The number of New Zealanders dying from strokes has dropped dramatically in the last 20 years, but it's affecting more young and middle-aged people, a major new study has found.
The ground-breaking study, led by New Zealand researchers, found a startling 25 per cent global increase in the number of stroke cases among people aged 20 to 64 over the last two decades.
The findings, published today in the medical journal The Lancet, come from the first comprehensive and comparable analysis of the regional and country-specific burden of the killer condition, traditionally associated with old age, between 1990 and 2010.
The Global Burden of Disease Study's lead author, Professor Valery Feigin, director of the National Institute for Stroke and Applied Neurosciences at AUT University, said the worldwide stroke burden was growing very fast.
"There is now an urgent need for culturally acceptable and affordable stroke prevention, management and rehabilitation strategies to be developed and implemented worldwide," he said.
"This is the first study to compare incidence and impacts of stroke between countries on a global scale.
"Now every country in the world has estimates of their stroke burden, based on the best available evidence."
For New Zealand, the results are a mixed bag.
The amount of Kiwis dying of strokes has halved in the last 20 years, matching trends in most other developed countries.
Stroke survival had also jumped, by 82 per cent, due to better acute care.
But it came at a cost, Professor Feigin said, given that 75 per cent of stroke survivors required rehabilitation services, which are already under a heavy strain.
"Stroke remains the No.3 cause of death for New Zealanders," he said.
"But I believe if the current trend continues, stroke will drop down to No.4, which is great news."
While the number of strokes has declined in New Zealand, the decline was lagging almost four times behind other developed countries, "which is not good news", Professor Feigin said.
The study authors warned that the shift in stroke burden towards younger populations was likely to continue globally unless effective preventive strategies were urgently implemented.
In low-income and middle-income countries, strokes claimed more lives (42 per cent higher mortality) and was associated with more disability and illness (46 per cent greater) than in high-income countries.
The researchers put it down to a rise in the prevalence of risk factors in these countries involving unhealthy diet, high blood pressure, obesity, physical inactivity and smoking.