Collins, J., Short, R., Carter, B., Verduri, A., Myint, P., Quinn, T., Vilches-Moraga, A., Stechman, M., Moug, S., McCarthy, K. & Hewitt, J. 2020, 'The clinical frailty scale: estimating the prevalence of frailty in older patients hospitalised with COVID-19. The COPE study', Geriatrics, 5(3), article no: 58. http://dx.doi.org/10.3390/geriatrics5030058