Patients with equally high needs for a hip replacement waited radically different amounts of time for elective surgery, contrary to Government policy, an audit has found.

One waited 16 days, the other eight months, both at the same, unnamed, district health board.

Under a strategy adopted in 2000, elective surgery patients should be treated in order of clinical priority, from most to least sick.

But a draft report by the Office of the Auditor-General says "little relationship exists between a patient's priority and the time spent waiting for treatment".

The report, obtained by the Herald, also says about 10 per cent of elective patients wait longer than the Government policy of six months for treatment, and DHBs appear to have their own target of nine months.

Health Minister Tony Ryall, who hasn't seen the draft report, yesterday acknowledged problems with the patient ranking system, but reiterated that DHBs had surpassed the Government target of an average increase of 4000 a year in people receiving elective surgery.

Only 2 to 3 per cent of patients waited more than six months for treatment, he said.

National has continued the Labour-led Administration's policy that regardless of where patients live, those with a similar level of need and ability to benefit from elective medical and surgical services, should have similar access.

The intention was to create nationwide ranking systems or "assessment tools", but the report says there are only 30 national tools, most of which are inadequate, and many local assessment tools are used.

Eight of the national tools, including those for thoracic surgery, respiratory medicine and paediatric medicine, rank patients into broad urgency categories without a number score. Some DHBs then give a generic number score to each category, like 90 points for all "urgent" patients.

"[These practices] undermine the Strategy's principles... When scores are allocated in this way, they are not fulfilling their intended purpose of identifying those patients with a higher need for services than other patients," the report says.

The report highlights the need for more scoring tools in general surgery, pointing out that the only one is for varicose veins.

A leading general surgeon told the Herald yesterday that many local assessment tools were used in his field and national ones were needed for each procedure.

"It would be very helpful if we had some agreement across the country how to ensure equitable access. I don't think there's been enough of a drive to do it, because everyone has been content doing things locally."

Mr Ryall said, "We're aware that prioritisation in some services isn't as good as it is in others, and that's why, for example, we got involved with Auckland DHB's cardiac waiting list."

In 2009, the Government gave Auckland DHB a $5 million top-up to help shorten its unacceptably long heart surgery waits.

The report gives examples of actual patients' priority rankings and how long they waited for surgery in 2009/10.

Cardiac surgery:
Patient A scored 95 points out of 100. Waited 60 days for surgery.
Patient B, 85 points, waited seven and a half months.

Patient A, 100 points, waited 11 days.
Patient B, 86 points, waited 11 months.

Hip replacement:
Patient A, 100 points, waited 16 days.
Patient B, 100 points, waited eight months.