A recent Connecticut Department of Public Health report indicates that adverse events — preventable incidents that occur during hospitalization, resulting in patient harm — are down 12 percent in state hospitals, though the frequency of certain surgical adverse events has increased.

The report, released in October 2015, covers the 2014 fiscal year, during which the Connecticut DPH received 471 adverse event reports, 80 of which occurred at Yale-New Haven Hospital. There are nearly 30 types of incidents that qualify for mandatory adverse-event reporting, and according to the DPH report, 89 percent of events fell into four categories, including perforations during procedures and retention of foreign objects in patients after surgery. While adverse events have decreased in these areas, there have been increases in some other areas, including surgeries performed on the wrong body part and incorrect surgery performed on a patient.

While an apparent increase in some adverse events may cause concern, these higher numbers more likely indicate greater transparency in hospital reporting than complacency in health care, according to state health officials interviewed. For instance, the apparent rise in surgery performed on the wrong site — up from nine incidents in 2012 to 15 incidents last year — is likely due to smaller, less severe events now being included in required reporting, as of 2013.

“If I cut off the wrong leg, there’s no way people wouldn’t have known about it,” said Mary Cooper, vice president and chief quality officer of the Connecticut Hospital Association. “It’s the minor procedures — someone puts an anesthetic block on the wrong eye for cataract surgery, but it’s caught before the surgery happened — that would now be reported.”

Thomas Balcezak, chief medical officer at Yale-New Haven Hospital, said that changes in definitions and addition of new events also impact the numbers.

“As a state and as a nation, we should be aiming for and expecting over time a reduction of events,” Balcezak said. “But those reductions of events, we should all hope, come from an actual improvement in care and not a reduction in reporting and detection and not a change in definition.”

Adverse events usually occur as a result of multiple, small errors that coincide, he added.

Balcezak further noted that there are potential errors “constantly bombarding the processes of care” when attempting to treat the patient. He then referenced James Reason’s “Swiss cheese model” as a compelling way to think about how errors happen.

The model compares layers of defenses set up to reduce risk of adverse events as similar to when a person stacks many slices of Swiss cheese, Balcezak explained. For the most part, the layers cover holes in other slices. But there is a possibility that all the holes align, he said. When this happens, errors can get through, reaching the patient and causing harm, Balcezak said.

“One patient being harmed unnecessarily is one patient too many,” said Lisa Freeman, executive director of the Connecticut Center for Patient Safety, which advocates for patients harmed by adverse events. She emphasized the importance of patients taking an active role in their medical experience, bringing lists of questions to doctors and working to weigh the risks of surgery prior to undergoing operation. “It’s been shown that when the patients are more engaged in their care, more involved, the outcomes tend to be better,” she added.

Statewide organizations such as the Connecticut Hospital Association, as well as individual clinics, are working to bring the occurrence of adverse events to zero, Balcezak and Cooper said. One promising strategy is the use of a High Reliability model, a new protocol used across Connecticut hospitals that ensures standardized, quality care based on a science used in, amongst other things, aviation and nuclear power, Cooper said.

According to Cooper, the model has already been used to train 40,000 physicians in the state. While Freeman agreed that the High Reliability collaborative is a good start, she cautioned against placing too much faith in any one solution.

“We have to recognize that it is one tool, and no one tool is going to answer every need and every situation,” she said.

Hospitals now require stricter use of mandatory timeouts prior to surgery for surgeons to confirm the type of surgery and the patient identity, Balcezak said. They also conduct intensive root-cause analyses should something go wrong, he added.

Cooper also addressed the importance of accountability at hospitals.

“When someone does something wrong, it is approached with an algorithm that is fair and just and relies on a lot of science,” she said.

This algorithm includes educating surgeons who make mistakes and retraining those who work in more than one hospital and may operate under a different protocol.

“Adverse events can and do occur in the process of delivering health care. That’s a fact,” Balcezak said. “It is all of our responsibility, everyone involved, to reach the goal of zero events of harm. That can be the only acceptable goal for us in health care.”