instruction: what is the number of patients whose diagnoses short title is fall on stair/step nec and drug route is buccal?
response: SELECT COUNT(DISTINCT demographic.subject_id) FROM demographic INNER JOIN diagnoses ON demographic.hadm_id = diagnoses.hadm_id INNER JOIN prescriptions ON demographic.hadm_id = prescriptions.hadm_id WHERE diagnoses.short_title = "Fall on stair/step NEC" AND prescriptions.route = "BUCCAL"