What is case mix analysis

Case Mix Management

CMI usage and calculations

By: Deborah Balentine M.Ed, RHIA, CCS-P

*

What is a Case-Mix?

Age
Gender
Type of Insurance
Diagnosis
Risk Factors
Treatments received
Resources used
*

The case mix of a patient population is a description of that population based on any number of the following characteristics:

Purposes

To determine reimbursement.
DRGs
APCS
MPFS
To describe a population being served.
To identify differences in practice patterns or coding complexity.
*

Case-mix methodologies are used for a number of purposes with the most common usage being for reimbursement. Case-mix methodology is used to determine relative weights and base payments for DRGs and APCs. Case-mix methodology is used with the MPFS when calculating the Geographic Practice Cost Index (GCPI).

Case-mix methodology can be used for statistical purposes to describe or identify a particular patient population.

Case-mix methodology can also be used to identify differences in coding practice patterns and the complexity of the coding because surgical cases are generally more resource extensive than medical cases.

Severity of Illness Classifications

Extent of the disease
Risk of mortality
Need for intervention
Urgency of care
Intensity of resources
Difficulty of treatment
*

The most common case mix methodology is to group cases by diagnoses and procedures. The major criticism to this type of grouping is that the diagnoses and procedures do not accurately measure the severity of an illness. The APR-DRG case-mix methodology was developed to address those concerns.

Severity of Illness Classfications

Adjusted Clinical Groups
National Association of Children’s Hospital and Related Institutions (NACHRI)
Medical Outcomes Study Short Form Health Survey
Atlas System
*

Severity of Illness Classifications includes the following:

Adjusted Clinical Groups - classifies individuals into groups that are likely to have similar resource requirements.

National Association of Children’s Hospitals and Related Institutions (NACHRI) - classifies diseases based on the progression of the disease, the anticipated course of the disease, and treatment goals.

Medical Outcomes Study Short Form Health Survey - classifies by severity of the disease and health status measures. Also uses patient feedback to obtain a total picture of the disease process.

Atlas System - uses information abstracted from the medical record from all points of care including ancillary service data excluding diagnosis data.

Diagnostic/Procedural/Severity Classifications

Resource Utilization Groups (RUGs)
Functional Related Group System (IRFPPS)
Home Health Resource Grouping System (HHPP