What outcomes should be measured in feline chronic kidney disease treatment trials? Establishing a core outcome set for research.

Chronic Kidney Disease (CKD) is an important cause of feline morbidity and mortality. There is currently no agreement on which outcomes are most important in CKD treatment trials to assist evidence-based decision making. Core Outcome Sets (COSs) originated in human healthcare and are an agreed set of outcomes to be measured and reported as a minimum in any trial conducted relating to a particular disease. To establish a COS for feline CKD, this study used a systematic review and two consensus methodologies (an electronic Delphi (eDelphi), and an in-person consensus meeting), with an international panel of key stakeholders. The systematic review identified 104 unique published parameters, which were rated by panellists in round 1 of the eDelphi. Panellists were also asked to suggest additional parameters. In round 2 these additional parameters were rated and any parameters not understood by >10 % of panellists in round 1 were redefined and re-rated. Parameters reaching consensus in rounds 1 and 2 were removed from round 3, when all remaining parameters were re-rated by panellists who could view their own previous rating alongside the median rating of the whole panel. To reach inclusion in the COS, parameters had to be rated 8 or 9 on a Likert scale of 1-9 (where 1 was not important and 9 was very important) by more than 80 % of panellists. In the consensus meeting, panellists discussed and re-rated borderline parameters and streamlined the final COS. Borderline parameters were those that had been closest to, but not achieved, the 80 % threshold for inclusion. The eDelphi panel (n = 73) rated 24/104 parameters highly enough for inclusion and proposed an additional 20 parameters, of which 3 reached the inclusion threshold. This totalled 27 parameters for inclusion. The consensus meeting panel (n = 16) rated an additional 6/20 borderline parameters highly enough for inclusion. During the streamlining process, 4 parameters were removed as one was considered not an outcome, and three were already addressed by other parameters. The remaining COS totalled 29 parameters. These were grouped into 9 core themes: clinical examination, quality of life, serum biochemistry, complete blood count, urinalysis, total amount of food eaten, CKD progression, survival time and cause of death. This is the first COS for feline medicine. In future treatment efficacy trials the COS will strengthen the evidence-base for this condition, by facilitating easier comparison of results between studies, and reduce research waste.

A systematic review of the quality of life assessment tools for cats in the published literature.

Quality of life (QoL) is an important parameter to assess in cats, as it can be pivotal to important decision-making. Research reports that owners of cats with heart disease would trade longevity for QoL, and treatment associated improvement in QoL is very important for cats with chronic kidney disease. This systematic review aimed to explore the published literature to identify the number and range of QoL assessment tools available to researchers and veterinary professionals, by discovering tools which have already been used in published studies. Medline and CAB Abstracts were searched in March 2018, using terms relevant to cats and QoL or well-being. Inclusion and exclusion criteria were applied and information on uniqueness, validation and a short description of each tool extracted. A total of 1138 manuscripts were identified, of which 96 met all criteria. Forty of 96 manuscripts contained an assessment of QoL, using one of 32 unique tools identified. Sixteen of the tools identified were structured, making detailed patient assessments. Only eight of the structured tools were validated, and of these, three could be applied to healthy cats; the remainder being specific to a disease or being hospitalised. Some validated tools appeared in more than one manuscript. Overall, 12 manuscripts used a validated tool. In the 16 unstructured tools, five tools assessed QoL by assigning a single word (e.g. 'poor'). Eight tools assessed QoL on a single Likert scale (e.g. a number between 1 and 5). This work identifies the tools that are currently available for the assessment of QoL by researchers and veterinary professionals. Additionally, it demonstrates that many are not validated or lack detailed animal assessment, highlighting that further work in this important area is needed.