Health authorities have ordered a major overhaul of how assaults on mental health workers are recorded after a Herald on Sunday investigation.
The Auckland District Health Board shake-up followed one nurse quitting as it was too dangerous to work at acute mental health unit Te Whetu Tawera.
Nurse Lauren Meraw left the country after writing to Health Minister Tony Ryall saying staff and patients were "at serious risk of harm".
The inquiry prompted the health board to check statistics, conceding 131 assaults were committed in 12 months against staff.
The revelations sparked criticism from opposition health spokesman Grant Robertson and Public Service Association general secretary Richard Wagstaff.