World Journal of Cardiovascular Diseases
Vol.05 No.07(2015), Article ID:58469,17 pages
10.4236/wjcd.2015.57021

How Group-Based Cardiovascular Health Education Affects Treatment Adherence and Blood Pressure Control among Insured Hypertensive Nigerians: A Pre-Test, Post-Test Study

Aina Olufemi Odusola1,2*, Heleen Nelissen1, Marleen Hendriks1, Constance Schultsz1, Ferdinand Wit1, Oladimeji Akeem Bolarinwa3, Tanimola Akande3, Charles Agyemang2, Gbenga Ogedegbe4, Kayode Agbede5, Peju Adenusi6, Akin Osibogun7, Karien Stronks2, Joke Haafkens8

1Department of Global Health, Academic Medical Center, University of Amsterdam, Amsterdam Institute for Global Health and Development, Amsterdam, Netherlands

2Department of Public Health, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands

3Department of Epidemiology and Community Health, University of Ilorin Teaching Hospital, Ilorin, Nigeria

4Division of Health and Behavior, Center for Healthful Behavior Change, Department of Population Health, NYU School of Medicine, New York, USA

5Ogo Oluwa Hospital, Bacita, Nigeria

6Hygeia Community Health Care, Hygeia HMO, Lagos, Nigeria

7Department of Community Health, Lagos University Teaching Hospital, Lagos, Nigeria

8Department of General Practice, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands

Email: *A.O.Odusola@amc.uva.nl, h.nelissen@aighd.org, m.hendriks@aighd.org, schultsz@gmail.com, f.wit@aighd.org, drdeji@yahoo.com, akandetm@yahoo.com, c.o.agyemang@amc.uva.nl, Olugbenga.ogedegbe@nyumc.org, agbedejk@yahoo.com, dradenusi@hygeiahmo.com, akinosibogun@yahoo.co.uk, k.stronks@amc.uva.nl, j.a.haafkens@amc.uva.nl

Copyright © 2015 by authors and Scientific Research Publishing Inc.

This work is licensed under the Creative Commons Attribution-NonCommercial International License (CC BY-NC).

http://creativecommons.org/licenses/by-nc/4.0/

Received 13 June 2015; accepted 27 July 2015; published 30 July 2015

ABSTRACT

In sub Saharan Africa (SSA), access to affordable hypertension care through health insurance is increasing. But due to poor adherence, hypertension treatment outcomes often remain poor. Patient-centered educational interventions may reverse this trend. Using a pre-test/post-test design, in this study we investigated the effects of a structured cardiovascular health education program (CHEP) on treatment adherence, blood pressure (BP) control and body mass index (BMI) among Nigerian hypertensive patients who received guideline-based care in a rural primary care facility, in the context of a community based health insurance program. Study participants included 149 insured patients with uncontrolled BP and/or poor self-reported medication adherence after 12 months of guideline-based care. All patients received three group-based educational sessions and usual primary care over 6 months. We evaluated changes in self-reported adherence to prescribed medications and behavioral advice (primary outcomes); systolic BP (SBP) and/or diastolic BP (DBP) and BMI (secondary outcomes); and beliefs about hypertension and medications (explora- tory outcomes). Outcomes were analyzed with descriptive statistics and regression analysis. 140 patients completed the study (94%). At 6 months, more participants reported high adherence to medications and behavioral advice than at baseline: respectively, 101 (72%) versus 70 (50%), (p < 0.001) and 126 (90%) versus 106 (76%), (p < 0.001). Participants with controlled BP doubled from 34 (24%) to 65 (46%), (p = 0.001). The median SBP and DBP decreased from 129.0 to 122.0 mmHg, (p = 0.002) and from 80.0 to 73.5 mmHg, (p < 0.001), respectively. BMI did not change (p = 0.444). Improved medication adherence was associated with a decrease in medication concerns (p = 0.045) and improved medication self-efficacy (p < 0.001). By positively influencing patient perceptions of medications, CHEP strengthened medication adherence and, consequently, BP reduction among insured hypertensive Nigerians. This educational approach can support cardiovascular disease prevention programs for Africa’s growing hypertensive population.

