CalHospitalCompare.org

About the Data and Ratings

Some hospitals provide better care than others. This site rates quality of care, including clinical quality, patient experience, and patient safety, for participating California hospitals.

As of 2012, CHART contains information on 332 acute care hospitals in California. This represents California hospitals with publically available performance information. Other types of hospitals, such as psychiatric hospitals, rehabilitation facilities, long-term acute care hospitals and single specialty hospitals are not included on the website. Some small, rural and Critical Access Hospitals do not have publically available data or a sufficient amount of data to score them accurately. The conditions and procedures rated are among the most common reasons for being admitted to a hospital. Currently, measures of children’s health care are not included nor widely available.

Hospitals on this Web site are rated on several aspects of health care quality including the effectiveness and timeliness of care; patient experience; and how often hospitals follow recommended patient safety practices. In addition, readmissions rates for common conditions are reported.

As data become available, other conditions and measures will be included in future updates to this Web site.

To produce the information available on this Web site, a rigorous process is followed:

• Data are gathered by Truven Health Analytics from publically available data sources.
• Data are then compared to a benchmark value, either a national, state, or CHART standard.
• Ratings are assigned to measures when it is technically feasible (for example, a large enough sample or an accepted risk-adjustment approach) and there is an accepted standard.

Guidelines established by an oversight committee and expert statisticians determine how the data are processed during each of these steps.

Data Sources and Collection

Data collected by California hospitals are reported to various federal and state agencies and the CHART project directly, as noted in the table below. In all cases, we use the most recent data available. The time periods vary for different measures.

Risk-Adjustment Methods

Some patients respond better to treatment than others. For example, having diabetes can reduce your chances of surviving heart surgery. So it would not be fair for a hospital with more diabetic patients to have a worse rating just because they treat more sick patients. "Risk adjustment" is the process that levels the playing field among hospitals to fairly compare hospital performance.

However, some measures do not need to be risk adjusted. For example, having diabetes does not prevent the nurse from checking your wristband before giving a medication, so there should be no adjustment for diabetes in that measure.

The following organizations provided the rules for collecting data and adjusting for variations in patient mix when necessary:

• California Hospital Assessment and Reporting Taskforce (CHART)
• The Joint Commission
• The federal Medicare program
• California Office of Statewide Health Planning and Development (OSHPD)
• California Department of Public Health, Center for Family Health, Genetic Disease Screening Program, Newborn Screening Data
• California Children's Services
• California Nursing Outcomes Coalition
• National CAHPS (the national center for collecting patient surveys)
• The federal Agency for Healthcare Research and Quality (data collection and validation methods)

In general, the effect of the risk-adjustment process on hospital scores is small.

Applying a Margin of Error to Data

Another way to make sure that fair comparisons can be made between different hospitals is to apply a "margin of error." This helps compare hospitals that perform very few procedures with those that perform many. For example, a hospital that does only one heart surgery will have a death rate of either 0% (if the patient lives) or 100% (if the patient dies). Based on the outcome for one patient, it is difficult to determine how the hospital would perform for many surgeries on many patients. So we apply a wide margin of error that says the death rate is not very reliable because it is based on just one case.

For hospitals that have only a few patients with a particular condition, their margin for error in that condition is broad, while for hospitals with hundreds of patients the margin for error is narrow. (For this reason, for any single measure on this site, two hospitals with the same rating may have very different percentages shown.)

In rating the hospitals, the margin of error is taken into account by calculating an estimated range of hospital performance for each condition, with the range wider for hospitals with fewer patients and narrower for hospitals with many patients.

Performance Ratings

The performance rating icons indicate how well a hospital performed compared with other hospitals:

Depending on the type of measure, the scale will use all five (superior, above average, average, below average, and poor) or only three of these ratings (superior, average, and poor).

Case Volume Ratings

Research has shown that the more cases a hospital handles for a particular procedure, then the surgical team has more practice, which may lead to better results for the patients.

This Web site provides case volume ratings for some surgical procedures. Hospitals are rated as either having "enough cases" or "not enough cases." To determine the rating, the hospital reports the number of cases performed and it is compared to a specific "cut point" as determined by medical research.

For hospitals that meet the cut point in volume, then the Web site also shows the risk-adjusted death rate for the procedure.