One in 3 US adults has hypertension (HTN),1 and African Americans (AAs) are disproportionately affected with incidence rates of 40.5% in AA men and 44.3% in AA women.2 Fifty percent of those with a diagnosis of HTN (blood pressure [BP] >140/90 mm Hg) are controlled on their current treatment regimen3; however, the rate of uncontrolled HTN for the years 2007 to 2010 was 71.5% in AA men and 51% in AA women.2(p207)
Hypertension is a leading contributor to cardiovascular disease (CVD), end-stage renal disease, and strokes4,5 and contributes to shorter overall life expectancy.6 Thus, achieving adequate control of HTN is essential. An important component of HTN control is treatment adherence. However, despite years of research, intensive treatment guidelines, and the development of new pharmacological therapies,7 adherence remains problematic in persons diagnosed with HTN. Furthermore, several studies8–11 have provided evidence of poorer adherence in AA populations than non-Hispanic whites.
Adherence is conceptually defined as following the prescribed treatment (medications, diet, and appointment keeping), consistent with the work of Hill and colleagues.12,13 The consequences of nonadherence are well known: Patients present with hypertensive urgencies, emergency department visits, and strokes. Bender et al,14 who conducted a retrospective analysis of 50 hypertensive patients who presented to emergency departments in hypertensive urgency (symptomatic systolic BP [SBP] >180 mm Hg or diastolic BP [DBP] >110 mm Hg), found medication issues present in more than 50% of patients: 12% were noncompliant with medications, 16% had run out of medications, and 30% were not taking any antihypertensive medications. The terms congruence, adherence, and compliance are used interchangeably.
The adapted Hill-Levine conceptual model12(p954) provided the framework for this study by conceptualizing factors that positively or negatively affect the adherence behaviors that lead to improved health outcomes. The Hill-Levine model was adapted from the PRECEDE-PROCEED model.15
PRECEDE is an acronym for predisposing, reinforcing, and enabling constructs in educational diagnosis and evaluation. PROCEED is an acronym for policy, regulatory, and organizational constructs in educational and environmental development. The variables that mediated the outcomes were the predisposing factors of knowledge, attitudes, and beliefs; enabling factor of healthcare resources; and the reinforcing factor of social support. The culturally tailored educational intervention focused on increasing knowledge and affecting culturally derived attitudes and beliefs about HTN, social support, and awareness of healthcare access. Behavioral and health outcomes include increased adherence to HTN treatment, increased BP knowledge, and lower BPs.
The specific aims of this study were to (1) increase adherence to HTN therapy among AA women with primary HTN, (2) increase AA women’s knowledge of high BP (HBP) prevention and treatment, and (3) reduce resting BP among AA women with primary HTN to less than 140/90 mm Hg.
Design, Setting, and Sample
The study used a randomized block experimental design with repeated measures at baseline, at weeks 3 and 6, and at 6 months. Institutional review board approvals were granted by the University of Texas Health Science Center–Houston and the University of Texas at Tyler.
This study was conducted at 3 locations (2 Baptist churches and 1 community center) in a rural Northeast Texas community from September 2009 to October 2010. Inclusion criteria were (a) self-identification as black or AA 18 years or older; (b) diagnosis of primary HTN; (c) a resting SBP greater than 140 mm Hg or a DBP greater than 90 mm Hg; (d) ability to read, understand, and speak English; and (e) prescriptions for 1 or more antihypertensive medications. We excluded women who were pregnant, had a history of stroke or myocardial infarction within the last year, were diagnosed with end-stage renal disease and on dialysis, or were currently participating in another research trial on HTN.
Three local AA women were hired as research assistants (RAs), 1 at each study site, and were trained in the study protocol. Recruitment consisted of contacting local churches and distributing colorful flyers to AA churches, health fairs, hospitals, physicians’ offices, and beauty shops. Recruitment efforts also included an interview on a local religious radio station and word-of-mouth advertising throughout the community. After eligibility screening 1 week apart, the author (DBG) explained the study and obtained written informed consent from all eligible participants. Sixty AA women met the inclusion criteria and were enrolled in the study. There was no attrition, and all 60 subjects completed the study.
