Use of pedometers and accelerometers in clinical populations: validity and reliability issues

Abstract

Background: Pedometers and accelerometers are often used in clinical research studies, and have the potential to provide valid and objective information on physical activity. Objectives: The purposes of this review are to introduce clinicians to various activity monitors that are commercially available, and to discuss their strengths and limitations. Scientific articles over the past 20 years were reviewed, and the most common types of physical activity monitors were identified. Emphasis was placed on devices with established validity and reliability, which were acceptable to participants and did not interfere with their activities. Ease-of-use from the investigator's standpoint was also considered. Major findings: A number of activity monitors were identified, including four pedometers (Yamax SW digiwalker, New Lifestyles NL-2000, Omron HJ-720 ITC, and StepWatch), three accelerometer-based activity monitors (ActiGraph, Actical, and RT3), and a multisensor device (Sensewear Armband). Validity and reliability of these devices is discussed. Conclusions: Pedometers and accelerometers are useful for tracking ambulatory physical activity in clinical populations, and those that display steps and/or calories are useful in motivating patients to increase their activity levels.

Wearable Sensor/Device (Fitbit One) and SMS Text-Messaging Prompts to Increase Physical Activity in Overweight and Obese Adults: A Randomized Controlled Trial

“…Therefore, participants were inadvertently exposed to some PA intervention with the Fitbit One during baseline measure of PA and prior to the start of the study, which could have diminished the effects of either the Fitbit One and/or text messaging. A strength of this study was the use of the Actigraph GT3X + , which is a valid and reliable measure of PA. 46,47 A validation study has compared Fitbit One measures with the Actigraph GT3X+ for steps that were taken on a treadmill, 51 and validation in a real-world setting is currently underway. More generally, improvements are needed in these technologies for more accurate measures across an array of activities beyond steps (e.g., cycling and swimming).…”

“…Outcome measures were number of steps and minutes of PA by intensity level using two accelerometers: the Actigraph (Pensacola, FL) GT3X+ (primary measure) and Fitbit One (secondary measure). The Actigraph GT3X+ is a valid and reliable measure of PA among adults 46,47 and thus provided primary measures of PA change from the baseline week to Week 6. The Fitbit One's technology allowed collection of additional days of PA measurement throughout the entire study period (up to 49 days).…”

Physical performance and self-report outcomes associated with use of passive, adaptive, and active prosthetic knees in persons with unilateral, transfemoral amputation: Randomized crossover trial

“…The StepWatch 3 activity monitor was selected to measure participants' activity over the duration of the study. The StepWatch 3 records the number of steps taken by the wearer in 1 min increments for periods of up to 60 d. The StepWatch 3 has excellent evidence of measurement reliability and validity across patient populations, including persons with limb loss [69][70]. Data from the activity monitor was downloaded to a laptop computer at each assessment, according the manufacturer's instructions.…”

Evaluating the Feasibility and Impact of an Internet-Based Lifestyle Management Program in a Diabetes Care Setting

“…Accelerometers also have limited intrarater consistency. 19 The prevalence rates of individuals living with type 2 diabetes and obesity continue to increase. The VLM program is a virtual lifestyle change program based on the DPP protocols and curriculum offering a novel approach to extend behavioral counseling beyond the usual clinical setting.…”