Wearable sensor-based detection of stress and craving in patients during treatment for substance use disorder: A mixed methods pilot study

Abstract

Aims: To determine the accuracy of a wearable sensor to detect and differentiate episodes of self-reported craving and stress in individuals with substance use disorders, and to assess acceptability, barriers, and facilitators to sensor-based monitoring in this population.

Methods: This was an observational mixed methods pilot study. Adults enrolled in an outpatient treatment program for a substance use disorder wore a non-invasive wrist-mounted sensor for four days and self-reported episodes of stress and craving. Continuous physiologic data (accelerometry, skin conductance, skin temperature, and heart rate) were extracted from the sensors and analyzed via various machine learning algorithms. Semi-structured interviews were conducted upon study completion, and thematic analysis was conducted on qualitative data from semi-structured interviews.

Results: Thirty individuals completed the protocol, and 43 % (N = 13) were female. A total of 41 craving and 104 stress events were analyzed. The differentiation accuracies of the top performing models were as follows: stress vs. non-stress states 74.5 % (AUC 0.82), craving vs. no-craving 75.7 % (AUC 0.82), and craving vs. stress 76.8 % (AUC 0.8). Overall participant perception was positive, and acceptability was high. Emergent themes from the exit interviews included a perception of connectedness and increased mindfulness related to wearing the sensor, both of which were reported as helpful to recovery. Barriers to engagement included interference with other daily wear items, and perceived stigma.

Conclusions: Wearable sensors can be used to objectively differentiate episodes of craving and stress, and individuals in recovery from substance use disorder are accepting of continuous monitoring with these devices.

Keywords: Craving; Sensor; Stress; Substance use disorder; Wearable; mHealth.

Figure 1:

Empatica E4 wrist-mounted sensor

Figure 2:

Stress vs. No-Stress Analysis A) Confusion Matrix B) ROC Curve

Figure 3:

Craving vs. No-Craving Analysis A) Confusion Matrix B) ROC Curve

Figure 4:

Craving vs. Stress Analysis A) Confusion Matrix B) ROC Curve

Figure 5:

Craving vs. No-Stress vs. Stress Analysis A) Confusion Matrix B) ROC Curve