title: Risk of fractures in vitiligo patients treated with phototherapy-A retrospective population-based cohort study.
abstract: BACKGROUND
  Phototherapy might increase bone mineral density. However, it is unknown whether phototherapy can reduce the risk of fractures in patients with vitiligo.
  
  
  OBJECTIVE
  To investigate the effect of phototherapy on fracture risks in vitiligo patients aged 40 or older.
  
  
  METHODS
  This population-based cohort study used the 2000-2010 Taiwan National Health Insurance Research Database (NHIRD) to identify 3863 patients newly diagnosed with vitiligo between 2003 and 2009 at age ≥40 years. Study subjects were classified into three cohorts: (1) frequent phototherapy; (2) infrequent phototherapy; and (3) no phototherapy. Patients were followed until the first hip or vertebral fracture or 31 December 2010. Data were analysed using Cox regression models and also stratified by age and gender.
  
  
  RESULTS
  Frequent phototherapy decreased the fracture risks (adjusted hazard ratio (aHR)=0.32, p=0.009) in vitiligo patients. Stratification by age and gender confirmed the fracture prevention effect of frequent phototherapy in patients aged 40-64 years (aHR=0.14, p=0.016) and in female patients (aHR=0.31, p=0.024).
  
  
  CONCLUSIONS
  This study provides the first evidence that frequent phototherapy can reduce the risk of fractures among middle-aged and among female vitiligo patients.
authors.affiliation: Institute of Health and Welfare Policy, National Yang Ming University, Taipei, Taiwan.
authors.forename: Po-Ching
authors.initials: PC
authors.lastname: Lo
authors.affiliation: Department of Dermatology, National Yang Ming University, Taipei, Taiwan; Graduate Institute of Clinical Medicine, National Taiwan University College of Medicine, Taipei, Taiwan; Department of Dermatology, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Cheng-Yuan
authors.initials: CY
authors.lastname: Li
authors.affiliation: Institute of Health and Welfare Policy, National Yang Ming University, Taipei, Taiwan. Electronic address: huang@ym.edu.tw.
authors.forename: Weng-Foung
authors.initials: WF
authors.lastname: Huang
authors.affiliation: Institute of Health and Welfare Policy, National Yang Ming University, Taipei, Taiwan.
authors.forename: Yi-Wen
authors.initials: YW
authors.lastname: Tsai
authors.affiliation: Department of Dermatology, National Yang Ming University, Taipei, Taiwan; Department of Dermatology, Taipei Veterans General Hospital, Taipei, Taiwan; National Defense Medical Center, Taipei, Taiwan.
authors.forename: Han-Nan
authors.initials: HN
authors.lastname: Liu
authors.affiliation: Department of Dermatology, National Yang Ming University, Taipei, Taiwan; Department of Dermatology, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Yun-Ting
authors.initials: YT
authors.lastname: Chang
authors.affiliation: Department of Dermatology, National Taiwan University Hospital Hsin-Chu Branch, Hsinchu, Taiwan.
authors.forename: Hsien-Yi
authors.initials: HY
authors.lastname: Chiu
authors.affiliation: Department of Dermatology, National Taiwan University Hospital,Taipei, Taiwan; Department of Dermatology, National Taiwan University College of Medicine, Taipei, Taiwan. Electronic address: tftsai@yahoo.com.
authors.forename: Tsen-Fang
authors.initials: TF
authors.lastname: Tsai
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D015519:Bone Density / Q000528:radiation effects*; D005260:Female; D006620:Hip Fractures / Q000453:epidemiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010789:Phototherapy; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012306:Risk; D012737:Sex Factors; D016103:Spinal Fractures / Q000453:epidemiology*; D013624:Taiwan / Q000453:epidemiology; D014820:Vitiligo / Q000628:therapy*
keywords: Fracture; Gender; National Health Insurance Research Database; Phototherapy; Vitiligo