COVID-19 has caused a sizeable global outbreak and a fundamental public health issue but the pandemic did not affect everyone to the same extent. Early on, it became apparent in many studies that various socioeconomic factors cause people to be affected very differently (1–8).

A recent systematic review of 52 studies found moderate to solid evidence that in the US, especially African American/Black and Hispanic populations experience a disproportionate burden of SARS-CoV-2 infections and COVID-19-related mortality (9). However, analyses in the United States always face the problem that the health care system is considered particularly expensive and inefficient and that, unlike in most European countries, there is no guaranteed care for the entire population (10).

Switzerland is considered to have one of the best health care systems in the world, which reaches the entire population in essentially the same manner and scope (11). A major study has shown that Switzerland ranks among the top three healthcare systems in the world regarding access to healthcare and successful treatment of diseases (12). The life expectancy in Switzerland (82.8 years) is the highest in Europe after Iceland, and healthy life expectancy is several years above the EU average (11).

Despite this good health care system, it is difficult in Switzerland to uncover differences in the impact of COVID-19 on marginalized populations and to compare them to data from the United States or other countries. This is because data on hospitalized patients' ethnic or racial identity or immigrant status are not recorded regularly in Switzerland. However, in Switzerland death data can be linked to citizenship data, allowing a subdivision into people with and without Swiss passports. People without Swiss citizenship make up about 26% of the permanent resident population in Switzerland (27% of men and 24% of women), with Italy, Germany, Portugal, France, Kosovo, Spain, and Turkey as the main countries of origin. They include immigrants and—due to high naturalization barriers—the children and grandchildren of immigrants who are born in Switzerland.

If one considers only the effectiveness of the health care system, the risk of dying from COVID-19 in Switzerland could be expected to be better managed than in countries without guaranteed access to health care services. Furthermore, differences between various segments of the population in infection rates, hospitalization, and mortality should be small. To address how the pandemic affects the two population segments of people with and without Swiss citizenship, we compared the increase in the number of deaths in the first year of the pandemic. With the data provided by the death statistics, only limited conclusions can be drawn about the effects of social inequality and discrimination on health variables. Nevertheless, the differences in the number of deaths make it possible to spotlight one area of concern.

We analyzed the death statistics of people with and without Swiss citizenship provided by the Swiss Federal Statistical Office. We used weekly deaths from January 2020 to May 2021 (the first two infection waves where general vaccination was not yet available) as well as annual death numbers from 2015 to 2020 (1969–2020 in the Supplementary material), disaggregated by age groups and citizenship status. The number of deaths without Swiss citizenship is calculated as the difference between the total number of deaths and the number of deaths with Swiss citizenship. Hence, the deaths among those without Swiss citizenship also include persons who died without any citizenship (stateless persons) and deaths with status “unknown” regarding their citizenship. Swiss authorities record data such as citizenship for all residents of Switzerland who have a residence title based on the Ordinance on Civil Status of the Federal Council (Zivilstandsverordnung). In the event of a death, these data are checked by the authorities, which makes it practically impossible—according to the Swiss Federal Statistical Office—for a person with Swiss citizenship to be listed in the official death statistics with the citizenship status “unknown.” In 2019 and 2020, only one deceased person was “stateless,” and 27 (2019) and 73 (2020) deaths were recorded as “unknown” regarding their citizenship status.

In this article, we first analyze the total number of deaths (13) in a year-to-year comparison (see also Supplementary Figure 1) as well as weekly data from 2020 and the first weeks of 2021 relative to the death data in 2019. Second, we compare the increase in mortality (deaths per 100,000 persons) for all deaths in 2020 and for the age groups for both segments of the population (14). This separate mortality calculation is necessary, since in Switzerland demographic changes are mainly caused by younger people added through births and immigration, while it is mainly older people who die from COVID-19. In order to compare the increase in mortality in different age groups, we show the difference between the measured value for 2020 relative to the mortality that would have been expected for 2020 based on the extrapolation of a citizenship and age group-specific linear trend (using linear regression, the confidence level was set at 95%). We consider that a linear trend based on the last 5 years describes relatively well the development of the observed data of the number of deaths for most age groups, both with and without Swiss citizenship. Therefore, we believe that a linear trend can also provide a realistic expected value for 2020 and offers an advantage over the repeatedly used method of setting the expected mortality for a year to the average mortality of the previous 5 years. In particular, the method we use accounts for the group-specific trends in mortality over time, which is especially relevant for age groups without Swiss citizenship, as can be inferred from Supplementary Figure 1.

