Development and validation of a chronic diagnosis inventory that enables reliable documentation of canine multimorbidity in the Dog Aging Project.

Objective: To develop and validate a novel chronic diagnosis inventory (CDI) to enable the study of canine multimorbidity. Methods: An initial CDI draft was created by a veterinary internist, a veterinary epidemiologist, and a human health epidemiologist, and 34 nonspecialist veterinarians were chosen by convenience sampling throughout the US to review medical records and apply the CDI during 2 pilot studies conducted in January and February 2021 (pilot 1) and May and June 2021 (pilot 2). We specified the following inclusion criteria for records: (1) contained within an electronic veterinary medical record system, (2) from a general veterinary practice, (3) dogs ≥ 8 years old, (4) documented ≥ 3 veterinary visits, and (5) most recently documented patient visit within 2 months prior to the study. The CDI was assessed through commercially available survey-generating instruments, and correlation analyses were performed. Results: Inter-rater κ statistics in the first pilot were poor, leading to clarifications and minor alterations to the CDI. Inter- and intrarater agreement for the second pilot indicated high diagnostic reliability. Conclusions: The CDI was validated as a tool for documenting multimorbidity in dogs. Clinical Relevance: The CDI will enable veterinarians to accurately and consistently document multimorbidity in diverse settings, which will enable the construction of multimorbidity tools. These tools can be used to predict the development of new morbidities in a multimorbid dog, anticipate the impact of new diagnoses on patient lifespan and quality of life, and plan for associated healthcare costs.