{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,3]],"date-time":"2026-04-03T08:16:57Z","timestamp":1775204217367,"version":"3.50.1"},"update-to":[{"DOI":"10.1371\/journal.pcbi.1011394","type":"new_version","label":"New version","source":"publisher","updated":{"date-parts":[[2023,8,23]],"date-time":"2023-08-23T00:00:00Z","timestamp":1692748800000}}],"reference-count":43,"publisher":"Public Library of Science (PLoS)","issue":"8","license":[{"start":{"date-parts":[[2023,8,11]],"date-time":"2023-08-11T00:00:00Z","timestamp":1691712000000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001656","name":"Helmholtz-Gemeinschaft","doi-asserted-by":"publisher","award":["SIMCARD"],"award-info":[{"award-number":["SIMCARD"]}],"id":[{"id":"10.13039\/501100001656","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001656","name":"Helmholtz-Gemeinschaft","doi-asserted-by":"publisher","award":["SIMCARD"],"award-info":[{"award-number":["SIMCARD"]}],"id":[{"id":"10.13039\/501100001656","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001656","name":"Helmholtz-Gemeinschaft","doi-asserted-by":"publisher","award":["COCAP"],"award-info":[{"award-number":["COCAP"]}],"id":[{"id":"10.13039\/501100001656","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100002347","name":"Bundesministerium f\u00fcr Bildung und Forschung","doi-asserted-by":"publisher","award":["RESPINOW"],"award-info":[{"award-number":["RESPINOW"]}],"id":[{"id":"10.13039\/501100002347","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100002347","name":"Bundesministerium f\u00fcr Bildung und Forschung","doi-asserted-by":"publisher","award":["RESPINOW"],"award-info":[{"award-number":["RESPINOW"]}],"id":[{"id":"10.13039\/501100002347","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100002347","name":"Bundesministerium f\u00fcr Bildung und Forschung","doi-asserted-by":"publisher","award":["RESPINOW"],"award-info":[{"award-number":["RESPINOW"]}],"id":[{"id":"10.13039\/501100002347","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001659","name":"Deutsche Forschungsgemeinschaft","doi-asserted-by":"publisher","award":["512483310"],"award-info":[{"award-number":["512483310"]}],"id":[{"id":"10.13039\/501100001659","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100007316","name":"Klaus Tschira Stiftung","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100007316","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100009318","name":"Helmholtz Association","doi-asserted-by":"publisher","award":["HIDSS4Health"],"award-info":[{"award-number":["HIDSS4Health"]}],"id":[{"id":"10.13039\/501100009318","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100010269","name":"Wellcome Trust","doi-asserted-by":"publisher","award":["210758\/Z\/18\/Z"],"award-info":[{"award-number":["210758\/Z\/18\/Z"]}],"id":[{"id":"10.13039\/100010269","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100010269","name":"Wellcome Trust","doi-asserted-by":"publisher","award":["210758\/Z\/18\/Z"],"award-info":[{"award-number":["210758\/Z\/18\/Z"]}],"id":[{"id":"10.13039\/100010269","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100004785","name":"NordForsk","doi-asserted-by":"publisher","award":["105572"],"award-info":[{"award-number":["105572"]}],"id":[{"id":"10.13039\/501100004785","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["www.ploscompbiol.org"],"crossmark-restriction":false},"short-container-title":["PLoS Comput Biol"],"abstract":"<jats:p>Real-time surveillance is a crucial element in the response to infectious disease outbreaks. However, the interpretation of incidence data is often hampered by delays occurring at various stages of data gathering and reporting. As a result, recent values are biased downward, which obscures current trends. Statistical nowcasting techniques can be employed to correct these biases, allowing for accurate characterization of recent developments and thus enhancing situational awareness. In this paper, we present a preregistered real-time assessment of eight nowcasting approaches, applied by independent research teams to German 7-day hospitalization incidences during the COVID-19 pandemic. This indicator played an important role in the management of the outbreak in Germany and was linked to levels of non-pharmaceutical interventions via certain thresholds. Due to its definition, in which