People with multiple sclerosis (MS) are living longer but not necessarily better lives, and this portends reduced health-related quality of life (HRQOL). Physical activity (PA) may be a correlate of HRQOL for people with MS. We examined differences in HRQOL and PA between older adults with and without MS to examine whether PA is associated with HRQOL and whether it accounts for group differences in HRQOL.
Thirty-one older adults with MS and 30 age- and sex-matched controls without MS completed the 36-Item Short Form Health Survey (SF-36) and the Godin Leisure-Time Exercise Questionnaire (GLTEQ). Data were analyzed using the Baron and Kenny approach for examining PA via the GLTEQ as a mediator of group differences in HRQOL.
The MS group had significantly lower component scores on the SF-36 and the GLTEQ than the control group. The GLTEQ scores were correlated with SF-36 physical component scores (r = 0.52), whereas the correlation with mental component scores (r = 0.23) was small and nonsignificant. Group assignment initially explained 31% of the variance in physical component scores (β = 0.55) and adding GLTEQ to the model accounted for an additional 12% of the variance in physical component scores. Thus, group (β = 0.42) and GLTEQ (β = 0.37) were both significant correlates of physical component scores. The group effect was modestly attenuated with the addition of GLTEQ in step 2 (step 1 β = 0.55; step 2 β = 0.42) and indicated partial rather than full mediation.
These results provide cross-sectional support for future research examining approaches to increase PA to possibly improve the physical component of HRQOL in older adults with MS.