CREATE TABLE lab (subject_id CLOB, hadm_id CLOB, itemid CLOB, charttime CLOB, flag CLOB, value_unit CLOB, label CLOB, fluid CLOB)
CREATE TABLE procedures (subject_id CLOB, hadm_id CLOB, icd9_code CLOB, short_title CLOB, long_title CLOB)
CREATE TABLE prescriptions (subject_id CLOB, hadm_id CLOB, icustay_id CLOB, drug_type CLOB, drug CLOB, formulary_drug_cd CLOB, route CLOB, drug_dose CLOB)
CREATE TABLE demographic (subject_id CLOB, hadm_id CLOB, name CLOB, marital_status CLOB, age CLOB, dob CLOB, gender CLOB, language CLOB, religion CLOB, admission_type CLOB, days_stay CLOB, insurance CLOB, ethnicity CLOB, expire_flag CLOB, admission_location CLOB, discharge_location CLOB, diagnosis CLOB, dod CLOB, dob_year CLOB, dod_year CLOB, admittime CLOB, dischtime CLOB, admityear CLOB)
CREATE TABLE diagnoses (subject_id CLOB, hadm_id CLOB, icd9_code CLOB, short_title CLOB, long_title CLOB)

how many patients with drug type as additve had the lab test for calculated thyroxine (t4) index?
SELECT COUNT(DISTINCT demographic.subject_id) FROM demographic INNER JOIN prescriptions ON demographic.hadm_id = prescriptions.hadm_id INNER JOIN lab ON demographic.hadm_id = lab.hadm_id WHERE prescriptions.drug_type = "ADDITIVE" AND lab.label = "Calculated Thyroxine (T4) Index"
SELECT COUNT(DISTINCT "demographic"."subject_id") FROM "demographic" JOIN "lab" ON "Calculated Thyroxine (T4) Index" = "lab"."label" AND "demographic"."hadm_id" = "lab"."hadm_id" JOIN "prescriptions" ON "ADDITIVE" = "prescriptions"."drug_type" AND "demographic"."hadm_id" = "prescriptions"."hadm_id"