title: Fractures lead to worsening of disease activity in rheumatoid arthritis.
abstract: OBJECTIVE
  The cause of rheumatoid arthritis (RA) flares is multifactorial and not well understood. No reports of fractures influencing disease activity in patients with RA have been published. The purpose of this study was to determine whether fractures influence disease activity in patients with RA.
  
  
  METHODS
  Hospital records of 470 patients with RA between 2011 and 2014 were analyzed. We first examined the incidence of flare using multiple regression analysis. Secondly, we examined the incidence of flare using DAS28-ESR, DAS28-CRP, and drug changes before bone fracture until bone union in the fracture cases.
  
  
  RESULTS
  Multiple linear regression analysis showed that female sex (p < 0.001), bottom DAS28-ESR (p < 0.001), and fracture (p = 0.041) were independent factor for DAS28-ESR at the last observation period, and sex (p = 0.040), bottom DAS28-CRP (p < 0.001), and fracture (p = 0.019) were independent factor for DAS28-CRP at the last observation period. The average DAS28-ESR value was significantly increased from 3.19 (prefracture) to 3.58 (bone union). The average DAS28-CRP value was also significantly increased from 2.45 (prefracture) to 2.79 (bone union).
  
  
  CONCLUSIONS
  We have demonstrated that fractures influence disease activity in patients with RA. Larger numbers of fracture cases are required to confirm the present observations; however, the prevention of fracture is clearly required in patients with RA.
authors.affiliation: a Department of Orthopedic Surgery , University of Yamanashi , Chuo , Yamanashi , Japan.
authors.forename: Kensuke
authors.initials: K
authors.lastname: Koyama
authors.affiliation: b Department of Orthopedic Surgery , Yamanashi Prefectural Central Hospital , Kofu , Yamanashi , Japan , and.
authors.forename: Michitomo
authors.initials: M
authors.lastname: Sakuma
authors.affiliation: a Department of Orthopedic Surgery , University of Yamanashi , Chuo , Yamanashi , Japan.
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Ohba
authors.affiliation: c Department of Health Sciences, Basic Science for Clinical Medicine, Division of Medicine, Graduate School of Interdisciplinary Research , University of Yamanashi , Chuo , Yamanashi , Japan.
authors.forename: Kohta
authors.initials: K
authors.lastname: Suzuki
authors.affiliation: a Department of Orthopedic Surgery , University of Yamanashi , Chuo , Yamanashi , Japan.
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Haro
mesh_terms: D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000453:epidemiology*; D005260:Female; D050723:Fractures, Bone / Q000453:epidemiology*; D006801:Humans; D008297:Male; D008875:Middle Aged
keywords: Disease activity score; Flare; Fracture; Rheumatoid arthritis