title: Impact of diabetes control on mortality by race in a national cohort of veterans.
abstract: OBJECTIVE
  The association between glycated hemoglobin (HbA1c), medication use/adherence, and mortality stratified by race/ethnicity was examined in a national cohort of veterans with type 2 diabetes.
  
  
  METHODS
  A total of 892,223 veterans with diabetes in 2002 were followed through 2006. HbA1c category was the main exposure (i.e., HbA1c <7%, HbA1c 7%-8% [reference], HbA1c 8%-9%, and HbA1c >9%). Covariates included age, sex, marital status, rural/urban residence, geographic region, number of comorbidities, and diabetes medication use/adherence (i.e., adherent, medication possession ratio ≥80%; nonadherent; and nonusers). HbA1c and medication use/adherence varied over time, and Cox regression models accounting for time-varying variables were used.
  
  
  RESULTS
  In nonmedication users, HbA1c greater than 9% predicted higher mortality risk relative to HbA1c of 7%-8% in non-Hispanic whites (hazard ratio [HR], 1.55; 95% confidence interval [95% CI], 1.43-1.69), non-Hispanic blacks (NHB) (HR, 1.58; 95% CI, 1.34-1.87), and Hispanics (HR, 2.22; 95% CI, 1.75-2.82). In contrast, in nonadherent medication users, HbA1c less than 7% predicted higher mortality risk in NHB (HR, 1.12; 95% CI, 1.05-1.20), whereas HbA1c greater than 9% only predicted mortality in non-Hispanic whites (HR, 1.11; 95% CI, 1.06-1.16). In adherent medication users, HbA1c less than 7% predicted higher mortality in NHB (HR, 1.18; 95% CI, 1.07-1.31), whereas HbA1c greater than 9.0% predicted higher mortality risk across all race/ethnic groups.
  
  
  CONCLUSIONS
  We found evidence for racial/ethnic differences in the association between glycemic control and mortality, which varied by medication use/adherence.
authors.affiliation: Center for Disease Prevention and Health Interventions for Diverse Populations, Ralph H. Johnson Department of Veterans Affairs Medical Center, Charleston, SC 29425-0539, USA.
authors.forename: Kelly J
authors.initials: KJ
authors.lastname: Hunt
authors.forename: Mulugeta
authors.initials: M
authors.lastname: Gebregziabher
authors.forename: Cheryl P
authors.initials: CP
authors.lastname: Lynch
authors.forename: Carrae
authors.initials: C
authors.lastname: Echols
authors.forename: Patrick D
authors.initials: PD
authors.lastname: Mauldin
authors.forename: Leonard E
authors.initials: LE
authors.lastname: Egede
mesh_terms: D000328:Adult; D001741:Black or African American / Q000706:statistics & numerical data; D000368:Aged; D000369:Aged, 80 and over; D001786:Blood Glucose / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000188:drug therapy / Q000208:ethnology*; D005260:Female; D005500:Follow-Up Studies; D006442:Glycated Hemoglobin / Q000032:analysis*; D006630:Hispanic or Latino / Q000706:statistics & numerical data; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use; D008297:Male; D055118:Medication Adherence / Q000208:ethnology*; D008875:Middle Aged; D009026:Mortality / Q000208:ethnology*; D015995:Prevalence; D016016:Proportional Hazards Models; D044469:Racial Groups / Q000208:ethnology* / Q000706:statistics & numerical data; D012111:Residence Characteristics; D012189:Retrospective Studies; D012959:Socioeconomic Factors; D014481:United States / Q000453:epidemiology; D014728:Veterans / Q000523:psychology / Q000706:statistics & numerical data*; D044465:White People / Q000706:statistics & numerical data; D016903:Drug Monitoring
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin; D007004:Hypoglycemic Agents