External validation of unsupervised COVID-19 clinical phenotypes and their prognostic impact

Ann Med. 2023 Dec;55(1):2195204. doi: 10.1080/07853890.2023.2195204.

Abstract

Background: Hospitalized patients with coronavirus disease 2019 (COVID-19) can be classified into different clinical phenotypes based on their demographic, clinical, radiology, and laboratory features. We aimed to validate in an external cohort of hospitalized COVID-19 patients the prognostic value of a previously described phenotyping system (FEN-COVID-19) and to assess the reproducibility of phenotypes development as a secondary analysis.

Methods: Patients were classified in phenotypes A, B or C according to the severity of oxygenation impairment, inflammatory response, hemodynamic and laboratory tests according to the FEN-COVID-19 method.

Results: Overall, 992 patients were included in the study, and 181 (18%), 757 (76%) and 54 (6%) of them were assigned to the FEN-COVID-19 phenotypes A, B, and C, respectively. An association with mortality was observed for phenotype C vs. A (hazard ratio [HR] 3.10, 95% confidence interval [CI] 1.81-5.30, p < 0.001) and for phenotype C vs. B (HR 2.20, 95% CI 1.50-3.23, p < 0.001). A non-statistically significant trend towards higher mortality was also observed for phenotype B vs. A (HR 1.41; 95% CI 0.92-2.15, p = 0.115). By means of cluster analysis, three different phenotypes were also identified in our cohort, with an overall similar gradient in terms of prognostic impact to that observed when patients were assigned to FEN-COVID-19 phenotypes.

Conclusions: The prognostic impact of FEN-COVID-19 phenotypes was confirmed in our external cohort, although with less difference in mortality between phenotypes A and B than in the original study.

Keywords: COVID-19; SARS-CoV-2; external validation; pandemic; phenotypes; prognosis; unsupervised clustering.

Plain language summary

Hospitalized patients with COVID-19 can be classified into different clinical phenotypes based on their demographic, clinical, radiology, and laboratory featuresIn this study, we externally confirmed the prognostic impact of clinical phenotypes previously identified by Gutierrez-Gutierrez and colleagues in a Spanish cohort of hospitalized patients with COVID-19, and the usefulness of their simplified probabilistic model for phenotypes assignmentThis could indirectly support the validity of both phenotype’s development and their extrapolation to other hospitals and countries for management decisions during other possible future viral pandemics.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • COVID-19* / diagnosis
  • Humans
  • Prognosis
  • Proportional Hazards Models
  • Reproducibility of Results
  • Retrospective Studies
  • SARS-CoV-2

Grants and funding

The present work was partly supported by “donazioni per ricerca scientifica su coronavirus” to the Department of Health Sciences (DISSAL), University of Genoa, and by ““fondi donazioni COVID-19” to IRCCS Ospedale Policlinico San Martino.