title: Increased risk of avascular necrosis in patients with psoriatic disease: A nationwide population-based matched cohort study.
abstract: BACKGROUND
  Avascular necrosis (AVN) and psoriasis have some pathogenic mechanisms and associated conditions in common.
  
  
  OBJECTIVE
  To examine the association between psoriasis and AVN.
  
  
  METHODS
  This study used data from the Taiwan National Health Insurance Research Database for the period 2004-2006 and identified 28,268 patients with psoriasis, who were then matched for age and sex with 113,072 controls without psoriasis from the Taiwan Longitudinal Health Insurance Database 2000. Multivariate Cox proportional hazards models were used for the analysis.
  
  
  RESULTS
  The unadjusted risk of AVN was significantly higher for patients with psoriasis than for controls (hazard ratio [HR] 2.29) and remained significant after adjustment for other risk factors (adjusted HR 1.96; 95% confidence interval 1.62-2.38). The risk for AVN increased in relation to psoriasis severity and was higher for patients with psoriasis and arthritis than for patients without arthritis. The adjusted HRs were higher for male patients than for female patients and for patients younger than 30 years compared with older patients.
  
  
  CONCLUSIONS
  We lacked information on daily tobacco use, alcohol consumption, and physical activity.
  
  
  CONCLUSIONS
  The risk for AVN increased with the disease severity of psoriasis.
authors.affiliation: Institute of Biomedical Engineering, College of Medicine and College of Engineering, National Taiwan University, Taipei, Taiwan; Department of Dermatology, National Taiwan University Hospital Hsin-Chu Branch, Hsin-Chu, Taiwan; Department of Dermatology, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Hsien-Yi
authors.initials: HY
authors.lastname: Chiu
authors.affiliation: Department of Physical Therapy and Assistive Technology, National Yang-Ming University, Taipei, Taiwan.
authors.forename: I-Ting
authors.initials: IT
authors.lastname: Wang
authors.affiliation: Institute of Health and Welfare Policy, National Yang-Ming University, Taipei, Taiwan.
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: Faculty of Pharmacy, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Ming-Neng
authors.initials: MN
authors.lastname: Shiu
authors.affiliation: Department of Dermatology, National Taiwan University Hospital and 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; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010020:Osteonecrosis / Q000453:epidemiology*; D016016:Proportional Hazards Models; D011565:Psoriasis / Q000453:epidemiology*; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D012737:Sex Factors; D013624:Taiwan / Q000453:epidemiology
keywords: National Health Insurance Research Database; avascular necrosis; comorbidities; inflammation; osteonecrosis; psoriasis