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
Purposes • To determine reimbursement. • DRGs • APCS • MPFS • To describe a population being served. • To identify differences in practice patterns or coding complexity.
Severity of Illness Classifications • Extent of the disease • Risk of mortality • Need for intervention • Urgency of care • Intensity of resources • Difficulty of treatment
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
Diagnostic/Procedural/Severity Classifications • Resource Utilization Groups (RUGs) • Functional Related Group System (IRFPPS) • Home Health Resource Grouping System (HHPPS)
Risk Adjustment • Age and gender adjustments • Clinical risk adjustments • Situation-specific adjustments • Adjustments for specific clinical conditions • Adjustments by specialty type
Case-Mix Index • Classification by Disease Conditions and/or Procedures • Determines patterns of resource use • Used to determine anticipated reimbursement. • Comparison to other facilities
Factors that influence Case-Mix • Changes in Relative Weights • Changes in Services • Accuracy in Documentation and Coding • Accuracy in DRG/APC assignment
Calculating Case-Mix Indexes • Calculating Total CMS Relative Weight • Calculating Case Mix Index • Calculating Medicare Payment • Determining the Highest Relative Weight
Calculating Case-Mix Index • Services to be measured • Relative Weight • # of Cases
Case Mix Formulas • Calculating Total CMS Relative Weights • Calculating Medicare/Third-Party Payment • Calculating Case-Mix Index • Determining the Highest Relative Weight for a group of cases
Calculating Total CMS Relative Weight Multiply the “CMS Relative Weight” by the total number of cases (patients) in the DRG group
Example One A facility has 29 Medicare cases that are assigned to DRG 69 which has a relative weight of 1.0005. What is the Total Relative Weight for the cases?
Answer 29.0145 1.0005 x 29
Example Two A facility has 15 Medicare cases that are assigned to DRG 117 which has a relative weight of 0.7789. What is the Total Relative Weight for all of the cases?
Answer 11.6835 0.7789 x 15
Calculating Medicare Payment Multiply the reimbursement per case by the number of cases performed
Example Three A facility has 22 Medicare cases which are reimbursed at $6,175 per case. What is the total Medicare reimbursement for all of the cases?
Answer $135,850.00 $6,175 x 22
Example Four A facility has 59 Medicare cases that are assigned to DRG 175 which has a relative weight of 0.9557. If the hospital PPS rate is $4,200, what is the total reimbursement for all of the cases?
Answer $236,822.46 Step One: Calculate the reimbursement per case 0.9557 x $4,200 (PPS rate) = $4,013.94 Step Two: Multiply by the number of cases $4,013.94 x 59 = $236,822.46
Calculating Case Mix Index The total number of CMS Relative Weights divided by the total number of patients served.
Example Five The top ten DRG surgical procedures performed by a facility have a total CMS Relative Weight of 45.8775. If the total number of patients served is 29, what is the Case-Mix Index for the facility?
Answer 1.5819 44.8775 / 29 = 1.5819
Example Six The top ten DRG medical procedures performed by a facility have a total CMS Relative Weight of 23.6651 If the number of patients served is 55, what is the Case-Mix Index for the facility?
Answer 0.4302 23.6651 / 55 = 0.43027 or 0.43028
Recap • The case mix of a patient population is a description of that population based on any number of characteristics. • Case-Mix indexes are used to describe a population that is being served, to determine reimbursement, and to identify differences in practice patterns or coding complexity. • The most commonly used Case-Mix Index uses disease conditions and/or procedures to determine resource use.
Recap (cont.) • Severity of Illness case-mix methodologies were developed to address concerns that traditional case-mix methodologies do not capture the severity of an illness. • Risk Adjustment is any method used to compare the severity of illness in one group of patients in comparison to the severity of illness in another group of patients. Used make a fair comparison of diverse populations and treatment patterns