title: Septic arthritis in gout patients: a population-based cohort study.
abstract: OBJECTIVE
  To evaluate the association of incident gout with the risk of incident septic arthritis in a general population context.
  
  
  METHODS
  We investigated the association of incident gout with the risk of incident septic arthritis using the Health Improvement Network, a computerized medical record database from general practices in the UK. We conducted a cohort analysis of the risk of an incident septic arthritis diagnosis among adults with incident gout compared with up to five non-gout individuals matched by age, sex, date of study entry and enrolment year. We performed Cox proportional hazard regression models to adjust for lifestyle variables, physician visits, comorbidities and medication use.
  
  
  RESULTS
  We identified 72 073 incident gout patients and 358 342 matched non-gout patients. The incidence rates of a septic arthritis diagnosis were 0.24 cases and 0.09 cases per 1000 person-years in the gout and comparison cohorts, respectively. Matched univariate and multivariate hazard ratios of a septic arthritis diagnosis were 2.82 (95% CI 2.15, 3.71) and 2.60 (95% CI 1.93, 3.51), respectively. The association persisted among subgroups stratified by sex, age group (<75 and ≥75) and socio-economic deprivation level.
  
  
  CONCLUSIONS
  This general population-based study suggests that gout is associated with an increased likelihood of septic arthritis.
authors.affiliation: Division of Rheumatology, Allergy and Immunology, Massachusetts General Hospital, Harvard Medical School and sylim@partners.org.
authors.forename: Sian Yik
authors.initials: SY
authors.lastname: Lim
authors.affiliation: Division of Rheumatology, Allergy and Immunology, Massachusetts General Hospital, Harvard Medical School and Clinical Epidemiology Research and Training Unit, Boston University School of Medicine, Boston, MA, USA.
authors.forename: Na
authors.initials: N
authors.lastname: Lu
authors.affiliation: Division of Rheumatology, Allergy and Immunology, Massachusetts General Hospital, Harvard Medical School and Clinical Epidemiology Research and Training Unit, Boston University School of Medicine, Boston, MA, USA.
authors.forename: Hyon K
authors.initials: HK
authors.lastname: Choi
mesh_terms: D000367:Age Factors; D000368:Aged; D001170:Arthritis, Infectious / Q000453:epidemiology*; D016022:Case-Control Studies; D015331:Cohort Studies; D016208:Databases, Factual / Q000706:statistics & numerical data*; D005260:Female; D058006:General Practice / Q000706:statistics & numerical data*; D006073:Gout / Q000150:complications* / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012307:Risk Factors; D012737:Sex Factors; D006113:United Kingdom / Q000453:epidemiology
keywords: epidemiology; gout; infection; population-based cohort study; septic arthritis