From the Research
The Severity of Illness (SOI) and Risk of Mortality (ROM) are distinct metrics calculated according to the Diagnosis-Related Group (DRG) assignment, with SOI measuring the extent of physiologic decompensation and ROM estimating the likelihood of dying, both ranked in severity from 1 to 4. These metrics are used in healthcare settings to assess patient acuity and expected resource utilization. The SOI and ROM scores are calculated using complex algorithms that consider principal and secondary diagnoses, procedures performed, age, and other clinical factors 1.
Key Points
- The SOI measures the extent of physiologic decompensation or organ system loss of function, while ROM estimates the likelihood of dying.
- Both use a 4-point scale where 1 represents minor severity or risk, 2 indicates moderate, 3 signifies major, and 4 denotes extreme severity or risk.
- These classifications help healthcare facilities with resource allocation, quality improvement initiatives, and appropriate reimbursement.
- Understanding a patient's SOI and ROM scores helps clinicians make informed decisions about treatment plans and level of care needed.
Recent Evidence
A recent study published in 2024 found that SOI and ROM are two scales of different concepts, rather than two sides of the same coin, with high heterogeneity across APR-DRGs 1. Another study published in 2022 found that SOI or ROM, combined with age and sex, perform better than more widely used comorbidity indices in predicting in-hospital mortality 2.
Clinical Application
Healthcare providers use these metrics to prioritize care, determine appropriate staffing levels, and identify patients who may require more intensive monitoring or intervention. For example, a study published in 2023 found that patients in the Advanced Care at Home program had an average APR-DRG SOI of 2.89 and ROM of 2.73, indicating moderate to major severity of illness and risk of mortality 3.
Recommendation
Based on the most recent and highest quality study, it is recommended to use SOI and ROM scores in conjunction with other clinical factors to inform treatment decisions and resource allocation 1. This approach can help clinicians make informed decisions about treatment plans and level of care needed, ultimately improving patient outcomes and reducing morbidity and mortality.