Severity of illness (SOI) is defined as the extent of organ system derangement or physiologic decompensation for a patient. It gives a
medical classification
A medical classification is used to transform descriptions of medical diagnoses or procedures into standardized statistical code in a process known as clinical coding. Diagnosis classifications list diagnosis codes, which are used to track dise ...
into minor, moderate, major, and extreme. The SOI class is meant to provide a basis for evaluating
hospital
A hospital is a healthcare institution providing patient treatment with specialized Medical Science, health science and auxiliary healthcare staff and medical equipment. The best-known type of hospital is the general hospital, which typically ...
resource use or to establish
patient care
Health care, or healthcare, is the improvement or maintenance of health via the prevention, diagnosis, treatment, amelioration or cure of disease, illness, injury, and other physical and mental impairments in people. Health care is delivered ...
guidelines.
Patients are assigned their SOI based on their specific diagnoses and procedures performed during their medical encounter, which is generally an inpatient hospital stay. Patients with higher SOI (e.g. major or extreme) are more likely to consume greater healthcare resources and stay longer in hospitals than patients with lower SOI in the same
diagnosis-related group
Diagnosis-related group (DRG) is a system to classify hospital cases into one of originally 467 groups, with the last group (coded as 470 through v24, 999 thereafter) being "Ungroupable". This system of classification was developed as a collabora ...
(DRG).
The
Centers for Medicare and Medicaid Services
The Centers for Medicare & Medicaid Services (CMS) is a federal agency within the United States Department of Health and Human Services (HHS) that administers the Medicare program and works in partnership with state governments to administer ...
considered the 3M APR-DRG and SOI system as a potential evolution to the DRG system in 2006, but received such negative feedback from the industry that in March 2007 decided to adopt another internally developed system evolved from the DRG.
SOI is still commonly used throughout the United States to adjust for patient complexity, so that physicians and other groups can compare resource utilization, complication rates, and length of stay.
See also
*
Diagnosis-related group
Diagnosis-related group (DRG) is a system to classify hospital cases into one of originally 467 groups, with the last group (coded as 470 through v24, 999 thereafter) being "Ungroupable". This system of classification was developed as a collabora ...
(DRG)
*
Risk of mortality
The risk of mortality (ROM) provides a medical classification to estimate the likelihood of in-hospital death for a patient. The ROM classes are minor, moderate, major, and extreme. The ROM class is used for the evaluation of patient Death, mortali ...
(ROM)
*
Case mix index
Case mix index (CMI) within health care and medicine, is a relative value assigned to a diagnosis-related group of patients in a medical care environment. The CMI value is used in determining the allocation of resources to care for and/or treat t ...
(CMI)
*
Diagnosis code
In health care, diagnosis codes are used as a tool to group and identify diseases, disorders, symptoms, poisonings, adverse effects of drugs and chemicals, injuries and other reasons for patient encounters. Diagnostic coding is the translation of ...
References
{{reflist
* Averill RF, ''The evolution of case-mix measurement using DRGs: past, present and future'', Stud Health Technol Inform. 1994;14:75-83.
* Averill R, Muldoon J, Vertrees J, Goldfield N, et al., ''The evolution of case mix measurement using diagnosis-related groups (DRGs)'', Physician Profiling and Risk Adjustment. In: Goldfield N, ed. 2nd ed. Frederick, MD: Aspen Publishers, Inc; 19
Medical terminology
Medical manuals
Diagnosis codes