count the number of times that patient 28443 had a dialysate out output during this month.
select count(*) from outputevents where outputevents.icustay_id in ( select icustays.icustay_id from icustays where icustays.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 28443 ) ) and outputevents.itemid in ( select d_items.itemid from d_items where d_items.label = 'dialysate out' and d_items.linksto = 'outputevents' ) and datetime(outputevents.charttime,'start of month') = datetime(current_time,'start of month','-0 month')