Keywords:

BP-Control, Education, Adherence, Self-Efficacy, Insurance, Nigeria

1. Introduction

Hypertension is a major risk factor for cardiovascular disease (CVD) [1] . The highest prevalence of adults with hypertension has been found in SSA, where a quarter of all premature deaths are due to this condition [1] [2] . In Nigeria, 49% of the adults, aged 25 years and older, had hypertension in 2008 [2] . Long-term treatment with behavioral interventions alone, or in combination with drugs can lower BP and, thereby, the risk of developing CVD [1] [3] - [5] . However, as in many other African countries, in Nigeria anti-hypertensive treatment coverage is low and treatment outcomes are poor [6] [7] .

Previous research in Nigeria and other countries in SSA has indicated that health system interventions such as health insurance coverage, organizational support to facilities and the training of health professionals can facilitate the access to and delivery of high quality CVD prevention care in primary care settings [8] - [14] . But even if high quality care is available, there is evidence that many patients fail to adhere to the recommended treatment and do not meet their treatment goals [15] - [17] . For that reason, the World Health Organization has emphasized that any attempt to improve hypertension and cardiovascular care should also address barriers to treatment adherence [18] .

Theoretical models of health behavior have proposed that patients and health professionals have different explanatory models or beliefs about health and illness and that beliefs held by patients are important determinants of treatment adherence [19] [20] . This has been confirmed by empirical studies of treatment adherence among patients with hypertension [20] [21] . Evidence suggests that patient education can be effective in supporting treatment adherence and hypertension self-management, especially if the educational programs pay attention to underlying barriers to adherence such as patients’ beliefs and concerns about the nature of hypertension and the prescribed treatment, medication self-efficacy and specific social, cultural and individual barriers to optimal hypertension management [22] - [25] . A systematic review of studies on various strategies for improving the quality of primary hypertension care in high income countries concludes that organizational health system changes and patient education have the biggest impact on blood pressure (BP) outcomes [26] . Some recent primary care studies from Nigeria also demonstrate that organizational quality improvement interventions can lead to improved clinical outcomes in hypertensive patients [14] [27] [28] . However, to date little information is available about the impact of patient education on hypertension management in low resource communities in Nigeria or other countries in SSA. We had the opportunity to investigate this issue in a rural primary care facility in Kwara State Nigeria, where clinical guidelines were introduced in 2010 in order to improve the quality of hypertension management for patients enrolled in a Community Based Health Insurance (CBHI) program. To strengthen this quality improvement program, we implemented a tailored community-based cardiovascular health education program (CHEP) for patients. CHEP was developed and structured on the basis of the theoretical frameworks of Kleinman and Leventhal [19] [20] , and the content was based on findings from a previous qualitative study on perspectives on hypertension and treatment adherence among hypertensive patients from the local community [29] . Because patients in this facility had been offered free guideline-based cardiovascular prevention care, in the context of their health insurance, the setting allowed for a focused analysis of the value of patient education. The aims of this study were to evaluate the effects of CHEP on treatment adherence, BP control and body mass index (BMI) and to explore to what extent the changes that occurred in medication adherence after patients had completed CHEP were related to changes in the underlying determinants of adherence behavior that were addressed during the training (i.e. patients’ perceptions of hypertension, medication, and self- efficacy).

2. Methods

The study design has been published previously [30] . This section summarizes the main procedures.

2.1. Study Site and Context

The study was conducted at Ogo Oluwa hospital (OOH) in Bacita, a rural low-income community in Kwara State. OOH was contracted by the Kwara State Health Insurance (KSHI) program to provide primary and limited secondary care to patients who are enrolled in the health insurance plan. Financed by an international organization―the Health Insurance Fund (HIF) [31] , the KSHI program was launched in Kwara State in 2007 with the aim to provide subsidized health insurance for low and middle income groups.

As part of the insurance company’s quality assurance program, OOH had implemented guidelines and treatment protocols for CVD prevention [4] [32] [33] , and upgraded its diagnostic equipment and medical record system. In a previously reported study, Quality Improvement Cardiovascular care Kwara (QUICK)-I, we evaluated the feasibility and quality of this program [28] [34] . The QUICK-I study included 349 insured patients with hypertension and/or diabetes from OOH between June 2010 and January 2011, followed these patients over a period of 12 months and assessed them for health-related and other outcomes, including medication adherence, systolic BP (SBP) and diastolic BP (DBP). Of the 349 included patients 323 completed the study at one year of follow up [28] .