This analysis of the death statistics during the first two waves of the COVID-19 pandemic revealed a substantial increase in the number of deaths among people with and without Swiss citizenship in Switzerland. Among people with Swiss citizenship, an increase in deaths of 11.4% over the year before the pandemic was recorded, whereas the proportion of deaths among people without Swiss citizenship increased by 21.8% in the same period. Further differentiation—by weekly data and by age groups—shows that the increased number of deaths among people without Swiss citizenship started 1 week before that of people with Swiss citizenship and shows a much larger increase compared to the year before. In addition, the comparison of the mortality of age groups shows a particular vulnerability of people without Swiss citizenship in early retirement age (65–74). However, our findings from the analysis of the death statistics of people with and without Swiss citizenship should not be understood as limited to these segments of the population. Instead, they point to a broader area of concern.

Numerous studies worldwide have shown an increased risk for members of marginalized and underserved communities and immigrants dying from COVID-19 compared to the majority population. This is usually interpreted as resulting from inadequate medical care in the respective health systems, a generally high level of inequality in society that also leads to differing comorbidities, and differences in the level of trust in the medical profession and the health sector in general (9, 20, 21). The question that arises is whether these reasons are also the cause of the differences in mortality between people with and without Swiss citizenship presented in this study.

The Swiss healthcare system is considered to be one of the best healthcare systems in the world, with a high degree of specialization and low-threshold access to health care for the entire population (12). It is necessary to mention that the cost of this effort is relatively high. In 2019, Switzerland invested 11.3% of gross domestic product (GDP) in healthcare spending as a percentage of national income, whereas the average of all OECD states was nearly 9% in the same year (22). Despite the high quality of the health care infrastructure, our analyses show that the COVID-19 pandemic affected people without Swiss citizenship substantially more.

Based on international research on health inequities, differences in the increases in deaths associated with citizenship can be expected to correlate with socioeconomic disparities (23, 24). Income and wealth inequalities, household crowding, occupations with direct customer contact or in labor-intensive or physically demanding areas, and reliance on public transport may all increase the risk of infection (25, 26). Socioeconomic status also correlates with a higher risk for a wide range of diseases, such as hypertension, hyperlipidemia, brain ischemia, alcoholism, nicotine addiction, and obesity (27) that are also associated with severe disease progression in COVID-19 infection. In addition, economic segregation and experiences of discrimination can significantly affect health status and disease risks (28–30).

The measured disparity in the effect of COVID-19 on different segments of the population in Switzerland can be attributed to comparatively high inequality in income, besides the factors just mentioned. Mortality from COVID-19 is closely related to income inequality, for example, as quantified in the Gini coefficient (31, 32). When considering economic equality, Switzerland performs relatively poorly compared to other European countries. The prevailing paradigm that highly specialized medicine and high total spending lead to better care for the entire population must be questioned in light of the data presented here. Social equity may be more relevant than the degree of specialization and overall health care spending (33). This means that in addition to classic risk factors, social determinants should be considered as the more relevant factors for improving and maintaining health (34). We advocate for closer cooperation between public health and prevention efforts, in addition to a good health care infrastructure, as the most vulnerable parts of society will again be at high risk of insufficient protection and support during future health crises.

Switzerland is considered to have one of the highest quality healthcare systems in the world, providing a broad access to health care for the whole population. Nonetheless, in the first two COVID-19 waves, there were significant differences in the death rates of people with or without Swiss citizenship. In addition to the known risk factors of age and preexisting conditions, further vulnerabilities are also associated with an increased risk and indicate a corresponding need for social protection and support. To reduce health risks and increased mortality in the future, socioeconomic risks and social equity should be given much greater consideration than they are now.

The original contributions presented in the study are included in the article/Supplementary material, further inquiries can be directed to the corresponding author.

Material preparation, data collection, and analysis were performed by TP, LS, SM, and HM. Those responsible for the first draft of the manuscript and editing the manuscript were TP and AG. The data analysis and presentation were conducted by TP, SM, HM, HS, NE, and CS-M. All authors contributed to the study conception and design, commented multiple times on previous manuscript versions, read, and approved the submitted version.

The Independent Research Group SoSciBio was funded by the German Federal Ministry of Education and Research, FKZ 01GP1790.

Author SM was employed by Demo SCOPE AG. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

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