Rothman Index at Time of Admission Identifies Patients With COVID-19 Susceptible to Rapid Deterioration

February 2, 2021

By Eric Ramos

CHICAGO -- February 1, 2021 -- Using the Rothman Index (RI) acuity score at the time of admission can identify patients with coronavirus disease 2019 (COVID-19) who are susceptible to rapid deterioration, according to a study presented at the Virtual 50th Annual Meeting of the Society of Critical Care Medicine (SCCM).

“The Rothman Index is an excellent predictor to stratify COVID-19 patient risk at the time of admission,” said Joseph Beals, PhD, PeraHealth, Charlotte, North Carolina. “In particular we found that patients with COVID-19 who present with raised but unremarkable acuity may be flagged as high risk for physiological deterioration.”

“Early recognition of patients’ risk is crucial to the effective delivery of care,” he added. “The need to determine the appropriate level of care for patients holds true even as treatments change and outcomes improve.”

The researchers analysed data from 3,499 patients with COVID-19 who were admitted to 1 of 4 hospitals (Sinai Hospital, Baltimore, Maryland; Yale New Haven Hospital, New Haven, Connecticut; Bridgeport Hospital, Bridgeport, Connecticut; Greenwich Hospital, Greenwich, Connecticut). They also analysed data from 14,658 non-COVID-19 adult admissions at these hospitals.

As a direct measure of acuity, the Rothman Index was a substantially better predictor of COVID-19 in-hospital mortality than the Charlson Comorbidity Index or age, with area under the curve values of ≥0.80 at all 4 hospitals.

“This shouldn’t be a surprise since the Rothman Index incorporates a wide range of clinical data that reflects acuity, and by extension, patient risk,” said Dr. Beals. “Even more telling was the difference in risk when comparing patients on the bases of physiological acuity, as measured by the Rothman Index.”

For example, among patients without COVID-19 with a score of 40, which is the level of acuity for which patients are considered for intensive care unit (ICU) admission, the mortality risk was 5%. However, for patients with COVID-19 with the same score, their mortality risk was around 25%.

“That’s a startling difference,” said Dr. Beals. “This has an important implication. It means that a clinicians experience with non-COVID patients and their sense of the patient’s risk, based on how the patient presented to admission, does not translate to an understanding of risk for COVID-19 patients on admission. In other words, a clinician’s experience and intuition can actually be misleading and needs to be recalibrated.”

At selected RI cut-points, the high-risk segment constituted 18-27% of COVID-19 patients with a mortality rate of 39-46%. The low-risk segment constituted 48%-58% of patients with a mortality rate of 1%-3%.

The Rothman Index computed at the time of admission provided a high degree of discrimination to differentiate COVID-19 populations into high and low-risk groups, with 2 selected cut-off points. An index score 70 (~50% of patients with COVID-19) indicates low risk, necessitating lower level care or earlier discharge.

Dr. Beals said that using the Rothman Index to stratify patients can “aid providers in aligning level of care decisions at admission with hospital and ICU capacity constraints.”

[Presentation title: Early Identification of COVID-19 Patients Susceptible to Rapid Deterioration Using the Rothman Index]