Physical Activity Together for MS: Quality Participation Experiences of People With Multiple Sclerosis and Their Caregivers in a Dyadic Physical Activity Intervention

Many people with multiple sclerosis (MS) and their family caregivers experience challenges with managing the disease and require support for their individual and collective well-being.^1,2  A behavioral approach to promote well-being in families affected by chronic diseases, such as MS, is physical activity (PA).³  Regular PA may have disease-modifying effects and is a critical component of comprehensive MS management.⁴  Despite benefits, many people with MS⁵  and their caregivers⁶  find it challenging to fully participate in PA to the same extent as the general population. Qualitative study results show that people with MS and their caregivers perceive PA as an interdependent experience⁷  and report many psychological, physical, and social barriers to full participation.⁸  These findings underscore the importance of dyadic behavioral PA approaches (ie, supporting the pursuit of PA goals and coparticipation of 2 individuals in a socially significant relationship, such as care recipients and their care-givers³ ) for full participation.

When promoting full participation in PA, 2 dimensions are crucial: quantity (frequency and intensity)⁹  and quality (a feeling state derived when participation experiences are satisfying values and needs). Six experiential elements or building blocks of quality participation (QP) have been identified, including autonomy (having choice and control), belonging (feeling included, part of the group), challenge (feeling appropriately tested), engagement (feeling focused and absorbed), mastery (experiencing success), and meaning (working toward a personal or socially meaningful goal and feeling a sense of responsibility to others).¹⁰  The Quality Parasport Participation Framework (QPPF)¹¹  further outlines key considerations and 25 actionable strategies for fostering QP in sports programs for people with physical disabilities. The strategies are arranged within the physical, social, and activity environments, where conditions for quality experiences can be shaped. Extending the QPPF to community-based exercise programming, Tomasone and colleagues¹²  recently developed a strategy matrix with 85 strategies for enabling QP in community-based exercise for people with disabilities. Identifying these strategies has been critical in applying the concept of QP in several contexts and across many disability groups.^13-17  However, it is important to note that existing work focuses solely on individuals with disabilities, not on dyads where 1 partner does not have a disability.

In dyadic chronic disease management literature, including dyadic PA programming, there continues to be a strong focus on increasing PA levels (quantity),¹⁸  with limited attention to understanding QP experiences. A dyadic approach to PA may inherently address QP, for example, when dyads support each other (belonging) to achieve individual and shared meaningful PA goals (meaning).¹⁹  Dyads with quality PA experiences may also report improved subjective well-being and sustained or increased PA over time.^20,21  Thus, it is crucial to consider QP in the context of dyadic PA interventions.

Importantly, insights into QP and strategies for fostering quality experiences may be gleaned from theories of human-motivated behavior, eg, Self-Determination Theory.²²  However, accessing and interpreting theoretical literature may be challenging for clinicians.²³  The QPPF¹¹  addresses this challenge by conceptualizing QP experiences and offering actionable, evidence-informed strategies for clinicians to create quality PA experiences. To date, no studies have applied the QPPF in the context of dyadic PA programming in MS. This study takes a crucial first step in exploring QP experiences of MS dyads and will inform future efforts to optimize full participation in PA. Specifically, using the QPPF,¹¹  we explored whether people with MS and their caregivers who completed a 12-week, group-based, dyadic, behavioral PA intervention called Physical Activity Together for MS (PAT-MS)^24,25  perceived it as a quality intervention and experienced QP during the intervention.

PAT-MS prioritizes PA goal pursuit and supports coparticipation among people with MS who have moderate to severe disability and their caregivers.²⁶  Recently tested in a pilot feasibility trial,²⁵  PAT-MS integrates theoretically grounded strategies for developing PA self-regulatory skills (eg, goal setting, problem-solving). This manualized intervention consists of 6 modules with associated practice sheets, delivered biweekly via Zoom videoconferencing (Zoom Communications, Inc) by a trained interventionist over 12 weeks. People with MS and their caregivers also received one-on-one calls with the interventionist to supplement and troubleshoot in the weeks when the group sessions did not occur. The study protocol²⁴  details the week-by-week intervention content. In the trial, a demographic questionnaire was completed at baseline and the Measure of Experiential Aspects of Participation (MeEAP)²⁷  assessed QP elements (autonomy, belonging, challenge engagement, mastery, meaning) post intervention. The MeEAP is a 12-item scale, with 2 items per element, rated using a 7-point scale from 1 strongly disagree to 7 strongly agree. Each item is added for a maximum score of 84 points. It is important to note that the pilot trial was not powered based on this outcome measure, as the focus was not on determining change in QP, but rather experiences of QP. Questionnaires were completed via a university-licensed SurveyMonkey account. Ethics approval was granted by the Ottawa Hospital Research Ethics Board (20190329-01H) and the University of Ottawa Research Ethics Board (H-09-19-4886).

