There is no evidence that legalised physician assisted suicide, results in disproportionate numbers of vulnerable people having their lives ended prematurely by doctors, finds research in the Journal of Medical Ethics .
Opponents of legislation, which enables doctors to help people to die, have claimed that it leads to a "slippery slope."
It makes it easier to end the lives of those who might be deemed a burden to society or their families, such as those with disabilities, stigmatised disease, or mental illness, they say.
But an analysis of figures from the Netherlands and Oregon, USA, where physician assisted dying is legal, shows that this is not the case.
The authors assessed all cases recorded as physician assisted deaths in Oregon, USA, between 1998 and 2006, as well as three independent studies on the topic.
And they looked at end of life decisions in The Netherlands in four government sponsored nationwide surveys conducted in 1990, 1995, 2001 and 2005, as well as specialised research.
The figures show that only a few people choose the option of physician assisted suicide.
In Oregon, 292 people have taken advantage of the legislation since it came on to the statute books in 1997. This amounts to 0.15% of all deaths.
In The Netherlands, voluntary euthanasia and physician assisted suicide have been tolerated since the 1980s, and legal since 2002, provided strict guidelines are followed.
Advance directives, requesting euthanasia in the event of a coma or dementia, are now also legal.
Around 1.7% of all deaths are categorised as voluntary euthanasia, and 0.1% as physician assisted suicide in The Netherlands.
The average age of people receiving help to die was around 70 in both places. Most had cancer. There were higher numbers of people with AIDS among those choosing to die with the aid of their doctor, the data showed.
But there was no evidence of any excess bias towards race, gender, age, socioeconomic status, disability, chronic illness or mental ill health in either place.
No prosecutions related to illegal deaths have been brought in Oregon. And of those brought in the Netherlands, there was no evidence that those from vulnerable groups have featured more heavily.
"We found no evidence to justify the grave and important concern often expressed about the potential for abuse," say the authors.
The evidence "does show that there is no current factual support for so called slippery slope concerns about the risks of legislation of assisted dying - concerns that death in this way would be practised more frequently on persons in vulnerable groups," they conclude.