The department shall develop and implement a sliding scale of patient liability for kidney disease aid under s. 49.68, cystic fibrosis aid under s. 49.683, and hemophilia treatment under s. 49.685, based on the patient’s ability to pay for treatment. The department shall continuously review the sliding scale for patient liability and revise it as needed to ensure that the amounts budgeted under s. 20.435 (4) (e) and (je) are sufficient to cover treatment costs.