Year-long waiting lists and high medical fees are causing people in NSW to stop or delay treatment, health professionals say.

A Bureau of Health Information report shows that despite NSW having one of the best healthcare systems in the world, 15per cent of patients put off GP visits, filling a prescription and getting basic medical tests because of out-of-pocket expenses.

Treatment delays: Patients are being put off visiting GPs because of expensive medical fees and long waiting lists.

One third did not see the dentist because they could not afford to.

Doctors were also concerned preventative health measures were being left behind, with many patients not getting basic check-ups that could prevent serious illness.