Prognostic value of novel indices combining Shock Index, Reverse Shock Index, age, and oxygen saturation for predicting mortality in COVID-19 patients in Iran at emergency department triage: a cross-sectional study.

BACKGROUND

The objective of the study was to investigate the role of the Shock Index (SI), the Reverse Shock Index (RSI) along with oxygen saturation in predicting mortality in coronavirus disease 2019 (COVID-19).

METHODS

This cross-sectional study was conducted at an academic hospital over a period of 6 months and involved patients over the age of 18 who had been diagnosed with COVID-19 via positive polymerase chain reaction tests. The data were recorded anonymously using a checklist. The study focused on indices such as the SI and RSI, both alone and in conjunction with age and oxygen saturation, to predict hospital mortality. Statistical analysis was conducted using SPSS software.

RESULTS

The study involved 500 COVID-19 patients with a 14.4% mortality rate. Key differences were found between survival and mortality groups in terms of age, vital signs except diastolic blood pressure, length of stay, and a series of laboratory tests. Logistic regression showed gender, oxygen saturation, hemoglobin, direct bilirubin, lactate dehydrogenase, D-dimer, and Age SI/oxygen saturation (SpO2) and RSI×SpO2/Age indices significantly associated with hospital mortality. Receiver operating characteristic analysis indicated Age SI/SpO2 and RSI×SpO2/Age as effective mortality predictors, exhibiting an area under the curve of 0.80 and achieving a sensitivity, specificity, and accuracy of over 70%.

CONCLUSIONS

The combination of SI, the RSI along with hypoxia, and age has been identified as a potentially more significant role in ruling out hospital mortality in COVID-19 patients than vital signs alone, given the established role of hypoxia as a major risk factor in such cases.