hospitalization counts are aggregated by the date of case report rather than admission, German hospitalization incidences are particularly affected by delays and can take several weeks or months to fully stabilize. For this study, all methods were applied from 22 November 2021 to 29 April 2022, with probabilistic nowcasts produced each day for the current and 28 preceding days. Nowcasts at the national, state, and age-group levels were collected in the form of quantiles in a public repository and displayed in a dashboard. Moreover, a mean and a median ensemble nowcast were generated. We find that overall, the compared methods were able to remove a large part of the biases introduced by delays. Most participating teams underestimated the importance of very long delays, though, resulting in nowcasts with a slight downward bias. The accompanying prediction intervals were also too narrow for almost all methods. Averaged over all nowcast horizons, the best performance was achieved by a model using case incidences as a covariate and taking into account longer delays than the other approaches. For the most recent days, which are often considered the most relevant in practice, a mean ensemble of the submitted nowcasts performed best. We conclude by providing some lessons learned on the definition of nowcasting targets and practical challenges.<\/jats:p>","DOI":"10.1371\/journal.pcbi.1011394","type":"journal-article","created":{"date-parts":[[2023,8,11]],"date-time":"2023-08-11T13:34:45Z","timestamp":1691760885000},"page":"e1011394","update-policy":"https:\/\/doi.org\/10.1371\/journal.pcbi.corrections_policy","source":"Crossref","is-referenced-by-count":26,"title":["Collaborative nowcasting of COVID-19 hospitalization incidences in Germany"],"prefix":"10.1371","volume":"19","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0318-3669","authenticated-orcid":true,"given":"Daniel","family":"Wolffram","sequence":"first","affiliation":[]},{"given":"Sam","family":"Abbott","sequence":"additional","affiliation":[]},{"given":"Matthias","family":"an der Heiden","sequence":"additional","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2842-3406","authenticated-orcid":true,"given":"Sebastian","family":"Funk","sequence":"additional","affiliation":[]},{"given":"Felix","family":"G\u00fcnther","sequence":"additional","affiliation":[]},{"given":"Davide","family":"Hailer","sequence":"additional","affiliation":[]},{"given":"Stefan","family":"Heyder","sequence":"additional","affiliation":[]},{"given":"Thomas","family":"Hotz","sequence":"additional","affiliation":[]},{"given":"Jan","family":"van de Kassteele","sequence":"additional","affiliation":[]},{"given":"Helmut","family":"K\u00fcchenhoff","sequence":"additional","affiliation":[]},{"given":"S\u00f6ren","family":"M\u00fcller-Hansen","sequence":"additional","affiliation":[]},{"given":"Diell\u00eb","family":"Syliqi","sequence":"additional","affiliation":[]},{"given":"Alexander","family":"Ullrich","sequence":"additional","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4400-134X","authenticated-orcid":true,"given":"Maximilian","family":"Weigert","sequence":"additional","affiliation":[]},{"given":"Melanie","family":"Schienle","sequence":"additional","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3777-1410","authenticated-orcid":true,"given":"Johannes","family":"Bracher","sequence":"additional","affiliation":[]}],"member":"340","published-online":{"date-parts":[[2023,8,11]]},"reference":[{"issue":"4","key":"pcbi.1011394.ref001","doi-asserted-by":"crossref","first-page":"665","DOI":"10.1016\/j.jmoneco.2008.05.010","article-title":"Nowcasting: The real-time informational content of macroeconomic data","volume":"55","author":"D Giannone","year":"2008","journal-title":"Journal of Monetary Economics"},{"issue":"3","key":"pcbi.1011394.ref002","doi-asserted-by":"crossref","first-page":"443","DOI":"10.1017\/S1357321700003809","article-title":"Stochastic claims reserving in general insurance","volume":"8","author":"PD England","year":"2002","journal-title":"British Actuarial Journal"},{"issue":"1226","key":"pcbi.1011394.ref003","doi-asserted-by":"crossref","first-page":"135","DOI":"10.1098\/rstb.1989.0078","article-title":"A process of events with notification delay and the forecasting of AIDS","volume":"325","author":"DR Cox","year":"1989","journal-title":"Philosophical