A doctors' union insists having more staff is the answer to elective surgeries cancellations

Health NZ analysis shows hospitals cancel about eight percent of those surgeries - within 24 hours of going ahead.

One in five were to give way to an emergency case - but a significant number of cancellations were from resourcing problems, like staff illness or unavailability.

Association of Salaried Medical Specialists Executive Director, Sarah Dalton, says it's about how many people are available.

She says current inefficiencies are because we don't have an extensive-enough health service.