This study is framed within ontological relativism and epistemological subjectivism, assuming the existence of multiple, subjective, mind- and context-dependent realities. We also believe that knowledge is coconstructed through intricate interactions among researchers, participants, and the broader sociocultural environment.²⁸  Grounded in this perspective, we sought to gather rich accounts of QP experiences from the perspective of a small group of people with MS and their caregivers.

Participants (N = 10) who completed the intervention condition of the pilot trial²⁵  between April 2021 and February 2022 were eligible and invited to participate in the current study. Six participants agreed and completed the interviews. Further information on eligibility criteria is available in the study protocol,²⁴  with COVID-19–related modifications reported in the feasibility manuscript.²⁵ 

We utilized a qualitative interpretative methodology through individual semistructured interviews. Participants confirmed verbal consent before each interview. Using an interview guide, the second author (M.L.) conducted the interviews via Zoom. Interview questions captured reasons for participating in PAT-MS, relationships developed during PAT-MS, and experiences and outcomes of participating in PAT-MS. People with MS and their caregivers were interviewed separately. Interviews lasted 45 to 60 minutes and were audio-recorded and professionally transcribed for analysis.

Descriptive statistics (median, range, frequency) were computed for the sample and MeEAP²⁷  scores. Qualitative data were analyzed using reflexive thematic analysis,²⁹  a theoretically flexible approach that aligns with our worldview. In the first phase, 4 authors (A.F., M.K., K.C., and E.B.) independently read and reread each transcript, noting points relevant to the research aim.²⁹  In the second phase, 3 authors (A.F., M.K., and E.B.) systematically generated codes to identify key features and points of interest. NVivo version 12 (QSR International Pty Ltd) was used to facilitate coding and data organization. One author (K.C.) acted as a “critical friend,” challenging initial codes, contributing to new codes, and stimulating reflection on alternative perspectives.³⁰ 

In the third phase, we used an inductive approach to organize codes into possible themes that indicated participants’ experiences. In the fourth phase, a deductive approach was applied to map potential themes to the QPPF.¹¹  For instance, theme 6 (accountability to one another) is conceptually akin to “belonging” (feeling included, part of the group) in the QPPF.¹¹  The fifth phase involved ongoing discussion among the authors to clarify each theme's scope, boundary, and alignment with research objectives. Finally, a coherent written report was created, incorporating exemplar quotations to enhance understanding of the themes.

Contemporary qualitative research methodologists have critiqued member checking as a universal method of establishing rigor in qualitative research.^28,30,31  Instead, they urge researchers not to consider criteria for ensuring methodological rigor as universal or concrete but to draw from a dynamic list of relevant traits from different sources^32-34  while remaining flexible and not bound by said techniques.³⁰  With these considerations in mind and consistent with our philosophical worldview, we ultimately chose 4 criteria for rigor: resonance, plausibility, ethical conduct, and reflexivity. Resonance was ensured by offering “thick” descriptions and interpretations, enhancing transferability to different situations (naturalistic generalizability).³³  We used direct quotations from participants to allow readers to independently assess our interpretations and the appropriateness of our themes. Quotations from all 6 participants were given equal attention in the coding process, and themes were developed from robust, supportive quotations from all participants rather than a couple of unconvincing examples.³² Ethical conduct was maintained through informed consent and participant anonymity. We sought plausibility by situating our findings within the QPPF.¹¹ Reflexivity was ensured by using a “critical friend” to stimulate reflection and explore alternative explanations and interpretations.³⁰  These strategies are consistent with reflexive thematic analysis²⁹  and contemporary approaches for rigor in qualitative research.³⁰ 

To maintain the anonymity of the small sample of participants, the decision was made to remove all identifiable information, replace names with pseudonyms, and withhold a table containing demographic information. Participants in this study included 3 people with MS (2 women and 1 man) and 3 caregivers (2 men and 1 woman). These participants represent 2 paired partners (n = 4), 1 unpaired person with MS, and 1 unpaired caregiver. The median age of participants was 51.5 (range, ± 21) years old. The median MeEAP²⁷  score was 61.5 (range, ± 17.0), with the highest scores on the autonomy and mastery (both at 6.0), followed by challenge, engagement, and meaning (all at 5.3) subscales. The lowest score was on the belonging subscale (4.8).

