Risk Factors for Low Pharmacy Refill Adherence Among Older Hypertensive Men and Women by Race.

BACKGROUND: Sex-race stratification may lead to identification of risk factors for low antihypertensive medication adherence that are not apparent when assessing risk factors in women and men without race stratification. We examined risk factors associated with low pharmacy refill adherence across sex-race subgroups (white women, black women, white men, black men) within the Cohort Study of Medication Adherence among Older Adults (n = 2,122). METHODS: Pharmacy refill adherence was calculated as proportion of days covered using all antihypertensive prescriptions filled in the year prior to a baseline risk factor survey. Sex- and sex-race-stratified multivariable Poisson regression models with robust standard errors were used to estimate adjusted prevalence ratios and 95% confidence intervals for associations between participant characteristics and low adherence. RESULTS: Prevalence of low adherence was 22.9% vs. 40.7% in white vs. black women (P < 0.001) and 26.3% vs. 37.2% in white vs. black men (P = 0.003). In multivariable models, reducing antihypertensive medication due to cost was associated with low adherence within each sex-race subgroup. Additional factors associated with low adherence included shorter hypertension duration and comorbidities in white women; not being married and depressive symptoms in white men; and ≥6 primary care visits/year and complementary and alternative medicine use in black men. Among men, not being married and reporting depressive symptoms were associated with low adherence for whites, but not blacks. CONCLUSIONS: Identification of sex-race-specific risk factors for low antihypertensive medication adherence may guide development and implementation of tailored interventions to increase antihypertensive medication adherence and blood pressure control among older patients.

Adverse effects of complementary and alternative medicine on antihypertensive medication adherence: findings from the cohort study of medication adherence among older adults.

OBJECTIVES: To determine the association between complementary and alternative medicine (CAM) use and antihypertensive medication adherence in older black and white adults. DESIGN: Cross-sectional. SETTING: Patients enrolled in a managed care organization. PARTICIPANTS: Two thousand were hundred eighty black and white adults aged 65 and older and prescribed antihypertensive medication. MEASUREMENTS: Information on CAM use (health food and herbal supplements, relaxation techniques) for blood pressure control and antihypertensive medication adherence were collected in a telephone survey between August 2006 and September 2007. Low medication adherence was defined as a score less than 6 using the eight-item Morisky Medication Adherence Scale. RESULTS: The mean age of participants was 75.0+/-5.6, 30.7% were black, 26.5% used CAM, and 14.1% had low antihypertensive medication adherence. In managing blood pressure, 30.5% of black and 24.7% of white participants had used CAM in the last year (P=.005), and 18.4% of black and 12.3% of white participants reported low adherence to antihypertensive medication (<.001). After multivariable adjustment for sociodemographic information, depressive symptoms, and reduction in antihypertensive medications because of cost, the prevalence ratios of low antihypertensive medication adherence associated with CAM use were 1.56 (95% confidence interval (CI)=1.14-2.15; P=.006) in blacks and 0.95 (95% CI=0.70-1.29; P=.73) in whites (P value for interaction=.07). CONCLUSION: In this cohort of older managed care patients, CAM use was associated with low adherence to antihypertensive medication in blacks but not whites.