A device, a system and a method for a patient attempting to quit smoking such that the program is configured to cause a computer to execute the steps of: receiving, from a patient-side electronic device, patient's understanding information indicative of the patient's understanding about a smoking-related matter, which is input by the patient, at a patient's understanding information acquisition timing decided based on at least one of an input of information indicative of a current patient's condition and smoking cessation-related health-care history information; deciding, based on the received patient's understanding information and correct response information for the smoking-related matter, whether or not the patient's understanding is incorrect; and, when decided to be incorrect, transmitting, to the patient-side electronic device, cognitive-behavioral therapy (CBT) information based on the correct response information, wherein the CBT information includes information deemed to be correct with respect to the smoking-related matter.