title: Drug survival of tumor necrosis factor α inhibitors in patients with ankylosing spondylitis in Korea.
abstract: To evaluate drug survival of the tumor necrosis factor α inhibitors (TNFi) and risk factors for the drug discontinuation in patients with ankylosing spondylitis (AS).
  
  
  
  We retrospectively evaluated 487 AS patients at a single tertiary hospital. Among the TNFi users, drug survival and risk factors of TNFi discontinuation were investigated.
  
  
  
  Among 487 patients, 128 AS patients were treated with at least one TNFi. Patients who were treated with TNFi were younger at disease onset, had more peripheral manifestations, and had higher level of acute phase reactants and body mass index than those of TNFi non-users at baseline. Of 128 patients, 28 patients (21.9%) discontinued first TNFi therapy during the follow-up period of 65.1 ± 27.9 months. In the multivariable analysis, female (hazard ratio [HR], 6.08; 95% confidence interval [CI], 2.27 to 16.27;p= 0.003), hip involvement (HR, 2.52; 95% CI, 1.08 to 5.87;p= 0.033) and a high C-reactive protein (CRP; HR, 1.10; 95% CI, 1.00 to 1.21;p= 0.044) were risk factors for drug discontinuation. Etanercept showed better survival rate than infliximab. The main reason for discontinuation of TNFi was inefficacy.
  
  
  
  TNFi discontinuation rate of Korean patients with AS seems to be similar to those with the European patients. Female sex, hip involvement, CRP, and the type of TNFi were associated with TNFi discontinuation.
authors.affiliation: Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Hyemin
authors.initials: H
authors.lastname: Jeong
authors.affiliation: Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Yeong Hee
authors.initials: YH
authors.lastname: Eun
authors.affiliation: Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: In Young
authors.initials: IY
authors.lastname: Kim
authors.affiliation: Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Hyungjin
authors.initials: H
authors.lastname: Kim
authors.affiliation: Department of Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Joong Kyong
authors.initials: JK
authors.lastname: Ahn
authors.affiliation: Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Jaejoon
authors.initials: J
authors.lastname: Lee
authors.affiliation: Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Eun-Mi
authors.initials: EM
authors.lastname: Koh
authors.affiliation: Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Hoon-Suk
authors.initials: HS
authors.lastname: Cha
mesh_terms: D000068879:Adalimumab / Q000627:therapeutic use; D018501:Antirheumatic Agents; D000068800:Etanercept / Q000627:therapeutic use; D005260:Female; D006801:Humans; D000069285:Infliximab / Q000627:therapeutic use; D056910:Republic of Korea; D012189:Retrospective Studies; D066106:Seoul; D013167:Spondylitis, Ankylosing / Q000188:drug therapy; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors
chemical_list: D018501:Antirheumatic Agents; D014409:Tumor Necrosis Factor-alpha; D000069285:Infliximab; D000068879:Adalimumab; D000068800:Etanercept
keywords: Risk factors; Spondylitis, ankylosing; Survival; Tumor necrosis factor-alpha