Do hospitals respond to changing incentive structures? Evidence from Medicare's 2007 DRG restructuring

Area of Science:

• Health economics
• Healthcare policy
• Medical billing and reimbursement

Background:

• In 2007, Centers for Medicare and Medicaid Services (CMS) revised the diagnosis-related group (DRG) system.
• The revision expanded DRG categories to account for patient complications and condition severity.
• This restructuring aimed to enable differential reimbursement based on case complexity.

Purpose of the Study:

• To investigate whether the 2007 DRG system changes incentivized hospitals to upcode patient severity.
• To quantify the extent of potential upcoding in hospital reimbursements.
• To assess the impact of upcoding on different payer types.

Main Methods:

• Utilized National Inpatient Survey data from the Healthcare Cost and Utilization Project (HCUP) spanning 2005-2010.
• Employed three distinct methodologies to detect and quantify patient upcoding.
• Analyzed reimbursement data across various hospital ownership types (government, non-profit, for-profit).

Main Results:

• Estimated that upcoding accounts for an additional 3% of reimbursements, using a conservative approach.
• Confirmed the presence of upcoding practices in government, non-profit, and for-profit healthcare facilities.
• Identified spillover effects of upcoding, affecting private insurance companies in addition to Medicare.

Conclusions:

• The 2007 DRG restructuring may have inadvertently encouraged patient upcoding for increased financial gain.
• Upcoding represents a significant financial issue affecting multiple payers within the healthcare system.
• Further research is warranted to explore the long-term implications and potential regulatory responses to hospital upcoding.