Large bills are one of the main reasons people are dissatisfied with their private health insurance — especially when these bills come as a surprise.

Doctors charge what they like, and patients rarely have any information about what they are getting for their money. Even patients with top-level cover are left paying large and unexpected out-of-pocket costs when they use their insurance.

Patients have little power to bargain with their doctors about fees and have almost no information about whether their doctor has higher or lower complication rates than other doctors.

A Grattan Institute report released Tuesday proposes that patients’ fees should be negotiated between doctors and private hospitals, rather than between the doctor and the patient.