"It addresses the topics of excess mortality and its measurement based on available data. It addresses the effects of COVID-19 on inpatient care and the effect of forced ventilation in intensive care. And it addresses evidence on collateral damage and the long-term effects of the decline in hospital admissions for other diseases during COVID-19." With these words, MVF editor Prof. Dr. Reinhold Roski outlined the range of topics for the second part of the MVF conference, "Pandemic Impact on Health Care." Roski continued: "We need to review the past and initiate a learning process – we want to contribute to this today, because health services research has a decisive contribution to make."

> "Covid-19 mortality has been one of the most important indicators of the disease burden during the pandemic and has also been used to create regional and international comparisons." Professor Dr. rer. nat. Daniel Wollschläger from the Institute of Medical Biometry, Epidemiology and Informatics (IMBEI) at Mainz University Medical Center emphasized in his lecture, which he prepared together with his colleague, Univ.-Prof. Dr. rer. nat. Maria Blettner, that this request is anything but trivial. He explicitly answered the fundamental question of his lecture, "Was there actually excess mortality due to Covid-19?", but also clearly qualified this statement, citing various difficulties in determining Covid-19 mortality. On the one hand, there is the potential for underestimation bias if Covid-19 deaths are incorrectly attributed to other causes of death or if not all Covid-19 deaths are identified as such due to a lack of testing capacity. On the other hand, he said, there is also the risk of overestimation, especially when comorbidities in the main risk group – typically the elderly – exacerbate the already high uncertainty in determining the cause of death. For example, the excess mortality estimated by the WHO, which, particularly for Germany, was millions of deaths higher than the direct estimate, had to be subsequently corrected. According to Wollschläger, this was due to methodological limitations that led to estimates of excess mortality for Germany in the peak coronavirus years ranging from 50,000 to around 200,000 – i.e., differing by a factor of four.
A key aspect is that other factors besides the COVID-19 pandemic also influence mortality. These include, on the one hand, trends over longer periods, such as demographic change or different mortality rates across age groups, or even changing life expectancy due to socioeconomic factors (education, income, etc.). On the other hand, there are also short-term influences on mortality, such as cold spells and heatwaves, influenza activity, and the quality of clinical care for diseases with high mortality (such as cancer). Wollschläger: "There are heatwaves that cause 19,000 or even 20,000 deaths per week to suddenly occur instead of perhaps 15,000, thus causing a very dramatic increase in the death rate at specific points." The same applies to influenza. This means, Wollschläger continues: “There are local and time-limited, isolated influences that are generally important for mortality and that were, of course, also important during the Covid-19 pandemic.” Therefore, anyone who wants to investigate the actual level of Covid-19-related mortality must, according to his statements, incorporate as many influencing factors as possible into a calculation, such as heat waves and cold spells, influenza activities and social deprivation,
and then present these at a spatial and temporal resolution at the federal state level. This is the only way to do justice to the great regional heterogeneity of Covid-19-related mortality, which, however, also means that it essentially makes no sense to talk about excess mortality in Germany as a whole.

