title: Insurance, self-reported medication adherence and LDL cholesterol: The REasons for Geographic And Racial Differences in Stroke study.
abstract: BACKGROUND
  Lack of health insurance may adversely impact medication adherence and the control of cardiovascular risk factors. We examined if the association between insurance and LDL-C is due to self-reported low medication adherence.
  
  
  METHODS
  This cross-sectional study included 8685 black and white men and women aged 45 and older who participated in the REasons for Geographic And Racial Differences in Stroke (REGARDS) cohort and used statins. Medication adherence was assessed using the 4-item Morisky Medication Adherence Scale (MMAS-4). Mean differences in LDL-C between participants with and without insurance were calculated using generalized linear models before and after adjustment for MMAS-4. Subgroups stratified by age, annual household income, diabetes, and CHD were compared. Separately, individual MMAS-4 questions were examined for mediation effects.
  
  
  RESULTS
  After multivariable adjustment but without MMAS-4, LDL-C was 2.5mg/dL (95% CI -0.6, 5.6) higher among uninsured versus insured participants. After further adjustment for MMAS-4, LDL-C was 2.6mg/dL (95% CI -0.5, 5.6) higher. Stratified analyses produced similar results. No mediating effect was observed when each MMAS-4 question was examined separately.
  
  
  CONCLUSIONS
  High medication adherence does not mediate the association between having health insurance and lower LDL-C.
authors.affiliation: Department of Epidemiology, University of Alabama at Birmingham, Birmingham, AL, USA.
authors.forename: Matt
authors.initials: M
authors.lastname: Mefford
authors.affiliation: Department of Internal Medicine, Weill Cornell Medicine, Cornell University, New York, NY, USA.
authors.forename: Monika M
authors.initials: MM
authors.lastname: Safford
authors.affiliation: Department of Epidemiology, University of Alabama at Birmingham, Birmingham, AL, USA.
authors.forename: Paul
authors.initials: P
authors.lastname: Muntner
authors.affiliation: Division of Preventive Medicine, School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA.
authors.forename: Raegan W
authors.initials: RW
authors.lastname: Durant
authors.affiliation: Division of Cardiovascular Disease, School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA.
authors.forename: Todd M
authors.initials: TM
authors.lastname: Brown
authors.affiliation: Department of Epidemiology, University of Alabama at Birmingham, Birmingham, AL, USA. Electronic address: elevitan@uab.edu.
authors.forename: Emily B
authors.initials: EB
authors.lastname: Levitan
mesh_terms: D000368:Aged; D008078:Cholesterol, LDL / Q000097:blood; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D054625:Healthcare Disparities / Q000191:economics / Q000639:trends; D006801:Humans; D019458:Insurance Coverage / Q000191:economics; D008297:Male; D055118:Medication Adherence; D008875:Middle Aged; D044469:Racial Groups; D057566:Self Report; D020521:Stroke / Q000097:blood / Q000191:economics / Q000453:epidemiology*; D014481:United States / Q000453:epidemiology
chemical_list: D008078:Cholesterol, LDL
keywords: Insurance; Low density lipoprotein cholesterol; Medication adherence