Transactions of the Royal Society of London B, Biological Sciences"},{"issue":"4","key":"pcbi.1011394.ref004","doi-asserted-by":"crossref","first-page":"993","DOI":"10.1111\/biom.12194","article-title":"Bayesian nowcasting during the STEC O104:H4 outbreak in Germany, 2011","volume":"70","author":"M H\u00f6hle","year":"2014","journal-title":"Biometrics"},{"issue":"3","key":"pcbi.1011394.ref005","doi-asserted-by":"crossref","first-page":"195","DOI":"10.1007\/s10654-011-9566-5","article-title":"Nowcasting pandemic influenza A\/H1N1 2009 hospitalizations in the Netherlands","volume":"26","author":"T Donker","year":"2011","journal-title":"European Journal of Epidemiology"},{"issue":"11","key":"pcbi.1011394.ref006","doi-asserted-by":"crossref","first-page":"e1009570","DOI":"10.1371\/journal.pcbi.1009570","article-title":"A nowcasting framework for correcting for reporting delays in malaria surveillance","volume":"17","author":"TF Menkir","year":"2021","journal-title":"PLOS Computational Biology"},{"issue":"22","key":"pcbi.1011394.ref007","doi-asserted-by":"crossref","first-page":"4363","DOI":"10.1002\/sim.8303","article-title":"A modelling approach for correcting reporting delays in disease surveillance data","volume":"38","author":"LS Bastos","year":"2019","journal-title":"Statistics in Medicine"},{"issue":"4","key":"pcbi.1011394.ref008","doi-asserted-by":"crossref","first-page":"e1007735","DOI":"10.1371\/journal.pcbi.1007735","article-title":"Nowcasting by Bayesian Smoothing: A flexible, generalizable model for real-time epidemic tracking","volume":"16","author":"SF McGough","year":"2020","journal-title":"PLOS Computational Biology"},{"issue":"3","key":"pcbi.1011394.ref009","doi-asserted-by":"crossref","first-page":"490","DOI":"10.1002\/bimj.202000112","article-title":"Nowcasting the COVID-19 pandemic in Bavaria","volume":"63","author":"F G\u00fcnther","year":"2021","journal-title":"Biometrical Journal"},{"issue":"5","key":"pcbi.1011394.ref010","first-page":"1266","article-title":"Nowcasting COVID-19 deaths in England by age and region","volume":"71","author":"SR Seaman","year":"2022","journal-title":"Journal of the Royal Statistical Society: Series C (Applied Statistics)"},{"issue":"4","key":"pcbi.1011394.ref011","first-page":"834","article-title":"Bayesian imputation of COVID-19 positive test counts for nowcasting under reporting lag","volume":"71","author":"R Jersakova","year":"2022","journal-title":"Journal of the Royal Statistical Society: Series C (Applied Statistics)"},{"issue":"7","key":"pcbi.1011394.ref012","first-page":"1","article-title":"Bayesian back-calculation and nowcasting for line list data during the COVID-19 pandemic","volume":"17","author":"T Li","year":"2021","journal-title":"PLOS Computational Biology"},{"key":"pcbi.1011394.ref013","unstructured":"Hawryluk I, Hoeltgebaum H, Mishra S, Miscouridou X, Schnekenberg RP, Whittaker C, et al. Gaussian process nowcasting: application to COVID-19 mortality reporting. In: Proceedings of the Thirty-Seventh Conference on Uncertainty in Artificial Intelligence. vol. 161 of Proceedings of Machine Learning Research. PMLR; 2021. p. 1258\u20131268."},{"issue":"1","key":"pcbi.1011394.ref014","doi-asserted-by":"crossref","first-page":"e25538","DOI":"10.2196\/25538","article-title":"Nowcasting for Real-Time COVID-19 Tracking in New York City: An Evaluation Using Reportable Disease Data From Early in the Pandemic","volume":"7","author":"SK Greene","year":"2021","journal-title":"JMIR Public Health Surveill"},{"key":"pcbi.1011394.ref015","unstructured":"German Federal Government. Videoschaltkonferenz der Bundeskanzlerin mit den Regierungschefinnen und Regierungschefs der L\u00e4nder am 18. November 2021; 18 November 2021 [Cited 19 July 2023]. Available from: https:\/\/www.bundesregierung.de\/resource\/blob\/974430\/1982598\/defbdff47daf5f177586a5d34e8677e8\/2021-11-18-mpk-data.pdf."},{"key":"pcbi.1011394.ref016","unstructured":"Norddeutscher Rundfunk. Nach MPK-Beschluss: Verwirrung um Hospitalisierungsinzidenz; 20 November 2021 [Cited 19 July 2023]. Available from: https:\/\/www.ndr.de\/nachrichten\/info\/Nach-MPK-Beschluss-Verwirrung-um-Hospitalisierungsinzidenz,hospitalisierungsinzidenz100.html."