Because if you need to choose between a resistant to illnesses have been treated with the higher payments to get fast service, patients would choose to receive services quickly.
If I had to choose between resistance to the illness to be treated. To pay higher to get the fastest service, the patient is selected to receive the fastest service.
Because if you had to choose between live to wait to treat illness. With giving higher payout to get fast service patients would choose to get บริการที่รวดเร็ว.