instruction: when did patient 67468 get in their last hospital encounter a lab test for the last time?
response: SELECT labevents.charttime FROM labevents WHERE labevents.hadm_id IN (SELECT admissions.hadm_id FROM admissions WHERE admissions.subject_id = 67468 AND NOT admissions.dischtime IS NULL ORDER BY admissions.admittime DESC LIMIT 1) ORDER BY labevents.charttime DESC LIMIT 1