Canine Orthopedic Index. Step 2: Psychometric Testing

• Published in: Veterinary surgery 2014-03, Vol.43 (3), p.241-246
• Main Author: Brown, Dorothy Cimino
• Format: Article
• Language: English
• Subjects: Animals; Data Collection; Dog Diseases - diagnosis; Dog Diseases - pathology; Dog Diseases - therapy; Dogs; experimental design; Forelimb - pathology; gait; Hindlimb - pathology; Humans; Orthopedic Procedures - standards; Orthopedic Procedures - veterinary; Orthopedics; Osteoarthritis - diagnosis; Osteoarthritis - veterinary; Patient Outcome Assessment; Psychometrics - methods; quality of life; Quantitative psychology; questionnaires; readability; Surveys and Questionnaires; Veterinary medicine
• ISSN: 0161-3499; 1532-950X
• DOI: 10.1111/j.1532-950X.2014.12141.x

OBJECTIVE: To perform psychometric testing an owner self‐administered questionnaire, the Canine Orthopedic Index (COI), designed to assess outcome in dogs with orthopedic disease. STUDY DESIGN: Original study. SAMPLE POPULATION: Owners (n = 20) of dogs with osteoarthritis (OA) for item (question) pretesting, and 80 owners of dogs with OA for reliability and validity testing. METHODS: Standard methodology for the stepwise development and testing of instruments designed to assess subjective states was followed. Items generated in previous studies were pretested for readability, ambiguity, and inter‐item correlations; poorly performing items were removed; and the reduced set of items subjected to factor analysis, reliability, and validity testing. RESULTS: Four factors were identified and named on the basis of the items contained in them: “Stiffness,” “Gait,” “Function,” and “Quality of Life.” Cronbach's α ranged from 0.76 to 0.86, suggesting the items in each factor could be assessed as a group to compute factor scores (i.e., stiffness, gait, function, and quality of life scores). The test–retest analysis revealed κ values from 0.68 to 0.80. Overall, the scores amongst the 4 factors correlated moderately well (r = 0.52–0.58), with a mild correlation (r = 0.35) between gait and function scores. CONCLUSIONS: The COI is a psychometrically sound owner completed instrument that can assess 4 domains in dogs with OA: Stiffness, Gait, Function, and Quality of Life.