Development and Validation of the COVID-NoLab and COVID-SimpleLab Risk Scores for Prognosis in 6 US Health Systems

J Am Board Fam Med. 2021 Feb;34(Suppl):S127-S135. doi: 10.3122/jabfm.2021.S1.200464.


Purpose: Develop and validate simple risk scores based on initial clinical data and no or minimal laboratory testing to predict mortality in hospitalized adults with COVID-19.

Methods: We gathered clinical and initial laboratory variables on consecutive inpatients with COVID-19 who had either died or been discharged alive at 6 US health centers. Logistic regression was used to develop a predictive model using no laboratory values (COVID-NoLab) and one adding tests available in many outpatient settings (COVID-SimpleLab). The models were converted to point scores and their accuracy evaluated in an internal validation group.

Results: We identified 1340 adult inpatients with complete data for nonlaboratory parameters and 741 with complete data for white blood cell (WBC) count, differential, c-reactive protein (CRP), and serum creatinine. The COVID-NoLab risk score includes age, respiratory rate, and oxygen saturation and identified risk groups with 0.8%, 11.4%, and 40.4% mortality in the validation group (AUROCC = 0.803). The COVID-SimpleLab score includes age, respiratory rate, oxygen saturation, WBC, CRP, serum creatinine, and comorbid asthma and identified risk groups with 1.0%, 9.1%, and 29.3% mortality in the validation group (AUROCC = 0.833).

Conclusions: Because they use simple, readily available predictors, developed risk scores have potential applicability in the outpatient setting but require prospective validation before use.

Keywords: COVID-19; Clinical Decision Support; Clinical Prediction Rule; Logistic Models.

Publication types

  • Multicenter Study
  • Validation Study

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • COVID-19 / diagnosis*
  • COVID-19 / mortality
  • Decision Support Systems, Clinical / standards*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Pandemics
  • Prognosis
  • Risk Assessment / methods*
  • Risk Factors
  • SARS-CoV-2
  • United States / epidemiology