have there been any organism found during the first aspirate microbiology test of patient 4718 until 3 years ago?
select count(*)>0 from microbiologyevents where microbiologyevents.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 4718 ) and microbiologyevents.spec_type_desc = 'aspirate' and microbiologyevents.org_name is not null and datetime(microbiologyevents.charttime) <= datetime(current_time,'-3 year') order by microbiologyevents.charttime asc limit 1