Psychometric Validation of a General Health Quality of Life Tool for Cats Used to Compare Healthy Cats and Cats with Chronic Kidney Disease

Abstract

Background: Numerous validated psychometric tools are available to assess impact of disease on a human's quality of life (QoL). To date, no psychometrically validated general health-related QoL tool exists for cats. Hypothesis/Objectives: To develop and validate a tool for assessment of owner-perceived QoL in cats (CatQoL) and to use this tool to compare QoL between healthy cats and those with chronic kidney disease (CKD). Animals/Subjects: Total of 204 owners of young healthy cats (YH, n = 99; <9 years), older healthy cats (OH, n = 35), and cats diagnosed with CKD (CKD, n = 70) completed the CatQoL. Methods: Discussions with a focus group and 2 pilot surveys informed design of 16 QoL questions grouped into 4 domains. Each item scored according to frequency and importance, and item-weighted-impact-scores were calculated. The validity of the tool was assessed using principal components analysis and Cronbach's α. The average item-weighted-impact-score (AWIS) was compared among groups and domains. Results: Sixteen-item CatQoL showed good internal consistency reliability (Cronbach's α, 0.77) and unidimensionality with significant loadings (0.2-0.7) and communalities (>0.3). Young healthy cats had significantly higher AWIS (median [IQR], 1.25 [0.63, 1.88]) than OH (0.56 [-0.06, 1.00]) and CKD cats (-0.06 [-0.81, 0.88]), P <001). CKD cats had significantly lower AWIS for eating domain (YH: 2.00 [1.00, 3.00]; OH: 2.00 [0.67, 3.00]; CKD : 1.00 [0.00, 2.67]) when compared with the YH group and OH group, and all groups differed significantly in their management domain (YH: -0.50 [-1.00, 0.00]; OH: -1.00 [-1.88, -0.50]; CKD : -1.50 [-2.50, -1.00], P <001). Conclusions and Clinical Importance: The CatQoL was validated for use in cats, and can be used as additional assessment parameter in clinical and research settings.