The DiSCover Project: Protocol and Baseline Characteristics of a Decentralized Digital Study Assessing Chronic Pain Outcomes and Behavioral Data

Background: Chronic pain affects approximately 50 million adults in the United States and impacts mood, everyday functioning, and quality of life. The challenges of analgesic clinical trials and, therefore, the approval of new non-opioid analgesics, are based in part on a fundamental lack of understanding of those outcomes that are relevant to an individual's overall functioning. Objectives: To determine the behaviors and health outcomes associated with chronic pain. This manuscript presents an overview of the study design, baseline health and behavioral characteristics of our sample, and preliminary findings of how behavioral characteristics differ between individuals with and without chronic pain. Methods: The study is a decentralized digital longitudinal cohort study of 10,036 individuals (5,832 with chronic pain [CP] and 4,204 with no chronic pain [NCP), age 18 years or older, living in the United States. The study period was one year. Data were collected from wearable activity trackers and health or fitness mobile applications to capture passively collected behavioral data including steps, sleep, and heart rate. Patient-reported outcomes on mood and pain, including the BPI-SF, PHQ-9, and GAD-7, were collected at various timepoints during the study. Results: The data suggest greater levels of depression and anxiety, lower quality of life, less physical activity, more variable sleep, and higher resting heart rate are associated with CP. Conclusions: The longitudinal data from the larger study will yield substantial contributions to the body of literature in chronic pain, particularly in delineating relational and causal factors relevant to the impact of chronic pain, and potential development of a digital biomarker to assess and monitor patients' everyday experience with chronic pain.