key: cord-0771310-f80xucbb
authors: Esmaeili, Elham D.; Fakhari, Ali; Naghili, Behrouz; Khodamoradi, Farzad; Azizi, Hosein
title: Case fatality and mortality rates, socio‐demographic profile, and clinical features of COVID‐19 in the elderly population: A population‐based registry study in Iran
date: 2022-01-28
journal: J Med Virol
DOI: 10.1002/jmv.27594
sha: 1ec28e41a8e74ef7ce36bc0c6d5ed3d1e1647ea7
doc_id: 771310
cord_uid: f80xucbb

We aimed to investigate COVID‐19 case fatality rate (CFR), mortality, and screening in the older population of East Azerbaijan Province. We conducted a population‐based registry study from Death Registration System in the elderly population (N = 433 445) from the outbreak that emerged up to May 30, 2021 (before vaccination). We analyzed CFR and mortality rates due to COVID‐19 as well as the case findings and characteristics in the elderly population. Logistic regression analysis was carried out for the association between COVID‐19 mortality and effective factors. During the study, the province had 18 079 confirmed cases and 4390 deaths. The male to female CFR risk ratio was 3.2. The overall CFR and mortality rates were 24% and 1%, respectively. CFR and mortality ranged from 9.56% to 0.37% in the 60–64 age group to 70% and 2.6% in the age group ≥85 years, respectively. We found a significant trend in CFR and mortality of COVID‐19 with advanced age. Male sex, advanced age, marital status, and living alone were associated with an increased risk of COVID‐19 fatality. COVID‐19 mortality measures were higher in the older population of this province. Advanced treatment supports and interventions are needed to reduce mortality rates of COVID‐19 in the elderly population.

due to COVID-19 in the elderly is higher compared to other age groups. 7 The elderly are considered among the most vulnerable group of society in the COVID-19 pandemic for a variety of reasons:

weakened immune system, chronic underlying diseases that can mask the symptoms of infection, multidrug therapy, inattention, and inability to fully observe the principles of personal hygiene and selfcare, poor hygiene of the living environment, loneliness, and lack of adequate support from other family members, so forth. 8 It is estimated that out of every 10 deaths due to 8 cases occurred in people with age group 65 years and above. This proportion is 90 and 630 times higher in the age groups of 65-74 and above 85 years than people with 18-29 years, respectively. 7 Likewise, the rate of COVID-19 hospitalization increases with advanced age. The risk of hospitalization in 74-65 years is five times more than in the age group of 18-29 years. 9, 10 Since to make the best decisions on COVID-19 prevention and control measures and regulations, an accurate estimation of mortality and epidemiological measures are required, especially fatality and mortality rates and associated comorbidities in high-risk groups.

Previous investigations on COVID-19 mortality often focused on hospitalized patients with limited participants, 5 adult age groups, 11 and children. 12 Given that the risk of case fatality and mortality due to COVID-19 is higher in elderly patients, advanced prevention and treatment supports are required. Quantifying mortality measures, risk factors, and early detection of COVID-19 infection among older people is an essential step in COVID-19 prevention and planning for health managers and policymakers. In the elderly population, mortality measures and characteristics of COVID-19 are poorly understood at the population level, at least in Iran. We aimed to estimate and analyze the CFR and mortality rates due to COVID-19 in the older population of East Azerbaijan Province, Iran.

This population-based registry study was performed based on the Death Registration System (DRS) or known vital registration system, and Health Information System in East Azerbaijan Province (Tabriz University of Medical Sciences) from February 20, 2020 (emerged COVID-19 outbreak in Iran) up to May 30, 2021 (before or concurrent with COVID-19 vaccination). The study population was the elderly population (above 60 years) living in East Azerbaijan Province of Iran.

DRS system is a valid and reliable data source for mortality in Iran. 13, 14 In the DRS system, all deaths, as well as COVID-19 deaths, were collected from all over community-based health houses and health centers, hospitals, legal medicine, civil registration bureau, cemeteries, and other probable sources based on the same "death certificates" in each county and then all confirmed deaths were included in the DRS.

