The Glasgow University Veterinary School Questionnaire (GUVQuest) was developed to measure canine chronic pain through its impact on health-related quality of life. The content validity of the questionnaire (ie, how relevant items in it are for purposes of the study), had been previously established. This study analyzed how well the responses fit the hypothetical construct on which the questionnaire was developed. In this case, the hypothesis was that chronic pain in dogs has an impact on quality of life and that this will be shown by behavioral changes that the owner can observe/report on. One hundred eight dogs with chronic degenerative joint disease and 26 healthy dogs were enrolled, and factor analysis from 221 questionnaires was performed. On approximately 13% of occasions, when compared with clinician-assigned pain scores, questionnaire-based scores did not correctly classify dogs as having chronic pain. The questionnaire could not be used to rule out the presence of chronic pain because of the risk for false-negative results. However, the data from this study did suggest that the questionnaire effectively discriminates between healthy dogs and those with chronic orthopedic pain. It can also alert clinicians to the possible presence of pain that might not otherwise be apparent because of the subtle nature of behavioral changes. The authors believe that with further testing and refinement, the questionnaire can help improve clinical decision making and simplify the development of evidence-based therapeutic options by reliably assessing clinical changes after treatment. Supported in part by Pfizer Animal Health

COMMENTARY: Despite a tremendous improvement in management of animal pain in the past 20 years, we still struggle with some very basic questions: How do we know when animals, especially cats, are in pain, and how does it affect their quality of life? For many years, the authors of this article have worked to develop a validated questionnaire to help answer these questions. As the authors point out, validity is the most fundamental attribute of such an instrument. However, determining validity is an almost impossible task when self-reporting is not possible and answers are from observers, who bring their own biases to the survey. Nonetheless, by using well-known validation techniques, the authors are continuing to refine an instrument that may improve clinical decision making for quality-of-life issues in our patients.

Validation of a structured questionnaire as an instrument to measure chronic pain in dogs on the basis of effects on health-related quality of life. Wisemann-Orr ML, Scott EM, Reid J, Nolan AM. AM J VET RES 67:1826-1836, 2006.