title: Better adherence to antithyroid drug is associated with decreased risk of stroke in hyperthyroidism patients.
abstract: BACKGROUND
  An increased risk for ischaemic stroke has been reported in young hyperthyroidism patients independent of atrial fibrillation (AF). However, whether the use of antithyroid drugs in hyperthyroidism patients can reduce the occurrence of ischaemic stroke remains unclear.
  
  
  METHODS
  A total of 36,510 newly diagnosed hyperthyroidism patients during 2003-2006 were identified from the Taiwan National Health Insurance Research database. Each patient was individually tracked for 5 years from their index date (beginning the antithyroid drugs) to identify those who suffered from new episode of ischaemic stroke. Medication possession ratio (MPR) was used to represent the antithyroid drug compliance. The association between the MPR and the risk of stroke was examined.
  
  
  RESULTS
  The stroke incidence rates for hyperthyroidism patients with age < 45 years and age ≥ 45 years were 0.42 and 3.76 per 1000 person-years, respectively. The patients aged < 45 years with MPR < 0.2 (adjusted hazard ratio, HR, 2.30; 95% CI, 1.13-4.70; p = 0.02) and 0.2 ≤ MPR < 0.4 (adjusted HR, 2.24; 95% CI, 1.06-4.72; p = 0.035) had a significantly increased risk of ischaemic stroke as compared to those with ≥ 0.6. In patients of the age ≥ 45 years, only the patients with MPR < 0.2 (adjusted HR, 1.44; 95% CI, 1.03-2.01; p = 0.036) had a significantly higher risk of ischaemic stroke as compared to those with MPR ≥ 0.6. In hyperthyroidism patients without AF, good antithyroid drugs compliance also reduced the incidence of stroke significantly (adjusted HR, range: 1.52-1.61; p = 0.02); but not in hyperthyroidism with AF.
  
  
  CONCLUSIONS
  Hyperthyroidism patients with good antithyroid drug compliance had a lower risk of ischaemic stroke than patients with poor compliance.
authors: Department of Emergency Medicine, National Taiwan University Medical College and Hospital, Taipei, Taiwan.
authors: M-S
authors: MS
authors: Tsai
authors: School of Health Care Administration, Taipei Medical University, Taipei, Taiwan.
authors: P-Y
authors: PY
authors: Chuang
authors: Department of Emergency Medicine, National Taiwan University Medical College and Hospital, Taipei, Taiwan.
authors: C-H
authors: CH
authors: Huang
authors: Department of Internal Medicine, National Taiwan University Medical College and Hospital, Taipei, Taiwan.
authors: S-R
authors: SR
authors: Shih
authors: Department of Emergency Medicine, National Taiwan University Medical College and Hospital, Taipei, Taiwan.
authors: W-T
authors: WT
authors: Chang
authors: Department of Emergency Medicine, Taoyuan General Hospital, Ministry of Health and Welfare, Taoyuan County, Taiwan.
authors: N-C
authors: NC
authors: Chen
authors: Department of Emergency Medicine, Taipei Hospital, Ministry of Health and Welfare, Taipei, Taiwan.
authors: P-H
authors: PH
authors: Yu
authors: Department of Emergency Medicine, National Taiwan University Medical College and Hospital, Taipei, Taiwan.
authors: H-J
authors: HJ
authors: Cheng
authors: School of Health Care Administration, Taipei Medical University, Taipei, Taiwan.
authors: C-H
authors: CH
authors: Tang
authors: Department of Emergency Medicine, National Taiwan University Medical College and Hospital, Taipei, Taiwan.|Department of Emergency Medicine, Lotung Poh-Ai Hospital, Yilan County, Taiwan.
authors: W-J
authors: WJ
authors: Chen
mesh_terms: D000328:Adult; D000368:Aged; D013956:Antithyroid Agents / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D006980:Hyperthyroidism / Q000150:complications / Q000188:drug therapy*; D015994:Incidence; D008297:Male; D055118:Medication Adherence; D008875:Middle Aged; D016016:Proportional Hazards Models; D012307:Risk Factors; D020521:Stroke / Q000453:epidemiology* / Q000209:etiology; D013624:Taiwan / Q000453:epidemiology; D055815:Young Adult
chemical_list: D013956:Antithyroid Agents