A new report on 'Health Inequalities in Europe' finds that Ireland's two-tiered health system may contribute to disparities between high and low-income earners when accessing healthcare.
The report says people in the so-called "twilight zone", with incomes above the medical card threshold but without private health insurance, could be losing out most.
Health Inequalities in Europe: Setting the Stage for Progressive Policy Action confirms that Ireland remains unique in the EU as the only Western European country not to have universal health coverage of primary care.
This is despite government commitments made since 2011 and reiterated as a core vision of Sláintecare in 2016.
The report is published by TASC, the Think-tank for Action on Social Change, and FEPS, the Foundation for European Progressive Studies.
It will form the evidential backbone of an international conference on Health Inequalities in Ireland: The Role of Policy, taking place at The Long Room Hub, Trinity College Dublin, today.
Ireland's life expectancy at 81.5 years is one of the highest in the EU. The report also shows that people in Ireland have the best self-reported health in the EU.
However, relative to other Western European countries, there is a high level of disparity between high and low-income groups of 21.5%.
Ireland is also unusual in a Western European context in the proportion of health funding that derives from out-of-pocket payments or voluntary health insurance.
Out-of-pocket payments often stop people seeking preventative and necessary healthcare, which can often result in more serious conditions and more expense at a later point.
Speaking on RTÉ's Morning Ireland, one of the report's co-authors said Ireland was unique in the EU in that it did not provide universal healthcare coverage for primary care.
Timon Forster said that coupled with a "two-tier system", this contributed partly to health inequalities.
He said that for people in the "twilight zone" of having incomes above the medical card threshold, but without private insurance, access to health services was limited by the cost.
As a result, some people are potentially not getting treatments they need, which leads to adverse outcomes for productivity in the workforce, he said.
Mr Forster said the cost of introducing free GP care for everyone should be considered in terms of long-term savings in productivity.
The report found that Irish people has the best self-reported health in EU.
However, Mr Forster said there were income discrepancies among those who reported themselves to be in good or very good health.