Detecting Feigned Pain Using an Eye-Tracker Integrated Numerical Pain Rating Scale (NPRS)

Area of Science:

• Pain assessment
• Medical technology
• Psychology

Background:

• The Numerical Pain Rating Scale (NPRS) is a standard tool for assessing pain severity.
• Feigned pain detection is a significant clinical challenge.
• A novel NPRS integrated with an eye tracker (NPRS_ETI) has been developed.

Purpose of the Study:

• To explore the utility of the NPRS_ETI in detecting feigned pain.
• To evaluate eye movement patterns and pain ratings as potential indicators of pain simulation.

Main Methods:

• Chronic pain outpatients were randomly assigned to either a simulation (exaggerating pain) or a control (genuine pain reporting) group.
• Participants rated their pain severity using the NPRS_ETI.
• Eye movement data and pain ratings were analyzed for discriminative capacity.

Main Results:

• Simulators exhibited different eye movement patterns (more time on high ratings, less on 'No pain' anchor) but with poor discrimination.
• NPRS_ETI pain ratings demonstrated excellent discriminative capacity, with a rating of 10 showing 94.3% specificity and 26.5% sensitivity for feigned pain.
• Eye movement measures were inadequate for detecting feigned pain, but pain ratings showed promise.

Conclusions:

• The NPRS_ETI is feasible for pain assessment, especially for patients with motor or speech impairments.
• While eye movement metrics did not effectively detect feigned pain, pain ratings from the NPRS_ETI show potential as a simple screening tool.
• Further research is recommended to refine feigned pain indicators and understand cognitive processes in pain deception.