title: Differential impact of longitudinal medication non-adherence on mortality by race/ethnicity among veterans with diabetes.
abstract: OBJECTIVE
  To examine the differential effect of medication non-adherence over time on all-cause mortality by race/ethnicity.
  
  
  METHODS
  Data on a longitudinal cohort of veterans with type 2 diabetes was examined. The main outcome was time to death. Primary independent variables were race/ethnicity and mean medication possession ratio (MPR) categorized into quintiles over the study period. Cox regression was used to model the association between time to death and MPR quintiles and race/ethnicity, adjusting for relevant covariates.
  
  
  RESULTS
  The cohort of 629,563 veterans was followed for 5 years. After adjusting for all covariates, the hazard ratios (HR) for subjects in the lowest versus highest MPR quintile was 12.21 (95 % CI 11.89, 12.55) for non-Hispanic white (NHW), 10.01 (95 % CI 9.18, 10.91) for non-Hispanic black (NHB), 12.65 (95 % CI 11.10, 14.43) for Hispanic and 10.41 (95 % CI 9.06, 11.96) for Other race veterans. Furthermore, type of diabetes therapy (oral versus insulin) maintained a significant relationship with mortality that varied by racial/ethnic group.
  
  
  CONCLUSIONS
  This study demonstrates the differential impact of medication non-adherence on mortality by race. It also demonstrates that type of diabetes therapy (insulin with or without oral agents) is associated with mortality and varies by racial/ethnic group.
authors.affiliation: Center for Disease Prevention and Health Interventions for Diverse Populations, Ralph H Johnson Veterans Affairs Medical Center, P.O. Box 250593, Charleston, SC 29425-0593, USA. Egedel@musc.edu
authors.forename: Leonard E
authors.initials: LE
authors.lastname: Egede
authors.forename: Cheryl P
authors.initials: CP
authors.lastname: Lynch
authors.forename: Mulugeta
authors.initials: M
authors.lastname: Gebregziabher
authors.forename: Kelly J
authors.initials: KJ
authors.lastname: Hunt
authors.forename: Carrae
authors.initials: C
authors.lastname: Echols
authors.forename: Gregory E
authors.initials: GE
authors.lastname: Gilbert
authors.forename: Patrick D
authors.initials: PD
authors.lastname: Mauldin
mesh_terms: D000284:Administration, Oral; D001741:Black or African American / Q000523:psychology / Q000706:statistics & numerical data; D000368:Aged; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy* / Q000208:ethnology / Q000401:mortality; D005260:Female; D006630:Hispanic or Latino / Q000523:psychology / Q000706:statistics & numerical data; D006801:Humans; D007004:Hypoglycemic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D007328:Insulin / Q000008:administration & dosage / Q000627:therapeutic use; D053208:Kaplan-Meier Estimate; D008137:Longitudinal Studies; D008297:Male; D008498:Medical Record Linkage; D055118:Medication Adherence / Q000208:ethnology*; D008875:Middle Aged; D012307:Risk Factors; D014481:United States / Q000453:epidemiology; D014728:Veterans / Q000523:psychology / Q000706:statistics & numerical data; D044465:White People / Q000523:psychology / Q000706:statistics & numerical data; D016903:Drug Monitoring
chemical_list: D007004:Hypoglycemic Agents; D007328:Insulin