In Reply

Letters to the Editor regarding the article Initial Cancer Treatment in Certified Versus Non-certified Hospitals: Results of the WiZen Comparative Cohort Study by Prof. Dr. med. Jochen Schmitt, Prof. Dr. med. Monika Klinkhammer-Schalke, Dr. rer. nat. Veronika Bierbaum, Dr. med. Michael Gerken, Christoph Bobeth, Dr. rer. pol. Martin Rößler, Patrik Dröge, Thomas Ruhnke, Christian Günster, Kees Kleihues-van Tol, and PD Dr. rer. nat. Olaf Schoffer, on behalf of the WiZen Study Group in issue 39/2023

The WiZen Comparative Cohort Study (1, 2) provides important scientific evidence for the already implemented system innovation“Initial Cancer Treatment in Certified Centers,” which that is based on the National Cancer Plan. The study uses complementary, quality assured, notifiable data from inpatient and outpatient care (routine data from the statutory health insurance system) and clinical cancer registers, uses a longitudinal control group design with adjustment not only for comorbidities but also for numerous demographic, clinical, and hospital/clinic related variables and time trends, and meets the crucial criteria of a target trial emulation. The WiZen Study shows robustly—confirmed by various sensitivity analyses and consistently in cancer registry and statutory health insurance data—a longer overall survival for each type of cancer under study in patients initially treated in hospitals certified by the German Cancer Society. Even though a randomized design was not—and will not be—possible, the results can be interpreted as causal on the basis of the Bradford-Hill criteria. In contrast to the explanation given by Professor Stang in his editorial (3), the evidence to date in the subject under study is not sparse. Numerous publications are available that consistently show the advantages/benefits of initial treatment of cancer patients in certified centers, also in terms of the effects on symptom burden and quality of life (1). The editorial does not discuss this evidence base but cites a Cochrane review that investigated different interventions in other countries and in another context—namely, the practical quality of an accreditation process for reducing MRSA infections in hospitals in South Africa and the UK. Routine data from the statutory health insurance system are firmly established in Germany in healthcare services research and quality assurance, among others in the Federal Joint Committee, and are the best resource for generating evidence in the context of standard care. We did not—as described by Hanisch—use DRG data but validated routine data from the statutory health insurance system including in- and outpatient care. These data also form the basis of quality assurance procedures according to paragraph 136 of the fifth book of the German Social Code. All-cause mortality—the primary endpoint of the WiZen Study—is certainly valid, as are data on the certification status of hospitals. Fröhner writes that the study was funded by “interested parties.” The WiZen Study was funded by the German Innovation Fund and evaluated by the Innovation Fund Committee as a proof of a notable improvement in “chances of survival” as a result of treatment in certified oncology centers. It was categorized as “pioneering/game changing” and “convincing.” We assume that all members of the Innovation Fund Committee are interested in continuous optimization of the healthcare system.

According to the German Research Foundation (4), the task of health services research is to describe, evaluate, and optimize healthcare. The results of the Wizen Study provide every indication that all patients should receive initial treatment in certified hospitals, and very little speaks to the contrary. From an ethical perspective, the consequences of acting and non-acting bear the same weight. We therefore recommend that politicians, self governance, patients, and referrers bear the results of the WiZen Study in mind in their actions.

DOI: 10.3238/arztebl.m2023.0265

Prof. Dr. med. Jochen Schmitt, PD Dr. rer. nat. Olaf Schoffer

Zentrum für Evidenzbasierte Gesundheitsversorgung, Medizinische Fakultät

Carl Gustav Carus,TU Dresden

Prof. Dr. med. Monika Klinkhammer-Schalke

Tumorzentrum Regensburg, Zentrum für Qualitätssicherung und Versorgungsforschung der Universität Regensburg

Conflict of interest statement

The project was supported by the Innovation Fund of the Federal Joint Committee.

While undertaking the study, JS, MK-S, VB, MG, CB, MR and OS work, or worked, at university hospitals with certified cancer centers.

MK-S is Honorary Chairperson of the ADT.

JS is a member of the Expert Advisory Board Health and Nursing Care of the Federal Ministry of Health and member of the Government Commission for a Modern and Needs-based Hospital Care. He receives an institutional grant for scientific research from the German Joint Federal Committee, the Federal Ministry of Health, the Federal Ministry of Education and Research, the Free State of Saxony, from Novartis, Sanofi, ALK, and Pfizer. Outside the context of the WiZen study, he participated as an advisor at advisory board meetings of Sanofi, Lilly, and ALK for which he received a personal fee.

OS receives reimbursement of travel expenses and conference fees from the German Cancer Society. He receives funding for compiling the WiZen project manuscript for the journal GGW (Healthcare Society Science) of the AOK Research Institute (WIdO) and received fees for a presentation for the Lung Cancer Center Gera about the WiZen project. He has received consulting fees from Novartis. He received fees for membership of the expert committee of the project “Development of Criteria for the Evaluation of Certificates and Quality Seals according to Section 137a Subsection 3 (2) No. 7 Book V of the German Social Code” for the Institute for Quality Assurance and Transparency in the Healthcare System (IQTIG).

References

1. Schmitt J, Klinkhammer-Schalke M, Bierbaum V, et al., on behalf of the WiZen Study Group: Initial cancer treatment in certified versus non-certified hospitals: results of the WiZen comparative cohort study. Dtsch Arztebl Int 2023;120: 647–54

2. Schoffer O, Rößler M, Bierbaum V, et al.: Ergebnisbericht zum Projekt Wirksamkeit der Versorgung in onkologischen Zentren (WiZen). https://innovationsfonds.g-ba.de/downloads/beschluss-dokumente/268/2022–10–17_WiZen_Ergebnisbericht.pdf (last accessed on 16 November 2023).

3. Stang A: Evaluierbarkeit des Effekts der Zertifizierung onkologischer Zentren—Editorial zum Beitrag: Erstbehandlung in zertifizierten versus nichtzertifizierten Krankenhäusern—Ergebnisse der vergleichenden Kohortenstudie WiZen von Schmitt J, et al. Dtsch. Arztebl Int 2023; 120: 645–6

4. Raspe H, Pfaff H, Härter M, et al.: Versorgungsforschung in Deutschland: Stand–Perspektiven–Förderung. Stellungnahme. In: DFG-Standpunkte. Weinheim/Berlin: Wiley-VCH 2010; 1–50.