Inter-accelerometer comparison to measure physical activity and sedentary time in female fibromyalgia patients: the al-Ándalus project.

OBJECTIVES

The purpose of the current study was to compare physical activity (PA) levels and sedentary time between two accelerometers, the SenseWear Pro3 Armband (SWA) and the Actigraph GT1M, in Spanish female fibromyalgia patients.

METHODS

Patients wore the SWA and the Actigraph for 7 consecutive days. Total minutes/day spent in sedentary, light, moderate and moderate-to-vigorous PA were analysed. The agreement between the SWA and the Actigraph were assessed by using Bland-Altman plots.

RESULTS

Total PA, light, moderate, and moderate-vigorous PA levels in total-week, weekdays and weekends were higher (all, p ≤ 0.001), and sedentary time in total-week, weekdays and weekends lower (all, p<0.001) for the SWA when compared to the Actigraph. Concordance correlation coefficients between the SWA and the Actigraph ranged from 0.12 to 0.45 and Pearson's correlation coefficients ranged from 0.28 to 0.77. The Bland-Altman plots showed an overall lack of agreement between both methods.

CONCLUSIONS

The present study showed that the SWA and the Actigraph provide different estimates of PA and sedentary time in Spanish female fibromyalgia patients. Caution must be taken when using different devices and the location on the body must be noted. Our results suggest that the PA levels and sedentary time provided by both devices should be interpreted independently across studies.