Article Text
Abstract
Background and Objectives Large-scale application of Quantitative Sensory Tests (QST) is impaired by lacking standardized testing protocols. One unclear methodological aspect is the number of records needed to minimize measurement error. Traditionally, measurements are repeated 3 to 5 times, and their mean value is considered. When transferring QST to a clinical setting, reducing the number of records would be desirable to meet the time constraints encountered in a routine clinical environment and to reduce the testing burden to chronic pain patients. However, there might be a trade-off between measurement error and number of records. We determined the measurement error of a single versus the mean of 3 records of pressure pain detection threshold (PPDT), electrical pain detection threshold (EPDT), and nociceptive withdrawal reflex threshold (NWRT) in 429 chronic pain patients recruited in a routine clinical setting.
Methods We calculated intraclass correlation coefficients and performed a Bland-Altman analysis.
Results Intraclass correlation coefficients were all clearly greater than 0.75, and Bland-Altman analysis showed minute systematic errors with small point estimates and narrow 95% confidence intervals. Reducing the number of records from traditionally 3 to only 1 did not lead to relevant measurement error in PPDT, EPDT, or NWRT.
Conclusions This study contributes to a standardized QST protocol, and based on the minimal measurement error of 1 single record of PPDT, EPDT, and NWRT, we submit to reduce the testing burden. This would allow saving time, resources, and patient discomfort.
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Footnotes
M.M. and J.A.B.M. contributed equally to this work.
Author contributions: M.M., J.A.B.M., and M.C. conceived the study. M.M. and K.S. were responsible for data collection. M.M., J.A.B.M., and A.L. did the data analysis. M.M. and M.C. wrote the first draft of the paper, and all authors contributed to the final draft.
The study was funded by the Scientific Funds of the Department of Anaesthesiology and Pain Medicine, Inselspital, Bern University Hospital.
The results of this study were not presented at any conference; nor was the manuscript under consideration by any other journal.
The authors declare no conflict of interest.
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