Problem Statement: Multiple sclerosis (MS) is a chronic disease of the central nervous system and is among the most common neurological disorders in adults. MS causes significant disability and has no cure. Neurological disease severity is thought to contribute to disability but may not be the main determinant. Individual and environmental factors may modify the relationship between disease severity and disability or directly influence it. Research simultaneously relating these factors in MS has not yet been conducted.

Methods: Participants completed an internet questionnaire and a telephone-administered cognitive recall performance task. Clinical data were extracted from a data registry maintained by the Multiple Sclerosis Center at Dartmouth-Hitchcock Medical Center (DHMC) in Lebanon, New Hampshire. Correlation and multiple regression analyses were conducted to determine the relationships between disease severity, individual factors, environmental factors and biopsychosocial disability (BPSD).

Results: One hundred-eighty (180) adults with relapsing forms of MS participated in the study, representing approximately 15% of the total MS patient population followed by the database registry at DHMC. The study population was 76% female, had 14.6 years of education, a mean annual income of $35,000, was 75% relapsing-remitting MS (RRMS), had a mean EDSS of 2.4, and a mean ARR of 0.21. In multiple regression analyses, disease severity explained 3%, demographic variables 6%, individual factors 69%, and environmental factors 64% of the variance in BPSD, respectively. The final model incorporating disease severity, individual factors, and environmental factors explained 74% of the variance in BPSD. Depression and environmental status demonstrated the strongest associations with BPSD.

Conclusions: Neuropsychiatric status, bowel and bladder function, self-efficacy, social support, and environmental status are key factors associated with BPSD. These factors are modifiable by medical, psychosocial, and/or case management interventions. This study has three major limitations: (1) inability to predict causality or directionality of associations; (2) susceptibility to self-report bias; and (3) susceptibility to temporal bias. This study provides a basis for continued research on biopsychosocial disability reduction and to related healthcare quality improvement, shared decision making, and health policy initiatives.