Participants were randomized using a block design based on participants’ baseline Hill-Bone Compliance to High Blood Pressure Therapy (HBCHBPT) scale16 scores. The HBCHBPT scale ranges from 14 (perfect adherence) to 56 (nonadherent), with a range of 42. A cutoff score of 22 (which is half of the range, 42) was used to distinguish high and low adherence. The author selected participants for the intervention and control groups by dividing the scores above and below 22 and randomly drawing participants for each block.
The culturally tailored intervention consisted of six 90-minute sessions offered once a week for 6 weeks to groups of 8 to 12 women. The groups were led by the author (DBG) who has a background in cardiovascular nursing. The 14 standards derived from the Office of Minority Health Culturally Linguistic Appropriate Standards were used as a framework.17 Key Culturally Linguistic Appropriate Standards followed included race concordance of the RAs and author (DBG), culturally tailored educational materials that were easy to understand, setting in the AA community, culturally appropriate language respectful of AAs, and an ongoing assessment of the intervention through participant feedback. Terms known to participants were used to discuss pressure medicine, fluid pills, use of pickle juice and other folk remedies to lower high blood, and hidden sources of salt. Participants were given a blank family tree to outline ancestors and descendants, and discussions on medication adherence were tied to ancestors and descendants (and their medical histories). Participants were asked to discuss managing medication adherence, adverse effects, and ways of coping with HTN. Content on physical activity, weight management, stroke prevention, and target organ damage was also included.
Each session began with prayer and ended with a unity circle and prayer, in which all persons joined hands while 1 person said a prayer. The gospel song Never Would Have Made It18 was also played at each session. Content was delivered through lectures, videos, pictures, and handouts in an easy-to-read format. The average Flesch-Kincaid19 reading level of the materials was grade level 8.5. Of the 60 participants, 11.6% (n = 7) had less than a high school education.
The curriculum included materials from the American Heart Association and the National Heart Lung and Blood Institute. Participants were provided with a notebook of materials from the American Heart Association, the National Heart Lung and Blood Institute, and The Power to End Stroke (PTES) Campaign. The PTES DVD,20 in which laypersons and key celebrities such as the late Yolanda King discuss HBP and stroke prevention, was also shown to participants. Additional content included scriptures on health and wellness, information for increasing healthcare access and resources, the importance of social support, and attitudes and cultural beliefs about HBP.
Participants randomized to a wait-list control group (n = 30) received only usual care from their healthcare provider. After the 6-month data collection, participants in the wait-list group were offered the classes, and 11 of 30 women enrolled, were shown the PTES DVD,20 and received the lecture materials, pamphlets, and handouts.
Demographic data were collected at baseline. Blood pressures were measured before completion of questionnaires using the Omron digital BP device model HEM-780-N3 Intellisense with an adjustable cuff (9–17 in) (Omron Healthcare Inc, Bannockburn, IL). The Omron digital BP devices were calibrated and tested by a certified biomedical technician before study initiation and at the end of the study. Blood pressure knowledge, adherence, and attitudes, beliefs, and social support were assessed by questionnaires at baseline, at 3 and 6 weeks, and at 6 months.
The HBP Prevention IQ (HBPIQ) quiz is a 12-item true-false quiz developed by the National HBP Education Program, National Heart Lung Blood Institute,21 to test subjects’ general knowledge about HBP and its prevention. It is scored cumulatively, with total possible scores ranging from 0 to 12. Responses are coded as 0 for correct and 1 for incorrect. Higher scores reflect greater HBP knowledge. The HBPIQ quiz has face validity, and a previous study by Kim et al22 reported an α coefficient of .78. Alpha coefficients (KR-20) ranged from .55 to .75 in this study of 60 women.