We identified 6 interrelated themes conceptually aligned with QP elements/building blocks in the QPPF,¹¹  conditions necessary to achieve these elements in the strategy matrix,¹²  and an additional theme related to further refinement of PAT-MS. Although we found a high degree of interaction between QP elements, for ease of representation, themes are illustrated as separate entities here and the relationships between themes are subsequently explored in the discussion. The themes are discussed below, with exemplar quotations included for more context. Quotations are referenced by participant pseudonyms.

Participants described how PAT-MS provided them with a sense of choice and control over their PA participation (autonomy), which was reflected in being able to set individual and shared PA goals with their partners in collaboration with the interventionist. “It is a program that helps you throughout each week to kind of identify an activity of interest and then maintain that activity post program…and so, it becomes almost muscle memory,” Luke, a caregiver, said. Participants valued that PAT-MS emphasized the notion that “any movement is good,” and it helped them to redefine possible options for PA (eg, the inclusion of household chores) and offered flexibility to choose specific activities based on their interests. Jill, a person with MS, remarked: “She [interventionist] explained what defines an activity, and in our mind, an activity would be something where we were working out in the gym, but she included other choices and things around the house like doing housework or chores. So it helped us understand a little bit better [and] to maximize our participation.”

With the expansion in their knowledge of what constitutes PA, participants were able to make decisions relative to how they would incorporate familiar, valued activities into their daily routine and explore new options that they could continue beyond the intervention context. This decision-making regarding the frequency, intensity, and type of activity was perceived as necessary for a sense of personal agency and independence: “And now [I have] a better understanding… because before I would say, ‘How come I get so tired if I didn't do anything?’ But doing laundry, doing this, doing that, it all counts as physical activity, so you understand more about physical activity and can prioritize and schedule and understand where does your fatigue come from,” Barb, a person with MS, said.

Participants shared that they experienced a sense of accomplishment when they observed incremental improvement in their skills and abilities and increased competence for PA (mastery) during the intervention period. “For us, we set out with very low ambitions of going to the pool twice a week, and I think it was really meaningful when, all of a sudden, she was able to do the third and fourth time per week. So, in short order, we doubled our expectations of what I thought and what she thought she was capable of doing,” Luke shared. They also described mastery experiences relative to their perceived improvements in outcomes, including physical fitness and psychological well-being. Barb commented, “I am in better physical shape than I was 4 months ago.” Matt, a caregiver, said, “You do feel more positive because you're up and active and just not sitting sedentary all day; you feel happier.”

Participants appreciated the weekly PA log in the PAT-MS manual, which was used to record and self-monitor progress and improvement during the intervention. Jill added, “To visualize what we have accomplished, what our goals are in the PA log, so this gave me a great opportunity to work with a spreadsheet and, looking back on week 1 and week 2, to see how much I actually [did].”

Participants reflected on the importance of activities that physically challenged them to develop skills and personal competence for PA, progressively difficult tasks that pushed them beyond their comfort zone (challenge) while not generating frustration or failure. To facilitate a sense of physical challenge, participants used the average daily number of minutes, perceived level of intensity, and feeling after PA, which were recorded in the weekly PA log to make necessary adjustments to their activities. Mary, a caregiver, said, “Those are real milestones. So, you're pushing yourself, but you are being pushed by the study, too. I think what the program has spelled out to us as participants is that we can push ourselves. We can work with our partners to help them push themselves too.” Tailored support to participants’ abilities was considered essential to guide activity progression. Barb commented, “It really does depend on the abilities and levels of the participants. There are times [when] you know you have participants [who] require additional support or [something] extra—someone [who is] able to guide them a little bit more.”