We reviewed and analyzed estimates for mortality and morbidity due to COVID-19 for the total older population of East Azerbaijan Province from the outbreak that emerged up to May 30, 2021. We calculated COVID-19 CFR and mortality rate via the DRS system. CFR was calculated by dividing the number of people who died from COVID-19 by all cases diagnosed with COVID-19 infection during the study time interval as defined in the previous study. 15 Mortality rate was calculated by dividing the total number of deaths due to COVID-19 infection by the total elderly population during the study time interval. 15 We also collected characteristics and common symptoms of the older population who had been screened for COVID-19. Since the outbreak of coronavirus, according to the plan of the Iran Health Ministry, in the first stage, all suspected people are screened by healthcare providers and if necessary, they are referred to clinicians to continue the process of diagnosis and treatment. 16, 17 In the health care system of Iran, COVID-19 morbidity statistics, screening, prevention, and intervention programs have been collected from all hospitals and sampling centers, and then registered by the Primary Health Care system of the University. COVID-19 case findings, suspected, and confirmed cases have been recorded by the various Community Health Workers (CHWs). 16 CHWs have face-to-face contact with large numbers of community members as part of their usual routine performance in the health care system of Iran. 18 Detailed methods of COVID-19 case finding and screening programs among Iranian health workers have been published previously. 16 

All over 60 years of age were eligible if they had inclusion criteria as listed below: older people who resided in one city of the East Azerbaijan Province for at least 6 months except Sarab and Maragheh (since these two cities have separate health register systems). We also excluded subjects who did not match the inclusion criteria.

STATA software version 13.0 was carried out for data analysis.

Variables were summarized by frequencies, percentages, and standard deviation. χ 2 test was used to assess the relationship between COVID-19 death and dichotomous variables. T-test was used for the comparison of continuous variables. Logistic regression analysis was used to estimate odds ratios and 95% confidence intervals (CIs) for COVID-19 mortality and morbidity risk and effective factors. Table 1 shows the demographic characteristics of the older population (total) in East Azerbaijan Province. Overall, the older population size was 433 445 people in this province. The sex distribution for the older population of the Province was 223 688 (51.62%) females, and the sex ratio (female to male) was 1.07. The age distribution was ESMAEILI ET AL. (48%) of death and confirmed cases were males. The overall CFR and mortality rates were 24.28% and 1.01% in the older population, respectively. CFR and mortality ranged from 9.56% and 0.37% in the 60-64 age group to 70.94% and 2.64% in the age group ≥85, respectively. We found a significant trend in CFR and mortality due to COVID-19 by advanced age (p = 0.001).

Regarding sex, CFR was 37.89% and 11.68% in males and females, respectively. The male to female risk ratio was 3.2. Similarly, the mortality rate in males was higher than in females (1.57% vs. 0.50%). Analysis indicated that the male sex increased odds of COVID-19 death more than four times that of females. We found a significant positive association between marital status (widow and diverse) and life alone with death by COVID-19 infection (p = 0.001).

We also found no association between COVID-19 death and habitat in urban and rural areas (p = 0.316). In this study, CFR and mortality ranged from 9.56% to 70.94% and 0.37% to 2.64% in the older population, respectively. Overall, COVID-19 was responsible for 32.07% and 1.01% of CFR and mortality rate in the elderly population of the Province, respectively. The study found a high rate of COVID-19 mortality in advanced age groups and male sex, which is consistent in hospitalized patients in Iran 5 and Brazil. 19 In the current study, the proportion of COVID-19-confirmed cases was 4.17% among the elderly population of this province during the study. This study is one of the rare studies which investigated COVID-19 mortality and epidemiological aspects in Iran at the community level in the older population, while previous studies had focused on hospitalized patients. 3, 5, [20] [21] [22] CFR is varied from 0.4% to 15% in the general population. 15, 23 Systematic review studies were reported pooled estimated of 2.67% 24 and 7.4% 25 due to COVID-19 in the general population.

However, limited studies estimated CFR in elderly patients and populations. A study in Korea found 20.4% CFR for COVID-19 in the elderly patients, 22 which was lower than our study (32%). In the present study, the CFR was 9.56% among patients aged 60-64 years, 16 Regarding sex distribution, CFR was 37.89% and 11.68% in males and females in this study, respectively. However, the proportion of positive PCR was higher in females than in males. Consistent with our study, a study from China observed the high attack rate of COVID-19

infection among females. 27 However, similar to our study, a population-based registry study was found male sex was associated with higher disease severity and CFR, 28 and also a large between countries study showed that male COVID-19 patients had higher mortality with a risk ratio varying between 1.08 in Canada and 2.01 in the Netherlands. However, in this study male to female fatality risk ratio was 3.2. 29 The overall elderly population of the province was assessed regarding COVID-19 probable infection by first-line healthcare providers. This is a good practice for the first-line healthcare providers and the health system of the province. The overall detection rate of COVID-19 in the province was 4.17% up to May 30, 2021. It seems that this detection rate is low for 32% CFR. Likewise, the proportion Our findings in comparison to other countries indicated that mortality and fatality rates were higher in this Province. Advanced treatment supports and interventions are needed to reduce mortality measures of COVID-19 in the elderly population in this region.

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Case fatality and mortality rates, socio-demographic profile, and clinical features of COVID-19 in the elderly population: a population-based registry study in Iran

The authors declare that there are no conflict of interests.

The present study was derived from recorded data and no human interviews or samples were used. The study protocol was approved 

The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.