title: Adherence, persistence, and treatment discontinuation with sitagliptin compared with sulfonylureas as add-ons to metformin: A retrospective cohort database study.
abstract: BACKGROUND
  Data are limited regarding adherence to dipeptidyl peptidase-4 inhibitors.
  
  
  METHODS
  The present retrospective cohort study of a claims database involved adults with type 2 diabetes mellitus, continuous enrollment for 12 months before the first prescription of add-on sitagliptin (SITA) or a sulfonylurea (SU) to metformin (MET) monotherapy (index date), and ≥45 days of MET coverage ≤90 days before the index date. The SITA and SU users were matched on duration of follow-up and propensity score (PS). Logistic regression analysis incorporated age, gender, comorbidities, and concomitant medications as independent variables.
  
  
  RESULTS
  Approximately 99 % of SITA patients were PS matched, resulting in 14 807 well-balanced PS-matched SITA/SU pairs. Mean proportion of days covered (PDC) was significantly higher for SITA (vs SU) + MET after 1 year (P < 0.001). Adherence (PDC ≥80 %) to SITA (vs SU) + MET was 59.1 % (vs 55.9 %; P < 0.001) at 1 year and 52.6 % (vs 49.9 %; P = 0.007) at 2 years. Using logistic regression models including out-of-pocket expense (OPE) as a covariate, we found improved mean PDC and adherence for SITA (vs SU) + MET. Numbers of patients who continued to use SITA (vs SU) + MET were significantly higher after Years 1, 2, and 3 (all P < 0.05).
  
  
  CONCLUSIONS
  Users of SITA + MET had significantly higher mean PDC, adherence, and persistence than those on SU + MET. These trends were robust to model alterations and were more marked when accommodating OPEs.
authors.affiliation: Department of Medicine, Division of Endocrinology, Diabetes, and Bone Disease, Icahn School of Medicine at Mount Sinai Hospital, New York, New York, USA.
authors.forename: Zachary T
authors.initials: ZT
authors.lastname: Bloomgarden
authors.affiliation: Merck & Co. Inc., Kenilworth, New Jersey, USA.
authors.forename: Kaan
authors.initials: K
authors.lastname: Tunceli
authors.affiliation: Merck & Co. Inc., Kenilworth, New Jersey, USA.
authors.forename: Jinan
authors.initials: J
authors.lastname: Liu
authors.affiliation: Merck & Co. Inc., Kenilworth, New Jersey, USA.
authors.forename: Kimberly G
authors.initials: KG
authors.lastname: Brodovicz
authors.affiliation: Merck & Co. Inc., Kenilworth, New Jersey, USA.
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Mavros
authors.affiliation: Merck & Co. Inc., Kenilworth, New Jersey, USA.
authors.forename: Samuel S
authors.initials: SS
authors.lastname: Engel
authors.affiliation: Merck & Co. Inc., Kenilworth, New Jersey, USA.
authors.forename: Larry
authors.initials: L
authors.lastname: Radican
authors.affiliation: Merck & Co. Inc., Kenilworth, New Jersey, USA.
authors.forename: Yong
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Merck & Co. Inc., Kenilworth, New Jersey, USA.
authors.forename: Swapnil
authors.initials: S
authors.lastname: Rajpathak
authors.affiliation: Merck & Co. Inc., Kenilworth, New Jersey, USA.
authors.forename: Ying
authors.initials: Y
authors.lastname: Qiu
authors.affiliation: Merck & Co. Inc., Kenilworth, New Jersey, USA.
authors.forename: Philippe
authors.initials: P
authors.lastname: Brudi
authors.affiliation: Tulane University Health Sciences Center, New Orleans, Louisiana, USA.
authors.forename: Vivian
authors.initials: V
authors.lastname: Fonseca
mesh_terms: D000368:Aged; D001786:Blood Glucose / Q000378:metabolism; D016208:Databases, Factual / Q000706:statistics & numerical data; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000188:drug therapy*; D054873:Dipeptidyl-Peptidase IV Inhibitors / Q000627:therapeutic use; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use; D016015:Logistic Models; D008297:Male; D008687:Metformin / Q000627:therapeutic use*; D008875:Middle Aged; D057216:Propensity Score; D012189:Retrospective Studies; D000068900:Sitagliptin Phosphate / Q000627:therapeutic use*; D013453:Sulfonylurea Compounds / Q000627:therapeutic use*; D028761:Withholding Treatment / Q000706:statistics & numerical data*; D016903:Drug Monitoring
chemical_list: D001786:Blood Glucose; D054873:Dipeptidyl-Peptidase IV Inhibitors; D007004:Hypoglycemic Agents; D013453:Sulfonylurea Compounds; D008687:Metformin; D000068900:Sitagliptin Phosphate
keywords: adherence; dipeptidyl peptidase-4 inhibitors; metformin; sitagliptin; sulfonylureas; 二甲双胍; 二肽基肽酶-4抑制剂; 依从性; 磺脲类; 西格列汀