Developing a COVID-19 WHO Clinical Progression Scale inpatient database from electronic health record data

Abstract

Objective: There is a need for a systematic method to implement the World Health Organization's Clinical Progression Scale (WHO-CPS), an ordinal clinical severity score for coronavirus disease 2019 patients, to electronic health record (EHR) data. We discuss our process of developing guiding principles mapping EHR data to WHO-CPS scores across multiple institutions.

Materials and methods: Using WHO-CPS as a guideline, we developed the technical blueprint to map EHR data to ordinal clinical severity scores. We applied our approach to data from 2 medical centers.

Results: Our method was able to classify clinical severity for 100% of patient days for 2756 patient encounters across 2 institutions.

Discussion: Implementing new clinical scales can be challenging; strong understanding of health system data architecture was integral to meet the clinical intentions of the WHO-CPS.

Conclusion: We describe a detailed blueprint for how to apply the WHO-CPS scale to patient data from the EHR.

Keywords: COVID-19; World Health Organization; electronic health records; medical informatics; public health informatics.

Figure 1.

Star schema for COVID-19 patient encounter report. *Comorbidity data collected were the ICD-10 codes linked to a patient's medical history at the time of admission. **Other social/demographic data includes zip code, insurance type, smoking status, marital status, and language.

Figure 2.

Pseudocode for assigning a maximum WHO-CPS score per hospital day for each patient encounter, based on C19-Daily data columns. WHO-CPS: World Health Organization’s Clinical Progression Scale.

Figure 3.

Patient-days per week at each WHO-CPS scale on aggregate UTSW and UCSF. Total number of patient days at each WHO-CPS stage per week across aggregate UCSF and UTSW are shown. From February 3, 2020 to April 22, 2021, there were 32 435 patient days spanning 2756 patient hospital admissions. (a) Shows WHO-CPS scores 4–10 while (b) shows only WHO-CPS scores 7–10, capturing severe disease (ICU level care) and death. UCSF: University of California, San Francisco; UTSW: University of Texas Southwestern Medical Center; WHO-CPS: World Health Organization’s Clinical Progression Scale.