Classification of Qualitative Fieldnotes Collected During Quantitative Sensory Testing: A Step Towards the Development of a New Mixed Methods Approach in Pain Research

Abstract

Purpose Quantitative sensory testing (QST) is a standardized method to assess somatosensory function. The collection of qualitative information, during the QST procedure, could be an interesting way to facilitate the characterization of altered sensory perception and the identification of different pain phenotypes. The aims of this study were 1) to classify qualitative fieldnotes of sensory abnormalities collected during an independent QST study, and 2) to generate a qualitative interview guide that could be included in the traditional QST procedure as a step towards the implementation of a mixed methods approach. Patients and Methods QST data were collected from 48 chronic neuropathic pain patients treated with spinal cord stimulation (SCS). Three body areas, with or without SCS, were tested: the painful limb targeted by SCS, the contralateral area, and the ipsilateral upper limb. After each trial of each QST modality, patients were encouraged to report any sensory abnormalities they could identify with a pain quality scale or using their own words. Results Qualitative self-reported sensory abnormalities were dichotomized into two groups: altered sensory intensities and altered sensory perceptions. Altered sensory intensities were classified as sensory loss or sensory gain subgroups. Altered sensory perceptions were classified as paresthesia and dysesthesia subgroups Overall, 630 qualitative fieldnotes of altered sensations were collected: 385 on the painful limb, 173 at the contralateral area, and 72 at the ipsilateral upper limb. Based on these qualitative data, we propose a standardized method to collect qualitative data involving 9 open- and close-ended questions and 21 codes. Conclusion Our findings have highlighted the value of qualitative sensory evaluation during QST and constitute an important milestone in the development of a mixed methods protocol in phenotyping research.

Sensitization of supra-threshold pain responses—Translational aspects and mechanisms

“…Taken together, this perspective supports the idea of using differential behavioral read-outs to assess several clinically relevant aspects of pain, i. e. spontaneous pain, lowered pain thresholds and increased supra-threshold encoding. Thus, we not only confirm that even negative results of reflexive tests may be complementing the holistic clinical picture with valuable insights into contributing nociceptive signaling mechanisms (Bordeleau et al, 2021;Vollert et al, 2021), but also accentuate that the assessment of ongoing nociceptive activity and supra-threshold pain responses are emerging as substantial tools to study translational aspects and mechanisms of pain (Mogil and Crager, 2004;Mogil, 2012;Schmelz, 2020Schmelz, , 2022.…”

Beyond numbers: integrating qualitative analysis into quantitative sensory testing for neuropathic pain

“…Moreover, the method does not address the quality of ongoing pain, and there is a potential oversight of pain attacks unless they are provoked by one of the QST stimuli. It has been proposed that during the QST procedure, the exploration of participants' descriptions or interpretations of sensory perception could potentially improve the identification of sensory abnormalities ( 11 , 12 ).…”

“…Our team recently proposed a standardized mixed-methods approach that combines participant experiences with quantitative measurements to create a comprehensive sensory assessment ( 12 ). We designated this innovative approach as qualitative and quantitative sensory testing (QQST).…”

“… This scenario is based on a real-life event witnessed by our team during a previous QST assessment, in which the subject initially described a normal brush sensation on his skin in an unaffected area. However, in the painful area, the subject reported a very different sensation of water flowing on his skin ( 12 ). This situation illustrates how traditional QST methods can miss critical information that could indicate the presence of unusual sensations that could signal sensory abnormalities.…”

“…Previously, our team categorized 630 qualitative observations of sensory abnormalities collected during a QST study with participants experiencing complex regional pain syndrome or failed back surgery syndrome ( 12 ). It is essential to expand this work to include other populations, as the significance of this work lies in its potential to offer enhanced guidance for assessors in classifying sensory abnormalities.…”