Physical contact assaults decreased from 44 in 2016 to 26 in 2017.
Dunham provided a general overview of systems Lakes DHB had in place to safeguard staff.
"The DHB has a 24/7 security response and a Memorandum of Understanding with New Zealand Police.
"There is an electronic learning package for all staff to recognise and manage unacceptable behaviour, and specific education and training in de-escalation. Also an emergency call system, comprehensive risk assessment as part of individual care plans and robust policies and procedures to safeguard staff."
Dunham said the list provided was not exhaustive.
Rotorua police area prevention manager Brendon Keenan said police were called to the hospital, although not on a regular basis.
"There are security staff at the hospital, particularly around Accident and Emergency, which would act as a deterrent.
"Staff employed within the mental health unit are trained in dealing with violent situations."
Keenan said if police were at the hospital it was more in an escort role.
"If we have picked someone up who is being violent but needs medical attention, then we take them to the hospital. Sometimes we remain until the person has been calmed down or until a security staff member takes over."
Keenan said police were called to "high end" situations.
"If staff are having trouble removing someone who has become violent, or a patient has barricaded themselves into an area and staff are unable to get them out, then we might be called."
A spokeswoman from the Public Service Association (PSA), one of the unions representing mental health workers in New Zealand, said all New Zealanders had the right to feel safe and secure in their workplace.
"Our members working in mental health acknowledge their work involves volatile situations, and that sometimes this can spill over into violent behaviour.
"However, the PSA believes many are working in situations where the risks they face are too high. Due to years of underinvestment by the National-led Government, New Zealand's mental health system has come under extreme pressure.
"Many mental health units are severely understaffed and this makes it harder for our members to defuse potentially difficult situations. In addition, the under-resourcing of community mental health services means that by the time people reach hospital, their problems have become much worse."