JMIR Publications

ABSTRACT

Background:

Digital phenotyping provides insights into an individual’s digital behaviours and has potential clinical utility.

Objective:

In this observational study, we explore the digital biomarkers collected from both a wrist wearable device and a smartphone and their associations with clinical symptoms and functioning in patients with schizophrenia.

Methods:

100 outpatients with schizophrenia spectrum disorder were recruited, and various digital data from a commercially available wrist wearable and a smartphone were collected over a six-month period. In this report, we analyse the first one week of digital data on heart rate, sleep, and physical activity (from the wrist wearable) and travel distance, sociability, touchscreen tapping speed and screen time (from the smartphone). We analyse the relationship between these digital measures and patient baseline measurements of clinical symptoms, assessed with the Positive and Negative Syndrome Scale (PANSS), Brief Negative Symptoms Scale (BNSS), Calgary Depression Scale for Schizophrenia (CDSS), as well as functioning as assessed with the Social and Occupational Functioning Assessment Scale (SOFAS). Linear regression was performed for each digital and clinical measure, independently, with the digital measures being treated as predictors.

Results:

Digital data was successfully collected from both the wearable and smartphone throughout the study, with 91% of the total possible data successfully collected from the wearable and 82% from the smartphone during the first week of the trial - the period under analysis in this report. Among the clinical outcomes, negative symptoms were associated with the greatest number of digital measures (10 of the 12 studied here), followed by overall measures of psychopathology symptoms, functioning, and positive symptoms, which were each associated with at least three digital measures. Cognition and cognitive/disorganization symptoms were each associated with one or two digital measures.

Conclusions:

We have found significant associations between nearly all digital measures and a wide range of symptoms and functioning in a community sample of individuals with schizophrenia. These findings provide insights into the digital behaviours of individuals with schizophrenia and highlight the potential of using commercially available wrist wearables and smartphones for passive monitoring in schizophrenia.