Development of a core outcome set for the evaluation of interventions to prevent COVID-19 in care homes (COS-COVID-PCARE Study).

Background: People living in care homes have experienced devastating impact from COVID-19. As interventions to prevent the transmission of COVID-19 are developed and evaluated, there is an urgent need for researchers to agree on the outcomes used when evaluating their effectiveness. Having an agreed set of outcomes that are used in all relevant trials can ensure that study results can be compared.

Objective: The aim of the study was to develop a core outcome set (COS) for trials assessing the effectiveness of pharmacological and non-pharmacological interventions for preventing COVID-19 infection and transmission in care homes.

Methods: The study used established COS methodology. A list of candidate outcomes was identified by reviewing registered trials to evaluate interventions to prevent COVID-19 in care homes. Seventy key stakeholders participated in a Delphi survey, rating the candidate outcomes on a nine-point scale over two rounds, with the opportunity to propose additional outcomes. Stakeholders included care home representatives (n = 19), healthcare professionals (n = 20), people with personal experience of care homes (n = 7), researchers (n = 15) and others (n = 9). Outcomes were eligible for inclusion if they met an a priori threshold. A consensus meeting with stakeholders resulted in agreement of the final outcome set.

Results: Following the Delphi and consensus meeting, twenty-four outcomes were recommended for inclusion. These are grouped across four domains of infection, severity of illness, mortality, and 'other' (intervention specific or life impact). Due to the considerable heterogeneity between care homes, residents, and interventions, the relevance and importance of outcomes may differ between trial contexts. Intervention-specific outcomes would be included only where relevant to a given trial, thus reducing the measurement burden.

Conclusion: Using a rapid response approach, a COS for COVID-19 prevention interventions in care homes has been developed. Future work should focus on identifying instruments for measuring these outcomes, and the interpretation and application of the COS across different trial contexts. Beyond COVID-19, the outcomes identified in this COS may have relevance to other infectious diseases in care homes, and the rapid response approach may be useful as preparation for future pandemics.