Small Numbers Can Have Big Consequences: Many California Hospitals Perform Dangerously Low Numbers of Cancer Surgeries

Laurence Baker and Maryann O'Sullivan

Some hospitals perform one or two brain cancer surgeries; others do hundreds. Small volumes can mean greater risk of poor patient outcomes. See the numbers for 11 cancers.

June 2017
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Despite the staggering number of Californians who are diagnosed with cancer each year — 173,000 new cases in 2016 — there is very little information to guide patient decisionmaking about where to get care. For decades research has shown that hospitals performing a low volume of surgeries are more likely to have worse patient outcomes — more complications and deaths — than hospitals with higher volumes of surgeries.

But data for specific hospitals were not readily available until 2015 when CHCF published Safety in Numbers: Cancer Surgeries in California Hospitals (available below as a document download). The latest round of California cancer surgery hospital volume data are summarized in the issue brief Small Numbers Can Have Big Consequences: Many California Hospitals Performed Dangerously Low Numbers of Cancer Surgeries.

Researchers analyzed data from the California Office of Statewide Health Planning and Development (OSHPD), including rates at which California hospitals performed only one or two surgeries. They also documented the number of hospitals that fell below minimum standards recently set by the Dartmouth-Hitchcock Medical Center, the Johns Hopkins Hospital and Health System, and the University of Michigan Health System. 

Key findings include:

  • There is an association between low hospital surgery volume and higher mortality and complication rates for the following 11 cancers: bladder, brain, breast, colon, esophagus, liver, lung, pancreas, prostate, rectum, and stomach.
  • The majority of California's hospitals performed surgery for one or more of these 11 cancers only once or twice in the year analyzed.*
  • Of cancer patients who had surgery at a hospital that did a small number of those surgeries in the year analyzed, more than 74% were within 50 miles of a hospital performing higher volumes.**
  • 3,719 esophagus, lung, pancreas, and rectum cancer surgeries were performed at hospitals that fell below the Dartmouth/Hopkins minimum standards.
  • The 241 hospitals that performed only one or two of a particular procedure in the year analyzed do not fit into one category: They are located in urban and rural areas; are small, medium, and large; and are teaching and nonteaching hospitals.

These data and the accompanying issue brief, which are available as Document Downloads, can help patients, health care providers, payers, and policymakers bridge the gap between current practice and what the evidence says is best.

Data on California hospital-specific cancer surgery volumes are publicly available on the consumer website CalHospitalCompare.org and on the OSHPD website

Infographic: Choosing a Hospital for Cancer Surgery Is a Delicate Operation

See How Your Hospital Compares

Look up the number of surgeries performed at California hospitals for 11 cancer types at CalHospitalCompare.org.

*Researchers analyzed data from Q4 2014 - Q3 2015, the most recent years for which data were available.

**Low-volume is defined as one or two of that type of cancer surgery; higher-volume is defined as the top 20% of hospitals in the state by volume for that type of cancer surgery. Fifty miles was measured from the patient's residence to the hospital as the crow flies.

Datacards for selected cancer types are available under Document Downloads.