The CaOa-QoL-TS: Development and Validation of an Owner-Completed Health-Related Quality of Life and Treatment Satisfaction Measure in Canine Osteoarthritis


Gildea E1, Scales-Theobald E2, Thompson J3, Reid J3, Cook AJ4, Forde K5, Lawrie S5, Skingley G5, Williamson N6, Panter C5
1Zoetis, Dollar, CLK, UK, 2University of Surrey, Guildford, UK, 3Zoetis, Leatherhead, Surrey, UK, 4University of Surrey, Guildford, Surrey, UK, 5Adelphi Values Ltd, Bollington, Cheshire, UK, 6Adelphi Values, Bollington, England, UK

OBJECTIVES: Osteoarthritis (OA) causes pain and mobility impairment in dogs and reduces dog and owner quality of life (QoL). No valid instruments assess both canine and owner QoL simultaneously; this study aimed to develop and validate an owner-completed canine OA QoL, owner QoL and treatment satisfaction (CaOA-QoL-TS) instrument.

METHODS: The CaOA-QoL-TS instrument was developed using a conceptual model derived from a meta-synthesis of published literature. Cognitive interviews with owners of dogs with OA (N=10) evaluated the content validity. During a phase 4 field study, owners of OA treated dogs (N=93) completed the CaOA-QoL-TS at six timepoints across 70 days to assess the instrument’s psychometric properties.

RESULTS: Ten items were reworded, four removed, and two added, based on interview findings, resulting in 26 items that all owners understood and considered relevant. Recall period and response options were well understood and appropriate to almost all owners. Inter-item correlations suggested items clustered into distinct domains as hypothesized. Confirmatory factor analysis supported deletion of two items and calculation of three domain scores (dog QoL, owner QoL and treatment satisfaction), with acceptable model fit. The resulting 24-item CaOA-QoL-TS demonstrated strong internal consistency and good to excellent test-retest reliability. Convergent validity was supported by moderate to strong correlations with concurrent measures. Known-groups validity was supported by statistically significant differences between groups categorized by owner global impression of QoL. Statistically significant improvements in owner and dog QoL with larger effect sizes for improved compared to stable subjects, provided evidence of responsiveness. Anchor-based analyses supported 0.9 and 1.0 point within-group responder definitions for dog and owner QoL domains, respectively.

CONCLUSIONS: Findings support the content validity of the CaOA-QoL-TS in canine OA. The 24-item CaOA-QoL-TS instrument is a reliable and valid instrument to measure owner and canine QoL and treatment satisfaction and is sensitive to changes following OA treatment.

Conference/Value in Health Info

2023-11, ISPOR Europe 2023, Copenhagen, Denmark

Value in Health, Volume 26, Issue 11, S2 (December 2023)




Patient-Centered Research

Topic Subcategory

Instrument Development, Validation, & Translation, Stated Preference & Patient Satisfaction


Musculoskeletal Disorders (Arthritis, Bone Disorders, Osteoporosis, Other Musculoskeletal)

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