In total, n = 5.424 visits occurred during the analysed period between January 1st and April 19th 2019 and January 1st and April 19th of19th 2020 in the pediatric ED of our hospital. The mean age of all patients included in this analysis was 7.1 years (± SEM 0.1 yrs.), and 49.5% of cases were female. Given the fact that primary pediatric care in Germany is usually provided by pediatric practices during weekdays, more visits to the ED during weekends occurred. Overall, 16.4% ±SEM 1.5 of visits on Saturday/Sunday as compared to 13.5 ± SEM 0.4 on weekdays occurred. When we compared daily visit frequencies between 2019 and 2020, we observed a striking reduction in the number of patients presenting to the ED after March 16th 2020, the day that school closures and a nationwide lockdown began (Fig. 1A,B).
In calendar weeks 12 to 15 of 2020, case numbers decreased by 63.8% compared the same time period in 2019 (mean 26.8 ± SEM 1.5 visits per day in 2019 vs. mean 9.7 ± SEM 1 in 2020, p < 0.005, Fig. 1C). This reduction in emergency healthcare utilization was observed during daytime as well as overnight (mean 10.1 ± SEM 1.5 daily visits during daytime hours in 2019 vs. 3.5 ± SEM 0.6 in 2020, p < 0.05, Fig. 1D and mean 16.6 ± SEM 1.9 daily visits outside daytime hours in 2019 vs. mean 5.9 ± SEM 0.8 in 2020, p < 0.001, Fig. 1E).
While the mean age of patients did not differ significantly between calendar weeks 12 to 15 in each year (mean age of 5.8 ± SEM 0.2 years in 2019 and mean age of 5.8 ± SEM 0.3 years in 2020) a significant increase in ED visits by infants below the age of one year occurred (mean of 16.6% ±SEM 1.4 in 2019 vs 23.1% ±SEM 1.7 in 2020, p < 0.01, Fig. 1F). No significant differences in the daily proportion of school children below the age of six years between the two analysed periods was observed (mean of 62% ±SEM 1.9 in 2019 vs 61.7% ±SEM 2.9 in 2020), nor did we find a difference in sex distribution (mean daily proportion of female patients 44.9% ±SEM 1.6 in 2019 vs 42.5% ±SEM 2.7 in 2020).
Next, we analysed the complaints or diagnoses recorded in the ED in both years. Diagnoses of primary complaints were reported in n = 5.206 visits (96%). When tracing the frequency of daily consultations for noncommunicable diseases and of those with confirmed infections or signs thereof (Fig. 2A/B), a clear drop in visits was observed for both disease types.
This was confirmed by a separate analysis comparing the frequency of daily visits for noncommunicable diseases in calendar weeks 12 to 15 of 2019 vs the same period in 2020. Here, a 58% decrease (mean 11.2 ± SEM 0.7 visits per day in 2019 vs. mean 4.7 ± SEM 0.5 visits per day in 2020, p < 0.005, Fig. 2C) was observed.
Daily visits for suspected or confirmed communicable diseases displayed a 70.2% decrease in the four weeks after lockdown began (mean 15.1 ± SEM 1.5 visits per day in 2019 vs. mean 4.5 ± SEM 0.5 visits per day in 2020, p < 0.005, Fig. 2C). The proportion of daily patients with infectious diseases or signs and symptoms of infection, however, did not differ between calendar weeks 12 to 15 from one year to another (mean daily proportion of 45% ±SEM 2.9 in 2019 vs. mean 54.5% ±SEM 3.9 visits per day in 2020, Fig. 2E).
