KMAN Publication Inc. Quality of Life and Health Sciences 2 Serial Number 3 2026 01 01 Pain Severity and Health-Related Quality of Life Among Patients With Fibromyalgia: The Mediating Role of Sleep Quality and Pain Acceptance Pain Severity and Health-Related Quality of Life Among Patients With Fibromyalgia: The Mediating Role of Sleep Quality and Pain Acceptance 1 15 10.61838/d1ccr535 EN Journal Article 2025 09 20 <table> <tbody> <tr> <td> <p><strong>Objective:</strong> This study aimed to examine the relationship between pain severity and health-related quality of life among patients with fibromyalgia and to determine the mediating roles of sleep quality and pain acceptance in this relationship.</p> <p><strong>Methods and Materials: </strong>This descriptive-correlational cross-sectional study was conducted using a structural equation modeling approach. The statistical population included adult patients with fibromyalgia who referred to rheumatology clinics, pain management centers, and specialized outpatient clinics in Tehran, Iran. A total of 286 patients were selected through convenience sampling based on the inclusion and exclusion criteria. Data were collected using a demographic and clinical information form, the Brief Pain Inventory–Short Form, the Pittsburgh Sleep Quality Index, the Chronic Pain Acceptance Questionnaire–Revised, and the 36-Item Short Form Health Survey. Data were analyzed using SPSS and AMOS software. Descriptive statistics, Pearson correlation coefficients, and structural equation modeling were used to examine the relationships among the study variables. The bootstrap method with 5,000 resamples was applied to test the significance of indirect effects.</p> <p><strong>Findings: </strong>The inferential findings showed that pain severity had a significant positive effect on poor sleep quality (β = 0.52, p &lt; .001) and a significant negative effect on pain acceptance (β = -0.47, p &lt; .001). Poorer sleep quality significantly predicted lower health-related quality of life (β = -0.31, p &lt; .001), while pain acceptance significantly predicted higher health-related quality of life (β = 0.29, p &lt; .001). Pain severity also retained a significant direct negative effect on health-related quality of life (β = -0.31, p &lt; .001). Bootstrap analysis confirmed the significant indirect effects of pain severity on health-related quality of life through sleep quality (β = -0.16, p &lt; .001) and pain acceptance (β = -0.14, p &lt; .001).</p> <p><strong>Conclusion: </strong>The findings indicate that pain severity reduces health-related quality of life among patients with fibromyalgia both directly and indirectly through poorer sleep quality and lower pain acceptance, highlighting the importance of integrated interventions targeting pain management, sleep regulation, and acceptance-based coping.</p> </td> </tr> </tbody> </table> https://journals.kmanpub.com/index.php/qlhs/article/download/5775/10968