More than a quarter of Irish people say GP charges sometimes prevent them from seeing a doctor when they are sick, according to the Health Research Board.
In a report out today, the body says most of those put off by the high cost of seeing a GP are people in poor health, people with long-term illnesses and people with symptoms of depression.
Elsewhere, the board also says it has found that just 20% of medical-card holders visit a dentist each year, compared with 45% of PRSI clients who have to pay.
The findings are part of a new €100m research programme.