instruction: calculate the number of patients who were diagnosed with hypertension and did not return to the hospital in the same month until 2104.
response: SELECT (SELECT COUNT(DISTINCT t1.uniquepid) FROM (SELECT patient.uniquepid, diagnosis.diagnosistime FROM diagnosis JOIN patient ON diagnosis.patientunitstayid = patient.patientunitstayid WHERE diagnosis.diagnosisname = 'hypertension' AND STRFTIME('%y', diagnosis.diagnosistime) <= '2104') AS t1) - (SELECT COUNT(DISTINCT t2.uniquepid) FROM (SELECT patient.uniquepid, diagnosis.diagnosistime FROM diagnosis JOIN patient ON diagnosis.patientunitstayid = patient.patientunitstayid WHERE diagnosis.diagnosisname = 'hypertension' AND STRFTIME('%y', diagnosis.diagnosistime) <= '2104') AS t2 JOIN patient ON t2.uniquepid = patient.uniquepid WHERE t2.diagnosistime < patient.hospitaladmittime AND STRFTIME('%y', patient.hospitaladmittime) <= '2104' AND DATETIME(t2.diagnosistime, 'start of month') = DATETIME(patient.hospitaladmittime, 'start of month'))