activAnalyzer: An R Shiny app to analyse ActiGraph
accelerometer data and to implement the use of the PROactive Physical
Activity in COPD instruments

ActiGraph devices (ActiGraph LLC, Pensacola, FL) have been the most used accelerometers in scientific literature to measure physical activity (Bassett et al., 2015; Migueles et al., 2017). These devices, along with their software companion ActiLife (ActiGraph LLC, Pensacola, FL), allow to get movement data expressed in either activity counts or G-force units. Activity counts represent the amount of acceleration produced over a given epoch of time at the wearing position of the device. While analytic methods based on G-force data are developing, using activity counts to assess physical activity and sedentary behaviour remains common (Migueles et al., 2017). Interestingly, ActiGraph devices have been validated to implement the framework related to the use of the PROactive Physical Activity in COPD (chronic obstructive pulmonary disease) instruments (Dobbels et al., 2014; Garcia-Aymerich et al., 2021; Gimeno-Santos et al., 2015). Such a framework requires combining scores relating to answers of questionnaire items and scores relating to accelerometer metrics obtained from a week of measurement.