Background: Test-retest reliability is important to establish for any diagnostic tool. The reliability of quantitative sensory testing (QST) in the trigeminal region has recently been described in Caucasians as well as differences in absolute thresholds and responses between Caucasians and Chinese. However, the test-retest reliability has not been determined in a Chinese population.
Objective: To provide novel information on the test-retest reliability of thermal QST in the trigeminal and spinal system in healthy Chinese.
Methods: Twenty healthy volunteers (10 women and 10 men) participated. Cold detection threshold (CDT), warm detection threshold (WDT), cold pain threshold (CPT), and heat pain threshold (HPT) were measured at two sites: the surface of the left hand and the left masseter. The testing was performed over three consecutive stimuli trials, three sessions conducted on one day and repeated one week later. Data were analyzed with intra-tester reliability test and four-way analysis of variance (ANOVA) for repeated measures.
Results: There was a tendency for the first trial in CDT (p = 0.005), CPT (p = 0.02), and HPT (p < 0.001) to reflect higher sensitivity than the subsequent two trials. Most variables showed acceptable to excellent reliability and non-significant difference across different trials (ICC: 0.912-0.989), sessions (ICC: 0.791-0.977), and days (ICC: 0.415-0.837). Between-site differences were significant for CDT (p = 0.003) and HPT (p = 0.045) with higher sensitivity at the masseter muscle. There were significant gender differences with higher sensitivity in women for CPT (p = 0.001) and HPT (p = 0.001).
Conclusion: Test site and gender affect thermal thresholds substantially. The test-retest reliability of most thermal threshold measures were acceptable for assessing somatosensory function, however, innocuous thresholds appear to be associated with larger variability than noxious thresholds in a Chinese population.
Keywords: Orofacial pain; quantitative sensory testing; reliability.