title: Does disease activity at the start of biologic therapy influence health care costs in patients with RA?
abstract: OBJECTIVE
  To investigate whether disease activity at baseline influences health care costs in patients with RA initiating biologic treatment.
  
  
  METHODS
  In the Swedish Biologics Register, we identified patients with RA with baseline 28-joint DAS (DAS28) recorded and starting their first biologic in 2007-11 [n = 1638 with moderate disease activity (DAS28 3.2-5.1) and n = 1870 with high disease activity (DAS28 > 5.1)]. Data on inpatient and outpatient care and prescription drugs were retrieved from nationwide registers. Mean cost differences were estimated adjusted for age, sex and costs the year before treatment start.
  
  
  RESULTS
  Patients with high (vs moderate) disease activity were older (60 vs 56 years; P < 0.001), but did not differ in sex distribution (75 vs 74% women; P = 0.99) or disease duration (10 vs 10 years; P = 0.13). The year after initiation of biologics, patients with high (vs moderate) baseline disease activity accumulated 9% higher health care costs, but the difference was not statistically significant after adjustment [€19,333 vs €17,810; adjusted difference €870 (95% CI -2, 1742)]. In the subgroup of patients with up to 4 years of follow-up data, decreasing costs were observed over the follow-up time, but no difference was found between patients with high compared with moderate baseline disease activity [€13,704 vs €12,349; adjusted difference 878 (95% CI -364, 2120)]. Irrespective of baseline disease activity, health care costs were approximately three times higher the year after initiation of biologics than the year before due to increased drug costs.
  
  
  CONCLUSIONS
  Over up to 4 years of follow-up, no difference in health care costs was found after adjustment in patients starting their first biologic treatment with high vs moderate baseline disease activity.
authors: Clinical Epidemiology Unit, kari.johansson@ki.se.
authors: Kari
authors: K
authors: Johansson
authors: Clinical Epidemiology Unit.
authors: Jonas K
authors: JK
authors: Eriksson
authors: CLINTRID and Rheumatology Unit, Department of Medicine, Karolinska Institutet, Stockholm, Sweden.
authors: Ronald
authors: R
authors: van Vollenhoven
authors: CLINTRID and.
authors: Heather
authors: H
authors: Miller
authors: Clinical Epidemiology Unit, Rheumatology Unit, Department of Medicine, Karolinska Institutet, Stockholm, Sweden.
authors: Johan
authors: J
authors: Askling
authors: Clinical Epidemiology Unit.
authors: Martin
authors: M
authors: Neovius
mesh_terms: D018501:Antirheumatic Agents / Q000627:therapeutic use; D001172:Arthritis, Rheumatoid / Q000188:drug therapy* / Q000191:economics*; D001688:Biological Products / Q000191:economics / Q000627:therapeutic use*; D004359:Drug Therapy, Combination; D005260:Female; D005500:Follow-Up Studies; D017048:Health Care Costs / Q000639:trends*; D006801:Humans; D007297:Inpatients; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010045:Outpatients; D012720:Severity of Illness Index; D013548:Sweden; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors
chemical_list: D018501:Antirheumatic Agents; D001688:Biological Products; D014409:Tumor Necrosis Factor-alpha
keywords: DMARD; TNF inhibitors; disease activity; health care costs; rheumatoid arthritis