(Reuters Health) - Hospital accreditation isn’t necessarily tied to better outcomes for U.S. patients, researchers say.

Based on records for more than 4.2 million patients over age 65 covered by Medicare, the study team found no difference between accredited and unaccredited hospitals in patient death rates, and only a slightly lower rate of patient readmissions at accredited hospitals, according to the report in The BMJ.

“When you walk into a hospital, one thing you want to count on as a patient is that the hospital will do a good job and achieve the best outcomes possible,” said senior study author Dr. Ashish Jha of the Harvard T. H. Chan School of Public Health in Boston.

“The national strategy” has been to assure patients through accreditation, he said in a phone interview. “But for years, there has been concern that the (accreditation) process has lost sight of the bigger picture and now focuses on the minute details.”

To be reimbursed for care provided to Medicare patients, hospitals either need to be accredited by an independent organization approved by the Centers for Medicare and Medicaid Services, or they must have passed a review by a state survey agency.

To see if accredited hospitals offer better quality care, Jha and colleagues analyzed data from 4,400 U.S. hospitals, including 3,337 accredited facilities and 1,063 that passed state-based review in 2014-2017. They linked this data with Medicare files and with results of government-sponsored patient satisfaction surveys for all the hospitals.

Overall, they found that patients treated at accredited hospitals had slightly lower 30-day mortality than those at hospitals reviewed by a state agency (10.2 percent versus 10.6 percent), although the difference was too small to rule out the possibility it was due to chance.

The research team also found identical mortality rates (2.4 percent) and nearly identical readmission rates (15.9 percent versus 15.6 percent) for six types of major surgery at accredited and state-reviewed hospitals.

For the medical conditions, readmissions were lower at accredited hospitals, at 22.4 percent versus 23.2 percent, a statistically meaningful difference.

Patient experience scores were slightly higher at state-survey hospitals than at accredited hospitals.

In addition, the research team found no differences in mortality, readmission rates or patient experience scores between the hospitals accredited by The Joint Commission, considered the “gold standard” for accreditation, or other independent organizations, the study team notes.

“Mortality is the big measure that tends to matter most to patients,” Jha said. “In this case, accreditation doesn’t seem to do much in terms of improving outcomes.”

“This adds momentum to a national conversation that started a few months ago,” he said. “Policymakers are starting to ask hard questions about whether the strategy of accreditation is paying off for consumers.”

Future studies should look at what type of accreditation and by which organization seem most helpful for better patient outcomes. For instance, hospitals designated as stroke centers or rehabilitation centers may have better outcomes for particular medical conditions, said Laura Wagner of the University of California, San Francisco, who wasn’t involved in the study.

“Accreditation is seen as a Good Housekeeping Seal of Approval for some patients, especially those in the nursing home setting,” she said in a phone interview.

“The bottom line is that accreditation does matter, and it provides a framework for both patients and healthcare providers around quality,” Wagner said. “It can improve quality in some cases, and we need to improve that framework to provide care.”

SOURCE: bit.ly/2yzvbKz The BMJ, online October 18, 2018.