# PERCEIVED AND PHYSIOLOGICAL STRAINS OF SOCIETAL PARTICIPATION IN PEOPLE WITH MULTIPLE SCLEROSIS: A REAL-TIME ASSESSMENT STUDY

## TL;DR

This study found that perceived and physiological strain during daily activities in people with multiple sclerosis are not related, with fatigue being a key factor in perceived strain.

## Contribution

The study is the first to show that perceived and physiological strain are unrelated in real-time societal participation among people with multiple sclerosis.

## Key findings

- Perceived strain during societal participation ranged from low to moderate (3–6 on a 1–10 scale).
- Physiological strain, measured as heart rate reserve, ranged from 18.5% to 33.2%.
- Perceived and physiological strain were not significantly associated, even after adjusting for fatigue and mobility.

## Abstract

To examine the relationship between perceived and physiological strains of real-time societal participation in people with multiple sclerosis.

Observational study.

70 people with multiple sclerosis.

Perceived and physiological strain of societal participation (10 participation-at-location and 9 transport domains) were measured in real time using the Whereabouts smartphone app and Fitbit over 7 consecutive days. Longitudinal relationships between perceived (1 not strenuous to 10 most strenuous) and physiological strains (heart rate reserve) were examined using mixed-model analyses. Type of event (participation-at-location or transport) was added as covariate, with further adjustments for fatigue and walking ability.

Median perceived strain, summarized for all societal participation domains, varied between 3 and 6 (range: 1–10), whereas physiological strain varied between 18.5% and 33.2% heart rate reserve. Perceived strain (outcome) and physiological strain were not associated (β -0.001, 95%CI -0.008; 0.005, with a 7-day longitudinal correlation coefficient of -0.001). Transport domains were perceived as less strenuous (β -0.80, 95%CI -0.92; -0.68). Higher fatigue levels resulted in higher perceived strain (all societal participation domains) (β 0.05, 95%CI 0.02; 0.08).

Societal participation resulted in low-to-moderate perceived and physiological strain. Perceived and physiological strain of societal participation were unrelated and should be considered different constructs in multiple sclerosis.

LAY ABSTRACT

People living with multiple sclerosis often experience a wide variety of symptoms, such as muscle weakness and fatigue, which can result in high patient-perceived strain during daily living. Moreover, in research settings activities of daily living require more energy in people with multiple sclerosis when compared with healthy peers. During physical exercise the energy requirements are closely related to patient-perceived strain, but whether this is also the case in real-time daily living is unknown. Therefore, we examined the relationship between patient-perceived strain and energy requirements during real-time societal participation. With the Whereabouts smartphone application and Fitbit, we were able to measure both patient-perceived strain and energy demands. In 70 people living with multiple sclerosis, we found that these measures were unrelated. The level of fatigue played an important role in this relationship; a higher level of fatigue resulted in higher patient-perceived strain.