title: Patterns of medication initiation in newly diagnosed diabetes mellitus: quality and cost implications.
abstract: OBJECTIVE
  Six oral medication classes have been approved by the Food and Drug Administration for the treatment of type 2 diabetes. Although all of these agents effectively lower blood glucose, the evidence supporting their impact on other clinical events is variable. There also are substantial cost differences between agents. We aimed to evaluate temporal trends in the use of specific drugs for the initial management of type 2 diabetes and to estimate the economic consequences of non-recommended care.
  
  
  METHODS
  We studied a cohort of 254,973 patients, aged 18 to 100 years, who were newly initiated on oral hypoglycemic monotherapy between January 1, 2006, and December 31, 2008, by using prescription claims data from a large pharmacy benefit manager. Linear regression models were used to assess whether medication initiation patterns changed over time. Multivariate logistic regression models were constructed to identify independent predictors of receiving initial therapy with metformin. We then measured the economic consequences of prescribing patterns by drug class for both patients and the insurer.
  
  
  RESULTS
  Over the course of the study period, the proportion of patients initially treated with metformin increased from 51% to 65%, whereas those receiving sulfonylureas decreased from 26% to 18% (P<.001 for both). There was a significant decline in the use of thiazolidinediones (20.1%-8.3%, P<.001) and an increase in prescriptions for dipeptidyl peptidase-4 inhibitors (0.4%-7.3%, P<.001). Younger patients, women, and patients receiving drug benefits through Medicare were least likely to initiate treatment with metformin. Combined patient and insurer spending for patients who were initiated on alpha-glucosidase inhibitors, thiazolidinediones, meglitinides, or dipeptidyl peptidase-4 inhibitors was $677 over a 6-month period compared with $116 and $118 for patients initiated on metformin or a sulfonylurea, respectively, a cost difference of approximately $1120 annually per patient.
  
  
  CONCLUSIONS
  Approximately 35% of patients initiating an oral hypoglycemic drug did not receive recommended initial therapy with metformin. These practice patterns also have substantial implications for health care spending.
authors.affiliation: Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital, Boston, MA, USA.
authors.forename: Nihar R
authors.initials: NR
authors.lastname: Desai
authors.forename: William H
authors.initials: WH
authors.lastname: Shrank
authors.forename: Michael A
authors.initials: MA
authors.lastname: Fischer
authors.forename: Jerry
authors.initials: J
authors.lastname: Avorn
authors.forename: Joshua N
authors.initials: JN
authors.lastname: Liberman
authors.forename: Sebastian
authors.initials: S
authors.lastname: Schneeweiss
authors.forename: Juliana
authors.initials: J
authors.lastname: Pakes
authors.forename: Troyen A
authors.initials: TA
authors.lastname: Brennan
authors.forename: Niteesh K
authors.initials: NK
authors.lastname: Choudhry
mesh_terms: D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy*; D054873:Dipeptidyl-Peptidase IV Inhibitors / Q000008:administration & dosage / Q000191:economics / Q000627:therapeutic use; D019317:Evidence-Based Medicine; D005260:Female; D006801:Humans; D007004:Hypoglycemic Agents / Q000008:administration & dosage / Q000191:economics* / Q000627:therapeutic use*; D016015:Logistic Models; D008297:Male; D008687:Metformin / Q000008:administration & dosage / Q000191:economics / Q000627:therapeutic use; D008875:Middle Aged; D010818:Practice Patterns, Physicians' / Q000706:statistics & numerical data*; D011787:Quality of Health Care; D013453:Sulfonylurea Compounds / Q000008:administration & dosage / Q000191:economics / Q000627:therapeutic use; D045162:Thiazolidinediones / Q000008:administration & dosage / Q000191:economics / Q000627:therapeutic use; D014481:United States; D000520:alpha-Glucosidases / Q000008:administration & dosage / Q000191:economics / Q000627:therapeutic use
chemical_list: D054873:Dipeptidyl-Peptidase IV Inhibitors; D007004:Hypoglycemic Agents; D013453:Sulfonylurea Compounds; D045162:Thiazolidinediones; D008687:Metformin; D000520:alpha-Glucosidases