Wrist-Worn Activity Trackers in Laboratory and Free-Living Settings for Patients With Chronic Pain: Criterion Validity Study

Abstract

Background Physical activity is evidently a crucial part of the rehabilitation process for patients with chronic pain. Modern wrist-worn activity tracking devices seemingly have a great potential to provide objective feedback and assist in the adoption of healthy physical activity behavior by supplying data of energy expenditure expressed as metabolic equivalent of task units (MET). However, no studies of any wrist-worn activity tracking devices’ have examined criterion validity in estimating energy expenditure, heart rate, or step count in patients with chronic pain. Objective The aim was to determine the criterion validity of wrist-worn activity tracking devices for estimations of energy expenditure, heart rate, and step count in a controlled laboratory setting and free-living settings for patients with chronic pain. Methods In this combined laboratory and field validation study, energy expenditure, heart rate, and step count were simultaneously estimated by a wrist-worn activity tracker (Fitbit Versa), indirect calorimetry (Jaeger Oxycon Pro), and a research-grade hip-worn accelerometer (ActiGraph GT3X) during treadmill walking at 3 speeds (3.0 km/h, 4.5 km/h, and 6.0 km/h) in the laboratory setting. Energy expenditure and step count were also estimated by the wrist-worn activity tracker in free-living settings for 72 hours. The criterion validity of each measure was determined using intraclass and Spearman correlation, Bland-Altman plots, and mean absolute percentage error. An analysis of variance was used to determine whether there were any significant systematic differences between estimations. Results A total of 42 patients (age: 25-66 years; male: 10/42, 24%; female: 32/42, 76%), living with chronic pain (duration, in years: mean 9, SD 6.72) were included. At baseline, their mean pain intensity was 3.5 (SD 1.1) out of 6 (Multidimensional Pain Inventory, Swedish version). Results showed that the wrist-worn activity tracking device (Fitbit Versa) systematically overestimated energy expenditure when compared to the criterion standard (Jaeger Oxycon Pro) and the relative criterion standard (ActiGraph GT3X). Poor agreement and poor correlation were shown between Fitbit Versa and both Jaeger Oxycon Pro and ActiGraph GT3X for estimated energy expenditure at all treadmill speeds. Estimations of heart rate demonstrated poor to fair agreement during laboratory-based treadmill walks. For step count, the wrist-worn devices showed fair agreement and fair correlation at most treadmill speeds. In free-living settings; however, the agreement for step count between the wrist-worn device and waist-worn accelerometer was good, and the correlation was excellent. Conclusions The wrist-worn device systematically overestimated energy expenditure and showed poor agreement and correlation compared to the criterion standard (Jaeger Oxycon Pro) and the relative criterion standard (ActiGraph GT3X), which needs to be considered when used clinically. Step count measured with a wrist-worn device, however, seemed to be a valid estimation, suggesting that future guidelines could include such variables in this group with chronic pain.

The relationships between step count and all-cause mortality and cardiovascular events: A dose–response meta-analysis

“…However, the term “waist” usually included the hip. 56 , 57 , 58 When we stratified studies by the placement of the accelerometer, heterogeneity was not indicated in the group who wore accelerometers on their waist and hips ( p = 0.703). The pooled RRs for studies with waist- or hip-worn accelerometers was 0.86 (95%CI: 0.84–0.87; n = 8), and the pooled RRs for studies with wrist-worn acceleromenters was 0.68 (95%CI: 0.57–0.81; n = 1).…”

Effectiveness of the eVISualisation of physical activity and pain intervention (eVIS) in Swedish Interdisciplinary Pain Rehabilitation Programmes: study protocol for a registry-based randomised controlled clinical trial

“…Results confirmed previous study results in adjacent patient groups reporting that Fitbit Versa systematically overestimated energy expenditure, however, measurements of step count both in laboratory and in free-living setting were valid. 33 …”

“…The Fitbit device measures and estimates a range of physical activity outcomes such as number of steps, heart rate, energy expenditure, floors climbed, physical activity level and sleep. 33 53 In this trial, participants’ step count per day will automatically be synchronised to PATRON during the study period (6 months). The use of steps per day is considered to be a valid quantification of physical activity levels and this is acknowledged by the Swedish Health Authority.…”

“…Outcome assessments of physical activity level (steps/day) will be objectively collected by a wrist-worn activity tracker, Fitbit Versa 2. This device has been population-specifically validated and the measurement of step rate is indicated as valid for measurement in this population 33. Data on patient’s physical activity level, quantified as steps/day, will be automatically synchronised to the web application PATRON, where pain intensity (0–10),48 interference of pain on daily activities (0–10),49 pharmacological consumption (name, dose, number and form) and (optional) free-text comments will be reported by the patient daily.…”

“…eVIS is designed to target facilitating mechanisms for behaviour change, such as outcome expectations, self-monitoring, self-evaluation and self-efficacy,30–32 which are theoretically framed by the social cognitive theory 32. In eVIS, objectively measured physical activity tracking using a wrist-worn activity tracker33 (Fitbit Versa 2), is combined with a daily activity goal (steps/day) and daily patient reports of known important clinical outcome assessments: pain intensity and its interference on daily activities34–38 and pharmaceutical consumption. Data are collected and visualised in a purpose-developed web application, Pain And TRaining ON-line (PATRON), which can be used by the patient and the IPRP team to follow and adjust individual physical activity levels.…”