title: Retrospective study of adherence to glucagon-like peptide-1 receptor agonist therapy in patients with type 2 diabetes mellitus in the United States.
abstract: BACKGROUND
  Greater adherence to medications has been broadly demonstrated to be associated with improved clinical outcomes. However, there is limited real-world evidence on adherence to glucagon-like peptide-1 receptor agonist (GLP-1RA) therapy in patients with type 2 diabetes mellitus (T2DM).
  
  
  METHODS
  This retrospective cohort study used United States administrative claims data to compare adherence to GLP-1RAs in T2DM patients initiating exenatide once weekly (QW), exenatide twice daily (BID), or once-daily liraglutide (initiated therapy = index therapy). Patients were included if they had T2DM, were GLP-1RA-naïve, initiated a GLP-1RA from 02/01/2012-01/31/2013 (date of initiation = index), were ≥18 years at index, and had continuous enrollment for 12 months before (baseline) to 6 months after index (follow-up). Study outcome was index GLP-1RA adherence (proportion of days covered [PDC] during follow-up, dichotomized at ≥80% vs. <80%, and at ≥90% vs. <90%). Multivariable logistic regressions compared adherence between the GLP-1RAs, adjusting for potential confounders. Sensitivity analyses were performed separating liraglutide by dose (1.2 mg/1.8 mg).
  
  
  RESULTS
  Study sample included 4,041 exenatide QW, 4,586 exenatide BID, and 14,211 liraglutide (6,641 1.2 mg, 7,570 1.8 mg) patients. Median unadjusted PDC values were 0.783 for exenatide QW, 0.500 exenatide BID, 0.722 liraglutide, 0.761 liraglutide 1.2 mg, and 0.683 liraglutide 1.8 mg. Compared with patients treated with either exenatide BID or liraglutide, patients treated with exenatide QW had a statistically significantly greater multivariable-adjusted odds of achieving adherence of ≥80% (odds ratio vs. exenatide QW (OR) = 0.41 for exenatide BID; 0.80, liraglutide; 0.87, liraglutide 1.2 mg; 0.75, liraglutide 1.8 mg) and ≥90% (OR = 0.31 for exenatide BID; 0.60 liraglutide; 0.66 liraglutide 1.2 mg; 0.56 liraglutide 1.8 mg) (all P < 0.001).
  
  
  CONCLUSIONS
  Patients initiating exenatide QW had significantly higher adjusted odds of adherence compared with patients initiating other GLP-1RAs. Given differences in adherence across the GLP-1RAs, research correlating these factors with clinical and economic outcomes is warranted.
authors.affiliation: Truven Health Analytics, 7700 Old Georgetown Rd, Suite 650, Bethesda, MD, 20814, USA, stephen.johnston@truvenhealth.com.
authors.forename: Stephen S
authors.initials: SS
authors.lastname: Johnston
authors.forename: Hiep
authors.initials: H
authors.lastname: Nguyen
authors.forename: Eugene
authors.initials: E
authors.lastname: Felber
authors.forename: Katherine
authors.initials: K
authors.lastname: Cappell
authors.forename: James K
authors.initials: JK
authors.lastname: Nelson
authors.forename: Bong-Chul
authors.initials: BC
authors.lastname: Chu
authors.forename: Iftekhar
authors.initials: I
authors.lastname: Kalsekar
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000188:drug therapy; D004334:Drug Administration Schedule; D000077270:Exenatide; D005260:Female; D052216:Glucagon-Like Peptide 1 / Q000031:analogs & derivatives*; D000067757:Glucagon-Like Peptide-1 Receptor / Q000378:metabolism; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D007004:Hypoglycemic Agents / Q000008:administration & dosage; D000069450:Liraglutide / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D010455:Peptides / Q000008:administration & dosage*; D012189:Retrospective Studies; D014481:United States; D014688:Venoms / Q000008:administration & dosage*; D000097789:Glucagon-Like Peptide-1 Receptor Agonists; D016903:Drug Monitoring
chemical_list: D000077270:Exenatide; D052216:Glucagon-Like Peptide 1; D000067757:Glucagon-Like Peptide-1 Receptor; D006442:Glycated Hemoglobin; D007004:Hypoglycemic Agents; D000069450:Liraglutide; D010455:Peptides; D014688:Venoms; D000097789:Glucagon-Like Peptide-1 Receptor Agonists