The Impact of Familiarization on Pressure and Heat Pain Scores

Introduction: Quantitative sensory testing (QST) provides an effective means to better understand the pain process; however, inherent variability exists depending on how QST methods are implemented. The current study sought to investigate the impact of pain testing familiarization on pain pressure testing (PPT) and heat pain testing during QST in young, healthy participants. Methods: 25 participants (13(m)/12(f); 22.5 ± 2.5 yrs) underwent 4 separate testing sessions of pressure pain threshold (PPT) and pressure pain supra-threshold (PPTs) and heat pain threshold (HT) and 50/100 Visual Analogue Scale (H50), which included pain familiarization. Results: No significant effects were seen across session for PPT (F(3,184) = 1.205, p = 0.309) or PPTs (F(3,184) = 0.227, p = 0.8774) and trial type for PPT (F(1,184) = 0.12, p = 0.722) or PPTs (F(1,184) = 0.743, p = 0.390). A significant main effect for the independent variable of trial was found for the dependent variable of H50 (F(1,184) = 109.42, p = < 0.000) with the experimental trial values lower than familiarization values. This was not seen within the HT (F(1,184) = 3.374, p = 0.068) values. Conclusions: When testing for moderate levels of heat pain, familiarization should be considered. Additional research is still needed to support or deny the need for familiarization to be included in pain testing research to increase the accuracy of future research studies.