title: Effectiveness and drug adherence of biologic monotherapy in routine care of patients with rheumatoid arthritis: a cohort study of patients registered in the Danish biologics registry.
abstract: OBJECTIVE
  To estimate the prevalence of Danish RA patients currently on biologic monotherapy and compare the effectiveness and drug adherence of biologic therapies applied as monotherapy.
  
  
  METHODS
  All RA patients registered in the Danish biologics database (DANBIO) as receiving biologic DMARD (bDMARD) treatment as monotherapy without concomitant conventional synthetic DMARDs (csDMARDs) during the study period 1 May, 2011 through 30 April 2013 were eligible for inclusion. All patient files were checked to ensure that they were in accordance with the treatment registration in DANBIO. Descriptive statistics for prevalence, effectiveness and drug adherence of bDMARD monotherapy were calculated.
  
  
  RESULTS
  Of the 775 patients on bDMARD monotherapy, adalimumab (21.3%), etanercept (36.6%) and tocilizumab (15.3%) were the most prevalent biologic agents administered. At the 6-month follow-up, the overall crude clinical disease activity index remission rate in patients still on a biologic drug was 22%, the 28-joint DAS remission rate was 41% and the response rate of those with a 50% improvement in ACR criteria was 28%. At the 6-month follow-up, the drug adherence rates were similar for the different bDMARDs, with the exception of infliximab, which had significantly poorer drug adherence (P < 0.001). The overall drug adherence (except for infliximab) was approximately 70% after 2 years.
  