The HBCHBPT scale16 consists of fourteen 4-point Likert-type items (1 = none of the time, 2 = some of the time, 3 = most of the time, and 4 = all of the time). The HBCHBPT scale includes 3 domains of HTN treatment: salt intake, appointment keeping, and medication taking. Scores range from 14 to 56, with lower scores indicating greater adherence. The HBCHBPT scale has demonstrated adequate internal consistency reliability and construct and predictive validity with several independent populations of AA and non-Hispanic whites, with Cronbach’s α values ranging from .74 to .84.16(p93) Cronbach’s α for this study sample was .89. The operational definition of adherence/compliance is the total score on the HBCHBPT scale.16
Attitudes, Beliefs, and Social Support
The 11 questions that assessed attitudes and beliefs about HTN, social support, behavioral risks, and healthcare access were derived from the National Health Information Survey.23 The items have a Flesch-Kincaid19 reading level of 3.9 and have been tested and validated in studies by Hill and colleagues.12(p952) The attitudes, beliefs, and social support questions included both Likert-type and dichotomous (yes/no) scales. Items were coded as 0 to 4 for ordinal data and 0 and 1 for dichotomous data.
Baseline differences between groups were analyzed using χ2 for categorical variables, and the independent-samples t test and Mann-Whitney U test were used for continuous variables. The HBCHBPT subscales were analyzed for significant differences using repeated-measures analysis of variance. A linear mixed model for each dependent variable (HBPIQ score, HBCHBPT score, SBP, and DBP), with time (baseline, 3 weeks, 6 weeks, and 6 months) as the repeated-measure factor, was constructed. The independent variable was group assignment; thus, subjects’ ID was included in the model as a random effect. Age and individual annual income were included as covariates. A factorial interaction for group × time was also examined.
Sociodemographic Characteristics of the Sample
The participants were all non-Hispanic AA women. Fifty percent were married (n = 30). Sixty-three percent (n = 19) of participants in the control group reported having attained at least some college, compared with only 43% (n = 13) in the intervention group. The number of years diagnosed with HTN ranged from less than 5 (n = 26) to more than 15 (n = 19) years. Statistically significant baseline differences were found between groups in age (P = .035, 2 tailed), income (P = .032, 2 tailed), and DBP (P = .036, 2 tailed). The intervention group were, on average, 61.3 years old, 6.7 years older than the control group, who were, on average, 54.6 years old; the control group had higher yearly incomes (P = .032) than the intervention group. Diastolic BP for the intervention group was 5 mm Hg (SD, 9.03 mm Hg) lower than for the control group at baseline. No other significant baseline differences were found.
The HBCHBPT total scale scores and subscales are shown in Table 1. Intervention group scores decreased slightly (lower scores indicate greater adherence) more than control group scores did over the 4 time points, but the difference was not significant.
Although, initially, participants in the intervention group showed a slight increase in knowledge scores at week 6 and the 6-month follow-up (Table 2), there were no significant differences between the groups. Participants in both groups demonstrated correct knowledge of the relationship between being overweight and HTN and between sodium intake and HTN and that alcohol does not lower BP. Individual item responses are shown in Table 3.
After controlling for age and income, the linear mixed model analysis showed no statistically significant fixed effects for time or group (Table 4). Examination of the fixed effect coefficients for covariates in the model revealed that age and income did not contribute significantly to the model with the HBCHBPT scale. Repeated-measures analysis showed a statistically significant result for time effects of the appointment keeping subscale (F3,54 = 3.49, P = .02 within subjects). No statistically significance changes were found on the sodium or medication subscales after controlling for age and income.
Participants with higher annual income tended to have higher mean HBPIQ knowledge. With analysis of the HBPIQ knowledge scores, yearly income contributed to the model and was significant (F1,56 = 4.70, P = .034); however, no other significant findings were seen for group, time, or age.
There were no significant differences in participants’ attitudes, beliefs, and perceptions about HTN and general health. Both groups held similar attitudes and beliefs and similar social support at baseline and 6 months.
As shown in Table 4, a significant overall main effect (time) was found for SBP and DBP. On average, BPs decreased over time but did not significantly differ between groups. Controlling for age contributed to the model and was significant. That is, older participants tended to have higher DBPs. However, there were no other statistical differences. Table 5 shows the differences in BP scores between the intervention and control groups for 4 time points.
There was an overall decrease of 12.7 mm Hg in SBP and 3.9 mm Hg in DBP for the intervention group from baseline to the 6-month follow-up. Conversely, in the control group, there was a decrease of 15.2 mm Hg for SBP and 5.7 mm Hg for DBP from baseline to 6-month follow-up.
