RIVM has published the code for model projections of COVID-19 hospital and ICU admissions. The code has been shared as part of a manuscript about the model. The model for projecting healthcare pressure due to COVID-19 hospital and ICU admissions was used from March 2020 to March 2022 to provide information updates, not least for the Outbreak Management Team.

The manuscript offers more details about the model. During the COVID-19 pandemic, the forecasting model for projecting COVID-19 hospital and ICU admissions was systematically expanded over time, for example adding new data flows. The enclosed code of the model for projecting COVID-19 hospital and ICU admissions is for the version of 6 January 2021, just before the vaccination programme started.

The model needs data in order to run the code.  Since the data originally used in the model projections contains ‘person-disclosing information’, the confidential patient data has been replaced by synthetic data. For example, details have been swapped between patients to scramble the data. This helps us protect patient privacy. However, running the data analysis with the scrambled (synthetic) data gives results that are similar to the original data. The synthetic data set has also been included.  Replacing the original patient data with synthetic data was very labour-intensive. Synthetic data has now been provided for use in the model from 6 January 2021. In addition to the code and the synthetic data, the data analysis results based on the original data set have also been enclosed. This makes it possible to run the model projections for COVID-19 hospital and ICU admissions using the version from 6 January 2021.

Review and evaluation of mathematical health modelling at RIVM

The health models used at RIVM are reviewed and evaluated in various ways. A manuscript describing how a model works is one of the ways that models are subjected to peer review. By publishing the manuscript with the code and synthetic data, the model for projecting COVID-19 hospital and IC admissions is presented to national and international researchers working in the field. These fellow researchers can run the calculations again and check the results. This is not the first publication about COVID-19 modelling at RIVM. Other examples include the model used for advisory reports to the Health Council of the Netherlands, which were foundational in determining COVID-19 vaccination strategies. The code for that model was also published online.  Similarly, a manuscript was recently published for peer review regarding the model used to assess the effectiveness of the CoronaMelder app, also accompanied by the code for that model.

International scientific audit

The model projections that RIVM produced to support policy advice during the COVID-19 pandemic have since been reviewed by an international audit committee of peers. The audit committee will be sharing its findings about COVID-19 modelling at RIVM in an evaluation report that will be published in September 2023.

A previous international audit resulted in a report on the research review of mathematical health modelling at RIVM.