instruction: indicate the monthly maximum arterial bp [systolic] of patient 1561 since 08/01/2105.
response: SELECT MAX(chartevents.valuenum) FROM chartevents WHERE chartevents.icustay_id IN (SELECT icustays.icustay_id FROM icustays WHERE icustays.hadm_id IN (SELECT admissions.hadm_id FROM admissions WHERE admissions.subject_id = 1561)) AND chartevents.itemid IN (SELECT d_items.itemid FROM d_items WHERE d_items.label = 'arterial bp [systolic]' AND d_items.linksto = 'chartevents') AND STRFTIME('%y-%m-%d', chartevents.charttime) >= '2105-08-01' GROUP BY STRFTIME('%y-%m', chartevents.charttime)