what test has patient 26886 been given for the first time until 36 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 = 26886 ) and datetime(labevents.charttime) <= datetime(current_time,'-36 month') order by labevents.charttime asc limit 1 )