qcsi_score: Quick COVID-19 Severity Index (qCSI)

In cliot: Clinical Indices and Outcomes Tools

Quick COVID-19 Severity Index (qCSI)

Description

Calculates the qCSI score to predict the 24-hour risk of critical respiratory illness (defined as high-flow oxygen, non-invasive ventilation, intubation, or death) in patients admitted with COVID-19. The score relies on three bedside variables: respiratory rate, pulse oximetry, and oxygen flow rate.

Usage

qcsi_score(respiratory_rate, oxygen_saturation, o2_flow_rate)

Arguments

respiratory_rate	Numeric. Respiratory rate in breaths per minute. <= 22: 0 pts. 23-28: 1 pt. > 28: 2 pts.
oxygen_saturation	Numeric. Minimum documented pulse oximetry (SpO2) percent. > 92: 0 pts. 89-92: 2 pts. <= 88: 5 pts.
o2_flow_rate	Numeric. Oxygen flow rate in Liters per minute (L/min) at the time of minimum SpO2. 0 (Room air): 0 pts. 1-2 L/min: 4 pts. 3-4 L/min: 5 pts. >= 5 L/min: 6 pts.

Value

A list containing:

qCSI_Score	The calculated total score (Range 0-12).
Risk_Category	Risk classification (Low, Low-Intermediate, High-Intermediate, High).
Est_24hr_Critical_Illness_Risk	Estimated probability of critical illness within 24 hours.

References

Haimovich AD, Ravindra NG, Stoytchev S, et al. Development and Validation of the Quick COVID-19 Severity Index: A Prognostic Tool for Early Clinical Decompensation. Ann Emerg Med. 2020;76(4):442-453. doi:10.1016/j.annemergmed.2020.07.022

Examples

# Example 1: Low Risk
# RR 18, SpO2 95%, Room Air (0L)
# Score = 0
qcsi_score(18, 95, 0)

# Example 2: High Risk
# RR 30 (+2), SpO2 88% (+5), 4L O2 (+5)
# Score = 12
qcsi_score(30, 88, 4)

cliot documentation built on Dec. 1, 2025, 1:06 a.m.