what is the three most frequent drug that was prescribed during the same hospital visit to the female patients aged 60 or above after they had been diagnosed with chf nos, since 1 year ago?
select t3.drug from ( select t2.drug, dense_rank() over ( order by count(*) desc ) as c1 from ( select admissions.subject_id, diagnoses_icd.charttime, admissions.hadm_id from diagnoses_icd join admissions on diagnoses_icd.hadm_id = admissions.hadm_id where diagnoses_icd.icd9_code = ( select d_icd_diagnoses.icd9_code from d_icd_diagnoses where d_icd_diagnoses.short_title = 'chf nos' ) and datetime(diagnoses_icd.charttime) >= datetime(current_time,'-1 year') ) as t1 join ( select admissions.subject_id, prescriptions.drug, prescriptions.startdate, admissions.hadm_id from prescriptions join admissions on prescriptions.hadm_id = admissions.hadm_id where admissions.subject_id in ( select patients.subject_id from patients where patients.gender = 'f' ) and admissions.age >= 60 and datetime(prescriptions.startdate) >= datetime(current_time,'-1 year') ) as t2 on t1.subject_id = t2.subject_id where t1.charttime < t2.startdate and t1.hadm_id = t2.hadm_id group by t2.drug ) as t3 where t3.c1 <= 3