More staff is needed to help reduce growing violence at Christchurch Hospital's emergency department.

Research in the New Zealand Medical Journal says each and every staff member has experienced the abuse.

Emergency medicine specialist Dr John Bonning says more resource is needed across the health sector to reduce waiting times.

He told Kate Hawkesby they've produced hospital access targets like shorter stays -  but that requires the whole system buying in.

Bonning says with the transition into the new health authorities from July - it's still unknown what that means for those on the frontline.

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