when was the last creatinine, urine lab test done for patient 96833 on this hospital encounter?
select labevents.charttime from labevents where labevents.itemid in ( select d_labitems.itemid from d_labitems where d_labitems.label = 'creatinine, urine' ) and labevents.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 96833 and admissions.dischtime is null ) order by labevents.charttime desc limit 1