Roberts ET, et al. - By using methods that distinguish the correlation between patient characteristics and readmission from between-hospital differences in quality, authors evaluated the changes in hospital performance on readmission rates after adjusting for additional clinical and social patient characteristics. Findings indicated that hospitals tend to be penalized more so for serving sicker and poorer patients than for poor quality of care, emphasizing the need for improved risk adjustments in pay-for-performance programs.

Methods

• Experts used Medicare claims for admissions in 2013 through 2014 and linked US Census data to evaluate several clinical and social characteristics of patients not currently used for risk adjustment in the Hospital Readmission Reduction Program.
• They compared hospital readmission rates with and without adjustment for these additional characteristics, using only the average within-hospital associations between patient characteristics and readmission as the basis for adjustment, thereby appropriately excluding hospitals’ distinct contributions to readmission from the adjustment.
• Main outcomes and measures were all-cause readmission within 30 days of discharge.

Results

• The study sample consisted of 1,169,014 index admissions among 1,003,664 unique Medicare beneficiaries (41.5% of whom were men; mean [standard deviation] age, 79.9 [8.3] years) in 2,215 hospitals.
• Adjustment for the additional characteristics vs adjustment for patient characteristics currently implemented by Medicare reduced overall variation in hospital readmission rates by 9.6%, changed rates upward or downward by 0.37 to 0.72 percentage points for the 10% of hospitals most affected by the additional adjustments (±30.3% to ±58.9% of the hospital-level standard deviation), and would be expected to reduce penalties (in relative terms) by 52%, 46%, and 41% for hospitals with the largest 1%, 5%, and 10% of penalty reductions, respectively.
• Between hospitals in the top and bottom quintiles of high-risk patients the mean difference in readmission rates was reduced by 0.53 percentage points (95% CI: 0.50-0.55; P < 0.001), or 54% of the difference estimated with CMS adjustments alone due to the additional adjustments.
• Results demonstrated the contribution of both clinical and social characteristics to these reductions, and these reductions were considerably greater for conditions targeted by the Hospital Readmission Reduction Program.
• Adjustment for social characteristics led to greater changes in rates of readmission or death vs rates of readmission alone.