New Zealand's healthcare system is fragmented, unnecessarily complicated and lacking in leadership, a major review has found.

And it's raised questions about whether majority-elected health boards are needed and if there's currently too many DHBs.

An independent panel ordered by the Government to look at how the health and disability system could be improved has found a series of sweeping shortcomings in the way services are organised and provided around the country.

Led by former prime minister Helen Clark's chief of staff, Heather Simpson, the review has been tasked with looking at everything from whether the District Health Boards structure is working to how healthcare is funded.

Its 300-page interim review, delivered on Tuesday, has presented no recommendations but outlined major areas of concern.

In particular, it's found the structure of health providers, agencies and decision-making across the country as "very fragmented" and "overly complicated" and says that's leading to a lack of confidence in the sector.

It also described leadership as lacking "at all levels".

"From our discussions with stakeholders and analysis of the system, we have identified that there is still no coherent decision-making framework to guide the sector," the report found.

The review is being led by former prime minister Helen Clark's chief of staff, Heather Simpson. Photo / File

"There are no transparent, consistent principles to guide what decisions should be taken where within the system. It appears that existing collaborative efforts are mainly dependent on goodwill and personal relationships."

The authors said there was clear need for a "much more cohesive, collective, and collaborative style" across the public health system, and needed to be more designed around what patients needed.

It's raised a series of major questions about the future of the system for further investigation, including:

• Whether governance by majority-elected boards is the best way to get communities involved.

• Whether it would be better to have fewer DHBs, DHBs with different functions, or more sharing of resources at the national level.

• Whether the Ministry of Health or another agency should lead development of a more cohesive system.

The report also noted concerns about inequality in the system were widespread.

"The urgency for making improvements to outcomes for Māori, Pacific peoples, and low-income and rural households means priority needs to be given to getting more appropriate services to these communities, rather than simply making system-wide changes in the hope that the benefits trickle down."

The sweeping review was announced in 2018 by Health Minister David Clark.

Its next stage will aim to put the suggestions into practical recommendations after further consultations.

It's due to report back by March 2020.