title: Initiation of insulin among veterans with type 2 diabetes and sustained elevation of A1c.
abstract: OBJECTIVE
  To examine if the relationship between insulin initiation and glycemic control among veterans with poorly controlled type 2 diabetes (T2DM) varies by the number of oral-glucose-lowering-medication classes used prior to insulin initiation.
  
  
  METHODS
  The cohort consisted of veterans with T2DM with at least two glycosolated hemoglobins (A1c) ≥8.0% within a 12-month period but without prior insulin use. The study period was October 1998 until May 2006. Cox regression analyses were used to assess the predictors of the rate of insulin initiation.
  
  
  RESULTS
  Among 40,537 who met the inclusion criteria, 17,519 (43.2%) had insulin initiated over a median follow-up period of 58.6 months. The rate of insulin initiation due to 1% increase in A1c increased by 33.6%, 28.8%, 24.2%, 19.7%, 15.4% for patients exposed to 0, 1, 2, 3, 4 classes of oral-glucose-lowering agents. A higher insulin initiation rate was also associated with younger age, more comorbidities, non-Hispanic white race/ethnicity, obesity, longer diabetes duration, and attending endocrinology clinics.
  
  
  CONCLUSIONS
  Poor glycemic control is associated with increased rates of insulin initiation. This relationship is attenuated by the number of distinct oral-glucose-lowering-medication classes used prior to insulin initiation.
authors.affiliation: University of Texas Health Science Center San Antonio, TX 78229, United States. parchman@uthscsa.edu
authors.forename: Michael L
authors.initials: ML
authors.lastname: Parchman
authors.forename: Chen-Pin
authors.initials: CP
authors.lastname: Wang
mesh_terms: D020909:Acarbose / Q000008:administration & dosage; D000368:Aged; D015331:Cohort Studies; D015897:Comorbidity; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy* / Q000453:epidemiology / Q000378:metabolism; D057286:Electronic Health Records / Q000706:statistics & numerical data; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006801:Humans; D006943:Hyperglycemia / Q000188:drug therapy* / Q000453:epidemiology / Q000378:metabolism; D007004:Hypoglycemic Agents / Q000008:administration & dosage*; D007328:Insulin / Q000008:administration & dosage*; D008297:Male; D008687:Metformin / Q000008:administration & dosage; D008875:Middle Aged; D016016:Proportional Hazards Models; D013453:Sulfonylurea Compounds / Q000008:administration & dosage; D045162:Thiazolidinediones / Q000008:administration & dosage; D014728:Veterans
chemical_list: D020909:Acarbose; D006442:Glycated Hemoglobin; D007004:Hypoglycemic Agents; D007328:Insulin; D008687:Metformin; D013453:Sulfonylurea Compounds; D045162:Thiazolidinediones; C517652:hemoglobin A1c protein, human; C089946:2,4-thiazolidinedione