A new analysis on shootings over the past decade reveals that while 1.7 million people are victims of violent crime at the workplace in the United States, hospital shootings are rare events that are very hard to predict.

There were 154 hospital-related shootings in the United States, which resulted in 235 injured or dead victims, between 2000 and 2011, according to the study.

Results from the study, published in the Annals of Emergency Medicine, showed that shootings were more common in Southern states and larger hospitals. However, researchers noted that other than that "few patterns could be discerned to help profile vulnerable sites and situations."

Researchers said that that latest findings should quell fears about hospital gun violence.

"We have to ask overall, how at risk are patients in the average hospital to be exposed to a shooting incident?" said Jay Wolfson, a patient safety researcher from the University of South Florida in Tampa who didn't participate in the research, according to Reuters. "I think they're extremely rare."

Johns Hopkins University researchers decided to conduct a study after a shooting took place at their own hospital a year ago when a man shot his mother's cancer surgeon, then shot and killed his mother and himself. The doctor had survived the shooting.

Researcher Dr. Gabe Kelen and his team found that the majority of shootings involved a highly motivated killer with a grudge, a suicide or someone "euthanizing" a sick relative.

The results from the study showed that there were 31 shootings in the emergency rooms, 29 in patient rooms and 35 in hospital parking lots, and that hospital workers made up a fifth of the shooting victims.

Experts say that while shootings are relatively rare, other types of violence in the ER in particular are common.

"Harassment is an everyday experience for a lot of these people," Donna Gates, a nursing researcher from the University of Cincinnati who wasn't involved with the study, told Reuters.

"You're not going to get to a zero rate of physical violence against health care workers in settings such as emergency departments, but obviously there are ways to reduce that rate," she said.

Experts say that hospitals can set up a panel of experts to examine and put in place new security precautions, conduct de-escalation training as well as educate hospital personnel on detecting unusual behavior.

Researchers said that installing metal detectors in hospitals is often not feasible and that a quarter of the guns used in hospital shootings belong to security officers.

The team noted that hospital visitors, patients and staff shouldn't be alarmed about gun violence because the rate of shootings is lower than at many other job sites.

"The likelihood of being shot in a hospital is less than the likelihood of being struck by lightning," Kelen said. "The vast majority of shootings involve a targeted victim and not random violence."

Updated to include correct statistics.