Kastora, S., Kounidas, G., Perrott, S., Carter, B., Hewitt, J. & Myint, P. 2021, 'Clinical frailty scale as a point of care prognostic indicator of mortality in COVID-19: a systematic review and meta-analysis', EClinicalMedicine, 36, article no: 100896. https://doi.org/10.1016/j.eclinm.2021.100896