instruction: tell me the name of the last lab test that patient 31482 got since 04/2105?
response: SELECT d_labitems.label FROM d_labitems WHERE d_labitems.itemid IN (SELECT labevents.itemid FROM labevents WHERE labevents.hadm_id IN (SELECT admissions.hadm_id FROM admissions WHERE admissions.subject_id = 31482) AND STRFTIME('%y-%m', labevents.charttime) >= '2105-04' ORDER BY labevents.charttime DESC LIMIT 1)