Objective and subjective measures of physical functioning in women with fibromyalgia: what type of measure is associated most clearly with subjective well-being?

Abstract

Purpose: To find modifiable factors that are related to subjective well-being would be valuable for improving interventions in fibromyalgia. Physical activity, sedentary behaviour, and physical fitness may represent potential areas to optimize treatment regimens. In fibromyalgia, there is a discordance between clinical observations and patient-reported outcomes (objective and subjective assessments). Therefore, the present study aims at analyzing the associations of objective and subjective evaluations of physical activity, sedentary behaviour, and physical fitness with subjective well-being and determine if and how objective and subjective associations differ. Methods: In this population-based cross-sectional study participated 375 women with fibromyalgia from the al- Andalus project (Spain). Physical activity, sedentary behaviour, and physical fitness were objectively (accelerometers and performance testing) and subjectively (questionnaires) measured. Participants selfreported their levels of positive affect, negative affect, and life satisfaction. Results: In the most conservative multivariate analysis, we found independent associations of the objective measures of physical activity with positive affect and life satisfaction and sedentary behaviour with positive affect. No such relationship was seen with subjective measures of the same behaviours. Moreover, we observed that objective and subjective physical fitness evaluations were independent of each other related to subjective well-being. Conclusions: Independent associations of the objectivemeasures (but not the subjective assessments) of physical activity with positive affect and life satisfaction, and of sedentary behaviour with positive affect were observed. However, objective measures and subjective appraisals of physical fitness appear to be independently related to well-being,which should be consideredwhen developing physical exercise interventions for fibromyalgia.