title: Relationship between non-adherence to aminosalicylate medication and the risk of clinical relapse among Japanese patients with ulcerative colitis in clinical remission: a prospective cohort study.
abstract: BACKGROUND
  Thirty to forty-five percent of ulcerative colitis (UC) patients show non-adherence to aminosalicylates, and non-adherence has been reported to increase the risk of clinical relapse. Because Japan differs from Western countries in terms of health care and drugs administered, adherence to aminosalicylates in Japan may differ from that elsewhere. Therefore, we examined aminosalicylate adherence and its relationship to the risk of clinical relapse of UC in Japan.
  
  
  METHODS
  A 1-year, prospective cohort study was conducted in 104 outpatients with UC in remission who had taken aminosalicylates >6 months. Aminosalicylate adherence was evaluated using data from a self-administered questionnaire and medical records. Non-adherence was defined as taking <80 % of the prescribed dose of aminosalicylates. The primary outcome was the record of clinical relapse in medical charts.
  
  
  RESULTS
  Twenty-nine patients (27.9 %) were evaluated as showing non-adherence. Among all subjects, 24 patients (23.1 %) relapsed. The non-adherence group had a higher rate of 1-year relapse than did the adherence group (41.3 vs. 16.0 %). Multiple Cox regression analysis showed that non-adherence increased the risk of clinical relapse 2.3-fold (hazard ratio 2.3, 95 % confidence interval 1.004-5.24, p = 0.04).
  
  
  CONCLUSIONS
  Although the adherence rate in this study was slightly higher than that in previous studies, Japanese patients with UC who were not adherent to their medications had a twofold greater risk of relapse than those who were. These results indicate the importance of early identification of patients with non-adherence. A program to support medication taking behavior is needed to prevent UC relapse.
authors.affiliation: Department of Adult Nursing, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
authors.forename: Aki
authors.initials: A
authors.lastname: Kawakami
authors.forename: Makoto
authors.initials: M
authors.lastname: Tanaka
authors.forename: Masakazu
authors.initials: M
authors.lastname: Nishigaki
authors.forename: Makoto
authors.initials: M
authors.lastname: Naganuma
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Iwao
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Hibi
authors.forename: Hiromi
authors.initials: H
authors.lastname: Sanada
authors.forename: Noriko
authors.initials: N
authors.lastname: Yamamoto-Mitani
authors.forename: Keiko
authors.initials: K
authors.lastname: Kazuma
mesh_terms: D000328:Adult; D010131:Aminosalicylic Acid / Q000008:administration & dosage* / Q000627:therapeutic use; D015331:Cohort Studies; D003093:Colitis, Ulcerative / Q000188:drug therapy* / Q000523:psychology; D004334:Drug Administration Schedule; D005260:Female; D005765:Gastrointestinal Agents / Q000008:administration & dosage* / Q000627:therapeutic use; D006801:Humans; D007564:Japan; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012008:Recurrence; D012074:Remission Induction; D018570:Risk Assessment / Q000379:methods; D016903:Drug Monitoring
chemical_list: D005765:Gastrointestinal Agents; D010131:Aminosalicylic Acid