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

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. In this population-based cross-sectional study participated 375 women with fibromyalgia from the al-Ándalus project (Spain). Physical activity, sedentary behaviour, and physical fitness were objectively (accelerometers and performance testing) and subjectively (questionnaires) measured. Participants self-reported their levels of positive affect, negative affect, and life satisfaction. 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. Independent associations of the objective measures (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 considered when developing physical exercise interventions for fibromyalgia.Implications for rehabilitationThe analysis of concurrent associations of objective and subjective evaluations of physical functioning with subjective well-being offers indications for modifiable targets in rehabilitation that can improve well-being in fibromyalgia.Exercise-based rehabilitation may help women with fibromyalgia to improve subjective well-being, particularly positive affect.Rehabilitation should focus on both the objective physical performance of women with fibromyalgia and on their perceptions of what they can do physically.When rehabilitation aims at enhancing positive affect or life satisfaction by changing the lifestyle of women with fibromyalgia, physical activity and sedentary behaviour should be objectively monitored