We also investigated the specific complaints leading to pediatric ED visits in the calendar weeks 12 to 15 in 2019 and 2020. In both years, a proportion of diagnoses was either unknown or unspecific (in total 45.6% of diagnoses in 2019 and 32.9% of diagnoses in 2020). For reported diagnoses, the pattern of distribution was similar in both years. This held true even for critically ill patients. For example, three seizures in 2019, and two seizures in 2020 were observed during the four week period we analysed. As shown in Fig. 3A, however, some variation was observed, such as a larger proportion of patients presenting with malignant or neoplastic diseases in 2020 (1.6% 2019 vs. 11.6% in 2020). This change was confirmed by comparing absolute patients numbers (Fig. 3B). The only disease category with increased daily ER visits in after the lockdown began was that of malignant/neoplastic disease (mean of 0.18 visits per day ± SEM 0.4 in 2019 vs. 0.21 ± SEM 0.4 in 2020, p < 0.05). For the vast majority of noncommunicable diseases, daily visits were reduced (Fig. 2B). For example, complaints or diagnoses affecting the gastrointestinal system showed a decrease of 77.8% (mean of 1.3 visits per day ± SEM 0.2 in 2019 vs. 0.3 ± SEM 0.1 in 2020, p < 0.005), cases of intoxication or injury showed a 68.8% reduction (mean of 1.1 visits per day ± SEM 0.2 in 2019 vs. 0.4 ± SEM 0.1 in 2020, p < 0.005), and diagnoses and complaints affecting the eyes or ear were reduced by 89.5% in 2020 compared to 2019 (mean of 0.7 visits per day ± SEM 0.2 vs. 0.1 ± SEM 0.1, p < 0.005).
Similarly, the proportion of organ specific infectious diseases or signs thereof was analysed for the two time periods. As shown in Fig. 4A, the majority of daily diagnosed infections or typical complaints thereof concerned the respiratory or gastrointestinal tracts. In absolute numbers, presentations due to organ specific infectious disease decreased significantly during calendar weeks 12 to 15 of 2020 as compared to the same period in 2019 (Fig. 4B). Respiratory infections or signs thereof were reduced by 89% (4.9 visits per day ± SEM 0.5 in 2019 vs. 1.6 ± SEM 0.3 in 2020, p < 0.005), ear and throat infections or signs thereof were reduced by 88.2% (2.5 visits per day ± SEM 0.4 in 2019 vs. 0.3 ± SEM 0.1 in 2020, p < 0.005), and gastrointestinal infections or signs thereof were reduced by 85% (2.9 visits per day ± SEM 0.5 in 2019 vs. 0.4 ± SEM 0.1 in 2020, p < 0.005).
Finally, we analysed the rate of hospitalisation in the first month after pandemic-related school closures in 2020 as compared to the same period of time the previous year. Although the absolute rate of daily hospitalisation of pediatric ED patients dropped significantly (38.4% decrease; 4.5 visits per day ± SEM 0.4 in 2019 vs. 3 ± SEM 0.3 in 2020, p < 0.001, Fig. 1A), the proportion of hospitalisations among all patients presenting to the ED almost doubled in 2020 compared to 2019 (increase of 91%; mean of 13. 9% ±SEM 1.6 in 2019 vs. 26.6% ±SEM 3.3 in 2020, p < 0.001, Fig. 1B). The duration of hospitalisation, however, was not different, neither overall, (mean of 5.5 days ± SEM 0.6 in 2019 vs. 4.5 ± SEM 0.3 in 2020, Fig. 1C), nor for particular subgroups such as patients below the age of one year, those with infectious diseases, or those requiring intensive care.
We observed a similar pattern of diagnoses leading to hospitalisation from the ED in both years. Infectious disease, perinatal pathologies, injuries, gastrointestinal issues and neoplastic disease belonged to the most common indications for admission. The largest changes in absolute patient numbers were observed in patients with neoplastic diseases (5.6% in 2019 vs. 14.9% in 2020), those with pathologies of the perinatal period (22.5% in 2019 vs. 8.1% in 2020) and those with diseases of the heart and circulatory system (5.6% in 2019 vs. 0% in 2020).
During calendar weeks 12 to 15 in 2019, two patients presenting to the ED were admitted to the hospital´s pediatric intensive care unit (PICU). No fatalities occurred amongst these patients. In the same four week period in 2020, two patients were admitted from the ED directly to the PICU, and no deaths were observed. Only one case of pediatric COVID-19 was diagnosed during the analysed period.