The National Party says a report from the Business Roundtable pointing to a continued decline in the productivity of public hospitals contains nothing new and offers no solutions.
The report says the average cost for hospital services rose 18% between 2001 - 2006, but overall staff productivity fell by 8%.
Business Roundtable executive director Roger Kerr says this was despite large increases in health spending.
He says the report backs 2005 Treasury findings of a fall in hospital efficiency at that time.
Expenditure in the sector accounts for a fifth of Government spending.
National's health spokesman, Tony Ryall, says the report appears consistent with conclusions from the Treasury over the past few years.
Minister for Health David Cunliffe says the fundamental weakness in the report is that it confuses efficiency with effectiveness.
Former Treasury Secretary Dr Graham Scott, who wrote the foreward to the report, says health funding has been increasing by about 8.5% a year.
The Association of Salaried Medical Specialists, which represents senior hospital doctors, says the report is weak.
Executive director Dr Ian Powell says the information has been manipulated to make an ideological point.