patient 73713 has been tested since 2103 for the magnesium, urine?
select count(*)>0 from labevents where labevents.itemid in ( select d_labitems.itemid from d_labitems where d_labitems.label = 'magnesium, urine' ) and labevents.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 73713 ) and strftime('%y',labevents.charttime) >= '2103'