count the number of patients who were prescribed lr within 2 months after being diagnosed with crnry athrscl natve vssl since 2105.
select count( distinct t1.subject_id ) from ( select admissions.subject_id, diagnoses_icd.charttime 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 = 'crnry athrscl natve vssl' ) and strftime('%y',diagnoses_icd.charttime) >= '2105' ) as t1 join ( select admissions.subject_id, prescriptions.startdate from prescriptions join admissions on prescriptions.hadm_id = admissions.hadm_id where prescriptions.drug = 'lr' and strftime('%y',prescriptions.startdate) >= '2105' ) as t2 on t1.subject_id = t2.subject_id where t1.charttime < t2.startdate and datetime(t2.startdate) between datetime(t1.charttime) and datetime(t1.charttime,'+2 month')