Accuracy of smartphone applications and wearable devices for tracking physical activity data.

Accuracy of Smartphone Applications and Wearable Devices for Tracking Physical Activity Data Despite the potential of pedometers to increase physical activity and improve health,1 there is little evidence of broad adoption by the general population. In contrast, nearly twothirds of adults in the United States own a smartphone2 and technology advancements have enabled these devices to track health behaviors such as physical activity and provide convenient feedback.3 New wearable devices that may have more consumer appeal have also been developed. Even though these devices and applications might better engage individuals in their health, for example through workplace wellness programs,3 there has been little evaluation of their use.3-5 The objective of this study was to evaluate the accuracy of smartphone applications and wearable devices compared with direct observation of step counts, a metric successfully used in interventions to improve clinical outcomes.1