Presentations

TITLE: Epidemiology-of-1: Causal Inference via Single-case Observational Design for Sleep and Physical Activity Wearables Data

ABSTRACT: Temporally rich single-subject health data have become increasingly available thanks to wearable devices, mobile apps, sensors, and implants. Many health caregivers and “self-trackers” want to use such information to help a specific person figure out how to change their behavior to achieve desired health outcomes. However, this requires an approach for discerning possible causes from correlations using that person’s own observational time series data. In this paper, we posit and estimate some plausible idiographic average treatment effects of sleep duration on physical activity. We use a recently developed causal inference framework based on n-of-1 randomized trials to analyze one year of the lead author’s Fitbit sleep duration and step count data. We then compare our findings to those of standard methods that do not account for confounding to show that causal inference is needed to make realistic recommendations for personal behavior change.