First and second COVID-19 waves in Brazil: A cross-sectional study of patients' characteristics related to hospitalization and in-hospital mortality

Abstract

Background: Background The second wave of the COVID-19 pandemic was more aggressive in Brazil compared to other countries around the globe. Considering the Brazilian peculiarities, we analyze the in-hospital mortality concerning socio-epidemiological characteristics of patients and the health system of all states during the first and second waves of COVID-19.

Methods: We performed a cross-sectional study of hospitalized patients with positive RT-PCR for SARS-CoV-2 in Brazil. Data was obtained from the Influenza Epidemiological Surveillance Information System (SIVEP-Gripe) and comprised the period from February 25, 2020, to April 30, 2021, separated in two waves on November 5, 2020. We performed a descriptive study of patients analyzing socio-demographic characteristics, symptoms, comorbidities, and risk factors stratified by age. In addition, we analyzed in-hospital and intensive care unit (ICU) mortality in both waves and how it varies in each Brazilian state.

Findings: Between February 25, 2020 and April 30, 2021, 678 235 patients were admitted with a positive RT-PCR for SARS-CoV-2, with 325 903 and 352 332 patients for the first and second wave, respectively. The mean age of patients was 59 $·$ 65 (IQR 48 $·$ 0 - 72 $·$ 0). In total, 379 817 (56 $·$ 00%) patients had a risk factor or comorbidity. In-hospital mortality increased from 34 $·$ 81% in the first to 39 $·$ 30% in the second wave. In the second wave, there were more ICU admissions, use of non-invasive and invasive ventilation, and increased mortality for younger age groups. The southern and southeastern regions of Brazil had the highest hospitalization rates per 100 000 inhabitants. However, the in-hospital mortality rate was higher in the northern and northeastern states of the country. Racial differences were observed in clinical outcomes, with White being the most prevalent hospitalized population, but with Blacks/Browns (Pardos) having higher mortality rates. Younger age groups had more considerable differences in mortality as compared to groups with and without comorbidities in both waves.

Interpretation: We observed a more considerable burden on the Brazilian hospital system throughout the second wave. Furthermore, the north and northeast of Brazil, which present lower Human Development Indexes, concentrated the worst in-hospital mortality rates. The highest mortality rates are also shown among vulnerable social groups. Finally, we believe that the results can help to understand the behavior of the COVID-19 pandemic in Brazil, helping to define public policies, allocate resources, and improve strategies for vaccination of priority groups.

Funding: Coordinating Agency for Advanced Training of Graduate Personnel (CAPES) (C.F. 001), and National Council for Scientific and Technological Development (CNPq) (No. 309537/2020-7).

Keywords: COVID-19; Healthcare; In-hospital mortality; Pandemic response; SARS-CoV-2.

Figure 1

Study profile. Note: The continuous line represents the number of cases that met each of the cutoff criteria. Meanwhile, the dashed line informs the number of patients that were removed from the original dataset. The analysis period considered is from February 25, 2020, to April 30, 2021. We considered all hospitalizations in this period and divided them into two waves. The first wave corresponds to the period from February 25, 2020, to November 5, 2020. The second wave corresponds to the period from November 6, 2020, to April 30, 2021. SARS-CoV-2 = Severe acute respiratory syndrome coronavirus 2. RT-PCR = Reverse transcription polymerase chain reaction.

Figure 2

Prevalence of variants and frequency of hospitalizations and deaths from SARS-CoV-2 in Brazil. Note: the genomic analyzes considered were carried out in Brazil and made available in the GISAID database. The analysis period considered is from February 25, 2020, to April 30, 2021. We considered all hospitalizations in this period and divided them into two waves. The first wave corresponds to the period from February 25, 2020 to November 5, 2020. The second wave corresponds to the period from November 6, 2020 to April 30, 2021. With a programmatic objective, the World Health Organization (WHO) classified the variants as Variants of Concern (VOC) or Variants of Interest (VOI), depending on their transmissibility, virulence, clinical presentation, their ability to impact the epidemiological picture of the pandemic, and its power to reduce the effectiveness of public health measures, diagnostic tests, therapeutic measures or vaccines.

Figure 3

Hospital admission rates, hospital beds per 100 000 inhabitants, and in-hospital mortality per 1 000 admissions due to COVID-19 in the first and second wave, stratified by the Brazilian state. Note: the population considered for each state is an official estimate from Brazilian government agencies. The number of hospital beds considered was based on data for the first wave of October 2020 and the second wave of April 2021. The number of hospital beds per state was obtained from TABNET. Hospitalizations and deaths were assigned to each state according to hospital location.

Figure 4

ICU admission rates, ICU beds per 100 000 inhabitants, and in-ICU mortality per 1 000 admissions due to COVID-19 in the first and second wave, stratified by the Brazilian state. Note: the population considered for each state is an official estimate from Brazilian government agencies. The number of ICU beds considered was based on data for the first wave of October 2020 and the second wave of April 2021. The number of ICU beds per state was obtained from TABNET. ICU admissions and deaths were assigned to each state according to hospital location.

Figure 5

In-hospital mortality rate of patients with comorbidities in the first and second wave of the COVID-19 pandemic in Brazil. Note: We only considered patients with comorbidities informed at the time of admission. Death rates are calculated based on patients with reported outcomes. We only consider puerperal or parturient women up to 50 years of age.