Participants found the intervention sessions and activities fun and enjoyable (engagement) and emphasized how the dyadic and group-based approach and the opportunity to select their partner for coparticipation supported their continued engagement in the intervention. Barb said, “[It was] a little push in doing exercise, especially with my sister; I thought it was fun.” The resources and tools embedded in PAT-MS also promoted engagement: Matt shared, “Little sticky notes that you see first thing in the morning, I found that kind of fun. You hit the floor, and then you're like, ‘Oh, yeah, exercise.’” The interventionist's flexibility with scheduling the sessions and her group facilitation skills also contributed to perceptions of engagement. “[When] my sister and I work[ed] together, we rambled, so she [the interventionist] was very good at reining it in a little and getting to what we need[ed] without saying ‘Come on guys; wrap it up.’ I thought she was good at keeping us engaged,” Barb contributed. Participants also shared the importance of financial incentives, particularly for continued involvement in a program spanning several weeks. Jill said, “…A little bit of financial incentive can come in handy, especially with life being quite expensive…so it's nice to see that at least there is a little something for those who can benefit from it.”

Participation in PAT-MS held personal and social significance (meaning) for participants, who emphasized choosing to participate for the health benefits of PA. Austin, a person with MS, said, “It's all those things [symptoms of the disease] that wear you out, that put you on the sofa with the remote control. It's a debilitating illness, and it wears out the afflicted and the partners as well; it's tiresome.” Moreover, after COVID-19–related social and physical isolation measures, participation in PAT-MS was perceived as a catalyst to resume their engagement in activities. Matt commented, “After 2 years of COVID lockdown, I think the idea of something that helped motivate me to get in shape was going to be a good thing.” Jill shared how participation in PAT-MS helped her get out more and reduced feelings of being homebound: “It was…quite difficult for me to motivate myself. Sometimes I don't even leave the apartment, which isn't…necessarily a healthy thing, I guess, to stay cooped up all day…. When I do it [exercise], I feel a lot better…and that was similar…across the board, you know, from doing the program.”

Other participants chose to participate in PAT-MS for altruistic reasons, believing it allowed them to contribute to a socially meaningful goal. They valued the opportunity to contribute to promoting the well-being of others by sharing knowledge and experiences related to symptom management and reflections on the benefits of PA. Barb said, “I always like to participate in research that's going to help move management of the condition [MS] forward. Anything that's going to help the next cohort of people coming through Someone did it before me, so now it's my turn to do it for someone else.”

Despite remote delivery, participants built and strengthened personal relationships with partners and group members (belonging), offering and receiving encouragement and peer and familial support. Several participants shared how participation in PAT-MS improved the relationship quality and dynamic with their partners. Austin said, “We are now doing new things. We've been married for 25 or 27 years, and we are doing new things together. That's not a bad position to be [in]. We are active, and we are doing [it] together, which is not insignificant.” Luke offered this reflection, “[Learning] how to interact with my partner better is probably the biggest outcome. Because we've not had any…escalated arguments, I would say. [And] with regard to activity,…it's just about, you know, moving and being active as a human being.”

To promote belonging, participants emphasized the importance of having good group dynamics for in-depth relationships and comfort in sharing. Barb commented, “I realized that other people in the group have the exact same fears or concerns that I do. It's helpful working with other people with similar experiences because you can all share what you are going through, and you realize you are not the only one, which is quite often the case. Then there's kind of like a breath of fresh air…there's some camaraderie there.”

Open communication among group members while respecting personal boundaries contributed to a sense of belongingness and psychological safety. “Everybody was very friendly and open; everybody respected each other when we were discussing. I mean, maybe in the past, this would have been a group that met up in person, but we all met virtually.… Everybody was able to communicate with each other well. I think we knew that we were going to respect each other's privacy, so people were able to share a little bit more,” Luke commented. Participants also shared that they would like opportunities to socialize with other group members beyond the program delivery.

While all participants were supportive and appreciative of PAT-MS, they also commented on some features that could be improved in future iterations. For instance, some participants reflected on how disease fluctuations, the unpredictability of MS symptoms, or increasing caregiving responsibilities could affect the ability of people with MS and caregivers to commit to weekly calls spanning 12 weeks, and suggested reducing the frequency of these calls in future interventions. Austin remarked, “For the ones with the activity coach [interventionist] and the ones where we met in the group, I would say fewer calls.” A second area of concern was the requirement to simultaneously access the online PAT-MS manual and contribute during the Zoom videoconferencing group sessions. Barb noted, “I think the only part I didn't like was the guide [PAT-MS manual] being online.… I know there [are] ways you can open the guide and do Zoom at the same time, but I'm not the person [who can] figure stuff out like that…I'm not savvy when it [comes] to tech.” Another participant raised the issue of group composition and the importance of considering homogeneity in composition (eg, including those with similar disability levels and shared understanding of caregiving) in future iterations. Jill reflected, “I guess one negative [component] I felt was—this is a minor thing for me—but there were different ability levels in the group. I think in an ideal world, maybe the disability levels might have been paired a little more precisely, but maybe that was an objective…as well, to have different levels.”

