"You wouldn't work in a bank or supermarket and know that people are going to come in a swear at you, spit at you, threaten to kill you or follow you home," she said.
She began investigating the issue after she heard that Christchurch Hospital management had been congratulating staff for the low rates of violence. That conflicted with reports from colleagues, she said.
Her study, published today in the New Zealand Medical Journal, was based on responses from doctors, nurses and other staff at the hospital over a one-month period in 2014, with further surveys taken in following years.
During that month, 7896 patients came through ED and there were 107 incidents, 19 of them physical assaults. A woman staff member had her breast pinched, another was hit in the face, and others had pills spat in their face and water poured over them.
Most of the cases involved verbal abuse. In one case, a staff member was called a "f***ing ho and an ugly b***h" and endured nearly two hours of abuse while waiting for police to arrive.
The hospital's health and safety records, however, showed just 29 violent incidents were formally reported over a full year. Even when all of the cases in which security were called were counted, there were still just 20 to 40 cases a month – well below the figure found in the study.
There were many reasons for this, Richardson said. The main one was that nursing staff, who copped most of the abuse, were stretched and did not have the time or energy to fill out official paperwork.
Of greater concern was that staff had come to accept violence and aggression as part of the job.
Canterbury DHB's executive director of nursing Mary Gordon said it become apparent as a result of the audit that violent incidents had been under-reported.
"Canterbury DHB is aware of this under-reporting, and recognises the effect these incidents have on health care workers and first responders," she said.
It had made a number of changes in recent years, including a new electronic incident recording system, training staff in de-escalation, and better management of people who regularly came into ED.
Auckland District Health Board's emergency medicine specialist Anil Nair said violence had long been an unfortunate part of ED staff's jobs. His organisation had partly addressed the problem by improving communication with patients, to give them a better idea of their wait time for treatment.
The number of security staff at Auckland Hospital had been increased and they had been made more visible, he said. And ED had also been redesigned to make it possible to lock down areas so staff could escape a violent situation.
One month in an emergency department
• 7896 patients seen
• 107 cases of violence or aggression (19 of them physical)
• Most attacks (92 per cent) were on females
• Most incidents on Saturdays, and most common time between 1am and 4am
• Previous security reports indicated just 20 to 40 incidents a month