title: Clinical inertia in people with type 2 diabetes: a retrospective cohort study of more than 80,000 people.
abstract: OBJECTIVE
  To determine time to treatment intensification in people with type 2 diabetes treated with one, two, or three oral antidiabetes drugs (OADs) and associated levels of glycemic control.
  
  
  METHODS
  This was a retrospective cohort study based on 81,573 people with type 2 diabetes in the U.K. Clinical Practice Research Datalink between January 2004 and December 2006, with follow-up until April 2011.
  
  
  RESULTS
  In people with HbA1c ≥7.0, ≥7.5, or ≥8.0% (≥53, ≥58, or ≥64 mmol/mol), median time from above HbA1c cutoff to intensification with an additional OAD was 2.9, 1.9, or 1.6 years, respectively, for those taking one OAD and >7.2, >7.2, and >6.9 years for those taking two OADs. Median time to intensification with insulin was >7.1, >6.1, or 6.0 years for those taking one, two, or three OADs. Mean HbA1c at intensification with an OAD or insulin for people taking one, two, or three OADs was 8.7, 9.1, and 9.7%. In patients taking one, two, or three OADs, median time from treatment initiation to intensification with an OAD or insulin exceeded the maximum follow-up time of 7.2 years. The probability of patients with poor glycemic control taking one, two, or three OADs, intensifying at end of follow-up with an OAD, was 21.1-43.6% and with insulin 5.1-12.0%.
  
  
  CONCLUSIONS
  There are delays in treatment intensification in people with type 2 diabetes despite suboptimal glycemic control. A substantial proportion of people remain in poor glycemic control for several years before intensification with OADs and insulin.
authors.affiliation: Corresponding author: Kamlesh Khunti, kk22@leicester.ac.uk.
authors.forename: Kamlesh
authors.initials: K
authors.lastname: Khunti
authors.forename: Michael L
authors.initials: ML
authors.lastname: Wolden
authors.forename: Brian Larsen
authors.initials: BL
authors.lastname: Thorsted
authors.forename: Marc
authors.initials: M
authors.lastname: Andersen
authors.forename: Melanie J
authors.initials: MJ
authors.lastname: Davies
mesh_terms: D000284:Administration, Oral; D000368:Aged; D001786:Blood Glucose / Q000187:drug effects; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000188:drug therapy*; D004334:Drug Administration Schedule; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D006943:Hyperglycemia / Q000188:drug therapy; D007004:Hypoglycemic Agents / Q000008:administration & dosage*; D007328:Insulin / Q000008:administration & dosage; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin; D007004:Hypoglycemic Agents; D007328:Insulin