  
  CONCLUSIONS
  Nearly one in five (19%) biologic treatments for RA was prescribed in Denmark as monotherapy, of which 70% were on monotherapy from bio-initiation and 30% were on monotherapy after cessation of a concomitant csDMARD. Acceptable drug adherence and remission rates were achieved with bDMARDs. With the exception of infliximab, no statistically significant differences were observed between anti-TNFs and biologics with other modes of action.
authors.affiliation: Musculoskeletal Statistics Unit, The Parker Institute, Department of Rheumatology, Copenhagen University Hospital, Bispebjerg and Frederiksberg, Denmark, henning.bliddal@regionh.dk.
authors.forename: Tanja Schjødt
authors.initials: TS
authors.lastname: Jørgensen
authors.affiliation: Musculoskeletal Statistics Unit, The Parker Institute, Department of Rheumatology, Copenhagen University Hospital, Bispebjerg and Frederiksberg, Denmark, Department of Rheumatology, Lund University Hospital, Lund, Sweden.
authors.forename: Lars Erik
authors.initials: LE
authors.lastname: Kristensen
authors.affiliation: Musculoskeletal Statistics Unit, The Parker Institute, Department of Rheumatology, Copenhagen University Hospital, Bispebjerg and Frederiksberg, Denmark.
authors.forename: Robin
authors.initials: R
authors.lastname: Christensen
authors.affiliation: Musculoskeletal Statistics Unit, The Parker Institute, Department of Rheumatology, Copenhagen University Hospital, Bispebjerg and Frederiksberg, Denmark, henning.bliddal@regionh.dk.
authors.forename: Henning
authors.initials: H
authors.lastname: Bliddal
authors.affiliation: Department of Rheumatology, Diagnostic Centre, Silkeborg Regional Hospital.
authors.forename: Tove
authors.initials: T
authors.lastname: Lorenzen
authors.affiliation: ReumaKlinik Roskilde, Roskilde.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Hansen
authors.affiliation: Copenhagen Centre for Arthritis Research, Center for Rheumatology and Spine Diseases, Glostrup Hospital, Glostrup.
authors.forename: Mikkel
authors.initials: M
authors.lastname: Østergaard
authors.affiliation: Department of Rheumatology, Region Hospital Køge, Køge.
authors.forename: Jørgen
authors.initials: J
authors.lastname: Jensen
authors.affiliation: Copenhagen Centre for Arthritis Research, Center for Rheumatology and Spine Diseases, Glostrup Hospital, Glostrup.
authors.forename: Lida
authors.initials: L
authors.lastname: Zanjani
authors.affiliation: Department of Rheumatology, Copenhagen University Hospital, Gentofte.
authors.forename: Toke
authors.initials: T
authors.lastname: Laursen
authors.affiliation: Department of Rheumatology, Copenhagen University Hospital, Bispebjerg and Frederiksberg.
authors.forename: Sheraz
authors.initials: S
authors.lastname: Butt
authors.affiliation: Department of Rheumatology, Aarhus University Hospital, Aarhus.
authors.forename: Mette Y
authors.initials: MY
authors.lastname: Dam
authors.affiliation: Department of Rheumatology, Odense University Hospital, Odense.
authors.forename: Hanne M
authors.initials: HM
authors.lastname: Lindegaard
authors.affiliation: Department of Rheumatology, Hospital Lillebælt, Vejle.
authors.forename: Jakob
authors.initials: J
authors.lastname: Espesen
authors.affiliation: King Christian 10th Hospital for Rheumatic Diseases, Gråsten.
authors.forename: Oliver
authors.initials: O
authors.lastname: Hendricks
authors.affiliation: Department of Rheumatology, Sydvestjysk Hospital, Esbjerg.
authors.forename: Prabhat
authors.initials: P
authors.lastname: Kumar
authors.affiliation: Department of Rheumatology, Copenhagen University Hospital, Rigshospitalet.
authors.forename: Anita
authors.initials: A
authors.lastname: Kincses
authors.affiliation: Department of Rheumatology, Aalborg University Hospital, Aalborg.
authors.forename: Line H
authors.initials: LH
authors.lastname: Larsen
authors.affiliation: Department of Rheumatology, Hospital Vendsyssel, Hjørring.
authors.forename: Marlene
authors.initials: M
authors.lastname: Andersen
authors.affiliation: Department of Rheumatology, Diagnostic Centre, Silkeborg Regional Hospital.
authors.forename: Esben K
authors.initials: EK
authors.lastname: Næser
authors.affiliation: Department of Rheumatology, Copenhagen University Hospital, Gentofte, and Bornholms Hospital, Rønne.
authors.forename: Dorte V
authors.initials: DV
authors.lastname: Jensen
authors.affiliation: Department of Rheumatology, Region Hospital Viborg, Viborg.
authors.forename: Jolanta
authors.initials: J
authors.lastname: Grydehøj
authors.affiliation: Department of Rheumatology, Region Hospital Horsens, Horsens.
authors.forename: Barbara
authors.initials: B
authors.lastname: Unger
authors.affiliation: Department of Rheumatology, Nordsjællands Hospital, Helsingør.
authors.forename: Ninna
authors.initials: N
authors.lastname: Dufour
authors.affiliation: Department of Rheumatology, Region Hospital Randers, Randers.
authors.forename: Vibeke
authors.initials: V
authors.lastname: Sørensen
authors.affiliation: Department of Rheumatology, Region Hospital Holstebro, Holstebro.
authors.forename: Sara
authors.initials: S
authors.lastname: Vildhøj
authors.affiliation: Department of Rheumatology, Odense University Hospital, Svendborg.
authors.forename: Inger Marie Jensen
authors.initials: IM
authors.lastname: Hansen
authors.affiliation: Department of Rheumatology, Hospital Lillebælt, Fredericia.
authors.forename: Johnny
authors.initials: J
authors.lastname: Raun
authors.affiliation: ZiteLab ApS, Copenhagen, Denmark.
authors.forename: Niels Steen
authors.initials: NS
authors.lastname: Krogh
authors.affiliation: Copenhagen Centre for Arthritis Research, Center for Rheumatology and Spine Diseases, Glostrup Hospital, Glostrup, Faculty of Health and Medical Sciences, Department of Clinical Medicine, University of Copenhagen, Copenhagen and Danish Rheumatologic Database (DANBIO), Center for Rheumatology and Spine Diseases, Glostrup Hospital, Glostrup, Denmark.
authors.forename: Merete Lund
authors.initials: ML
authors.lastname: Hetland
mesh_terms: D000068879:Adalimumab / Q000627:therapeutic use; D000328:Adult; D000368:Aged; D061067:Antibodies, Monoclonal, Humanized / Q000627:therapeutic use; D018501:Antirheumatic Agents / Q000627:therapeutic use*; D001172:Arthritis, Rheumatoid / Q000188:drug therapy* / Q000453:epidemiology; D001688:Biological Products / Q000627:therapeutic use*; D003718:Denmark / Q000453:epidemiology; D000068800:Etanercept / Q000627:therapeutic use; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012042:Registries; D012074:Remission Induction; D012720:Severity of Illness Index; D016896:Treatment Outcome; D016903:Drug Monitoring
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D018501:Antirheumatic Agents; D001688:Biological Products; D000068879:Adalimumab; C502936:tocilizumab; D000068800:Etanercept
keywords: DMARDs; biologics; cohort study; monotherapy; rheumatoid arthritis