Patient Characteristics and Differences in Hospital Readmission Rates

Area of Science:

• Health Services Research
• Health Policy
• Medical Economics

Background:

• Medicare penalizes hospitals with high readmission rates, adjusting only for basic patient demographics and diagnoses.
• This system may disproportionately affect hospitals serving patient populations with higher inherent readmission risks.

Purpose of the Study:

• To determine if a broader set of patient characteristics explains variations in hospital readmission rates.
• To assess the impact of these additional factors on Medicare's readmission penalty calculations.

Main Methods:

• Utilized Health and Retirement Study (HRS) survey data linked with Medicare claims for over 8,000 hospital admissions (2009-2012).
• Assessed 29 patient characteristics beyond standard Medicare adjustments for predicting 30-day all-cause readmissions.
• Compared patient characteristics between hospitals with high vs. low Medicare-reported readmission rates.

Main Results:

• 22 of 29 additional patient characteristics significantly predicted readmission risk.
• 17 of these characteristics were unevenly distributed between high and low readmission rate hospitals.
• Adjusting for these factors reduced the readmission rate difference between top and bottom quintile hospitals by 48% (from 4.41 to 2.29 percentage points).

Conclusions:

• Patient factors not currently accounted for by Medicare explain a substantial portion of readmission rate disparities.
• Hospitals with high readmission rates may be penalized based on the complex needs of the patients they serve, rather than solely on quality of care.