Abstract 113: Adherence to Antihypertensive Medication in the Jackson Heart Study (JHS)

Abstract

Objectives: Adherence to antihypertensive medications is associated with increased blood pressure (BP) control and reduced cardiovascular disease and mortality. The Jackson Heart Study (JHS) is a longitudinal study of 5,301 adults recruited from the general population of the Jackson, Mississippi area designed to evaluate cardiovascular disease in African Americans. The goal of the current analysis was to develop a measure of adherence to antihypertensive medication from available JHS data to facilitate future research in this sample. Methods: JHS participants were asked to bring in all medications taken in the prior two weeks to the baseline interview and were asked if they had taken each medication in the past 24 hours. Non-adherence was defined as not taking all antihypertensive medications in the past 24 hours. The mean of two clinic BP measurements taken one minute apart with a Hawksley random zero sphygmomanometer was used for this analysis. The associations between non-adherence and systolic/diastolic BP and uncontrolled BP (systolic/diastolic BP ≥ 140/90 mm Hg) were examined using linear and Poisson regression. Analyses were adjusted for age, sex, smoking, years of education, income, cohabitation, diabetes, depressive symptoms, and weekly stress symptoms. Results: Of the 5,301 JHS participants, 2,415 who reported current use of antihypertensive medication and had valid clinic BP and 24-hour adherence data were included. The mean age was 54.9 (SD 12.9) years and 68.7% (n=1,660) were female. Overall, 25.3% of participants (n=612) were non-adherent to their antihypertensive medication. For adherent and non-adherent participants, the mean systolic BP was 130.0 (SD 17.2) and 135.2 (SD 19.8) mm Hg, respectively ( P <0.001), and the mean diastolic BP was 78.7 (SD 10.6) and 79.4 (SD 10.9) mm Hg, respectively ( P =0.15). After multivariable adjustment and compared to their adherent counterparts, non-adherent participants had 4.6 (SD 0.8) mm Hg higher systolic BP ( P <.001) and 1.1 (SD 0.4) mm Hg higher diastolic BP ( P =.01). The prevalence of uncontrolled BP was 31.3% among adherent participants and 41.7% among non-adherent participants. After multivariable adjustment, non-adherent participants were 1.28 times more likely to have uncontrolled BP (95% CI:1.14-1.43; P <.001). Conclusions: These findings suggest that 24-hour adherence to antihypertensive medications is a viable measure of medication adherence in the JHS. Implications: Evaluatingmedication adherence in patients with hypertension is important butchallenging. Valid and reliable self-report measures are needed when objectivemeasures are unavailable. If validated in future research, 24-hour adherence to antihypertensive medications may provide a parsimonious way of assessing medication adherence in epidemiological studies.