. 2020 Oct 17;17(20):7560.

doi: 10.3390/ijerph17207560.

Time between Symptom Onset, Hospitalisation and Recovery or Death: Statistical Analysis of Belgian COVID-19 Patients

Christel Faes¹, Steven Abrams^{1

2}, Dominique Van Beckhoven³, Geert Meyfroidt⁴, Erika Vlieghe⁵, Niel Hens^{1

6}; Belgian Collaborative Group on COVID-19 Hospital Surveillance³

Collaborators, Affiliations

Collaborators

Belgian Collaborative Group on COVID-19 Hospital Surveillance:
Amir-Samy Aouachria³, Kristof Bafort³, Leïla Belkhir³, Nathalie Bossuyt³, Vincent Colombie³, Nicolas Dauby³, Paul De Munter³, Jessika Deblonde³, Didier Delmarcelle³, Mélanie Delvallee³, Rémy Demeester³, Thierry Dugernier³, Xavier Holemans³, Benjamin Kerzmann³, Pierre Yves Machurot³, Philippe Minette³, Jean-Marc Minon³, Saphia Mokrane³, Catherine Nachtergal³, Séverine Noirhomme³, Denis Piérard³, Camelia Rossi³, Carole Schirvel³, Erica Sermijn³, Frank Staelens³, Filip Triest³, Nina Van Goethem³, Jens Van Praet³, Anke Vanhoenacker³, Sarah Cooreman³, Elise Willems³, Chloé Wyndham-Thomas³

Affiliations

¹ Data Science Institute (DSI), I-BioStat, Universiteit Hasselt, BE-3500 Hasselt, Belgium.
² Global Health Institute (GHI), University of Antwerp, BE-2000 Antwerp, Belgium.
³ Department of Epidemiology and Public Health, Sciensano, BE-1050 Brussels, Belgium.
⁴ Department and Laboratory of Intensive Care Medicine, University Hospitals Leuven and KU Leuven, Herestraat 49, Box 7003 63, 3000 Leuven, Belgium.
⁵ Department of General Internal Medicine, Infectious and Tropical Diseases, University Hospital Antwerp, BE-2000 Antwerp, Belgium.
⁶ Centre for Health Economics Research and Modelling of Infectious Diseases (CHERMID), Vaccine & Infectious Disease Institute (VAXINFECTIO), University of Antwerp, BE-2000 Antwerp, Belgium.

PMID: 33080869
PMCID: PMC7589278
DOI: 10.3390/ijerph17207560

Time between Symptom Onset, Hospitalisation and Recovery or Death: Statistical Analysis of Belgian COVID-19 Patients

Christel Faes et al. Int J Environ Res Public Health. 2020.

. 2020 Oct 17;17(20):7560.

doi: 10.3390/ijerph17207560.

Authors

Christel Faes¹, Steven Abrams^{1

2}, Dominique Van Beckhoven³, Geert Meyfroidt⁴, Erika Vlieghe⁵, Niel Hens^{1

6}; Belgian Collaborative Group on COVID-19 Hospital Surveillance³

Collaborators

Belgian Collaborative Group on COVID-19 Hospital Surveillance:
Amir-Samy Aouachria³, Kristof Bafort³, Leïla Belkhir³, Nathalie Bossuyt³, Vincent Colombie³, Nicolas Dauby³, Paul De Munter³, Jessika Deblonde³, Didier Delmarcelle³, Mélanie Delvallee³, Rémy Demeester³, Thierry Dugernier³, Xavier Holemans³, Benjamin Kerzmann³, Pierre Yves Machurot³, Philippe Minette³, Jean-Marc Minon³, Saphia Mokrane³, Catherine Nachtergal³, Séverine Noirhomme³, Denis Piérard³, Camelia Rossi³, Carole Schirvel³, Erica Sermijn³, Frank Staelens³, Filip Triest³, Nina Van Goethem³, Jens Van Praet³, Anke Vanhoenacker³, Sarah Cooreman³, Elise Willems³, Chloé Wyndham-Thomas³

Affiliations

¹ Data Science Institute (DSI), I-BioStat, Universiteit Hasselt, BE-3500 Hasselt, Belgium.
² Global Health Institute (GHI), University of Antwerp, BE-2000 Antwerp, Belgium.
³ Department of Epidemiology and Public Health, Sciensano, BE-1050 Brussels, Belgium.
⁴ Department and Laboratory of Intensive Care Medicine, University Hospitals Leuven and KU Leuven, Herestraat 49, Box 7003 63, 3000 Leuven, Belgium.
⁵ Department of General Internal Medicine, Infectious and Tropical Diseases, University Hospital Antwerp, BE-2000 Antwerp, Belgium.
⁶ Centre for Health Economics Research and Modelling of Infectious Diseases (CHERMID), Vaccine & Infectious Disease Institute (VAXINFECTIO), University of Antwerp, BE-2000 Antwerp, Belgium.

