Development and initial validation of the Cat HEalth and Wellbeing (CHEW) Questionnaire: a generic health-related quality of life instrument for cats

Objectives: The aims of the study were to define factors that owners consider relevant to the health-related quality of life (HRQoL) of cats, to develop an instrument based on this information, and to evaluate the validity and reliability of the final instrument (the Cat HEalth and Wellbeing [CHEW] Questionnaire). Methods: Psychometric research techniques and guidance from the US Food and Drug Administration on outcome measures were used to develop a valid and reliable instrument. Fifty-four cat owners and caregivers participated in the qualitative research, while 1303 cat owners were included in the quantitative validation phase (development dataset, n = 648; validation dataset, n = 655). A random subset of cat owners (n = 391) also participated in test-retest evaluation. Qualitative research was used to generate a draft instrument, which was then subjected to quantitative validation techniques. These included item reduction, domain identification, data quality assessment, and exploratory and confirmatory analysis to develop a final instrument, which underwent confirmatory reliability and validity assessment. Results: A draft instrument with 11 domains and 100 items based on qualitative research underwent online quantitative validation testing which refined the instrument to eight domains and 33 items. Confirmatory reliability and validity assessment showed that the final instrument had good validity, was able to discriminate between cats by age and overall health status, and demonstrated good internal and test-retest reliability. Conclusions and relevance: The CHEW Questionnaire was developed and validated. Additional research is needed to verify its ability to differentiate cats with and without disease, and to assess its potential as a screening tool.