title: The impact of initial antidiabetic agent and use of monitoring agents on prescription costs in newly treated type 2 diabetes: A retrospective cohort analysis.
abstract: OBJECTIVE
  To measure the costs associated with the use of antidiabetic agents, monitoring materials and cardiovascular disease (CVD) agents in the management of newly treated type 2 diabetes, and to investigate the factors associated with these costs.
  
  
  METHODS
  A population-based retrospective cohort study was conducted using the Irish national pharmacy claims database. Newly treated patients were identified for 2012 and followed for one year post treatment initiation. Factors associated with costs were assessed using a generalised linear model with gamma family and log-link function. Cost ratios (CR) and 95% CIs were used to determine the contributors of prescription costs. Adjusted odd ratios (OR) and 95% CIs were used to investigate factors associated with high frequency self-monitoring of blood glucose (SMBG).
  
  
  RESULTS
  Mean prescription costs for the 12,941 subjects was €871, while total costs were €11 million. CVD agents accounted for 58% of total costs; 22% of costs were for SMBG; antidiabetic agents accounted for 17% of costs. SMBG resulted in costs that were 80% higher than those without, CR 1.80 (95% CI 1.76-1.84). No significant differences were observed between initiation on metformin or sulphonylureas and high frequency SMBG (OR 1.01 95% CI 0.97-1.04 vs reference). Initiation on newer antidiabetic agents was a significant positive predictors of prescription costs (CR 2.36 95% CI 2.21-2.51 vs metformin).
  
  
  CONCLUSIONS
  Type of initial antidiabetic agent, and SMBG were significant predictors of prescription costs. SMBG represent a major proportion of total costs; however, its use in combination with antidiabetic agents that do not cause hypoglycaemia is questionable.
authors.affiliation: School of Pharmacy and Pharmaceutical Sciences, Trinity College Dublin, Ireland. Electronic address: grimesrt@tcd.ie.
authors.forename: R T
authors.initials: RT
authors.lastname: Grimes
authors.affiliation: Department of Pharmacology and Therapeutics, Trinity Centre for Health Sciences, St James's Hospital, Dublin 8, Ireland.
authors.forename: K
authors.initials: K
authors.lastname: Bennett
authors.affiliation: Consultant Diabetologist, St Vincent's University Hospital and HSE National Clinical Lead in Diabetes, Ireland.
authors.forename: R
authors.initials: R
authors.lastname: Canavan
authors.affiliation: National Centre for Pharmacoeconomics, St James's Hospital, Dublin 8, Ireland.
authors.forename: L
authors.initials: L
authors.lastname: Tilson
authors.affiliation: School of Pharmacy and Pharmaceutical Sciences, Trinity College Dublin, Ireland.
authors.forename: M C
authors.initials: MC
authors.lastname: Henman
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015190:Blood Glucose Self-Monitoring / Q000191:economics*; D002317:Cardiovascular Agents / Q000191:economics* / Q000627:therapeutic use; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy / Q000191:economics*; D019468:Disease Management; D005260:Female; D006801:Humans; D007004:Hypoglycemic Agents / Q000191:economics* / Q000627:therapeutic use; D008297:Male; D008687:Metformin / Q000191:economics / Q000627:therapeutic use; D008875:Middle Aged; D016017:Odds Ratio; D012189:Retrospective Studies; D013453:Sulfonylurea Compounds / Q000191:economics / Q000627:therapeutic use
chemical_list: D002317:Cardiovascular Agents; D007004:Hypoglycemic Agents; D013453:Sulfonylurea Compounds; D008687:Metformin
keywords: Prescription costs; Self monitoring of blood glucose; Treatment guidelines; Type 2 diabetes