Rasch Development and Validation of a New Faces Scale for Measuring Pain, and its Comparison with a Gold Standard: the Balparda–Herrera⟐ain Scale

Abstract

Aim: Faces pain scales are widely used to measure pain. So far, no faces pain scale has ever been constructed by Rasch modeling. Hence the authors aimed to construct a new scale by this method. Methods: Rasch modeling was used to provide an initial calibration and development of the ‘Balparda–Herrera Pain Scale’ (BHPS) and this scale was compared with the existing Faces Pain Scale – Revised. The scale was later refined. Results: Both the existing scale and the initial version of the BHPS required category collapsing. Statistical tests demonstrated an excellent concordance between both scales. The final version of the BHPS was found to behave excellently and to be capable of adequately measuring pain. Conclusion: The BHPS provides an excellent instrument for measuring pain in the adult population.

Lay abstract

Pain is an unpleasant experience for patients, and it is useful for physicians to try to measure how much pain the patient is experiencing. Some scales used by physicians include faces with different expressions to represent various amounts of pain. Rasch modeling is a mathematical approach to develop better scales. In this study, the researchers performed two surveys in order to develop and improve a new scale for measuring pain: the Balparda–Herrera Pain Scale. They used mathematical and statistical approaches to optimize the scale and to compare with another well-known scale. The authors found that the new scale is very useful for measuring pain.

Keywords::

• measurement
• pain
• quality of life

Acknowledgments

The authors are indebted to the subjects who volunteered to participate in this study. They would also like to thank H Bandara for drawing and digitalization of the original seven-category scale. This article is dedicated to the memory of Captain Kepa Balparda Sr.

Financial & competing interests disclosure

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

No writing assistance was utilized in the production of this manuscript.

Ethical conduct of research

The authors state that they have obtained appropriate institutional review board approval or have followed the principles outlined in the Declaration of Helsinki for all human or animal experimental investigations. In addition, for investigations involving human subjects, informed consent has been obtained from the participants involved.