},{"issue":"15","key":"pcbi.1011394.ref017","doi-asserted-by":"crossref","first-page":"e2113561119","DOI":"10.1073\/pnas.2113561119","article-title":"Evaluation of individual and ensemble probabilistic forecasts of COVID-19 mortality in the United States","volume":"119","author":"EY Cramer","year":"2022","journal-title":"Proceedings of the National Academy of Sciences"},{"issue":"1","key":"pcbi.1011394.ref018","doi-asserted-by":"crossref","first-page":"5173","DOI":"10.1038\/s41467-021-25207-0","article-title":"A pre-registered short-term forecasting study of COVID-19 in Germany and Poland during the second wave","volume":"12","author":"J Bracher","year":"2021","journal-title":"Nature Communications"},{"key":"pcbi.1011394.ref019","doi-asserted-by":"crossref","first-page":"e81916","DOI":"10.7554\/eLife.81916","article-title":"Predictive performance of multi-model ensemble forecasts of COVID-19 across European nations","volume":"12","author":"K Sherratt","year":"2023","journal-title":"eLife"},{"issue":"8","key":"pcbi.1011394.ref020","doi-asserted-by":"crossref","first-page":"3146","DOI":"10.1073\/pnas.1812594116","article-title":"A collaborative multiyear, multimodel assessment of seasonal influenza forecasting in the United States","volume":"116","author":"NG Reich","year":"2019","journal-title":"Proceedings of the National Academy of Sciences"},{"issue":"2","key":"pcbi.1011394.ref021","doi-asserted-by":"crossref","first-page":"e1008618","DOI":"10.1371\/journal.pcbi.1008618","article-title":"Evaluating epidemic forecasts in an interval format","volume":"17","author":"J Bracher","year":"2021","journal-title":"PLOS Computational Biology"},{"key":"pcbi.1011394.ref022","unstructured":"Bracher J, Wolffram D, the COVID-19 Nowcast Hub team and participants. Study Protocol: Comparison and combination of COVID-19 hospitalization nowcasts in Germany; Deposited 23 November 2021. Registry of the Open Science Foundation, https:\/\/osf.io\/mru75\/."},{"key":"pcbi.1011394.ref023","unstructured":"Robert Koch Institute. COVID-19-Hospitalisierungen in Deutschland; 12 January 2023. Available from: https:\/\/github.com\/robert-koch-institut\/COVID-19-Hospitalisierungen_in_Deutschland."},{"key":"pcbi.1011394.ref024","unstructured":"German Federal Ministry of Health. FAQ zur Hospitalisierungsinzidenz; 7 October 2021 [Cited 19 July 2023]. Available from: https:\/\/www.bundesgesundheitsministerium.de\/coronavirus\/hospitalisierungsinzidenz.html."},{"key":"pcbi.1011394.ref025","article-title":"Syndromic surveillance for severe acute respiratory infections (SARI) enables valid estimation of COVID-19 hospitalization incidence and reveals underreporting of hospitalizations during pandemic peaks of three COVID-19 waves in Germany, 2020-2021","author":"K Tolksdorf","year":"2022","journal-title":"medRxiv"},{"key":"pcbi.1011394.ref026","unstructured":"Abbott S, Lison A, Funk S, Pearson C, Gruson H. epinowcast: Flexible hierarchical nowcasting; 2021. Available from: https:\/\/github.com\/epinowcast\/epinowcast."},{"key":"pcbi.1011394.ref027","unstructured":"Heyder S, Hotz T. The ILM-prop model: method and code; 2023. Available from: https:\/\/github.com\/Stochastik-TU-Ilmenau\/ILM-prop."},{"issue":"0","key":"pcbi.1011394.ref028","article-title":"Statistical modelling of COVID-19 data: Putting generalized additive models to work","volume":"0","author":"C Fritz","year":"2022","journal-title":"Statistical Modelling"},{"issue":"3","key":"pcbi.1011394.ref029","doi-asserted-by":"crossref","first-page":"471","DOI":"10.1002\/bimj.202000143","article-title":"Nowcasting fatal COVID-19 infections on a regional level in Germany","volume":"63","author":"M Schneble","year":"2021","journal-title":"Biometrical Journal"},{"issue":"5","key":"pcbi.1011394.ref030","doi-asserted-by":"crossref","first-page":"737","DOI":"10.1097\/EDE.0000000000001050","article-title":"Nowcasting the number of new symptomatic cases during infectious disease outbreaks using constrained P-spline smoothing","volume":"30","author":"J van de Kassteele","year":"2019","journal-title":"Epidemiology (Cambridge, Mass)"},{"issue":"17","key":"pcbi.1011394.ref031","first-page":"10","article-title":"Sch\u00e4tzung der aktuellen Entwicklung der SARS-CoV-2- Epidemie in Deutschland\u2014Nowcasting","volume":"2020","author":"M an der Heiden","year":"2020","journal-title":"Epidemiologisches Bulletin"},{"issue":"1","key":"pcbi.1011394.ref032","doi-asserted-by":"crossref","first-page":"15","DOI":"10.2307\/3315826.n1","article-title":"Adjustments for