title: Rheumatoid Arthritis: Trends in Antirheumatic Drug Use, C-reactive Protein Levels, and Surgical Burden.
abstract: OBJECTIVE
  Over the past decade, the therapeutic approach used to treat patients with rheumatoid arthritis (RA) has considerably changed. It remains unclear whether these changes have been accompanied by decreased disease severity and surgical treatment burden at the population level. Therefore, we investigated time trends in antirheumatic drug consumption, C-reactive protein (CRP) levels, and use of orthopedic surgery among Danish patients with RA.
  
  
  METHODS
  Using medical databases, we identified all patients with RA living in Northern Denmark during 1996-2012. For each calendar year, we computed the annual rate of antirheumatic drug use (1996-2010), the median CRP value in mg/l (1996-2011), and the proportions of patients who underwent hip replacement and other orthopedic procedures (1996-2012).
  
  
  RESULTS
  Antirheumatic drug consumption per patient increased 5-fold, from 145.0 defined daily doses (DDD) in 1996 to 695.4 DDD in 2010. Median CRP declined from 20.5 mg/l [interquartile range (IQR), 10.0 to 43.5 mg/l] in 1996 to 10.0 mg/l (IQR, 4.2-17.8 mg/l) in 2011. From 1996 to 2012, declining proportions of patients with RA underwent hip replacement (14.9% to 10.1%) and other joint operations (29.1% to 23.4%), while the annual proportion of patients who underwent soft tissue procedures increased from 20.7% to 23.4%.
  
  
  CONCLUSIONS
  Antirheumatic drug consumption has substantially increased among patients with RA since 1996, in association with reduced disease activity (i.e., lower CRP levels), fewer joint procedures (including hip replacements), and more soft tissue procedures.
authors.affiliation: From the Department of Clinical Epidemiology, Institute of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark.A.B. Pedersen, MD, PhD, associate professor; A. Mor, MD, MPH, research fellow; F. Mehnert, biostatistician, Dipl Math; R.W. Thomsen, MD, PhD, associate professor; S.P. Johnsen, MD, PhD, associate professor; M. Nørgaard, MD, PhD, associate professor, Department of Clinical Epidemiology, Institute of Clinical Medicine, Aarhus University Hospital. abp@clin.au.dk.
authors.forename: Alma B
authors.initials: AB
authors.lastname: Pedersen
authors.affiliation: From the Department of Clinical Epidemiology, Institute of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark.A.B. Pedersen, MD, PhD, associate professor; A. Mor, MD, MPH, research fellow; F. Mehnert, biostatistician, Dipl Math; R.W. Thomsen, MD, PhD, associate professor; S.P. Johnsen, MD, PhD, associate professor; M. Nørgaard, MD, PhD, associate professor, Department of Clinical Epidemiology, Institute of Clinical Medicine, Aarhus University Hospital.
authors.forename: Anil
authors.initials: A
authors.lastname: Mor
authors.affiliation: From the Department of Clinical Epidemiology, Institute of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark.A.B. Pedersen, MD, PhD, associate professor; A. Mor, MD, MPH, research fellow; F. Mehnert, biostatistician, Dipl Math; R.W. Thomsen, MD, PhD, associate professor; S.P. Johnsen, MD, PhD, associate professor; M. Nørgaard, MD, PhD, associate professor, Department of Clinical Epidemiology, Institute of Clinical Medicine, Aarhus University Hospital.
authors.forename: Frank
authors.initials: F
authors.lastname: Mehnert
authors.affiliation: From the Department of Clinical Epidemiology, Institute of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark.A.B. Pedersen, MD, PhD, associate professor; A. Mor, MD, MPH, research fellow; F. Mehnert, biostatistician, Dipl Math; R.W. Thomsen, MD, PhD, associate professor; S.P. Johnsen, MD, PhD, associate professor; M. Nørgaard, MD, PhD, associate professor, Department of Clinical Epidemiology, Institute of Clinical Medicine, Aarhus University Hospital.
authors.forename: Reimar W
authors.initials: RW
authors.lastname: Thomsen
authors.affiliation: From the Department of Clinical Epidemiology, Institute of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark.A.B. Pedersen, MD, PhD, associate professor; A. Mor, MD, MPH, research fellow; F. Mehnert, biostatistician, Dipl Math; R.W. Thomsen, MD, PhD, associate professor; S.P. Johnsen, MD, PhD, associate professor; M. Nørgaard, MD, PhD, associate professor, Department of Clinical Epidemiology, Institute of Clinical Medicine, Aarhus University Hospital.
authors.forename: Søren P
authors.initials: SP
authors.lastname: Johnsen
authors.affiliation: From the Department of Clinical Epidemiology, Institute of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark.A.B. Pedersen, MD, PhD, associate professor; A. Mor, MD, MPH, research fellow; F. Mehnert, biostatistician, Dipl Math; R.W. Thomsen, MD, PhD, associate professor; S.P. Johnsen, MD, PhD, associate professor; M. Nørgaard, MD, PhD, associate professor, Department of Clinical Epidemiology, Institute of Clinical Medicine, Aarhus University Hospital.
authors.forename: Mette
authors.initials: M
authors.lastname: Nørgaard
mesh_terms: D000328:Adult; D000368:Aged; D018501:Antirheumatic Agents / Q000191:economics / Q000627:therapeutic use*; D001172:Arthritis, Rheumatoid / Q000097:blood / Q000188:drug therapy* / Q000191:economics / Q000601:surgery*; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism*; D003362:Cost-Benefit Analysis; D016208:Databases, Factual; D003718:Denmark; D018450:Disease Progression; D004363:Drug Utilization; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D019637:Orthopedic Procedures / Q000191:economics* / Q000379:methods; D012042:Registries; D012189:Retrospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D016896:Treatment Outcome
chemical_list: D018501:Antirheumatic Agents; D015415:Biomarkers; D002097:C-Reactive Protein
keywords: ANTIRHEUMATIC AGENTS; C-REACTIVE PROTEIN; EPIDEMIOLOGY; INCIDENCE; PREVALENCE; RHEUMATOID ARTHRITIS