Seven Cambridge Health Alliance patients committed suicide, tried to kill themselves or seriously harmed themselves last year, the highest number of such incidents at any acute-care hospital in the state.

The seven cases represent 30 percent of the 23 suicide and self-harm incidents reported by all hospitals, according to figures from the state Department of Public Health. The department collects mandatory reports of “serious reportable events” from hospitals and publishes an annual summary. Suicide or self-harm in an inpatient unit is considered a “never event,” meaning it shouldn’t occur if adequate safety measures are taken.

Five of the suicide/self-harm cases at the Alliance last year were at Cambridge Hospital, one at Somerville Hospital and one at Whidden Memorial Hospital in Everett, state health officials said.

In addition to the seven incidents, the Alliance also reported six medication errors resulting in serious harm, six falls leading to serious injury, one sexual assault on or by a patient, three physical assaults on or by a patient and two cases in which doctors unwittingly left an object inside a patient.

Alliance spokesman David Cecere said the health care system has “made significant investments in technology to improve our ability to deliver safe, quality care,” including an electronic system that administers and verifies medication at a patient’s bedside “that will enhance safety in our inpatient units by reducing medication errors.”

The Alliance is “installing new wireless nurse call systems” at Cambridge Hospital and Whidden “that will improve response times,” Cecere said. The system also introduced software that enables doctors and nurses “to more safely deliver and monitor chemotherapy” for patients, he said.

Prevention and priorities

Cecere said a majority of the assault cases, which all occurred at Whidden, were not preventable. The Alliance is putting “greater emphasis” on a training program on caring for aggressive patients that was launched in 2011, he said.

As for the suicide and self-harm incidents, the Alliance accounts for  more than 10 percent of inpatient psychiatric hospital stays statewide, Cecere said, and “our high concentration of patients seeking mental health care is a factor in our number of suicides/self harm reports.”

“Providing quality and safe patient-centered care is our highest priority,” Cecere said. “We take pride in both our environment and our work and actively promote a culture of safety at CHA.”

Asked whether any of the incidents in categories besides assaults were preventable, Cecere said the Alliance doesn’t track preventable incidents by category, but analyzes each case individually.

Although many psychiatric patients are sent to hospitals to protect them from killing or harming themselves, suicide and self-injury is one of the most frequently reported category of hospital “events.” And not all patients who kill or harm themselves are psychiatric patients.

Suicide by patients

Suicide by patients in the hospital was one of the top five “sentinel event” error categories reported to the Joint Commission on the Accreditation of Healthcare Organizations, the health care regulatory body, from 1995 to at least 2010, when the commission made that statement. There were 827 reports of patients killing themselves during that period; the commission observed that the reports are voluntary so the true number is likely to be larger.

The commission’s accreditation standards require hospitals to identify patients at risk for suicide and take steps to protect them. The commission’s 2010 alert also noted that the “health care environment” contained some materials that could and have enabled suicide, including bandages, bell cords, sheets, plastic bags and tubing. Other environmental risks in the hospital include “potential anchor points for hanging,” the alert said.

Some non-psychiatric patients kill themselves in the hospital, particularly cancer patients, according to studies of inpatient suicide. Even patients who are supposed to be checked every 15 minutes have committed suicide, the studies say.

The Alliance includes Cambridge, Somerville and Whidden Memorial Hospitals and 15 primary care clinics in Cambridge, Somerville, Revere and Malden. It is the second-largest “safety net hospital” in the state, serving mostly low-income people on Medicaid or uninsured.