title: Allopurinol use in a New Zealand population: prevalence and adherence.
abstract: Allopurinol is effective for the control of gout and its long-term complications when taken consistently. There is evidence that adherence to allopurinol therapy varies across population groups. This may exacerbate differences in the burden of gout on population groups and needs to be accurately assessed. The aim of this study was to describe the prevalence of allopurinol use in a region of New Zealand using community pharmacy dispensing data and to examine the levels of suboptimal adherence in various population groups. Data from all community pharmacy dispensing databases in a New Zealand region were collected for a year covering 2005/2006 giving a near complete picture of dispensings to area residents. Prevalence of allopurinol use in the region by age, sex, ethnicity and socioeconomic position was calculated. Adherence was assessed using the medication possession ratio (MPR), with a MPR of 0.80 indicative of suboptimal adherence. Multiple logistic regression was used to explore variations in suboptimal adherence across population groups. A total of 953 people received allopurinol in the study year (prevalence 3%). Prevalence was higher in males (6%) than in females (1%) and Māori (5%) than non-Māori (3%). The overall MPR during the study was 0.88, with 161 (22%) of patients using allopurinol having suboptimal adherence. Non-Māori were 54% less likely to have suboptimal allopurinol adherence compared to Māori (95% CI 0.30-0.72, p = 0.001). These findings are consistent with those from other studies nationally and internationally and point to the important role for health professionals in improving patient adherence to an effective gout treatment.
authors.affiliation: Department of Preventive and Social Medicine, University of Otago, PO Box 56, Dunedin, New Zealand, simon.horsburgh@otago.ac.nz.
authors.forename: Simon
authors.initials: S
authors.lastname: Horsburgh
authors.forename: Pauline
authors.initials: P
authors.lastname: Norris
authors.forename: Gordon
authors.initials: G
authors.lastname: Becket
authors.forename: Bruce
authors.initials: B
authors.lastname: Arroll
authors.forename: Peter
authors.initials: P
authors.lastname: Crampton
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Cumming
authors.forename: Shirley
authors.initials: S
authors.lastname: Keown
authors.forename: Peter
authors.initials: P
authors.lastname: Herbison
mesh_terms: D000328:Adult; D000368:Aged; D000493:Allopurinol / Q000627:therapeutic use*; D003157:Community Pharmacy Services / Q000706:statistics & numerical data; D003430:Cross-Sectional Studies; D005260:Female; D006073:Gout / Q000188:drug therapy* / Q000208:ethnology*; D006074:Gout Suppressants / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D055118:Medication Adherence / Q000208:ethnology*; D008875:Middle Aged; D009520:New Zealand / Q000453:epidemiology; D016017:Odds Ratio; D044382:Population Groups / Q000706:statistics & numerical data; D015995:Prevalence; D016903:Drug Monitoring
chemical_list: D006074:Gout Suppressants; D000493:Allopurinol