COMPARISON OF 3 METHODS USED FOR ASSESSMENT OF PAIN IN DOGS

Objective-To investigate the reliability of 3 scales used for assessme nt of pain in dogs. Design-Prospective study. Animals-50 dogs that had surgery. Procedure-Dogs were allocated into 3 groups (group 1, 25 dog s assessed 1 hour after the end of surgery; group 2, 41 dogs assessed between 21 and 27 hours after the end of surgery; group 3, 16 dogs ass essed on the day of surgery and on the subsequent day). Each dog was s cored for pain 4 times by 3 (groups 1 and 3) or 4 (group 2) veterinari ans, using all 3 scales (ie, simple descriptive, numerical rating, and visual analogue) during each scoring period. Analysis of data was per formed using ANOVA, loglinear modeling, calculation of reproducibility coefficients, and Cohen's kappa statistic. Results-Significant variab ility existed among observers for use of all 3 scales. Variability amo ng observers and between observers and dogs accounted for 29 to 36% of the total variability (group 1, 36.1 and 32.3% and group 2, 35.1 and 29.7%, for visual analogue scale and numerical rating scale scores, re spectively). Kappa statistic values calculated for data obtained by us e of the simple descriptive scale indicated that agreement was fair fo r the observers (group 1, 0.244 to 0.299; group 2, 0.211 to 0.368; gro up 3, 0.233 to 0.321). Clinical Implications-Analysis of pain score da ta in dogs must incorporate observer variability when more than 1 obse rver is used. Comparative analysis of data accrued from pain studies i n various hospitals must account for this variability.