Physical activity together for MS (PAT-MS): Secondary outcomes of a randomized controlled feasibility trial

Care partners provide essential care to those with multiple sclerosis (MS). Dyadic interventions promoting health behaviours have wide-reaching benefits for individuals with MS and their care partners. However, behavioural interventions to promote physical activity in patient-caregiver dyads have yet to be explored in an MS-specific context. This study examined the secondary outcomes of the "Physical Activity Together for Multiple Sclerosis (PAT-MS)" intervention, including dyadic adjustment, caregiving tasks, caregiver quality of life, coping, and MS impact in MS dyads.

A randomized controlled feasibility trial of the 12-week behavioural PAT-MS intervention. The Dyadic Adjustment Scale, Caregiving Tasks in MS Scale, Caregiver Quality of Life in MS Scale, Coping with MS Caregiving Inventory, and MS Impact Scale measured secondary outcomes of interest. Mixed-model ANOVAs were used to test changes in variables between groups (PAT-MS vs wait-list control) over time.

20 participants, including 10 people with MS (51.4 ± 10.1 years old; median patient-determined disease steps (PDDS) score= 4, IQR= 1.25) and 10 care partners (48.5 ± 12.1 years old) were recruited and randomized. There was no statistically significant effect of the intervention on any of the secondary outcomes (p= 0.67-1.00). However, large effect sizes and condition-by-time interaction effects indicated improvement in dyadic adjustment (d= 1.03, η_p²= 0.45), the criticism-coercion coping subscale (d= -0.93, η_p²= 0.49), and caregiving tasks (d= 1.05, η_p²= 0.52), specifically within psycho-emotional (d= 1.47, η_p²= 0.38) and socio-practical (d= 1.10, η_p² =0.37) sub-domains of caregiving tasks after the PAT-MS intervention compared to the wait-list condition.

While this pilot feasibility study was not powered based on the secondary outcomes herein, our findings indicate improvement in dyadic adjustment and emotional and social caregiving tasks, with reduced reliance on criticism-coercion coping in the PAT-MS group compared to controls following the intervention. Findings indicate that PAT-MS may improve dyadic psychosocial well-being of people with moderate-to-severe MS and their care partners, and this should be examined next in a fully-powered study.