ในการไปโรงพยาบาลครั้งล่าสุด ผู้ป่วย 22973 เข้าห้องไอซียูกี่ครั้ง?ไม่จำเป็นต้องใช้โต๊ะทั้งหมด
on the last hospital visit, how many times did patient 22973 visit the icu?It is not neccessary to use all the tables.
 cost:  row_id [ number]  subject_id [ number]  hadm_id [ number]  event_type [ text]  event_id [ number]  chargetime [ time]  cost [ number] 
SELECT COUNT(DISTINCT icustays.icustay_id) FROM icustays WHERE icustays.hadm_id IN (SELECT admissions.hadm_id FROM admissions WHERE admissions.subject_id = 22973 AND NOT admissions.dischtime IS NULL ORDER BY admissions.admittime DESC LIMIT 1)