There is no method for evaluating a person's likelihood of thinking about or trying to commit suicide available for doctors.
But an international group of scientists, in which the Hospital del Mar Research Institute (IMIM) has participated, has devised the first risk index in order to prevent suicides.
"It is of key importance to identify suicidal thoughts among people at increased risk. The most important contribution that our study has made is an international risk index to estimate the likelihood of a person moving on from these thoughts to any one of the following behaviours - planning or trying to commit suicide," said Jordi Alonso, head of the IMIM Healthcare Services Research Group.
The researchers followed a data from the WHO survey World Mental Health Surveys between 2001 and 2007, in which 108,705 adults from 21 countries responded to the Composite International Diagnostic Interview.
They looked at suicidal behaviour rather than suicides that result in death, since it is based on interviews carried out with adults.
The main factors associated universally with such behaviour were related to gender, age, education levels, employment status and mental illness, as well as a number of other factors.
The researchers found that suicidal behaviour rates were similar in both developed and developing countries. Additionally, all risk factors appear to be correlated for incidences of exhibiting suicidal behaviour.
However, there appears to be significant variations in mortality rates as a result of suicide based on geographical location and religious belief.
For example, Muslim countries experience lower rates of suicide, while countries in Eastern Europe and the former Soviet Union have the highest rates highest rates of suicide, with a number of the people who take their own lives expressing some form of mental illness.
"Our index for evaluating multiple risks could help to predict suicidal planning and attempts with a fairly high level of precision and help medical specialists to foresee such behaviour," concluded Alonso.
The finding has been reported in the Journal of Clinical Psychiatry.