This interactive map presents elective surgery and other procedure rates across California relative to the state averages and shows widely varying rates in spite of data adjustments for selected patient characteristics. The research includes Medicare patients and younger populations enrolled in commercial plans; Medicaid patients; and the uninsured.

To see how all areas compare, click on the  icon.

Note: This map works best with the latest versions of these web browsers: Chrome, Firefox, Internet Explorer, and Safari.

Some dramatic examples from the data (click each item to see it in the map above) are:

• Men living in Tracy are 479% more likely to undergo brachytherapy (internal radiation) for prostate cancer than the state average rate.

• Women living in Healdsburg receive lumpectomy without radiation for breast cancer (DCIS) at 248% of the state average rate.

• Women living in Orange County (Laguna Hills and San Clemente) have breast reconstruction surgery following mastectomy (Stages I, II, III) at 273% and 277% of the state average rate respectively.

• Residents of Watsonville undergo vertebroplasty or kyphoplasty for spinal fractures at 471% of the state average rate.

The consistency of results across all payers makes this a significant contribution to the literature documenting regional variation. While the authors note that some geographic variation in surgical rates is expected due to differences in disease prevalence, much of the variation in California cannot be explained by illness rates. The authors also noted that for elective procedures, patients should be well informed about treatment options and their values and preferences should be considered alongside clinicians' recommendations.

Available below are these Document Downloads: A revised summary discussing key factors in medical variation research and the important role that patient input can play in treatment decisions Nine "close-up" reports providing detailed discussion on the procedures studied Three spreadsheets containing adjusted rates for the procedures studied

A Clearer View: Humboldt Steps Out of the Fog of Medical Variation Following a 2011 CHCF study of geographic medical variation in California, leaders in Humboldt County came together to examine the causes of variation in their region. A multimedia story recounts what transpired.