Background and objective: Whereas pain is frequently measured using a visual analog scale (VAS) that can examine change over short time intervals in the same subject, such ratings are not useful in analyzing differences across subjects. We created a method for normalizing VAS pain reporting to control for the variation between different populations due to the differences in subjective perception or objective evaluation of pain.
Methods: A list of 226 pains was gathered from a convenience sample of persons on the street and patients waiting at medical and orthopedic clinics. These pains were ranked according to severity by health professionals and 19 pains with the most stable rankings were selected. These 19 pains were then rated by a sample of community-dwelling persons and a method of VAS standardization was developed, based on six selected pains.
Results: Individual variations in pain ratings were found to be independent of respondent age and gender, but were correlated with experience of the event or behavior and with self-reported health status. A new scoring method that takes into account these correlations is proposed.
Conclusion: It is possible to standardize VAS pain ratings to compare pain between different populations.