Study Overview
| Authors | Hinrichs R., van Rooij S.J.H., Michopoulos V., Schultebraucks K., Winters S. et al. |
| Institution | Emory University Atlanta, USA |
| Journal | Chronic Stress (SAGE) |
| Year | 2019 |
| DOI | 10.1177/2470547019844441 |
| PubMed | PMC6553652 |
| Product | eSense Skin Response |
| Participants | 95 trauma patients (emergency department) |
| Follow-up | 12 months |
What was investigated?
Researchers at Emory University investigated whether skin conductance response — measured immediately after a traumatic event in the emergency department — can predict the subsequent development of chronic post-traumatic stress disorder (PTSD). The central question was: Can a simple, mobile physiological measurement method be used directly in the emergency department to identify high-risk patients early? This would be the first prospective study of its kind.
Methods
95 individuals were enrolled on average 4.2 hours after their traumatic event at the emergency department of Grady Memorial Hospital (Atlanta, a Level-1 trauma center). The participants — 44% female, 82% African American — had experienced various trauma types: motor vehicle accidents (43%), stabbings (9%), physical and sexual assaults, and others. Skin conductance response was recorded during a standardized trauma interview. All participants were followed for 12 months, with measurements at 1, 3, 6, and 12 months. The statistical analysis used Latent Growth Mixture Modeling (LGMM), among other methods, to identify individual PTSD trajectories.
Mindfield Product in this Study
Skin conductance measurement was performed with the eSense Skin Response by Mindfield Biosystems on an iPad (iOS 10). The electrodes were attached to the middle phalanges of the middle and index fingers of the non-dominant hand, with a sampling rate of 5 Hz. After a two-minute resting phase for baseline determination, the response was recorded during a 41-item trauma interview (Standard Trauma Interview). The researchers explicitly reference the previously published validation study by Hinrichs et al. 2017 (r = 0.94 compared to lab standard) as the methodological basis.
Results
Using statistical trajectory analysis, the researchers identified three clearly distinguishable PTSD symptom trajectories: individuals with chronically high symptomatology (10.9%), those who recovered (32.9%), and resilient individuals with consistently low symptomatology (56.2%).
Key findings regarding the predictive power of skin conductance response:
- Individuals who later developed chronic PTSD showed significantly higher skin conductance responses in the emergency department than resilient individuals (p < 0.0000001) and recovering individuals (p = 0.005)
- The correlation between skin conductance response and the chronic PTSD trajectory was r = 0.489 (p < 0.000001)
- In the statistical regression analysis, skin conductance response emerged as the strongest single predictor — stronger than trauma type, subjective severity, depression symptoms, or childhood trauma
- The area under the ROC curve (AUC) was 0.90 (95% CI: 0.80–0.99) — a value indicating excellent discriminative ability
Significance
According to the authors, this study is the first prospective investigation demonstrating that skin conductance response measured immediately after a trauma can predict the subsequent course of chronic PTSD. Particularly noteworthy is that the physiological measure was more predictive than established clinical risk factors. The researchers explicitly describe the mobile eSense measurement as a “cost-effective and easy-to-use method” for emergency departments and paramedics in the field.
Important for scientific context: The study used a consumer device (eSense Skin Response) in a highly clinical environment and achieved results comparable to clinically validated measurement protocols. The authors themselves note the relatively small sample size (N = 95) and the need for further replication studies.
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