Full PA participation necessitates attention to both quantity and quality,³⁵  yet most dyadic PA studies have predominantly focused on quantity, neglecting the exploration of positive, satisfying, enjoyable experiences that generate personally valued outcomes (ie, quality).¹⁰  We addressed this gap by exploring the QP experiences of people with MS and their caregivers in a dyadic PA intervention. Below, we highlight key findings and discuss their implications for rehabilitation providers.

While individual quality elements were presented in the results, our analysis suggests potential interrelationships among them.¹⁶  For instance, autonomy was described as the ability to set meaningful, enjoyable PA goals and exert control over engagement levels. Participants further reported “pushing themselves” beyond their comfort zones (challenge) to achieve personalized and shared PA goals and feeling a sense of accomplishment and increased confidence (mastery) when achieving or surpassing initial goals. Achieving the goals empowered them to become self-sufficient in pursuing a physically active lifestyle, leading to improvements in health and well-being (meaning). Qualitative research in other chronic diseases supports the importance of choice and control over the type of activity and level of engagement for long-term PA.³⁶ 

Belonging received the lowest MeEAP score, possibly due to a lack of avenues for participants to connect outside the intervention, which is a key strategy for fostering this element.¹²  Nevertheless, the social bonds formed and/or strengthened with partners and peers during PAT-MS appeared linked to engagement. Previous research exploring PA programming, including technology-supported interventions, has reported that fostering a sense of community and camaraderie among participants with shared values can contribute to quality experiences and improve program adherence.³⁷  Given the isolating nature of MS for affected families,³⁸  the opportunity for participants, especially caregivers, to build new relationships during PAT-MS has implications for reducing social isolation.

Our findings suggest that remotely delivered PA interventions can foster QP experiences by tailoring the intervention to participants’ contexts and values. Remote PA programs via videoconferencing platforms (eg, Zoom) are gaining traction post COVID-19, offering increased opportunities for people with disabilities and their caregivers to be physically active.³⁹  However, trials evaluating technology-delivered PA interventions, including those for people with MS, often overlook QP considerations.⁴⁰  While the QPPF highlights 3 environments for shaping QP experiences,¹¹  we identified conditions within the activity (nature of PAT-MS) and social (relationships formed during PAT-MS) environments with no corresponding descriptions in the physical environment. The videoconference delivery of PAT-MS may have reduced the potential to identify conditions within the physical environment that were influencing QP experiences. Participants reported challenges regarding navigating the online PAT-MS manual while simultaneously participating in Zoom videoconferencing sessions. This finding suggests that further refinement of the technology platform may be necessary to improve the capacity to access the intervention remotely. This is a key consideration for future iterations of PAT-MS, as compliance with technology-mediated rehabilitation and positive intervention outcomes can be influenced by participants’ perceptions of the technology.^41,42  It is also possible that people who participate in technology-mediated PA interventions may experience QP differently from those who receive in-person interventions. Given concerns about the group composition and frequency of PAT-MS intervention sessions, moving forward, it may be worthwhile to test how different delivery settings, dose, frequency, and intensity of PA interventions influence QP experiences and outcomes; this would facilitate the incorporation of meaningful participation-enhancing PA interventions into routine clinical practice.

As this study was embedded in a pilot feasibility trial,²⁵  our main focus was to explore participants’ experiences to inform future intervention refinement. While not explicitly testing relationships among QP elements, our findings suggest that a proximal element (eg, challenge) may bring about the experience of a more distal (eg, meaning) element.¹³  While the strategies for fostering QP in this study align with the recent strategy matrix,¹²  suggesting potential generalizability to other contexts, the importance of novel strategies was also identified. For instance, opportunities for coparticipation with a self-selected partner and training to improve the technical expertise of participants to align with the delivery modality may be strategies to foster engagement. Future researchers may want to further test the QPPF¹¹  and strategy matrix¹²  in technology-delivered dyadic intervention contexts to identify the strongest predictors or most important elements and strategies to include in such interventions.

