes mellitus and cardiovascular disease, to examine the relationship between depression and HRQoL, and to identify the independent demographic and clinical predictors of depression severity and HRQoL. Methods A comparative cross‐sectional study was conducted in accordance with the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Statement. A purposive sample of 200 adult patients (100 with cardiovascular disease and 100 with diabetes mellitus) was recruited from the cardiology and diabetes outpatient clinics of Al‐Thawra Modern General Hospital, Sana’a, Yemen, between January and May 2025. Data were collected through face‐to‐face structured interviews using a demographic questionnaire, the Patient Health Questionnaire‐9 (PHQ‐9), and the 36‐Item Short Form Health Survey (SF‐36). Data were analyzed using descriptive statistics, chi‐square tests, independent‐samples t ‐tests, Pearson’s correlation, Cohen’s d effect size, and multiple linear regression analyses. Results Depressive symptoms were highly prevalent in both groups. Cardiac patients had significantly higher mean depression scores than diabetic patients. After adjustment for multiple comparisons using the Holm procedure, cardiac patients continued to demonstrate significantly lower scores than diabetic patients across all eight SF‐36 domains (all Holm‐adjusted p < 0.05). Cardiac patients were significantly older ( p = 0.01) and had higher educational attainment ( p = 0.01), whereas no significant differences were found regarding gender, marital status, or residence ( p > 0.05). Multivariable linear regression analyses showed that depression severity, older age, and longer disease duration were independently associated with lower Physical and Mental Component Summary scores, whereas higher educational attainment was associated with higher scores. Conclusion Depression is highly prevalent among patients with diabetes mellitus and cardiovascular disease and is independently associated with lower HRQoL. Integrating routine psychological assessment, patient education, and multidisciplinary, nurse‐led care into chronic disease management may improve mental well‐being and HRQoL, particularly among older patients and those with longer disease duration.