Trends and Risk Factors of In-Hospital Mortality of Patients with COVID-19 in Germany: Results of a Large Nationwide Inpatient Sample

Abstract

Unselected data of nationwide studies of hospitalized patients with COVID-19 are still sparse, but these data are of outstanding interest to avoid exceeding hospital capacities and overloading national healthcare systems. Thus, we sought to analyze seasonal/regional trends, predictors of in-hospital case-fatality, and mechanical ventilation (MV) in patients with COVID-19 in Germany. We used the German nationwide inpatient samples to analyze all hospitalized patients with a confirmed COVID-19 diagnosis in Germany between 1 January and 31 December in 2020. We analyzed data of 176,137 hospitalizations of patients with confirmed COVID-19-infection. Among those, 31,607 (17.9%) died, whereby in-hospital case-fatality grew exponentially with age. Overall, age ≥ 70 years (OR 5.91, 95%CI 5.70-6.13, p < 0.001), pneumonia (OR 4.58, 95%CI 4.42-4.74, p < 0.001) and acute respiratory distress syndrome (OR 8.51, 95%CI 8.12-8.92, p < 0.001) were strong predictors of in-hospital death. Most COVID-19 patients were treated in hospitals in urban areas (n = 92,971) associated with the lowest case-fatality (17.5%), as compared to hospitals in suburban (18.3%) or rural areas (18.8%). MV demand was highest in November/December 2020 (32.3%, 20.3%) in patients between the 6th and 8th age decade. In the first age decade, 78 of 1861 children (4.2%) with COVID-19-infection were treated with MV, and five of them died (0.3%). The results of our study indicate seasonal and regional variations concerning the number of COVID-19 patients, necessity of MV, and case fatality in Germany. These findings may help to ensure the flexible allocation of intensive care (human) resources, which is essential for managing enormous societal challenges worldwide to avoid overloaded regional healthcare systems.

Keywords: COVID-19; SARS-CoV2; health resources; intensive care unit; mechanical ventilation.

Figure 1

(Facing page). Temporal and regional trends regarding total numbers of hospitalized patients with COVID-19-infection, in-hospital mortality, and mechanical ventilation. Panel (A)—Temporal trends regarding total numbers of hospitalized patients with COVID-19-infection (yellow bars) and in-hospital mortality rate (black line) stratified for months. Panel (B)—Regional trends regarding total numbers of hospitalized patients with COVID-19-infection (yellow bars), mechanical ventilation (orange line), and in-hospital mortality rate (black line). Panel (C)—Regional trends regarding in-hospital death rates of hospitalized patients with COVID-19-infection. Panel (D)—Temporal trends regarding total numbers of hospitalized patients with COVID-19-infection (yellow bars) and in-hospital mortality rate (black line) stratified for age decades. Panel (E)—Temporal trends regarding deaths of hospitalized patients with COVID-19-infection stratified for days of hospitalization. Panel (F)—Regional trends regarding rates of mechanical ventilation of hospitalized patients with COVID-19-infection.

Figure 2

Temporal trends regarding total numbers of hospitalized patients with COVID-19-infection and mechanical ventilation in Germany 2020. Panel (A)—Temporal trends regarding total numbers of hospitalized patients with COVID-19-infection (yellow bars), as well as the proportion of COVID-patients with mechanical ventilation (orange line), stratified for months. Panel (B)—Temporal trends regarding total numbers of hospitalized COVID-19 patients with mechanical ventilation (orange bars) and percentage of annual mechanic ventilation procedures (grey line) stratified for months. Panel (C)—Temporal trends regarding total numbers of hospitalized patients with COVID-19-infection (yellow bars), as well as COVID-patients with mechanical ventilation (orange line), stratified for age decades. Panel (D)—Temporal trends regarding total numbers of hospitalized COVID-19 patients with mechanical ventilation (orange bars) and percentage of annual mechanic ventilation procedures (grey line) stratified for age decades.

Figure 3

Association of baseline and clinical parameters of COVID-19 patients with in-hospital mortality (A) and necessity of mechanical ventilation (B). Associations were presented as Odds Ratios (OR) and included the following parameters for adjustment: age, sex, cancer, coronary artery disease, heart failure, COPD, arterial hypertension, renal insufficiency (comprised diagnosis of chronic renal insufficiency stages 3 to 5 with glomerular filtration rate < 60 mL/min/1.73 m²), diabetes mellitus, atrial fibrillation, peripheral artery disease, and hyperlipidemia. Abbreviations: CAD, coronary artery disease; COPD, chronic obstructive pulmonary disease; VTE, venous thromboembolism, URTI, upper respiratory tract infection; LRTI, lower respiratory tract infection, other than pneumonia; ARDS, acute respiratory distress syndrome; ECMO, extracorporeal membrane oxygenation.