key: cord-0798958-vew4uxu4
authors: Mohanty, S. K.; Dubey, M.; Mishra, U. S.; Sahoo, U.
title: Impact of COVID-19 Attributable Deaths on Longevity, Premature Mortality and DALY: Estimates of USA, Italy, Sweden and Germany
date: 2020-07-07
journal: nan
DOI: 10.1101/2020.07.06.20147009
sha: 8e0f64ee736416735af7b0151c6a22ea2976f962
doc_id: 798958
cord_uid: vew4uxu4

In a short span of four months, the COVID-19 pandemic has added over 0.4 million deaths worldwide, which are untimely, premature and unwarranted. The USA, Italy, Germany and Sweden are four worst affected countries, accounting to over 40% of COVID-19 attributable deaths on longevity, years of potential life lost (YPLL) and disability adjusted life years (DALY) in USA, Italy, Germay and Sweden. Data from United Nation Population Projection, Statista and Centre for disease control and prevention were used in the analyses. Life expectancy, YPLL and DALY were estimated under four scenarios; no COVID-19 deaths, actual number of COVID-19 deaths as of 22nd May, 2020 and anticipating COVID-19 death share of 6% and 10% , respectively. The COVID-19 attributable deaths have lowered the life expectancy by 0.4 year each in USA and Sweden, o.5 year in Italy and 0.1 year in Germany. The loss of YPLL was 1.5, 0.5, 0.1 and 0.5 million in USA, Italy, Germany and Sweden. Comapression in life expectancy and increase in YPLL and DALY may intensify further if death continues to soar. COVID-19 has a marked impact on mortality. Reduction in longevity, premature mortality and loss of DALY is higher among elderly. Key Words: COVID-19, Mortality, life expectancy, Italy, USA, Germany, Sweden

COVID-19 attributable deaths are soaring each day in most of the countries with uncertainties over projected numbers, infection fatality ratio, development of a vaccine and possible end of pandemic. Globally, with over 6 million confirmed infections and additional deaths of over 360 thousand by end of May,2020, the COVID-19 attributable deaths accounts for 1% of total all-cause mortality. If the COVID-19 mortality continues with same pace, the life expectancy would begin to shrink by end of the year though the survival threat is more among the elderly and the chronically ill. Rapid spread of the infection as well as its associated fatality may well be due to novel disease, lack of medical know how, ill-prepared health care system, crowding in urban cities, administrative inefficacy, demographic and social determinants etc.

The case fatality ratio (CFR) is a crude measure of mortality, underestimate the mortality impact of COVID-19. An alternative CFR with 14 days' delay depicts at least twice higher mortality than CFR [1] . The mortality impact of COVID-19 is higher than many other disease [2] . The standardized metrics such as disability adjusted life years (DALY) and years lost due to disability (YLD) are suggested to infer infection fatality by age [3] .

Considerable attempts are made on tracing future trajectories, estimation of infection and fatality rate and risk factors of COVID-19 [4] [5] [6] [7] [8] [9] [10] [11] [12] . Demographic structure, co-morbidities and health-care burden explain COVID-19 attributable mortality to some extent [13] [14] [15] . Most common observation made as regard COVID-19 fatality is its greater risk among elderly and people with comorbidities including hypertension, diabetes, cardiovascular disease, myocardial injury [4, [16] [17] [18] [19] [20] [21] [22] . The Diamond Princes cruise ship study of Japan, a standard estimate of infection, estimated the overall case fatality ratio of 2.6% as against the same being 13% among the older aged 70 and above [23] .

. CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted July 7, 2020. . https://doi.org/10.1101/2020.07.06.20147009 doi: medRxiv preprint Inadequate testing and misclassification of deaths by cause underestimate the extent of COVID-19 deaths. In USA, the excess deaths due to pneumonia and influenza raise an apprehension as regard miss-classification of COVID-19 deaths in the absence of adequate testing [24] . In Italy, 54% deaths were attributed to COVID-19 making a case for misclassification of cause of death. The COVID-19 attributable mortality has potential to reduce life expectancy in India and seasonal life expectancy in Italy [25] [26] . In United States, 1 million deaths from COVID-19 would increase mortality by one-third and reduction in period life expectancy by 3.9 years in 2020 [27] .

