A biomarker based severity progression indicator for COVID-19: the Kuwait prognosis indicator score

Biomarkers. 2020 Dec;25(8):641-648. doi: 10.1080/1354750X.2020.1841296. Epub 2020 Nov 24.


Background: COVID-19 is a worldwide pandemic that is mild in most patients but can result in a pneumonia like illness with progression to acute respiratory distress syndrome and death. Predicting the disease severity at time of diagnosis can be helpful in prioritizing hospital admission and resources.

Methods: We prospectively recruited 1096 consecutive patients of whom 643 met the inclusion criterion with COVID-19 from Jaber Hospital, a COVID-19 facility in Kuwait, between 24 February and 20 April 2020. The primary endpoint of interest was disease severity defined algorithmically. Predefined risk variables were collected at the time of PCR based diagnosis of the infection. Prognostic model development used 5-fold cross-validated regularized logit regression. The model was externally validated against data from Wuhan, China.

Results: There were 643 patients with clinical course data of whom 94 developed severe COVID-19. In the final model, age, CRP, procalcitonin, lymphocyte percentage, monocyte percentages and serum albumin were independent predictors of a more severe illness course. The final prognostic model demonstrated good discrimination, and both discrimination and calibration were confirmed with an external dataset.

Conclusion: We developed and validated a simple score calculated at time of diagnosis that can predict patients with severe COVID-19 disease reliably and that has been validated externally. The KPI score calculator is now available online at covidkscore.com.

Keywords: COVID-19; adverse outcome; health policy; mortality; procalcitonin; prognosis.

MeSH terms

  • Adult
  • Aged
  • Biomarkers / blood*
  • C-Reactive Protein / metabolism*
  • COVID-19 / blood*
  • COVID-19 / epidemiology
  • COVID-19 / virology
  • Disease Progression
  • Female
  • Humans
  • Internet
  • Kuwait / epidemiology
  • Male
  • Middle Aged
  • Pandemics
  • Procalcitonin / blood*
  • Prognosis
  • Prospective Studies
  • SARS-CoV-2 / physiology
  • Serum Albumin / metabolism*
  • Severity of Illness Index


  • Biomarkers
  • Procalcitonin
  • Serum Albumin
  • C-Reactive Protein

Grant support

Suhail A. Doi and Mohammed Chowdhury were supported by Qatar University COVID19 Emergency Response Grant [QUERG-CENG-2020-1]. The responsibility for the findings herein are solely the responsibility of the authors.Open Access funding provided by the Qatar National Library.