Jan. 8 (UPI) -- The cost of treating a person with two or more non-communicable diseases, or comorbidities, is more expensive than treating the same diseases individually, a study says.
During a seven-year period, 59 percent of publicly-funded health spending in New Zealand went to treat non-communicable disease, and nearly 24 percent of that went to treat comorbidities. The findings were published Tuesday in PLOS Medicine.
"There is a surprising lack of disease-attributed costing studies involving multiple diseases at once," the authors wrote in the study.
The numbers come from a national healthcare database -- including data on hospitalization, outpatient, pharmaceutical, laboratory and primary care -- that showed New Zealand spent $26.4 billion on 18.9 million person-years.
The cost of treating chronic kidney disease, musculoskeletal disease or diabetes stood out most, ranging from $13,000 to $30,000.
Globally, the World Health Organization estimates that the global gross domestic product spent on healthcare was $7.2 trillion in 2015.
"Governments and health systems managers and funders can improve planning and prioritization knowing where the money goes," the authors wrote.
The study says that comorbidities affect young people more than older people, but they're not quite sure why that's the case.
"Whilst we have no direct evidence, it seems plausible that young people with comorbidities might be treated more aggressively than old people with comorbidities or perhaps that young people with comorbidities have more severe disease than their younger counterparts with just one disease," the authors wrote. "Further research to understand this age variation in comorbidity expenditure is warranted."