PMID: 33080869
PMCID: PMC7589278
DOI: 10.3390/ijerph17207560

Abstract

There are different patterns in the COVID-19 outbreak in the general population and amongst nursing home patients. We investigate the time from symptom onset to diagnosis and hospitalization or the length of stay (LoS) in the hospital, and whether there are differences in the population. Sciensano collected information on 14,618 hospitalized patients with COVID-19 admissions from 114 Belgian hospitals between 14 March and 12 June 2020. The distributions of different event times for different patient groups are estimated accounting for interval censoring and right truncation of the time intervals. The time between symptom onset and hospitalization or diagnosis are similar, with median length between symptom onset and hospitalization ranging between 3 and 10.4 days, depending on the age of the patient (longest delay in age group 20-60 years) and whether or not the patient lives in a nursing home (additional 2 days for patients from nursing home). The median LoS in hospital varies between 3 and 10.4 days, with the LoS increasing with age. The hospital LoS for patients that recover is shorter for patients living in a nursing home, but the time to death is longer for these patients. Over the course of the first wave, the LoS has decreased.

Keywords: COVID-19; length of stay in hospital; symptom onset to hospitalization; truncation and interval-censoring.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.

Figures

**Figure A1**
Flow diagram: ( $n_{1}$ ; $n_{2}$ ) on the left hand side correspond, respectively, to the number of patients for the analysis of time of symptom onset to hospitalization and for time of symptom onset to diagnosis. The number of patients $n_{3}$ on the right hand size correspond to the length of stay in hospital.

**Figure A2**
Observed number of new hospitalization in the national surveillance survey (black) and reported number of confirmed hospitalizations in the population (red).

**Figure A3**
Observed density (proportion of the population in the survey) of time between symptom onset and hospitalization (**top left**) and between symptom onset and diagnosis (**top right**); and observed length of stay in hospital (all COVID-19 patients (**middle left**), recovered patients (**middle right**), patients that died (**bottom left**) and length of stay in ICU (**bottom right**).

**Figure A4**
Comparison of delay distribution for different time periods. The boxplots show the estimated $5 %, 25 %, 50 %, 75 %$ and $95 %$ quantiles, based on Weibull regression. Results are based on the time period 01 March to 20 March (period 1), 21 March to 30 March (period 2), 31 March to 18 April (period 3) and 19 April to 12 June (period 4).

**Figure A5**
Comparison of delay distribution for different population groups. The boxplots show the estimated $5 %, 25 %, 50 %, 75 %$ and $95 %$ quantiles, based on (untruncated) Weibull regression. Results are based on period 21 March to 30 March.

**Figure A6**
Comparison of delay distribution for different population groups. The boxplots show the estimated $5 %, 25 %, 50 %, 75 %$ and $95 %$ quantiles, based on a truncated Weibull regression. The time intervals are assumed interval-censored in intervals $(x_{i} - 1, x_{i} + 1)$ . Results are based on period 21 March to 30 March.

**Figure A7**
Comparison of delay distribution for different population groups. The boxplots show the estimated $5 %, 25 %, 50 %, 75 %$ and $95 %$ quantiles, based on Weibull regression. Results are based on the time period 01 March to 20 March (period 1), 21 March to 30 March (period 2), 31 March to 18 April (period 3) and 19 April to 12 June (period 4).

**Figure A8**
Comparison of delay distribution for different population groups. The boxplots show the estimated $5 %, 25 %, 50 %, 75 %$ and $95 %$ quantiles, based on lognormal regression. The time intervals are assumed interval-censored in intervals $(x_{i} - 1, x_{i} + 1)$ . Results are based on period 21 March to 30 March.

**Figure 1**
Comparison of delay distribution for different population groups. Top: delay from symptom onset to hospitalization and diagnosis; Middle: LoS for all patients and for recovered patients; Bottom: LoS for patients that died and LoS in ICU. The boxplots show the estimated $5 %, 25 %, 50 %, 75 %$ and $95 %$ quantiles. Results are based on period 21 March to 30 March. The reported values correspond to the $50 % (25 %, 75 %)$ quantiles.

See this image and copyright information in PMC

References

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Time between Symptom Onset, Hospitalisation and Recovery or Death: Statistical Analysis of Belgian COVID-19 Patients

Collaborators

Affiliations

Time between Symptom Onset, Hospitalisation and Recovery or Death: Statistical Analysis of Belgian COVID-19 Patients

Authors

Collaborators

Affiliations

Abstract

Conflict of interest statement

Figures

References

Publication types

MeSH terms

LinkOut - more resources

Full Text Sources