A tactile pain evaluation scale for visually deficient persons.

OBJECTIVE: Pain evaluation scales often rely on the sense of sight. There is so far no pain assessment scale specifically designed for persons with visual impairment.

DESIGN: This study aims to validate a tactile pain evaluation scale, Visiodol©, in blind/visually impaired persons, by correlation with a numeric pain scale (NPS).

SETTING: The study took place in University Hospital Clermont-Fd, France.

METHODS: Pain intensity for a range of thermal stimuli (Pathway Medoc®) was evaluated with Visiodol© and NPS; secondary outcomes including pain thresholds, catastrophizing, emotion and quality of life were compared in blind/visually impaired and sighted persons. Lin's concordance correlation coefficient was estimated; weighted Cohen κ accounted for degrees of disagreement between scales with 95% confidence interval (95%CI).

SUBJECTS: 21 healthy sighted and 21 healthy non-sighted volunteers (n = 13 congenital, n = 8 acquired) were included.

RESULTS: Lin's correlation coefficient for repeated data was 0.967 (95%CI, 0.956; 0.978; P < 0.001) for visually impaired participants with a good agreement at each temperature plateau. Weighted Cohen κ of 0.90 (95% CI, 0.84-0.92) and 92.9% percentage of agreement for visually impaired participants was satisfactory. Pain perception, psychological components and quality of life were more impaired in blind/visually impaired persons than in sighted persons.

CONCLUSIONS: This study validates Visiodol©, a tactile scale for blind/visually impaired persons and addresses healthcare inequalities in the context of pain evaluation. It will now be tested on a larger population of patients in order to give the millions of blind/visually impaired persons worldwide, an option for pain intensity evaluation in clinical situations.