title: Outpatient wait time and diabetes care quality improvement.
abstract: OBJECTIVE
  To examine the relationship between glycated hemoglobin (A1C) levels and the number of days spent waiting for primary care appointments.
  
  
  METHODS
  Retrospective observational study that relied on Department of Veterans Affairs (VA) utilization data and Medicare claims data from 2001 to 2003. The outcome was A1C levels. The main explanatory variable of interest was facility-level primary care wait times measured in days.
  
  
  METHODS
  Heckman selection models simultaneously predicted the presence of an A1C value and its level. Models were risk adjusted for prior individual health status. Separate models were estimated on the entire sample and on subsamples stratified by baseline A1C levels.
  
  
  RESULTS
  Veterans who visited VA facilities with wait times of longer than 32.5 days had small significant increases in A1C levels of 0.14 percentage point for the whole sample, 0.07 percentage point for patients with baseline A1C levels less than 7%, 0.11 percentage point for patients with baseline A1C levels between 7% and 8%, and 0.18 percentage point for patients with baseline A1C levels greater than 8%.
  
  
  CONCLUSIONS
  Decreasing wait times has the potential to reduce A1C levels by 0.18 percentage point for patients with baseline A1C levels exceeding 8%. This effect is roughly one-third of what is achieved with the most successful existing quality improvement strategies. Ensuring timely access to outpatient care could be an important addition to future diabetes care quality improvement programs.
authors.affiliation: Department of Veterans Affairs, Center for Health Quality Outcomes and Economic Research, Boston University School of Public Health, 150 S Huntington Ave, Mail Stop 152H, Boston, MA 02130, USA. julia.prentice@va.gov
authors.forename: Julia C
authors.initials: JC
authors.lastname: Prentice
authors.forename: B Graeme
authors.initials: BG
authors.lastname: Fincke
authors.forename: Donald R
authors.initials: DR
authors.lastname: Miller
authors.forename: Steven D
authors.initials: SD
authors.lastname: Pizer
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003695:Delivery of Health Care / Q000592:standards*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000628:therapy*; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D010044:Outpatient Clinics, Hospital / Q000592:standards; D010045:Outpatients; D011320:Primary Health Care / Q000458:organization & administration*; D058996:Quality Improvement / Q000592:standards*; D012189:Retrospective Studies; D013997:Time Factors; D014481:United States; D014493:United States Department of Veterans Affairs; D014728:Veterans / Q000706:statistics & numerical data; D014850:Waiting Lists
chemical_list: D006442:Glycated Hemoglobin