Modifiable Factor Relationships with Biopsychosocial Disability In MS

Background:  The World Health Organization (WHO) defines disability from a biopsychosocial perspective which incorporates functional impairment secondary to disease severity, health-related quality of life (QOL) and capacity for societal participation. Individual and environmental factors have been shown to influence multiple sclerosis (MS) QOL.  Given that QOL is a component of WHO defined disability, these factors may also modify the relationship between MS disease severity and WHO defined biopsychosocial disability (BPSD).

Objectives:  To explore relationships between measures of disease severity, individual factors, environmental factors and BPSD in MS.

Methods:  Participants completed an internet questionnaire and a telephone-administered cognitive recall performance task.  Clinical data were extracted from a regional MS data registry maintained by an academic MS Center in New Hampshire.  Disease severity measures included brain MRI, annualized relapse rate (ARR), Extended Disability Status Scale (EDSS), and telephone cognitive recall task performance.  Individual measures included self-efficacy, perceived cognition, depression, bowel and bladder symptoms, fatigue, and pain.  Environmental measures included social support and environmental status.  Correlation and multiple regression analyses were conducted to determine relationships between disease severity, individual and environmental factors and BPSD.

Results:  180 adults with relapsing MS participated.  The sample was 76% female, had a mean education of 14.6 years, mean annual income of $35,000, mean EDSS of 2.4, and a mean ARR of 0.21.  26.7% had new T2 or post-gadolinium enhancing T1 lesions on MRI, and 79% were using disease modifying therapy (DMT).  A majority had medical insurance (95%), prescription insurance (92.8%), and DMT coverage (87.8%).  In bivariate analyses, strongest associations with BPSD were observed for cognition (r=0.74, p<0.01), depression (r=0.69, p<0.01) and environmental status (r= 0.79, p<0.01).  In multiple regression analyses, disease severity variables accounted for 3%, demographic variables 6%, individual factor variables 69%, and environmental factor variables 64% of the variance in BPSD.  The final combined regression model incorporating all factors predicted 74% of the variance in BPSD.  Depression (Coeff= 8.1, p<0.01) and environmental status (Coeff= 12.9, p<0.01) were the strongest predictors of BPSD. 

Conclusions: This is the first study targeting factor relationships with WHO defined disability in MS.  Individual and environmental factors were significantly associated with BPSD and substantially more predictive than disease or demographic factors.  Many of these factors are modifiable by medical, nursing, psychosocial, policy, and/or case management interventions.  These findings generally parallel those previously observed in studies of MS QOL, suggesting that QOL may be a predominant driver of BPSD in MS.