Similar to experiment 1, paired t-test results showed that HPT without sensory interference was significantly lower when patients were feigning pain (average, 95% CI=39.17°C, 39.7–40.56°C) compared with sincere pain (44.10°C, CI = 42.60–45.61°C; P<.0001), suggesting the findings were reproducible in an independent cohort with stimulation at a different site.
The researchers found that when participants were feigning pain, their WST increased and their HTP decreased. They also found that when participants feigned pain, sensory interference resulted in poor variability across trials and are distinguishable from sincere reports with high sensitivity (83%) and specificity (84%).
Existing research on pain malingering has primarily focused on the analyses of questionnaires, clinical examinations, facial expressions, and testing of physical performance such as range of joint motion.
“These studies have convincingly demonstrated some efficacy for detecting pain malingering,” wrote Dr. Kucyi. “However, no approaches provide foolproof detection on an individual participant basis.”
The high levels of specificity and sensitivity obtained in this study suggest that further investigations of this approach are worthwhile and could lead to practical clinical applications. This experimental set-up of measuring pain threshold twice with and without interference is easy to implement and can also be performed with devices other than computerized thermal stimulators to reduce costs.
“Given the novelty of our approach, future studies using our paradigm in nonclinical settings could be useful in determining how the test could be best implemented with minimized chances of false-positive results,” the researchers wrote.
Studies comparing or combining this test with other methods of detecting pain malingering may yield a more comprehensive approach, they concluded.