Too Sick to be True? Evaluating Potentially Problematic Diagnosis Coding Practices in Medicare's Patient-Driven...

Area of Science:

• Health Services Research
• Health Economics
• Gerontology

Background:

• The Patient-Driven Payment Model (PDPM) was implemented by Medicare to reform reimbursement in skilled nursing facilities (SNFs).
• PDPM links SNF payments to patient characteristics, emphasizing clinical complexity captured through diagnosis documentation.
• Understanding the impact of PDPM on SNF diagnosis documentation is crucial for payment accuracy and patient care.

Purpose of the Study:

• To quantify changes in skilled nursing facility (SNF) diagnosis documentation following the implementation of Medicare's Patient-Driven Payment Model (PDPM).
• To assess the association between PDPM and the number of diagnoses, clinical complexity scores, and the documentation of specific conditions.
• To examine variations in documentation changes based on SNF profit status.

Main Methods:

• A quasi-experimental design using a difference-in-differences approach was employed.
• Analysis utilized 100% Traditional Medicare claims data from 2018-2021, covering over 4.8 million hospital-to-SNF episodes.
• Fixed effect linear models and generalized linear models were used to estimate PDPM's effects and variations by SNF profit status.

Main Results:

• PDPM was associated with a 7.1% increase in the number of diagnoses and a 13.6% increase in Elixhauser comorbidity index scores.
• For-profit SNFs showed a greater relative increase in diagnoses (2.8%) and Elixhauser points (4%) compared to non-profit facilities.
• The probability of documenting specific conditions like chronic pulmonary disease, complicated diabetes, heart failure, obesity, and weight loss significantly increased post-PDPM.

Conclusions:

• PDPM implementation led to increased coding intensity in SNFs, with higher rates observed in for-profit facilities.
• There is a need to evaluate whether this increased documentation accurately reflects clinical complexity or represents inflated coding.
• Continued monitoring of SNF diagnosis coding behavior is essential for maintaining Medicare payment accuracy.