title: Cost-effectiveness of second-line antihyperglycemic therapy in patients with type 2 diabetes mellitus inadequately controlled on metformin.
abstract: BACKGROUND
  Metformin is widely accepted as first-line pharmacotherapy for patients with type 2 diabetes mellitus when glycemic control cannot be achieved by lifestyle interventions alone. However, uncertainty exists regarding the optimal second-line therapy for patients whose diabetes is inadequately controlled by metformin monotherapy. Increased use of newer, more costly agents, along with the rising incidence of type 2 diabetes, carries significant budgetary implications for health care systems. We conducted this analysis to determine the relative costs, benefits and cost-effectiveness of options for second-line treatment of type 2 diabetes.
  
  
  METHODS
  We used the United Kingdom Prospective Diabetes Study Outcomes Model to forecast diabetes-related complications, quality-adjusted life-years and costs of alternative second-line therapies available in Canada for adults with type 2 diabetes inadequately controlled by metformin. We obtained clinical data from a systematic review and mixed treatment comparison meta-analysis, and we obtained information on costs and utilities from published sources. We performed extensive sensitivity analyses to test the robustness of results to variation in inputs and assumptions.
  
  
  RESULTS
  Sulphonylureas, when added to metformin, were associated with the most favourable cost-effectiveness estimate, with an incremental cost of $12 757 per quality-adjusted life-year gained, relative to continued metformin monotherapy. Treatment with other agents, including thiazolidinediones and dipeptidyl peptidase-4 inhibitors, had unfavourable cost-effectiveness estimates compared with sulphonylureas. These results were robust to extensive sensitivity analyses.
  
  
  CONCLUSIONS
  For most patients with type 2 diabetes that is inadequately controlled with metformin monotherapy, the addition of a sulphonylurea represents the most cost-effective second-line therapy.
authors.affiliation: Department of Medicine, University of Alberta, Edmonton, Alta.
authors.forename: Scott
authors.initials: S
authors.lastname: Klarenbach
authors.forename: Chris
authors.initials: C
authors.lastname: Cameron
authors.forename: Sumeet
authors.initials: S
authors.lastname: Singh
authors.forename: Ehud
authors.initials: E
authors.lastname: Ur
mesh_terms: D003198:Computer Simulation; D003362:Cost-Benefit Analysis; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy*; D054873:Dipeptidyl-Peptidase IV Inhibitors / Q000191:economics / Q000627:therapeutic use; D004359:Drug Therapy, Combination; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D007004:Hypoglycemic Agents / Q000191:economics* / Q000627:therapeutic use*; D008687:Metformin / Q000627:therapeutic use; D008954:Models, Biological; D019057:Quality-Adjusted Life Years; D013453:Sulfonylurea Compounds / Q000191:economics / Q000627:therapeutic use; D045162:Thiazolidinediones / Q000191:economics / Q000627:therapeutic use
chemical_list: D054873:Dipeptidyl-Peptidase IV Inhibitors; D006442:Glycated Hemoglobin; D007004:Hypoglycemic Agents; D008687:Metformin; D013453:Sulfonylurea Compounds; D045162:Thiazolidinediones