title: Periodontitis and etanercept discontinuation risk in anti-tumor necrosis factor-naive rheumatoid arthritis patients: a nationwide population-based cohort study.
abstract: OBJECTIVE
  The objective of this study was to investigate the association between periodontitis (PD) and etanercept (ETN) discontinuation in anti-tumor necrosis factor (anti-TNF)-naive patients with rheumatoid arthritis (RA).
  
  
  METHODS
  This retrospective nationwide population-based cohort study identified 3359 anti-TNF-naive patients with RA (age at diagnosis ≥16 years) in whom ETN treatment was initiated using administrative data. We identified PD exposure within 5 years before ETN initiation and during ETN treatment. Cox proportional hazard models were used to assess ETN discontinuation risk associated with PD within 5 years before ETN initiation, shown as hazard ratios with 95% confidence intervals (CIs). Stratified analyses were performed on the basis of PD during ETN treatment to avoid violating the Cox regression assumptions.
  
  
  RESULTS
  Patients with PD history during the 5 years before ENT initiation had a higher risk of ETN discontinuation compared with those without such history; the hazard ratios of ETN discontinuation were 1.27 (95% CI, 1.01-1.60) and 1.17 (95% CI, 1.06-1.30) among patients with and without PD during ETN treatment, respectively. Other risk factors included age older than 65 years and daily prednisolone dose greater than 10 mg/d within 1 year before ETN initiation. Concomitant methotrexate, leflunomide, salazopyrin, or hydroxychloroquine administration had a protective effect on ETN discontinuation in patients without PD during ETN treatment, but the protective effect by leflunomide, salazopyrin, and hydroxychloroquine was attenuated in patients with PD during ETN treatment (P for interaction <0.05).
  
  
  CONCLUSIONS
  A PD history within 5 years before ETN administration was associated with increased ETN discontinuation risk in anti-TNF-naive patients with RA.
authors.affiliation: From the *Division of Allergy, Immunology and Rheumatology, Department of Internal Medicine, Taichung Veterans General Hospital, Taichung; †School of Medicine, National Yang-Ming University, Taipei; ‡School of Medicine, Chung-Shan Medical University, Taichung; §Institute of Public Health and Community Medicine Research Center, National Yang-Ming University, Taipei; ∥Institute of Biomedical Science, National Chung-Hsing University; ¶Department of Medical Research, Taichung Veterans General Hospital, Taichung; #Institute of Hospital and Health Care Administration, National Yang Ming University; and **Department of Education and Research, Taipei City Hospital, Taipei, Taiwan, Republic of China.
authors.forename: Hsin-Hua
authors.initials: HH
authors.lastname: Chen
authors.forename: Der-Yuan
authors.initials: DY
authors.lastname: Chen
authors.forename: Kuo-Lung
authors.initials: KL
authors.lastname: Lai
authors.forename: Yi-Ming
authors.initials: YM
authors.lastname: Chen
authors.forename: Yiing-Jenq
authors.initials: YJ
authors.lastname: Chou
authors.forename: Pesus
authors.initials: P
authors.lastname: Chou
authors.forename: Ching-Heng
authors.initials: CH
authors.lastname: Lin
authors.forename: Nicole
authors.initials: N
authors.lastname: Huang
mesh_terms: D000328:Adult; D018501:Antirheumatic Agents / Q000627:therapeutic use; D001172:Arthritis, Rheumatoid / Q000188:drug therapy* / Q000453:epidemiology*; D015897:Comorbidity; D004359:Drug Therapy, Combination; D000068800:Etanercept; D005260:Female; D006801:Humans; D006886:Hydroxychloroquine / Q000627:therapeutic use; D007074:Immunoglobulin G / Q000627:therapeutic use*; D007166:Immunosuppressive Agents / Q000627:therapeutic use*; D007555:Isoxazoles / Q000627:therapeutic use; D000077339:Leflunomide; D008297:Male; D008727:Methotrexate / Q000627:therapeutic use; D008875:Middle Aged; D010518:Periodontitis / Q000453:epidemiology*; D018124:Receptors, Tumor Necrosis Factor / Q000627:therapeutic use*; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012460:Sulfasalazine / Q000627:therapeutic use; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors*
chemical_list: D018501:Antirheumatic Agents; D007074:Immunoglobulin G; D007166:Immunosuppressive Agents; D007555:Isoxazoles; D018124:Receptors, Tumor Necrosis Factor; D014409:Tumor Necrosis Factor-alpha; D012460:Sulfasalazine; D006886:Hydroxychloroquine; D000077339:Leflunomide; D000068800:Etanercept; D008727:Methotrexate