KMAN Publication Inc. Quality of Life and Health Sciences 1 Serial Number 1 2025 07 01 Depression, Sleep Quality, and Quality of Life Among Patients With Cancer: A Structural Equation Modeling Study With Sleep Quality as a Mediator Depression, Sleep Quality, and Quality of Life Among Patients With Cancer: A Structural Equation Modeling Study With Sleep Quality as a Mediator 1 15 10.61838/0etrk679 EN Journal Article 2025 03 16 <table> <tbody> <tr> <td> <p>Objective: This study aimed to examine the relationship between depression and quality of life among patients with cancer in Indonesia and to determine whether sleep quality mediates this relationship.</p> <p><strong>Methods and Materials: </strong>This cross-sectional correlational study was conducted using a structural equation modeling approach. The participants were 386 adult patients with confirmed cancer diagnoses who were receiving oncology services in Indonesia. Participants were selected through convenience sampling based on inclusion and exclusion criteria. Depression was assessed using the Patient Health Questionnaire-9, sleep quality was measured using the Pittsburgh Sleep Quality Index, and quality of life was evaluated using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30. Data were analyzed using SPSS version 27 and AMOS version 24. Pearson correlation analysis was used to examine bivariate associations among the main variables, and structural equation modeling was applied to test the hypothesized mediation model. The indirect effect of depression on quality of life through sleep quality was examined using bootstrapping with 5,000 resamples and 95% bias-corrected confidence intervals.</p> <p><strong>Findings: </strong>The inferential findings showed that depression was significantly and positively associated with poor sleep quality and significantly and negatively associated with global quality of life. Sleep quality was also significantly and negatively associated with global quality of life. The structural model demonstrated good fit to the data, χ²/df = 2.14, CFI = 0.96, TLI = 0.94, RMSEA = 0.054, and SRMR = 0.041. Depression had a significant positive direct effect on sleep quality (β = 0.61, p &lt; 0.001), sleep quality had a significant negative direct effect on quality of life (β = -0.47, p &lt; 0.001), and depression had a significant negative direct effect on quality of life (β = -0.30, p &lt; 0.001). The indirect effect of depression on quality of life through sleep quality was significant (β = -0.29, p &lt; 0.001), confirming partial mediation.</p> <p><strong>Conclusion: </strong>Sleep quality is therefore an important modifiable mechanism in the relationship between depressive symptoms and quality of life. Integrating depression screening and sleep-focused interventions into oncology care may improve patients’ overall well-being and functioning.</p> </td> </tr> </tbody> </table> https://www.journals.kmanpub.com/index.php/qlhs/article/download/5770/10919