Based on a combination of Chinese and Spanish data, the COVID-19 Mortality Risk Calculator ("MRC") Version 7.0 has been designed to estimate mortality risk for an individual who is symptomatic and has been confirmed via testing to be infected with the virus. The MRC calculates mortality risk at the time of confirmation, as well as at the time of hospitalization. This calculator is designed to be used by a qualified healthcare professional and is not appropriate for any other use. The MRC is intended for general guidance and information purposes only. The MRC is not intended to be used or interpreted as medical advice, or as a recommendation for specific medical treatment. Any medical decision should be based on as many sources of information as possible, of which this may be one of them.
The development team consisted of Blair Manktelow, FCIA, FCAS (a Canadian actuary) and two consulting physicians, Dr. Scott Manktelow, MSc, MD, CCFP, a family physician in British Columbia and Ralph Manktelow, MD, FRCS(C) a retired University of Toronto academic surgeon. The MRC was prepared by Blair in his personal capacity and the physicians provided important feedback and recommended changes and improvements from their own medical perspective as well as from colleagues who used early versions of the calculator. The design, development, distribution and intended use of the MRC is solely Blair's responsibility but the MRC was peer reviewed by another Canadian actuary, an expert on mortality risk. It has been used by some Canadian healthcare professionals and was also recently posted on the COVID-19 Hub of the Canadian Institute of Actuaries website.
The original purpose of the MRC was to help colleagues of Dr. Scott Manktelow to self-identify their risk of working in the COVID-19 ward at the local hospital and minimize the number of deaths in the medical profession. Given the public welfare intention of the MRC, Blair does not expect to be liable for any losses or damages arising from its distribution or use. The MRC is designed to estimate mortality risk but does not determine whether a given individual will live or die. People with low indicated mortality risk will still occasionally die, and people with high indicated mortality risk may still survive the virus.
The MRC includes most of the important variables that we understand affect COVID-19 mortality risk. These variables are age, gender, smoking, and a number of comorbidities. Version 7.0 is based on publicly available data from three studies in China as well as publicly available data from the Spanish Ministry of Health (Ministerio de Sanidad, Consumo y Bienestar Social). A multi-dimensional minimum bias model was run on the aggregate data to estimate the impact of each factor on the expected mortality. For this purpose, based on a review of the relative mortality by the number of comorbidities in the Guan W et al paper on comorbidities, it was assumed that the combination of morbidities would result in an additive increase in risk, rather than a multiplicative increase. It may over-predict mortality risk in individuals with three or more comorbidities - this will be assessed as further data becomes available. Conclusions from Chinese or Spanish data may not be 100% transferable to other countries. The data was reviewed for reasonableness relative to other publicly available data, but no attempt has been made to independently verify the data. Due to the urgent need to have a useful model, the MRC has not been validated by Canadian data. Countries with different healthcare burden and/or different testing levels and/or different criteria for comorbidities and/or different medical care may have different mortality rates. An adjustment may need to be applied in order to reflect these differences.