when was the last time patient 86209 had a chloride test in the lab since 88 months ago?
select labevents.charttime from labevents where labevents.itemid in ( select d_labitems.itemid from d_labitems where d_labitems.label = 'chloride' ) and labevents.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 86209 ) and datetime(labevents.charttime) >= datetime(current_time,'-88 month') order by labevents.charttime desc limit 1