New research shows it costs more to treat patients with two or more chronic diseases than it would to treat each disease in isolation.
The study from the University of Otago, Wellington looked at health data for all adult New Zealanders and found 59 percent of the public health spend went on chronic diseases.
Lead author Tony Blakely said almost a quarter of that was spent caring for patients with two or more diseases above and beyond what the diseases cost individually.
"Put another way, if there were no additional costs due to the complexity of having two or more diseases at the same time, we would spend a quarter less on chronic conditions."
The study found that of the remaining three quarters of the spend on chronic diseases, 18.7 percent was going on heart diseases and stroke, 16.2 percent on muscoloskeletal disorders or back problems, and 14.4 percent on neurological conditions. Cancer accounted for 14.1 percent, lung, liver and kidney diseases 7.4 percent and diabetes 5.5 percent.
Professor Blakely said the finding that most of the spend was going towards back and neurological issues was surprising and not enough attention was paid to this in terms of research and planning.
He said the research offers an insight into the extra financial burden posed by patients suffering from multiple conditions and will be useful for health planners.
"Multimorbidity is likely to be an increasing driver of health spending in future, as people live longer."
The researchers analysed nationally linked health data for all adult New Zealanders, including all publicly funded hospitalisation, outpatient, medicines, laboratory and primary care over a period of seven years.