Ethnic disparities in adherence to antihypertensive medications of medicare part D beneficiaries.
OBJECTIVE
To determine the level of adherence to medications and characteristics of Part D beneficiaries associated with higher levels of antihypertensive medication adherence.


METHODS
Retrospective cohort study.


METHODS
Medicare claims and Part D event files.


METHODS
Medicare Part D enrollees with prevalent uncomplicated hypertension who filled at least one antihypertensive prescription in 2006 and two prescriptions in 2007.


METHODS
Medication adherence was defined as an average medication possession ratio of 80% or greater. Potential factors associated with adherence evaluated were age, sex, race or ethnicity, socioeconomic factors, comorbidity, medication use, copayments, being in the coverage gap, and number of unique prescribers.


RESULTS
Overall adherence was 79.5% of 168,522 Medicare Part D enrollees with prevalent uncomplicated hypertension receiving antihypertensive medicines in 2007. In univariate analysis, adherence varied significantly according to most patient factors. In multivariable analysis, lower odds of adherence persisted for blacks (odds ratio (OR) = 0.53, 95% confidence interval (CI) = 0.51-0.55), Hispanics (OR = 0.58, 95% CI = 0.55-0.61), and other non-white races (OR = 0.80 95% CI = 0.75-0.85) than for whites. Greater comorbidity and concurrent medication use were also associated with poorer adherence. Adherence was significantly different across several geographic regions.


CONCLUSIONS
A number of associations were identified between patient factors and adherence to antihypertensive drugs, with significant differences in adherence according to ethnicity. Improving adherence could have significant public health implications and could improve outcomes specific to hypertension, as well as improving cost and healthcare utilization.
Department of General Internal Medicine, UT MD Anderson Cancer Center, Houston, Texas 77030, USA. hholmes@mdanderson.org
Holly M
HM
Holmes
Ruili
R
Luo
Joseph T
JT
Hanlon
Linda S
LS
Elting
Maria
M
Suarez-Almazor
James S
JS
Goodwin
D000368:Aged; D000369:Aged, 80 and over; D000959:Antihypertensive Agents / Q000191:economics / Q000627:therapeutic use*; D015897:Comorbidity; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy* / Q000453:epidemiology; D016015:Logistic Models; D008297:Male; D054524:Medicare Part D; D055118:Medication Adherence / Q000208:ethnology*; D012189:Retrospective Studies; D014481:United States / Q000453:epidemiology
D000959:Antihypertensive Agents