Test-retest reliability of an adaptive thermal pain calibration procedure in healthy volunteers

Abstract

Quantitative sensory testing (QST) allows researchers to evaluate associations between noxious stimuli and acute pain in clinical populations and healthy participants. Despite its widespread use, our understanding of QST’s reliability is limited, as reliability studies have used small samples and restricted time windows. We examined the reliability of pain ratings in response to noxious thermal stimulation in 171 healthy volunteers (n = 99 female, n = 72 male) who completed QST on multiple visits ranging from 1 day to 952 days between visits. On each visit, participants underwent an adaptive pain calibration in which they experienced 24 heat trials and rated pain intensity after stimulus offset on a 0-10 Visual Analog Scale. We used linear regression to determine pain threshold, pain tolerance, and the correlation between temperature and pain for each session and examined the reliability of these measures. Threshold and tolerance were moderately reliable (Intra-class correlation [ICC]=0.66 and 0.67, respectively; p<.001), whereas temperature-pain correlations had low reliability (ICC=0.23). In addition, pain tolerance was significantly more reliable in female participants than male participants, and we observed similar trends for other pain sensitive measures. Our findings indicate that threshold and tolerance are largely consistent across visits, whereas sensitivity to changes in temperature vary over time and may be influenced by contextual factors.

Why the estrous cycle matters for neuroscience

“…This led to a trend that some researchers called "liberation of female animals" [22], implying that because females are similar to males in terms of variability, the estrous cycle can be dismissed, and that therefore females "deserve to be studied". And, this perceived need to justify the inclusion of females by rejecting female complexity, rather than by acknowledging a simple need for inclusivity, is still promoted to this day [23][24][25][26].…”

Instructions and experiential learning have similar impacts on pain and pain-related brain responses but produce dissociations in value-based reversal learning

“…Prior to the fMRI experiment, all participants underwent an adaptive pain calibration procedure ( Atlas et al, 2010 ; Mischkowski et al, 2019 ; Dildine et al, 2020 ; Amir et al, 2021 ) to identify each participant’s pain threshold, tolerance, and the reliability of the temperature-pain association (i.e. r 2 ; see Materials and methods).…”

“…Participants underwent an adaptive staircase pain calibration prior to the experimental task (see Figure 1A ). The adaptive staircase calibration procedure has been described in depth in previous work ( Atlas et al, 2010 ; Atlas et al, 2012 ; Mischkowski et al, 2019 ; Dildine et al, 2020 ; Amir et al, 2021 ). Participants experience temperatures across eight skin sites on the left volar forearm and provide ratings on a 10-point scale, where 1 denotes warmth, 2 denotes pain threshold, 5 denotes moderate pain, 8 denotes maximum tolerable pain, and 10 denotes the most pain imaginable.…”

How to make calibration less painful – a proposition of an automatic, reliable and time-efficient procedure

“…A high R 2 value indicates that the data are linear and that they fit the regression model for predicting the stimulation currents I corresponding to their NRS . A recent study on thermal stimulation (Amir et al, 2022) established that a successful calibration procedure, R 2 should be at least 0.4. The second criterium is related to the convergence of the parameters.…”

“…To be sure that calibration leads to adequate stimuli evaluation, a random strength stimulation verification of reliability should be performed a posteriori . Additionally, this could be used to check if the calibration results are consistent over time, as was done before for thermal stimulation (Amir et al, 2022). Reliability tests are important for future experimental studies on WASP electrodes and studies where pain biomarkers or signatures are evaluated (Davis et al, 2020; Pleil et al, 2018).…”