Mortality impact of COVID-19 is higher in urban counties and the social determinants are significant predictors of its mortality [28] . High and low fatality due to COVID-19 attributed to density and age structure in terms of elderly in UK [29] . Demographic vulnerability of COVID-19 mortality is lower in younger countries in Sub-Saharan Africa than the industrialized countries [30] . The spread of infection and mortality depends on containment measures, health system response and micro-management of epidemic which may alter reproduction number [31] .

By April 2020, the case fatality rate varied from 2.2% in South Korea to 13.0% in Italy. USA, Italy, Sweden and Germany were worst hit countries by the pandemic. By end of May 2020, USA had over 1.8 million confirmed cases and over 106 thousand deaths. About 80% of deaths occurred among adults aged 65 years or more [16] . In Italy, the CFR increased from 4.2% to 13.0% within 43 days and 90% of the change was due to increasing age specific case fatality rates [32] . In Italy, USA and Germany, estimated cases of infections are 6 times, 2 times and 1.2 times higher than the number of confirmed cases, respectively [33] .

. CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review)

The copyright holder for this preprint this version posted July 7, 2020. Existing studies of the pandemic on fatality is limited. Given its rise in intensity it becomes pertinent to gauge impact of COVID-19 attributable mortality on longevity, premature mortality and DALY. This will answer questions like "Would additional deaths due to COVID-19 reduce longevity and increase premature mortality and DALY".

We have analysed four worst affected countries; namely USA, Italy, Sweden and Germany that The total deaths obtained from UN projection are estimated deaths in the absence of COVID-19 infection. The age specific COVID-19 attributable deaths for USA is collected from Centres for Disease Control and Prevention [35] and that for Italy, Germany and Sweden is taken from Statista [36 -38] . The total number of confirmed cases and deaths for each country is collected from worldmeter website [39] . We have redistributed the total deaths available from worldmeter as per age distribution of deaths for which age data was available. Under the assumption that the estimated deaths without COVID-19 and deaths due to COVID-19 are mutually exclusive, we have added these deaths to derive age specific death rate (number of deaths per 1000 population). The age specific case fatality ratio (ASCFR) was computed for Italy and Sweden from given data. In case of Germany, the age group of number of infections were not uniform and deaths were available for 0-9, 10-19, 20-49, 50-69 and 70-89. We have redistributed the deaths as per population distribution in 10-year age group. In case of USA, . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review)

The copyright holder for this preprint this version posted July 7, 2020. . https://doi.org/10.1101/2020.07.06.20147009 doi: medRxiv preprint we have used the ASCFR of Diamond Cruise Study that had constant rate (0.2) till age 35 beyond which we have taken the age group close to nearest age group [23] . Scenario 2 considers COVID-19 deaths accounting for 6% of total deaths while scenario 3 would increase the death share to 10% of total deaths by the end of the year. Expected deaths due to COVID-19 are distributed in accordance with the age distribution of COVID-19 as of date. A brief description of YPLL and DALY estimation is given below.

The YPLL is a summary measure of premature mortality that estimates the average years a person would have lived had he or she not died prematurely. It gives higher weight to the deaths occurring at younger ages and lower weight to the deaths at higher ages [40] [41] . YPLL is estimated as:

where, . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted July 7, 2020. . https://doi.org/10.1101/2020.07.06.20147009 doi: medRxiv preprint L i is the life expectancy at age i and d i is the number of deaths at age i. The deaths are weighted by life expectancy at each age.

DALY measures the health of a population by combining data on mortality and non-fatal health outcomes into a single number. The DALY measures health gaps as opposed to health expectancies. It measures the difference between a current situation and an ideal situation where everyone lives up to the age of the standard life expectancy, and in perfect health. It combines in one measure the time lived with disability and the time lost due to premature mortality:

where, YLL= years of life lost due to premature mortality and YLD= years lived with disability.