2.2. Study Design and Participants

The present study, QUICK-II, was an observational one-group pre-test post-test study of 149 patients who had completed the QUICK-I study [30] . QUICK-I patients were recruited for QUICK-II if the following criteria were present at the one-year follow up assessment of QUICK-I: enrolled in KSHI program; registered at OOH; aged ≥ 18 years; diagnosed with hypertension; having uncontrolled BP (SBP ≥ 140 mmHg or DBP ≥ 90 mmHg without co-morbidity―diabetes, renal disease, cardiovascular diseases―or SBP ≥ 130 mmHg or DBP ≥ 80 mmHg with co-morbidity) and/or being non-adherent to behavioral recommendations or prescribed medications (score < 8 on the Morisky Medication Adherence Scale (MMAS-8) [35] [36] ; and willing to provide informed consent. Pregnant or lactating females were excluded from the study.

Baseline assessments for QUICK-II patients (T0) were conducted between November 2011 and March 2012, and six-month-follow up assessments (T1) were conducted between April 2012 and September 2012. Between T0 and T1, all included patients were offered cardiovascular health education program (CHEP) counseling, in addition to their regular hypertension care. Two trained research nurses, fluent in local languages, conducted baseline and follow-up assessments of physiological and self-report measures. Questionnaires for assessing self- report measures were designed and piloted in English, and translated into the two dominant local languages (Yoruba and Nupe). Patients received a reminder 2 days before the scheduled study visits. Incurred travel costs were reimbursed if study visits took place outside a patient’s usual clinic days.

2.3. Intervention―CHEP

The intervention, CHEP, consisted of: (i) three group-based educational sessions; and (ii) culturally tailored written and audio-visual educational materials (see table, Additional File 1). The content of CHEP was inspired by a hypertension education program that was developed by Beune et al. [23] , and results of a previous interview study with hypertensive patients of OOH [29] . All patients were randomly assigned to a group of 12 - 15 “trainees” which held the same composition throughout the program. The CHEP training sessions took place at OOH, at respectively 2, 6 and 14 weeks after T0. The first session lasted 2 hours and the second and third sessions lasted 2.5 hours each. The training was given by the researcher (AOO) and a trained research nurse. Sessions were held in the languages of choice of the group and interactive training techniques were used in all sessions.

2.4. Outcome Measures and Data Collection

2.4.1. Primary and Secondary Outcomes

The primary outcomes were the proportion of study participants who had improved self-reported adherence to medication and behavioral recommendations at six months past baseline.

Medication adherence was assessed with the MMAS-8 [35] [36] . The MMAS-8 asks participants 7 “yes” or “no” questions and 1 question that can be answered on a 5-point Likert scale. Low adherence is defined as MMAS-8 scores < 6; medium adherence as scores ranging from 6-to < 8, and high adherence as a score of 8 [36] . We defined improvement in medication adherence as a shift to a higher category of adherence between T0 and T1 (e.g. from low to medium adherence) or as ‘high adherence’ (MMAS-8 score of 8) at both points in time.

Adherence to behavioral advice was measured with the question “to what extent do you follow the behavioral advice from your doctor about smoking/nutrition/drinking alcohol/losing weight/physical activity or something else”? Answers were provided on a 4-point Likert scale, (1) never, (2) sometimes, (3) usually or (4) always. We defined improvement in adherence to behavioral recommendations as a shift from lower to a higher category of adherence between T0 and T1 or as high adherence (category 4) at both points in time.

Secondary outcomes were: the proportion of patients who showed an improvement in BP between T0 and T1; and the proportion of patients who showed a decrease in body mass index (BMI) by ≥1 unit kg/m2 between T0 and T1.

BP was measured three times, 5 minutes apart, with an automated BP monitor (Omron M6 Comfort, OMRON Corporation, Kyoto, Japan), after the patient had been seated for 5 minutes. The second and third readings were averaged to calculate the SBP and DBP. A controlled BP was defined as a SBP of <140 mmHg and a DBP of <90 mmHg for patients without co-morbidity, or as SBP < 130 mmHg and DBP < 80 mmHg for patients with co- morbidity. Improvement in BP was defined as a ≥10% decrease in SBP and/or DBP between T0 and T1 or having a controlled BP at both T0 and T1.

