title: Regional variation in medication-taking behaviour of new users of oral anti-hyperglycaemic therapy in Ireland.
abstract: BACKGROUND
  Few studies have investigated regional variation in medication-taking behaviour. The purpose of this study was to investigate whether there are regional differences in non-persistence and non-adherence to oral anti-hyperglycaemic agents in patients initiating therapy and examine if any association exists between different types of comorbidity in terms of medication-taking behaviour.
  
  
  METHODS
  The Irish Health Services Executive (HSE) pharmacy claims database was used to identify new users of metformin or sulphonylureas, aged ≥25 years, initiating therapy between June 2009 and December 2010. Non-persistence and non-adherence were examined up to 12 months post-initiation. Comorbidity was assessed using modified RxRisk and RxRisk-V indices, and classified as either concordant and/or discordant with diabetes. Adjusted hazard ratios (HRs) and 95% confidence intervals (95% CIs) for non-persistence were determined in relation to both HSE region and comorbidity type using Cox proportional hazards model, adjusting for age, sex and initial OAH prescribed. Logistic regression analysis, adjusting for these covariates, was used to determine the adjusted odds ratios (ORs) and 95% CIs for non-adherence for both HSE region and comorbidity type.
  
  
  RESULTS
  Results showed little overall difference between regions. The largest reduction for both non-persistence (HR 0.86, 95% CI 0.80, 0.94) and non-adherence (OR 0.83, 95% CI 0.74, 0.93) was observed in the south. Any comorbidity was associated with a reduced risk of non-persistence and non-adherence.
  
  
  CONCLUSIONS
  Interventions to optimise medication-taking in patients with T2DM should be implemented nationally to improve the overall level of adherence and persistence, especially in patients with no comorbidity.
authors.affiliation: Department of Pharmacology and Therapeutics, Trinity Centre for Health Science, St James's Hospital, Dublin 8, Ireland, osheami@tcd.ie.
authors.forename: M P
authors.initials: MP
authors.lastname: O'Shea
authors.forename: M
authors.initials: M
authors.lastname: Teeling
authors.forename: K
authors.initials: K
authors.lastname: Bennett
mesh_terms: D000328:Adult; D000368:Aged; D015897:Comorbidity; D016208:Databases, Factual; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy*; D011307:Drug Prescriptions; D005260:Female; D006801:Humans; D007004:Hypoglycemic Agents / Q000009:adverse effects / Q000627:therapeutic use*; D007494:Ireland; D008297:Male; D008687:Metformin / Q000009:adverse effects / Q000627:therapeutic use*; D008875:Middle Aged; D012189:Retrospective Studies; D013453:Sulfonylurea Compounds / Q000009:adverse effects / Q000627:therapeutic use*; D016903:Drug Monitoring
chemical_list: D007004:Hypoglycemic Agents; D013453:Sulfonylurea Compounds; D008687:Metformin