259491 Effects of pain on depression are mediated by fatigue, anxiety, and sleep in Multiple Sclerosis

Tuesday, October 30, 2012 : 2:53 PM - 3:11 PM

Robert Askew, MPH , Department of Rehabilitative Medicine, University of Washington, Seattle, WA
Dagmar Amtmann, PhD , Department of Rehabilitation Medicine, University of Washington, Seattle, WA
Jiseon Kim, PhD , Department of Rehabilitation Medicine, University of Washington, Seattle, WA
Hyewon Chung, PhD , Department of Psychology, John Jay College of Criminal Justice, City University of New York, New York, NY
Kurt L. Johnson, PhD , Department of Rehabilitation Medicine, University of Washington, Seattle, WA
Introduction: Relationships between pain and psychological functioning in Multiple Sclerosis have not been well studied. We examined whether fatigue, anxiety, and sleep disturbances mediate the effect of pain impact on depression. Methods: 1245 members of the National Multiple Sclerosis Society completed two scales assessing pain interference: Brief Pain Inventory (BPI) and Pain Impact Questionnaire (PIQ); 3 scales assessing fatigue: Modified Fatigue Impact Scale (MFIS), Fatigue Severity Scale (FSS), and Multidimensional Assessment of Fatigue (MAF); 2 scales assessing depression: Center for Epidemiologic Studies Depression Scale (CES-D) and Patient Health Questionnaire (PHQ-9); 2 scales assessing sleep: Medical Outcomes Survey (MOS-SAD) and Women's Health Initiative Insomnia Rating Scale (WHIIRS); and one scale for anxiety: Hospital Anxiety and Depression Scale (HADS). The model was controlled for age, gender, disability status, and social support. Results: Standardized factor loadings were moderate to high and statistically significant for Fatigue (FSS=0.83, MFIS=0.90, MAF=0.86), Sleep Disturbance (WHIIRS=0.66, MOS-SAD=-0.73), Pain Impact (PIQ=0.88, BPI=0.92), and Depression (CES-D=0.94, PHQ-9=0.91). All standardized direct effects were significant, including Pain Interference on Anxiety (0.51), Fatigue (0.56), and Sleep Disturbance (0.63); Anxiety on Depression (0.39); Sleep Disturbance on Fatigue (0.21) and Depression (0.22); and Fatigue on Depression (0.45). Standardized indirect effects of Pain Interference on Depression totaled 0.65. R2 for Pain Interference=0.21, Anxiety=0.33, Fatigue=0.57, Sleep Disturbance=0.40, and Depression=0.79. Model fit was adequate [X2=343.3(df=49), p<0.05, RMSEA=0.069, CFI=0.965, TLI=0.939, SRMR=0.033]. Discussion: The majority of the effects of pain interference on depression were mediated by anxiety, fatigue, and sleep disturbance suggesting a transdiagnostic approach to treatment.

Learning Areas:
Chronic disease management and prevention
Social and behavioral sciences

Learning Objectives:
1. Describe relationships between pain, fatigue, sleep, anxiety, and depression in Multiple Sclerosis (MS) 2. Describe strengths and limitations of Structural Equation Modeling with respect to modeling mediating effects 3. describe direct and indirect effects of pain on depression 4. Describe implications to MS research and the clinical treatment of depression

Keywords: Mental Health, Disability

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: I have a Masters in Epidemiology from the University of Texas School of Public Health and am currently pursuing a PhD in Psychology at the University of Washington (UW). As a member of the UW Center on Outcomes Research in Rehabilitation, my current research focuses on patient reported outcomes in a variety of chronic conditions. I have multiple publications related to quality of life in cancer, multiple sclerosis, and other chronic disease subpopulations.
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.