Measurement of sedentary time and physical activity in rheumatoid arthritis: an ActiGraph and activPAL™ validation study

Abstract

Accurate measurement of sedentary time and physical activity (PA) is essential to establish their relationships with rheumatoid arthritis (RA) outcomes. Study objectives were to: (1) validate the GT3X+ and activPAL3 μ ™, and develop RAspecific accelerometer (count-based) cut-points for measuring sedentary time, light-intensity PA and moderate-intensity PA (laboratory-validation); (2) determine the accuracy of the RA-specific (vs. non-RA) cut-points, for estimating free-living sedentary time in RA (field-validation). Laboratory-validation: RA patients (n = 22) were fitted with a GT3X+, activPAL3 μ ™ and indirect calorimeter. Whilst being video-recorded, participants undertook 11 activities, comprising sedentary, lightintensity and moderate-intensity behaviours. Criterion standards for devices were indirect calorimetry (GT3X+) and direct observation (activPAL3 μ ™). Field-validation: RA patients (n = 100) wore a GT3X+ and activPAL3 μ ™ for 7 days. The criterion standard for sedentary time cut-points (RA-specific vs. non-RA) was the activPAL3 μ ™. Results of the laboratoryvalidation: GT3X-receiver operating characteristic curves generated RA-specific cut-points (counts/min) for: sedentary time = ≤ 244; light-intensity PA = 245-2501; moderate-intensity PA ≥ 2502 (all sensitivity ≥ 0.87 and 1-specificity ≤ 0.11). ActivPAL3 μ ™-Bland-Altman 95% limits of agreement (lower-upper [min]) were: sedentary = (− 0.1 to 0.2); standing = (− 0.7 to 1.1); stepping = (− 1.2 to 0.6). Results of the field-validation: compared to the activPAL3 μ ™, Bland-Altman 95% limits of agreement (lower-upper) for sedentary time (min/day) estimated by the RA-specific cut-point = (− 42.6 to 318.0) vs. the non-RA cut-point = (− 19.6 to 432.0). In conclusion, the activPAL3 μ ™ accurately quantifies sedentary, standing and stepping time in RA. The RA-specific cut-points offer a validated measure of sedentary time, light-intensity PA and moderate-intensity PA in these patients, and demonstrated superior accuracy for estimating free-living sedentary time, compared to non-RA cut-points.

Pain and fatigue are longitudinally and bi-directionally associated with more sedentary time and less standing time in rheumatoid arthritis

“…The activPAL3 µ™ (PAL Technologies Ltd, Glasgow, UK) is an accelerometer with inclinometer function, which measures habitual behaviour over continuous 24-h periods. This device is considered the gold standard measure of free-living sedentary time [ 19 ] and has been validated for measurement of free-living sedentary, standing and stepping time in RA [ 20 ].…”

Reliability of activity monitors for physical activity assessment in patients with musculoskeletal disorders: A systematic review

“…On the other hand, the activPAL3 µ TM device accurately classified the amount of sedentary, standing and stepping time in O'Brien et al [41], by means of this result can be explained by the different impact of the same disease on the functional capabilities of patients [43]. The lack of differentiation between different degrees of functional impairment in RA patients is common to all the papers included in the synthesis, calling for further research in order to establish comparable gait patterns.…”

“…* = Papers were excluded also for more than one reason during the title and abstract screening phase. [27,[34][35][36][37][38][39][40][41] were included in the synthesis, as depicted by PRISMA Flow Chart in Fig. 1.…”

“…All the studies have been published in the last 10 years (from 2011 to 2020). Most of them, 8 (80%), are based in Europe (4 from United Kingdom [28,35,37,41], 2 from the Netherlands [36,38], 1 from Ireland [27] and 1 from Spain [40]), 1 in America (United States of America [34]) and 1 in Oceania (New Zealand [39]).…”

“…A wide heterogeneity of wearable devices was used, taking into account that 10 different types of wearable devices were used. Nine studies investigated the role of accelerometers to assess the degree of PA in musculoskeletal patients: 5 (55.6%) studies employed different versions of the ActiGraph accelerometer (GT1M [34], GT3X [28,37], GT3X+ [40,41]); 2 (22.2%) studies employed different versions of the Ac-tivPAL activity trackers (ActivPAL [27] and Activ-PAL3 µ TM [41]); 1 study (11.1%) employed the Step-N-tune, Activ4Life and the Intelligent Device for Energy Expenditure and Activity monitors [35]; 1 study (11.1%) employed the Tri-axial accelerometer (GCdataconcepts, US) [36]; 1 study (11.1%) the Actical accelerometer [38]; and 1 study (11.1%) the Fitbit-Zip accelerometer [28]. Finally, 1 study (11.1%) assessed the number of steps per day by means of a pedometer [39].…”