Reliability and validity of a continuous pain registration procedure
Version of Record online: 5 OCT 2012
© 2012 European Federation of International Association for the Study of Pain Chapters
European Journal of Pain
Volume 17, Issue 3, pages 394–401, March 2013
How to Cite
van Wijk, A.J., Lobbezoo, F. and Hoogstraten, J. (2013), Reliability and validity of a continuous pain registration procedure. European Journal of Pain, 17: 394–401. doi: 10.1002/j.1532-2149.2012.00194.x
No external funding was received for this work.
Conflicts of interest
There are no financial or other relationships concerning this manuscript that might lead to a conflict of interest.
- Issue online: 6 FEB 2013
- Version of Record online: 5 OCT 2012
- Manuscript Accepted: 9 JUN 2012
Conventional pain rating scales [i.e. visual analogue scales (VAS) or numerical rating scales (NRS)] only provide a summary for different levels of pain felt, while the duration of these levels is not accounted for. If pain can be rated continuously, the area under the curve (AUC) of varying pain intensity over time can be calculated, which integrates varying pain intensity with duration. The present study examined the reproducibility and validity of a continuous pain rating procedure.
Twenty-eight healthy volunteers participated. Pain was induced using constant current delivered to the non-dominant forearm using bipolar electrodes. Pain was rated continuously on an electronic VAS monitored by a computer. For each participant, the level of current needed to achieve a weak, mild, slightly moderate and moderate level of pain was determined (part I). Next, participants were asked to rate the painfulness of six periods of electrical stimulation (part II). Unknown to the participants, they were presented with the four levels of current obtained in part I, where the level of current for mild and moderate pain was presented twice (in order to assess consistency). The order of presentation was randomized for all subjects.
In general, participants produced reliable mean AUCs. In addition, the AUC of pain intensity over time could clearly discriminate between the four levels of pain used in the present study.
A continuous pain registration procedure, using an AUC approach, may be a promising direction to explore. Results can be improved by allowing more training on the use of the electronic VAS.