By Lisa Rapaport

(Reuters Health) – Community hospitals may have lower mortality rates for cancer surgeries when they’re affiliated with a top-ranked cancer center, a U.S. study suggests.

Public perception in the U.S. is that community hospitals provide better care when they’re affiliated with top-ranked hospitals, researchers note in JAMA Oncology. But research to date hasn’t offered a clear picture about how much these affiliations actually impact cancer surgery outcomes.

For the current study, researchers compared 90-day mortality rates for 11,464 patients who had complex cancer surgeries at community hospitals affiliated with top-ranked cancer centers and 2,729 patients who underwent similar procedures at nonaffiliated hospitals.

In absolute terms, in 2015, near the end of the study, the rate of death within 90 days of surgery was slightly above 6% at affiliated hospitals and slightly below 8% at nonaffiliated hospitals.

Overall, after taking individual patient and procedure characteristics into consideration, 90-day mortality rates were 13% higher at nonaffiliated hospitals, the study found. But once researchers also accounted for hospital characteristics known to affect surgical safety, the difference in mortality rates dropped to 9%.

“In general, top-ranked cancer hospitals are considerably safer than the affiliate hospitals that share their brand,” said Dr. Daniel Boffa, senior author of the study and a researcher at Yale School of Medicine in New Haven, Connecticut.

“Affiliates of top-ranked cancer hospitals are moderately safer than hospitals that are not affiliated,” Boffa said by email.

Researchers looked at major operations for cancers of the lung, colon, stomach, esophagus and pancreas. While all of the procedures appeared to have lower mortality rates at affiliated than nonaffiliated hospitals, most of the differences in outcomes for individual surgeries were too small to rule out the possibility that they were due to chance.

The study included data on mortality outcomes from 2013 to 2016 for patients over 65 covered by Medicare, the government health program.

A total of 144 affiliations began during the study period, allowing researchers to examine mortality data for the year before and after these affiliations began. Hospitals that formed affiliations tended to have more beds, more nurses, and were more likely to be accredited by the Commission on Cancer.

In the year after hospitals formed affiliations, their 90-day mortality rates decreased from 9.8% to 6.3% and the number of surgeries they performed increased.

The study wasn’t a controlled experiment designed to prove whether or how community hospital affiliations with top-ranked cancer hospitals might direct impact the quality of care or mortality rates.

Affiliate status appears to be a marker but not a robust predictor of favorable outcomes, the study team concludes.

“The formation of an affiliation with a top-ranked cancer hospital does not appear to independently change major hospital characteristics within the first year of affiliation,” Boffa said.

“While we have noted differences in safety within and outside of the cancer networks around top-ranked cancer hospitals, patients should not make any assumptions simply because the brand of a prestigious hospital is on the sign or webpage of a hospital in their community,” Boffa added. “Patients should take the time to investigate the safety within the hospitals in their specific area.”

SOURCE: JAMA Oncology, online July 11, 2019.