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Individual Patient Safety Indicator Rating
To determine a patient safety indicator score for each of the 13 PSIs for each hospital, HealthGrades statistically
compared the actual rate of individual patient safety events to the predicted rate. HealthGrades then displays if the
PSI was Best, As Expected, or Poor.
Best
Fewer patients were affected than expected.
As Expected
About the same number of patients were affected as expected.
Poor
More patients were affected than expected.
·
When a hospital is not rated, it means the hospital had too few cases to be eligible to receive a patient
safety rating.
HealthGrades also shows the number of patients (out of 1,000 patients examined) who experienced the problem. For
example, 10 per 1,000 means that for every 1,000 patients, only 10 were affected; whereas zero (0) indicates that no
patients were affected. Each patient safety indicator is rated independently and some indicators apply to more
patients than others. Some patient safety events occur more frequently than others. As a result, the number of
patients affected for each indicator may vary substantially.
Overall Patient Safety Score
To be eligible for an overall patient safety score, a hospital must have had outcomes in 11 of the 13 patient safety
indicators. Hospitals with 10 or fewer patient safety ratings were not eligible to receive an overall patient safety score,
but may have individual patient safety indicator ratings.
To determine the overall patient safety score by hospital, HealthGrades performed the following steps.
1.
HealthGrades statistically compared the actual rates of individual patient safety events to the predicted rate to
produce a score for each individual patient safety indicator that had a sufficient volume at a hospital.
2.
The average of the resulting scores determined a hospital's ranking. Star ratings were then assigned as follows:
Best (Top 15%)
As Expected (Middle 70%)
Poor (Bottom 15%)
·
When a hospital is rated Best in Patient Safety, it means that their patient safety record is better than
expected given their patient population and they scored within the top 15 percent of hospitals that qualify for
a patient safety rating.
·
When a hospital is rated As Expected, their patient safety record is as expected given their patient
population and they scored within the middle 70 percent of hospitals that qualify for a patient safety rating.
·
When a hospital is rated Poor, their patient safety record is worse than expected and they rated within the
bottom 15 percent of all hospitals that qualify for a patient safety rating.
·
When a hospital is not rated, it means the hospital had too few cases to be eligible to receive a patient
safety scoring.