Pits: less SARI, higher mortality
"During the pandemic, there were fewer infectious lung diseases in hospitals than before." This statement by Prof. Dr. Ralf Kuhlen, Chief Medical Officer and Group Managing Director of Medicine at Helios Health and Chairman of the Scientific Advisory Board of the IQM, surprised many of the conference participants. However, he was able to back up this statement with figures from the Initiative Qualitätsmedizin (Initiative for Quality Medicine), which, through its numerous member hospitals, covers approximately 40% of German hospitals.
hospital cases, which, according to Kuhlen, is very representative of what's happening in German hospitals. Because: These severe acute respiratory infections also include Covid-19. This is a message that no longer surprises many people today, but was completely unexpected during the pandemic, because at the time, hospitals were expected to be much fuller than usual. According to Kuhlen, this decline is astonishing because before the pandemic, there were a lot of SARI cases that had nothing to do with Covid-19, but strangely enough, they have decreased. One can now speculate whether this has something to do with contact restrictions and mask wearing. Kuhlen: "In any case, these cases have decreased. But the number of intensive care treatments has also decreased, which is certainly the most astonishing message, because during the pandemic, there were hospitals that were, on the whole, extremely full and overloaded, such as specialized and university hospitals."
However, according to Kuhlen, overall German care received less intensive care during the pandemic than before, and there were also fewer cases requiring ventilation. On the other hand, SARI cases treated in hospitals had a significantly higher in-hospital mortality rate (unadjusted 2.1 to 2.2 before and 2.9% during the pandemic) and a higher mortality rate for ventilation therapy, which has been around 30% for many years.
Overall, more deaths have actually occurred in German hospitals during the pandemic than before. According to Kuhlen, the unadjusted mortality rate was 15% higher, but adjusted for the difference from the normal risk mix (age, gender, and comorbidity), it was only 9% higher. If COVID-related deaths are then excluded, "the same number of deaths occurred as before the pandemic." Thus, the unadjusted excess mortality rate of 15% is attributable to a mix of a riskier hospital population and higher disease severity, plus the effect of COVID-19 as a truly particularly deadly disease.
Equally deadly, however, was apparently something equally disturbing: the high number of intensive care beds (and their use) in Germany, which, according to OECD statistics, is by far the highest in the world at 33.9 beds per 100,000 inhabitants. In an analysis comparing Switzerland with Germany, Kuhlen concludes that more deaths occurred in German hospitals than in Swiss ones; this applies to both patients without SARS-CoV-2 and those with COVID-19. Kuhlen: "That's astonishing when you consider that intensive care and the rate of ventilation were much higher in our country." Therefore, the treatment procedures used, especially with mechanical ventilation, must be discussed. Even if the result (see Fig.
2) When adjusted for the effects of different age and equally different multimorbidity using a matched-pair analysis, the mortality difference remains, with very comparable patient characteristics. The question of which patient is hospitalized, which is admitted to an intensive care unit, and which is then mechanically ventilated, was answered significantly differently in Germany and Switzerland. In Switzerland, the logic was that the lower the use of intensive care and ventilation, the higher the hospital mortality rate. But perhaps, Kuhlen asked, it was more likely that lower use of intensive care and ventilation contributed to lower hospital mortality. He was fully aware that this was a perfect fit for the next speaker, who would address precisely this topic.

Köhler: 80,000 patients died unnecessarily
Prof. Dr. Dieter Köhler, former medical director of Kloster Grafschaft Hospital, immediately responded, stating: "Forced ventilation has only brought disadvantages for patients." He argued that there had clearly been more deaths as a result of tube ventilation, and that post-COVID syndrome after an intensive care stay was partly the result of invasive ventilation. Studies at the very beginning of the pandemic had shown that the mortality rate for invasive ventilation was 97% in China, 66% in the UK, and 88% in New York. However, at the time, it was assumed that this was primarily due to the high mortality rate of the SARS-CoV2 virus.
However, with today's knowledge, Köhler's statements make it clear that this was only partially true. He sees the responsibility for the use of forced ventilation primarily in the unquestioned application of the still-unchanged S3 guideline on "Recommendations for the inpatient treatment of patients with Covid-19" in version 9/2022. Its algorithms require that patients be admitted to the intensive care unit if their oxygen saturation level is below 92%. According to Köhler, there are "systemic errors that permeate the guideline." This applies to mandatory admissions to the intensive care unit, but also to the consideration that intubation is necessary if the respiratory rate exceeds 30 per minute. However, there is no publication supporting the recommendation for intubation in cases of isolated hypoxemia, so there is no evidence available.
According to Köhler, two studies with comparable patient cohorts treated in intensive care units, comparing invasive ventilation versus non-invasive ventilation for COVID-19 pneumonia, provide important information. In the Hamburg study (75% intubation with ECMO), the mortality rate for ventilated patients was 44% and the mortality rate for all intensive care patients was 35%. In the Moers/Grafschaft study, with only 10% intubation, the mortality rate for ventilated patients was 5% and the mortality rate for all intensive care patients was 7.7%. According to Köhler, this results in a mortality difference of a factor of 4.5 when intubation was avoided. If, Köhler continues, one assumes 259,000 admissions to intensive care units due to COVID-19 and a mortality rate of 40% in the intensive care unit for ventilated patients, this results in approximately 103,000 deaths due to invasive ventilation. This means that, considering the factor 4.5, around 80,000 patients died unnecessarily due to intubation and ventilation. Köhler: "Approximately 45% of the coronavirus deaths in Germany could have been saved if they had not been intubated." In addition, there are secondary complications such as neuropathy and myopathy, which are not even taken into account here. Köhler's initial conclusion: "Although anchored in the guidelines, there is no evidence for intubation with ventilation in cases of isolated hypoxemia." And the second: "The established clinical practice of intubation in these cases causes many thousands of deaths worldwide and even more long-term complications, but because the guidelines specify the wrong indication, it is established in the legal system and therefore not enforceable."

Möckel: Collateral damage and long-term effects
Prof. Dr. Martin Möckel, Medical Director of Emergency and Acute Medicine, Central Emergency Departments and Chest Pain Units at the Charité Mitte Campus and the Virchow-Klinikum Campus, addressed precisely the collateral damage and long-term effects of the decline in hospitalizations during the pandemic mentioned by Köhler. First and foremost, like Wollschläger before him, he addressed the wave-like nature of the pandemic, which had also impacted the decline in hospitalizations, but also collateral damage. Using myocardial infarction cases as an example, he demonstrated that these had indeed decreased overall, but that there were also some hospitals whose case numbers were even higher than in 2019. A different effect was seen in COPD, with a sustained effect of the decline, even though there was an enormous incidence of respiratory infections such as influenza and RSV last winter. However, this did not lead to the existing intensive care units becoming full or to a lack of nursing staff.
Overall, Möckel said, one could say that strokes during the pandemic indicate collateral damage due to untimely treatment. His theory is that older people in particular suffer a stroke at home, and family members or neighbors come and take them to the hospital. This has no longer worked during the pandemic due to contact restrictions. And because older stroke patients are rarely able to call an ambulance themselves because they are often no longer able to speak, he believes this is one of the clear collateral damages of the pandemic. Using the keyword "theories," he provided a perfect transition to the closing speaker of the MVF Congress on the consequences of the pandemic, Prof. Pfaff.

Pfaff: Theories are congealed knowledge

In his lecture "EbM + Theory: How to Make Critical Decisions on the Basis of Uncertain Data," Prof. Dr. Holger Pfaff, Director of the Institute for Medical Sociology, Health Services Research and Rehabilitation Science at the University of Cologne, explained that a fundamentally different approach to evidence is necessary for highly dynamic events such as pandemics. His remarks, which he and Prof. Dr. Jochen Schmitt from Dresden developed together and published in two articles,
recommend, in the case of decision-making uncertainty in dynamic times, firstly an acceleration solution (Organic Turn of EbM), secondly an action-mechanistic solution (EbMplus) and thirdly a theory-integrating solution (EbM + Theory).
First and foremost, however, Pfaff postulated that medicine, including EBM and health services research, must adapt, as the future of medicine and the health sciences is characterized by constant change; highly dynamic is the "new normal." To solve the fundamental problem of decision uncertainty, it is necessary to rethink the approach of evidence-based medicine (EBM). While this is a good approach for reducing decision uncertainty in simple interventions and slowly developing areas of application, it reaches its limits in complex interventions and dynamically developing areas of application such as the COVID-19 pandemic. "The EBM lag thus becomes a fundamental problem," Pfaff explained, because the EBM system always lags behind social, biological, and technological changes and is only able to adapt to these new changes late. Therefore, he calls for an "organic shift," drawing on the contingency theory of Burns and Stalker (1961). This states that in a dynamic environment, organic, less formal forms of decision-making are better suited to dealing with environmental challenges than mechanistic, more formal forms. One element of the "Organic Turn" is the return of experts, as they reduce uncertainty for medical and political decision-makers. However, according to Pfaff, even a return to experts and eminences cannot be the solution for dynamic and complex environments, which is why a more systematic solution is needed, one based on the principles of evidence generation, but more flexible. This brings the approach of "EbMplus" into play, which he calls "Trisha Greenhalgh's solution to the EbM crisis." However, this is supplemented with a theory-integrating solution, namely "EbM + Theory." Pfaff, who described theories as congealed knowledge, stated: "The integration of empirical and theoretical
The transfer of theoretical knowledge for knowledge-based medicine and health science can only be achieved with EbM and theory.” However, in order to ensure better and faster scientific recommendations, the basis must be reversed: first the theory, then EbMplus and finally EbM.
A heated debate about the "how" erupted among the speakers and participants of the MVF Congress, a summary of which you can read on the following pages.