title: Effect of allopurinol on all-cause mortality in adults with incident gout: propensity score-matched landmark analysis.
abstract: OBJECTIVE
  To examine the association between allopurinol use and all-cause mortality for patients with incident gout.
  
  
  METHODS
  We compared all-cause mortality in incident gout patients who received allopurinol for at least 6 months within the exposure window (1 year or 3 years) with those who did not, using the UK Clinical Practice Research Data-link. Landmark analysis was used to account for immortal time bias and propensity score matching was used to control for potential effects of known confounders.
  
  
  RESULTS
  Of 23 332 incident gout patients identified, the propensity score-matched cohorts contained 1016 patients exposed to allopurinol on the date 1 year from diagnosis (landmark date) and 1016 allopurinol non-users. Over a median follow-up period of 10 years after the landmark date, there were 437 allopurinol users and 443 allopurinol non-users who died during follow-up. Allopurinol users and non-users had similar risk for all-cause mortality (hazard ratio 0.99; 95% CI 0.87, 1.12). In the 3-year landmark analysis, 3519 allopurinol users (1280 died) were compared with 3519 non-users (1265 died). The hazard ratio for all-cause mortality was 1.01 (95% CI 0.92, 1.09).
  
  
  CONCLUSIONS
  This propensity score-matched landmark analysis in a population of incident gout patients in the UK primary care setting found a neutral effect on the risk of all-cause mortality. Our study provides reassurance about the prescription of allopurinol for gout patients early in their disease course to prevent untoward consequences of chronic uncontrolled hyperuricaemia. However, whether higher than the commonly used dose of allopurinol could influence mortality remains to be determined.
authors.affiliation: Division of Rheumatology, Orthopaedics and Dermatology, School of Medicine, University of Nottingham, Nottingham, UK, Division of Rheumatology, Allergy and Immunology, Chang Gung Memorial Hospital, Taoyuan, Taiwan.
authors.forename: Chang-Fu
authors.initials: CF
authors.lastname: Kuo
authors.affiliation: Division of Epidemiology and Public Health, School of Medicine, University of Nottingham, Nottingham and.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Grainge
authors.affiliation: Arthritis Research UK Primary Care Centre, Keele University, Keele, UK.
authors.forename: Christian
authors.initials: C
authors.lastname: Mallen
authors.affiliation: Division of Rheumatology, Orthopaedics and Dermatology, School of Medicine, University of Nottingham, Nottingham, UK, weiya.zhang@nottingham.ac.uk.
authors.forename: Weiya
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Division of Rheumatology, Orthopaedics and Dermatology, School of Medicine, University of Nottingham, Nottingham, UK.
authors.forename: Michael
authors.initials: M
authors.lastname: Doherty
mesh_terms: D000368:Aged; D000493:Allopurinol / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D016208:Databases, Factual; D004334:Drug Administration Schedule; D005260:Female; D006073:Gout / Q000188:drug therapy* / Q000401:mortality; D006074:Gout Suppressants / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D057216:Propensity Score; D006113:United Kingdom / Q000453:epidemiology
chemical_list: D006074:Gout Suppressants; D000493:Allopurinol
keywords: allopurinol; gout; landmark analysis; mortality; propensity score