Night-time cardiac metrics from a wearable sensor predict intensity of next-day chronic pain

Chronic pain is devastating and its measurement is elusive, making intervention difficult for sufferers and practitioners alike. The present study explores the possibility of tracking fluctuations in pain over time with wearable sensors of heart-based metrics. We measured mean heart rate and heart rate variability with a wrist-worn sensor in persons with and without chronic pain for one month. Mixed model regressions were used to test the associations, revealing that heart rate measured at night was predictive of pain intensity on the next day in participants with chronic pain (p < .05), but not in healthy controls (p > .05). The results suggest that cardiac biometrics can predict pain intensity in primary chronic pain conditions.