did patient 23721 ever have any microbiology tests done this year?
select count(*)>0 from microbiologyevents where microbiologyevents.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 23721 ) and datetime(microbiologyevents.charttime,'start of year') = datetime(current_time,'start of year','-0 year')