Top Hospitals in CALIFORNIA

Name	Overall Rating
KAISER FOUNDATION HOSPITAL - SOUTH SAN FRANCISCO	5:
CALIFORNIA PACIFIC MEDICAL CENTER - MISSION BERNAL	5:
SEQUOIA HOSPITAL	5:
NOVATO COMMUNITY HOSPITAL	5:
ADVENTIST HEALTH ST HELENA	5:
SIERRA NEVADA MEMORIAL HOSPITAL	5:
FRENCH HOSPITAL MEDICAL CENTER	5:
HOAG MEMORIAL HOSPITAL PRESBYTERIAN	5:
UC SAN DIEGO HEALTH HILLCREST - HILLCREST MED CTR	5:
PENINSULA MEDICAL CENTER	5:

How is the Hospital Quality Star Rating Developed?

The Overall Hospital Quality Star Rating for the hospitals in California summarizes a variety of measures across 5 areas of quality into a single star rating for each hospital. Once reporting thresholds are met, a hospital’s Overall Star Rating is calculated using only those measures for which data are available. Hospitals report data to The Centers for Medicare & Medicaid Services ("CMS") through the Hospital Inpatient Quality Reporting (IQR) Program, Hospital Outpatient Quality Reporting (OQR) Program, Hospital Readmission Reduction Program (HRRP), Hospital-Acquired Condition (HAC) Reduction Program, and Hospital Value-Based Purchasing (VBP) Program. Overall Star Ratings aren’t calculated for Veterans Health Administration (VHA) or Department of Defense (DoD) hospitals.

Most hospitals will have an Overall Hospital Quality Star Rating of 3.

The methodology used to calculate Overall Star Ratings involves multiple steps to select, standardize, and calculate scores based on Care Compare measures. Overall Star Ratings are created using this seven-step process:

1. Selection and standardization of measures for inclusion in the Overall Star Rating
2. Assignment of measures to groups
3. Calculation and standardization of measure group scores
4. Calculation of hospital summary scores as a weighted average of available group scores
5. Application of minimum thresholds for receiving an Overall Star Rating
6. Assignment of hospitals to peer groups based on their number of measure groups (3, 4, or 5)
7. Application of clustering algorithm to categorize summary scores into star ratings

For each hospital, a hospital summary score is calculated by taking the weighted average of the hospital’s scores for each measure group. The table below shows the weight applied to each measure group. The hospital summary score is then used to assign hospitals to star ratings, using k-means clustering within each peer group.

Measure group	Weight used in calculation
Mortality	22%
Safety	22%
Readmission	22%
Patient Experience	22%
Timely & Effective Care	12%

Note that these percentage weights are out of 100%. If a hospital has no measures in a certain measure group, the weighted percentage is redistributed proportionally to the other measure groups. For example, if a hospital had no measures in the Timely & Effective Care category, the 12% weight would be redistributed evenly as 25% for each of the Mortality, Safety of Care, Readmission and Patient Experience groups.

National distribution of the Overall Hospital Quality Star Rating The following table shows the national distribution of the Overall Star Rating based on July 2022 results.

Overall rating	Number of hospitals / Percentage
1 star	198 (6.34%)
2 stars	702 (22.49%)
3 stars	895 (28.68%)
4 stars	895 (28.68%)
5 stars	431 (13.81%)
N/A	1,368 (30.47%)

Additional detailed on the method for calculating the Overall Hospital Quality Star Rating from this document.