what was the first test that was given to patient 6374 since 34 months ago?
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 = 6374 ) and datetime(labevents.charttime) >= datetime(current_time,'-34 month') order by labevents.charttime asc limit 1 )