instruction: how many patients received intracranial/cerebral perfusion pressure monitoring - csf drainage via ventriculostomy after the first procedure of the antiemetic - serotonin antagonist in the same month since 1 year ago?
response: SELECT COUNT(DISTINCT t1.uniquepid) FROM (SELECT patient.uniquepid, treatment.treatmenttime FROM treatment JOIN patient ON treatment.patientunitstayid = patient.patientunitstayid WHERE treatment.treatmentname = 'antiemetic - serotonin antagonist' AND DATETIME(treatment.treatmenttime) >= DATETIME(CURRENT_TIME(), '-1 year')) AS t1 JOIN (SELECT patient.uniquepid, treatment.treatmenttime FROM treatment JOIN patient ON treatment.patientunitstayid = patient.patientunitstayid WHERE treatment.treatmentname = 'intracranial/cerebral perfusion pressure monitoring - csf drainage via ventriculostomy' AND DATETIME(treatment.treatmenttime) >= DATETIME(CURRENT_TIME(), '-1 year')) AS t2 WHERE t1.treatmenttime < t2.treatmenttime AND DATETIME(t1.treatmenttime, 'start of month') = DATETIME(t2.treatmenttime, 'start of month')