Both groups in this study had small reductions in both systolic and diastolic BPs. However, the AA women had difficulty eliminating sodium from their daily intake. Whether this was because of cultural dietary habits, lower income, or lack of knowledge is unclear.
Knowledge scores did not increase in these participants, and the intervention group was no more knowledgeable than the control group. This finding may reflect the higher educational levels reported in the control group. Higher educational achievement may be related to better understanding and higher value and importance given to adherence. The low HBPIQ scale scores by participants in this study are consistent with other studies that used this same instrument.
The attitudes and beliefs reported in this study are also consistent with those reported in other studies.24,25 Other empirical studies have shown that culture plays a significant role in how HTN disease is perceived24(p787),26 and managed in AA women and other ethnic minorities. Culturally derived beliefs and attitudes may explain why the women in this study had higher levels of education yet consumed liberal amounts of salt. Thus, it could be argued that higher levels of education do not necessarily translate to health behavior change.
Contrary to findings from previous studies, AA women in this study indicated that they did not need or desire to talk to someone else. This may reflect the fact that they already had good support systems, with a mean of 10 close relatives or friends who they could count on; 61% were already talking to someone and only 23% felt the need to talk to someone else.
It is interesting to note that although there were no differences between groups in this study, there were positive changes reported by the participants as a whole. This suggests that involving AA women in an intervention study, regardless of group assignment, may help them to alter behavior. At the 6-month follow-up, 3 participants in the control group revealed that they had been dieting with substantial weight loss since enrollment in the study, 2 reported walking more since starting the study, and 2 had additional medications added to their HTN regimen by their physicians. These findings may partly explain the BP changes seen in the control group participants. In addition, treatment diffusion may have occurred because participants in the 2 groups attended the same churches and were in the same community settings. That is, through natural diffusion, the participants in the intervention group may have unconsciously shared information with family and church members in the control group. The changes seen in the control group may also reflect a Hawthorne effect in which participants who received special repeated attention (surveys and BP measurements) may have initiated behavior changes.
The intervention lasted only 6 weeks, which is a short period in which to make lifestyle changes, and there were no booster sessions during the remaining 4.5 months of the study. Interventions that are longer or that are followed by booster sessions may show greater improvement. In addition, the focus of the study was on adherence, and other important variables were not measured, including weight and physical activity, although obesity in AA women is known to be related to HBP.
In addition, although there were trends in the expected direction, a larger sample size might have shown statistical significance. Finally, this study was conducted in a rural area of Northeast Texas with AA women; therefore, generalizability to other populations is limited. Clearly, recruitment of rural populations should cover larger areas to avoid contamination. Furthermore, weight management and physical activity interventions should be included in interventions involving AA women of all age groups.
Although the culturally tailored educational intervention was not effective in improving adherence rates in AA women with HTN, small decreases in BP were obtained in both groups. Studies4,5,27 have shown that these small declines in BP do make a difference in AAs in preventing target organ damage. The study was noteworthy in that there was no attrition. Recruiting AA women from churches embedded in the AA community was a major factor that may have helped retain participants throughout the study. The historical fears and mistrust28,29 of AAs about biomedical research were not seen in this study primarily because of the cultural relevance of the study and the use of an interventionist and RAs from the community. Race concordance built trust, and participants expressed a sense of shared social support during the intervention and assessments. Moreover, during eligibility screenings, 2 women were identified with uncontrolled HBP who were not on antihypertensive medication; they were referred for treatment. The community-based screenings thus reached persons who might not otherwise have sought treatment for HTN. Lastly, the spiritual and cultural components of the intervention were consistent with AA culture and recognized its importance in the lives of the participants. Clearly, further work is needed to improve uncontrolled HTN in underserved minority populations. Nevertheless, studies that provide repeated points of personal contact over a period of time appear to be a worthwhile approach to improve health outcomes.
What’s New and Important
- Decreased sodium intake continues to be a major challenge in the AA population, despite educational efforts.
- Cultural values and beliefs have a strong influence on health practices and adherence.
- African Americans are enthusiastic about participating in research, and church-based settings are ideal as long as contamination effects can be controlled.
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Keywords:Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved
African American; culturally tailored program; hypertension