Recognizing that QP is individually and subjectively experienced and context specific,¹¹  future research could also explore the QP experiences of interventionists in dyadic PA interventions. Jackson et al¹⁶  reported that service providers (akin to interventionists) in a community-based PA program for persons with disabilities also experienced meaning, feeling a sense of responsibility and seeing a positive program impact on participants’ lives. Investigating whether interventionists experience all 6 QP elements, if those experiencing QP are more likely to foster the same among participants, and differences and interactions between interventionists’ and participants’ experiences could advance the field of dyadic PA.

Findings from this study offer some pearls for rehabilitation providers when designing and delivering PA programming for people with MS and their caregivers. Importantly, activities perceived as meaningful, enjoyable, and tailored to individual needs of the dyad must be prioritized when designing PA programming. Our findings indicate that it is possible for MS caregivers to also experience QP, and their needs and preferences should also be assessed and incorporated. Creating avenues for open communication about PA goals; education about how to be active and different ways to adapt activities, particularly for individuals with moderate-to-severe MS disability; and encouragement of progress tracking so that the dyad can see the gains they have made are some strategies that can be applied in clinical practice to foster repeated and continuous quality experiences in PA.

Having said this, providers must resist a narrow focus on elements of the activity alone (eg, frequency, type, intensity), as our findings indicate that participation is more than being involved in an activity. Indeed, various characteristics within the social environment can contribute to fostering QP experiences. For instance, health care providers and exercise professionals may want to pay attention to providing opportunities and support for people with MS to meaningfully coparticipate in PA alongside a self-selected partner.

Our sample size is admittedly small, although similar to previous qualitative research exploring experiences of PA programming in MS⁴³  and caregiver experiences participating in a technology-supported intervention in Alzheimer disease.⁴⁴  Statistical generalizability is not a relevant criterion for evaluating qualitative studies.³³  Nevertheless, it is important to address the likely impact of sample selection on this study's findings. Specifically, the sample included participants who volunteered for this interview component post intervention. It is possible that our findings may not represent the opinions and experiences of the pilot trial participants who chose not to take part in the postintervention interviews. Further, while the demographic profile of our participants is consistent with the full sample in the pilot feasibility trial (median age, 51.5 for people with MS and 51.0 years for caregivers²⁵ ), it is possible that younger or older people with MS and family caregivers have unique QP experiences during PA, an interesting avenue for future intervention development work.

Second, it is worth noting that conceptualizations of QP¹¹  have focused on self-described quality experiences, with less attention to objective quality of movements during PA. Given that low-quality movement patterns can increase the risk of injury during PA among apparently healthy adults and athletes,^45,46  future MS researchers may want to explore how perceptions of quality experiences intersect with quality of movement patterns to examine comprehensive PA participation.

Third, we note that MS dyads tend to view PA as an interdependent experience, with both individuals experiencing similar struggles, frustrations, and challenges as they attempt to enact a physically active lifestyle.⁷  With these considerations in mind, both partners were considered together in the data analysis in the pilot feasibility trial,²⁵  a practice followed in the current study. Nevertheless, we acknowledge that this approach may have obfuscated the distinct perceptions of QP—in particular, quality elements may not be experienced in the same manner for both people coping with a chronic disabling condition, such as MS, and their family caregivers who do not have a disability. Existing QP work in the field of PA promotion focuses solely on individuals with disabilities.^{11,12,16,20,47}  Thus, characterizing and identifying how to support the QP experiences of family caregivers who do not have a disability should be explored in future PA research.

Finally, PAT-MS was delivered during the COVID-19 pandemic, potentially positively influencing participants’ perception due to the significant reductions in PA levels in the MS population⁵  and increased reliance on teleheath⁴⁸  during this period. In addition, the involvement of a single interventionist in PAT-MS may have influenced participants’ experiences of the program, which should be tested with different program leaders moving forward.

This study advances our understanding of the experiential dimensions of quality PA participation in a dyadic context in MS, reinforcing the potential effectiveness of PAT-MS in this population. Our findings highlight the intricate interplay among autonomy, belonging, challenge, engagement, meaning, and mastery, offering a foundation necessary for designing and implementing future dyadic PA programs that support full participation for people with MS and their caregivers.

The authors thank Odessa McKenna, Julia Ludgate, Taylor Hume, Myriam Venasse, and Siona Phadke for their contributions to the intervention development and delivery, project management, and coding of interview data.