We have calculated YLL and YLD with discounting rate of 3% where discounting health with time reflects the social preference of a healthy year now, rather than in the future. The value of a year of life is generally decreased annually by a fixed percentage. For many years, a discount rate of 5% per annum has been standard in many economic analyses of health and in other social policy analyses, but recently environmentalists and renewable energy analysts have argued for lower discount rates for social decisions. The World Bank Disease Control Priorities study and the GBD project both used a 3% discount rate, and the US Panel on Cost-Effectiveness in Health and Medicine recently recommended that economic analyses of health also use a 3% real discount rate to adjust both costs and health outcomes [42] .

The YLL is estimated as:

where, N= number of deaths . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted July 7, 2020. is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted July 7, 2020. . https://doi.org/10.1101/2020.07.06.20147009 doi: medRxiv preprint Germany. At 10% share, the reduction in life expectancy would be 1.2 years for USA, 1 years for both Italy and Germany and 0.9 years for Sweden (Appendix 1).

Appendix 2(a) presents life table probability of death with and without COVID-19 in Italy, Germany and Sweden and Appendix 2(b) presents the same for USA (due to dissimilarity in age group). The probability of death without COVID-19 was lowest in Sweden followed by Italy and Germany. The COVID-19 attributable deaths have disproportionately increased the probability of death in 70+ age group in all these four countries. The pattern is also similar for USA.

Estimates from life table with and without COVID-19 for these four countries exhibit the changing age-specific survival patterns ( Table 2 The additional deaths due to COVID-19 results in a rise in CDR from 10.5 to 11 in Italy and this would rise to 11.6 with the COVID-19 death share rising to10%. In case of USA, it has also increased from 8.6 to 9.0 and the pattern is similar in Germany and Sweden as well.

Age specific assessment of Years of potential life lost (YPLL) under varying scenario of COVID-19 death share is presented in Table 3 is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted July 7, 2020. . https://doi.org/10.1101/2020.07.06.20147009 doi: medRxiv preprint Italy, Germany and Sweden. Higher age-groups (45 years and above) are contributing more than 70% of YPLL in all the countries.

The estimated DALY at current share of attributable COVID-19 deaths is 1.17 million in USA, Among all the four countries, the population 70 years and above account more than threefourth contribution in DALY while younger ages have relatively low contribution in all the scenarios.

The COVID-19 pandemic is one of the worst ever misery posed to mankind. While epidemics in the past have gripped limited geographical boundaries, the COVID-19 has engulfed the entire world within a brief period of four months with a reasonable degree of spread potential.

Apart from threat to human life, its containment measures have led to economic loss and generated psychological scare among individuals, households, community and the nation at large. The COVID-19 pandemic has paralysed the economic activities, deepened the global recession and has assumed a crisis proportion worldwide. Given the scale and intensity of this pandemic, this is first attempt in our knowledge to assess the mortality attributed to COVID-. CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted July 7, 2020. These findings are markers of tragedy experienced in countries ranked high in the level of human development, higher income level and are said to be having a better health care system.

Hence the failure of preparedness to confront this pandemic by the developed world exposes our vulnerability to emerging infection of similar kind in future. In the absence of a vaccine as well as no systematic medical intervention, the only way out is the containment of its spread . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted July 7, 2020. . https://doi.org/10.1101/2020.07.06.20147009 doi: medRxiv preprint or developing a herd immunity in due course. At present great efforts are made by national and local government for management and control of pandemic by diverting the resources (financial and physical) for health care and lock down measures.

We acknowledge that the COVID-19 attributable deaths are to some extent underestimated due to lack of comprehensive testing, under-reporting and misclassification of COVID-19 deaths in these countries. Despite these limitations, these estimates of mortality pattern do signals about its long-term implications towards structural and compositional balance of population across world regions. Though it is very early to gauge its final impact on population structure and composition, its persistence with its virulence unless curbed by introduction of an effective vaccine and means of cure may well change the world order to a significant extent.

. CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted July 7, 2020. . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted July 7, 2020. . https://doi.org/10.1101/2020.07.06.20147009 doi: medRxiv preprint . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted July 7, 2020. . CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review)

The copyright holder for this preprint this version posted July 7, 2020. Reduction in life expectancy due to COVID-19 death share of 10%

. CC-BY-NC-ND 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review)

The copyright holder for this preprint this version posted July 7, 2020. 

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