Winsorized Scoring Methodology

This method uses a continuous measure score rather than grouping composite results into deciles. In alignment with CMS, the Premier decile benchmarks have been replaced with comparisons based on a similar Winsorized z-scoring method.

The benefits of this methodology are that it:

• Creates a more level playing field than the previously used linear regression model
• Mitigates situations where hospitals with no adverse events and no score were eligible for a penalty
• Makes it easier to distinguish performance across hospitals
• Substantially reduces ties between composite scores

The FY2018 analysis includes the Premier Median and Premier 75th Percentile.

This is the Z-score calculation: