Coronavirus Disease 2019 (COVID-19) Diagnostic Clinical Decision Support: A Pre-Post Implementation Study of CORAL (COvid Risk cALculator)

Abstract

Background: Isolation of hospitalized persons under investigation (PUIs) for coronavirus disease 2019 (COVID-19) reduces nosocomial transmission risk. Efficient evaluation of PUIs is needed to preserve scarce healthcare resources. We describe the development, implementation, and outcomes of an inpatient diagnostic algorithm and clinical decision support system (CDSS) to evaluate PUIs.

Methods: We conducted a pre-post study of CORAL (COvid Risk cALculator), a CDSS that guides frontline clinicians through a risk-stratified COVID-19 diagnostic workup, removes transmission-based precautions when workup is complete and negative, and triages complex cases to infectious diseases (ID) physician review. Before CORAL, ID physicians reviewed all PUI records to guide workup and precautions. After CORAL, frontline clinicians evaluated PUIs directly using CORAL. We compared pre- and post-CORAL frequency of repeated severe acute respiratory syndrome coronavirus 2 nucleic acid amplification tests (NAATs), time from NAAT result to PUI status discontinuation, total duration of PUI status, and ID physician work hours, using linear and logistic regression, adjusted for COVID-19 incidence.

Results: Fewer PUIs underwent repeated testing after an initial negative NAAT after CORAL than before CORAL (54% vs 67%, respectively; adjusted odd ratio, 0.53 [95% confidence interval, .44-.63]; P < .01). CORAL significantly reduced average time to PUI status discontinuation (adjusted difference [standard error], -7.4 [0.8] hours per patient), total duration of PUI status (-19.5 [1.9] hours per patient), and average ID physician work-hours (-57.4 [2.0] hours per day) (all P < .01). No patients had a positive NAAT result within 7 days after discontinuation of precautions via CORAL.

Conclusions: CORAL is an efficient and effective CDSS to guide frontline clinicians through the diagnostic evaluation of PUIs and safe discontinuation of precautions.

Keywords: COVID-19 diagnosis; clinical decision support system; diagnostic algorithm; electronic health record.

Figure 1.

Overview of COvid Risk cALculator (CORAL) workflow. Persons under investigation for coronavirus disease 2019 (COVID-19) (PUIs) are eligible for CORAL if they have ≥1 nucleic acid amplification test (NAAT) with negative results and 1 imaging study performed. On completion of CORAL, PUIs are given a risk score which leads to either a prompt for discontinuation of PUI status with discontinuation of enhanced respiratory isolation (ERI) precautions, or a prompt for repeated nasopharyngeal NAAT, further diagnostics for COVID-19 workup, or infectious diseases (ID) physician review. (a If CORAL cannot be performed, clinicians are instructed to contact the ID physician for review.) See Study Setting and Design for explanation of how CoV-Risk and CoV-Presumed status was assigned. Abbreviations: CT, computed tomography; LRT, lower respiratory tract.

Figure 2.

Outcomes before and after implementation of the COvid Risk cALculator (CORAL). Testing and CoV-Risk status discontinuation outcomes are demonstrated for the pre-CORAL (A) and post-CORAL (B) periods. In the post-CORAL period, outcomes are shown for persons under investigation for coronavirus disease 2019 (COVID-19) (PUIs) for whom CORAL was initially used after 1 (green) or 2 (blue) negative nucleic acid amplification test (NAAT) results. See Study Setting and Design for explanation of how CoV-Risk and CoV-Presumed status was assigned. Abbreviation: ID, infectious diseases physician.

Figure 3.

Daily changes in key outcomes in the periods before and after implementation of the COvid Risk cALculator (CORAL) relative to coronavirus disease 2019 (COVID-19) incidence. The pre-CORAL period (left) is shown with the active evaluation window for persons under evaluation for COVID-19 (PUIs), from 18 March to 23 April 2020, and the passive PUI evaluation window from 24 April to 19 May (Methods). CORAL was launched on 20 May 2020, followed by a 1-week transition period, with the post-CORAL period spanning 27 May to 28 July 2020. The incidence of new COVID-19 diagnoses among hospitalized PUIs, shown as a 5-day moving average, is shown in black (left y-axis) in all panels. (Dates are given in month/date format.) A, Proportion of PUIs with an initial negative nucleic acid amplification test (NAAT) result who underwent repeated testing (solid red line; right y-axis) and the proportion of PUIs with 2 negative NAAT results who underwent additional testing (dashed red line; right y-axis). B, Mean total duration of PUI status (solid blue line; right y-axis) and the mean time from final negative NAAT result return to PUI status discontinuation (dashed blue line; right y-axis). C, Mean infectious diseases (ID) physician person-hours/day dedicated to PUI evaluations (solid green line; right y-axis). Of note, we excluded patients who became PUIs during the pre-CORAL or wash-in period, but who had resolution of CoV-Risk status with CORAL, owing to the duration of their PUI status; the greater fluctuation in results around the end of the pre-CORAL and wash-in period is likely because fewer patients were contributing to the data set in those weeks.