reporting delays and the prediction of occurred but not reported events","volume":"22","author":"JF Lawless","year":"1994","journal-title":"Canadian Journal of Statistics"},{"key":"pcbi.1011394.ref033","first-page":"1137","article-title":"Vincentization revisited","author":"C Genest","year":"1992","journal-title":"The Annals of Statistics"},{"issue":"7","key":"pcbi.1011394.ref034","doi-asserted-by":"crossref","first-page":"1594","DOI":"10.1287\/mnsc.1120.1667","article-title":"Is It Better to Average Probabilities or Quantiles?","volume":"59","author":"KC Lichtendahl","year":"2013","journal-title":"Management Science"},{"key":"pcbi.1011394.ref035","doi-asserted-by":"crossref","DOI":"10.1017\/CBO9780511754098","volume-title":"Quantile regression","author":"R Koenker","year":"2005"},{"issue":"3","key":"pcbi.1011394.ref036","doi-asserted-by":"crossref","first-page":"1093","DOI":"10.3982\/ECTA7880","article-title":"Quantile and probability curves without crossing","volume":"78","author":"V Chernozhukov","year":"2010","journal-title":"Econometrica"},{"issue":"477","key":"pcbi.1011394.ref037","doi-asserted-by":"crossref","first-page":"359","DOI":"10.1198\/016214506000001437","article-title":"Strictly proper scoring rules, prediction, and estimation","volume":"102","author":"T Gneiting","year":"2007","journal-title":"Journal of the American Statistical Association"},{"issue":"3","key":"pcbi.1011394.ref038","doi-asserted-by":"crossref","first-page":"505","DOI":"10.1111\/rssb.12154","article-title":"Of quantiles and expectiles: consistent scoring functions, Choquet representations and forecast rankings","volume":"78","author":"W Ehm","year":"2016","journal-title":"Journal of the Royal Statistical Society: Series B (Statistical Methodology)"},{"issue":"12","key":"pcbi.1011394.ref039","first-page":"371","article-title":"A Tutorial on Conformal Prediction","volume":"9","author":"G Shafer","year":"2008","journal-title":"Journal of Machine Learning Research"},{"key":"pcbi.1011394.ref040","unstructured":"Berliner Morgenpost. Triage in Sachsen: Kliniken bereiten sich auf Schlimmes vor; 23 November 2021 [Cited 19 July 2023]. Available from: https:\/\/www.morgenpost.de\/vermischtes\/article233915811\/corona-sachsen-triage-intensivstationen-ueberlastung.html."},{"key":"pcbi.1011394.ref041","doi-asserted-by":"crossref","first-page":"437","DOI":"10.1016\/S0140-6736(22)00017-4","article-title":"Early assessment of the clinical severity of the SARS-CoV-2 omicron variant in South Africa: a data linkage study","volume":"10323","author":"N Wolter","year":"2022","journal-title":"The Lancet"},{"issue":"12","key":"pcbi.1011394.ref042","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1371\/journal.pcbi.1010767","article-title":"Bayesian nowcasting with leading indicators applied to COVID-19 fatalities in Sweden","volume":"18","author":"F Bergstr\u00f6m","year":"2022","journal-title":"PLOS Computational Biology"},{"key":"pcbi.1011394.ref043","unstructured":"Heinsch M, Schmid-Johannsen J. Mit oder wegen Corona im Krankenhaus? So bedingt aussagekr\u00e4ftig sind die BW-Daten; 4 February 2022 [Cited 19 July 2023]. Available from: https:\/\/www.swr.de\/swraktuell\/baden-wuerttemberg\/was-sagt-die-hospitalisierungsinzidenz-in-der-omikron-welle-aus-100.html."}],"updated-by":[{"DOI":"10.1371\/journal.pcbi.1011394","type":"new_version","label":"New version","source":"publisher","updated":{"date-parts":[[2023,8,23]],"date-time":"2023-08-23T00:00:00Z","timestamp":1692748800000}}],"container-title":["PLOS Computational Biology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pcbi.1011394","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,8,23]],"date-time":"2023-08-23T13:33:43Z","timestamp":1692797623000},"score":1,"resource":{"primary":{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pcbi.1011394"}},"subtitle":[],"editor":[{"given":"James M","family":"McCaw","sequence":"first","affiliation":[]}],"short-title":[],"issued":{"date-parts":[[2023,8,11]]},"references-count":43,"journal-issue":{"issue":"8","published-online":{"date-parts":[[2023,8,11]]}},"URL":"https:\/\/doi.org\/10.1371\/journal.pcbi.1011394","relation":{"has-preprint":[{"id-type":"doi","id":"10.1101\/2023.04.17.23288668","asserted-by":"object"}]},"ISSN":["1553-7358"],"issn-type":[{"value":"1553-7358","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,8,11]]}}}