Comparison of characteristics and outcomes of patients admitted to hospital with COVID-19 during wave 1 and wave 2 of the current pandemic
- PMID: 34637079
- PMCID: PMC8505475
- DOI: 10.1007/s11739-021-02842-5
Comparison of characteristics and outcomes of patients admitted to hospital with COVID-19 during wave 1 and wave 2 of the current pandemic
Abstract
In this study of patients admitted with COVID-19, we examined differences between the two waves in patient characteristics and outcomes. Data were collected from the first COVID-19 admission to the end of study (01/03/2020-31/03/2021). Data were adjusted for age and sex and presented as odds ratios (OR) with 95% confidence intervals (CI). Among 12,471 admissions, 1452 (11.6%) patients were diagnosed with COVID-19. On admission, the mean (± SD) age of patients with other causes was 68.3 years (± 19.8) and those with COVID-19 in wave 1 was 69.4 years (± 18.0) and wave 2 was 66.2 years (± 18.4). Corresponding ages at discharge were 67.5 years (± 19.7), 63.9 years (± 18.0) and 62.4 years (± 18.0). The highest proportion of total admissions was among the oldest group (≥ 80 years) in wave 1 (35.0%). When compared with patients admitted with other causes, those admitted with COVID-19 in wave 1 and in wave 2 were more frequent in the 40-59 year band: 20.8, 24.6 and 30.0%; consisted of more male patients: 47.5, 57.6 and 58.8%; and a high LACE (Length of stay, Acuity of admission, Comorbidity and Emergency department visits) index (score ≥ 10): 39.4, 61.3 and 50.3%. Compared to wave-2 patients, those admitted in wave 1 had greater risk of death in hospital: OR = 1.58 (1.18-2.12) and within 30 days of discharge: OR = 2.91 (1.40-6.04). Survivors of COVID-19 in wave 1 stayed longer in hospital (median = 6.5 days; interquartile range = 2.9-12.0) as compared to survivors from wave 2 (4.5 days; interquartile range = 1.9-8.7). Patient characteristics differed significantly between the two waves of COVID-19 pandemic. There was an improvement in outcomes in wave 2, including shorter length of stay in hospital and reduction of mortality.
Keywords: Coronavirus; Frequent readmission; LACE index; Length of stay; Mortality.
© 2021. The Author(s).
Conflict of interest statement
The authors declare that they have no conflicts of interest.
Figures



Similar articles
-
Does the length of stay in hospital affect healthcare outcomes of patients without COVID-19 who were admitted during the pandemic? A retrospective monocentric study.Intern Emerg Med. 2022 Aug;17(5):1385-1393. doi: 10.1007/s11739-022-02945-7. Epub 2022 Feb 24. Intern Emerg Med. 2022. PMID: 35211848 Free PMC article.
-
Comparison of characteristics, predictors and outcomes between the first and second COVID-19 waves in a tertiary care centre in Switzerland: an observational analysis.Swiss Med Wkly. 2021 Aug 10;151:w20569. doi: 10.4414/smw.2021.20569. eCollection 2021 Aug 2. Swiss Med Wkly. 2021. PMID: 34375985
-
Association of Remdesivir Treatment With Survival and Length of Hospital Stay Among US Veterans Hospitalized With COVID-19.JAMA Netw Open. 2021 Jul 1;4(7):e2114741. doi: 10.1001/jamanetworkopen.2021.14741. JAMA Netw Open. 2021. PMID: 34264329 Free PMC article.
-
The risk of death or unplanned readmission after discharge from a COVID-19 hospitalization in Alberta and Ontario.CMAJ. 2022 May 16;194(19):E666-E673. doi: 10.1503/cmaj.220272. CMAJ. 2022. PMID: 35577377 Free PMC article.
-
Difference in mortality among individuals admitted to hospital with COVID-19 during the first and second waves in South Africa: a cohort study.Lancet Glob Health. 2021 Sep;9(9):e1216-e1225. doi: 10.1016/S2214-109X(21)00289-8. Epub 2021 Jul 9. Lancet Glob Health. 2021. PMID: 34252381 Free PMC article.
Cited by
-
COVID-19 in Iran: clinical presentations and outcomes in three different surges of COVID-19 infection.Virol J. 2022 Jul 26;19(1):123. doi: 10.1186/s12985-022-01846-7. Virol J. 2022. PMID: 35883172 Free PMC article.
-
Evaluation of the association of length of stay in hospital and outcomes.Int J Qual Health Care. 2022 May 2;34(2):mzab160. doi: 10.1093/intqhc/mzab160. Int J Qual Health Care. 2022. PMID: 34918090 Free PMC article.
-
Does the length of stay in hospital affect healthcare outcomes of patients without COVID-19 who were admitted during the pandemic? A retrospective monocentric study.Intern Emerg Med. 2022 Aug;17(5):1385-1393. doi: 10.1007/s11739-022-02945-7. Epub 2022 Feb 24. Intern Emerg Med. 2022. PMID: 35211848 Free PMC article.
-
Comparing Care Pathways Between COVID-19 Pandemic Waves Using Electronic Health Records: A Process Mining Case Study.J Healthc Inform Res. 2024 Dec 23;9(1):41-66. doi: 10.1007/s41666-024-00181-6. eCollection 2025 Mar. J Healthc Inform Res. 2024. PMID: 39897098 Free PMC article.
References
-
- World Health Organization. Coronavirus disease (COVID-19) pandemic. https://www.who.int/emergencies/diseases/novel-coronavirus-2019. Accessed 20 Apr 2021
-
- Onder G, Rezza G, Brusaferro S. Case-fatality rate and characteristics of patients dying in relation to COVID-19 in Italy. JAMA. 2020;323:1775–1776. - PubMed
-
- Docherty AB, Harrison EM, Green CA, Hardwick HE, Pius R, Norman L, Holden KA, Read JM, Dondelinger F, Carson G, Merson L. Features of 20 133 UK patients in hospital with COVID-19 using the ISARIC WHO Clinical Characterisation Protocol: prospective observational cohort study. BMJ. 2020;369:m1985. doi: 10.1136/bmj.m1985. - DOI - PMC - PubMed
Publication types
MeSH terms
LinkOut - more resources
Full Text Sources
Medical