CHILDREN in families with a medical card are seeing their GP twice as often as those whose parents have to pay.
Research has revealed, for the first time, the constraints on families who have to shell out at least €50 each time they see a doctor.
There is a concern that individuals and households whose income is just above the medical-card threshold may be particularly disadvantaged.
The findings from the ESRI show nine year olds in families with a medical card are much more likely to be seen by their GP.
And babies at the crucial age of nine months who do not have medical cards have just three-quarters of the number of annual GP visits as babies in families who receive free care.
The findings come amid speculation that the Government may tighten eligibility for medical cards in some groups in next week's Budget.
The number of people covered by a medical card rose to 1.8 million this year. It was approximately 1.3 million during the years looked at in the study, 2007-2008.
The latest findings are from the Growing Up in Ireland study which tracks children at different ages to gain insight into their health, education and overall well-being.
Richard Layte and Ann Nolan of the ESRI researched the links between a family having a medical card and the number of GP visits. They said previously studies largely concentrated on the adult population.
"Growing Up in Ireland gives us the chance to look at patterns of GP utilisation among infants and children in Ireland for the first time since the late 1980s," they pointed out.
They looked at medical-card coverage in 2007-2008 when 27pc of nine-month-old children were covered, and 28pc of nine-year-old children.
They said there were also other factors that contributed to the frequency of a child's GP visits. "Adjusting for child health and maternal characteristics, the difference between eligibility groups is reduced."
But they added: "Children not covered by a medical card or insurance are still significantly less likely to visit their GP than children covered by a medical card."
They point out they cannot say if medical-card holders are over-utilising the service or that those without cover are not seeing the doctor enough.