BMI was calculated from measures of the patient’s height and weight. Weight was measured with validated Omron BF 400 weighing scale, and height with a validated Leicester Stadiometer SECA 217. Both measures were taken without the patient wearing shoes and/or heavy clothing. Measurements were recorded to the nearest 0.1 cm (height) and 0.1 kg (weight). Normal weight was defined as a BMI below 25 kg/m2, overweight as a BMI between 25 and 29.9 kg/m2, and obesity as a BMI ≥ 30 kg/m2. Improvement in BMI was defined as a ≥ 1 unit kg/m2 decrease in BMI between T0 and T1 for patients with a baseline BMI ≥ 25 kg/m2.

2.4.2. Other Measures

The intervention targeted some determinants of medication adherence: patients’ perceptions of hypertension, medication, and medication self-efficacy. We measured these variables in order to obtain a better understanding of the expected change in primary outcomes.

Patients’ perceptions of hypertension were assessed with the well validated Revised Illness Perception Questionnaire (IPQ-R) [37] . The IPQ-R asks participants to provide answers to statements on a 5-point Likert scale (1 = “strongly disagree”, 5 = “strongly agree”) on 9 dimensions of illness (hypertension), 7 of which were used in this study. Scores are totaled and overall score represents the degree to which hypertension is perceived as threatening or benign. High scores on the dimensions 1) emotional representations, 2) timeline chronic, 3) consequences, 4) timeline cyclical represent strongly held beliefs about 1) number of symptoms attributed to hypertension, 2) its chronicity, 3) its negative consequences and 4) its cyclical nature. High scores on the personal control, treatment control and illness coherence dimensions represent positive beliefs about the controllability of hypertension and a personal understanding of the illness.

Patients’ beliefs about medicines were assessed with the Beliefs about Medicines Questionnaire (BMQ) [38] . BMQ is a well validated 18-item tool that consists of two sections. In this study we used only section 1 (BMQ- specific) which consists of two 5-item subscales. The first scale (Specific-necessity) assesses hypertensive patients’ beliefs about how necessary it is to take medications in order to improve/maintain their health. The second scale (Specific-concern) assesses respondents’ “concerns” about potential adverse consequences from taking their medications. BMQ uses 5-point Likert questions ranging from 1 = “strongly disagree” to 5 = “strongly agree”. The respondents’ scores on each item are totaled. Higher scores indicate stronger beliefs about the necessity of taking medicines and concerns about adverse effects of medications.

Medication self-efficacy was measured with the shortened Medication Adherence Self-Efficacy Scale (MASES-R) [39] [40] . This 13-item scale assesses the patients’ beliefs in their confidence to adhere to prescribed anti-hypertensive medications under a variety of challenging situations, such as when busy at home, when there are symptoms, while traveling etc. Items are scored using a 4-point Likert scale, (1 = “not at all sure”, 4 = “extremely sure”). The scores on all items are totaled. Higher scores indicate higher self-reported medication adherence self-efficacy.

In order to collect additional information about self-reported health behaviors, participants were asked questions about physical activity, dietary salt intake, alcohol and tobacco use. Daily moderate physical activity was defined as performing sports or exercise (e.g. walking to the market, performing heavy work) in addition to one’s normal daily activities such as dressing, washing and walking. Salt use was defined as adding any salt (a little/a lot) when cooking or when eating food. Alcohol use was defined as any self-reported use of alcohol daily, weekly or monthly. Tobacco use is self-reported use of any tobacco products, such as cigarettes, cigars or pipes. Information about patients’ socio-demographic characteristics was obtained from the QUICK-I study.

2.5. Statistical Analysis

Data were analyzed using STATA, version 12.0 (StataCorp LP, College Station, Texas, USA). Adherence to medications and behavioral advice, BP control and BMI were calculated using descriptive statistics. Changes between T0 and T1 were compared using the Wilcoxon signed rank test for categorical and continuous variables and the McNemar exact test for binary variables. Changes in illness perceptions, medication beliefs and self-effi- cacy between T0 and T1 were compared using the Wilcoxon signed rank test.

A first multivariable logistic regression analysis was performed to evaluate the association between improvement in BP between T0 and T1 (secondary outcome) and medication and behavioral adherence (primary outcome).

A second multivariable logistic regression analysis was performed to explore the associations between improvement in adherence to medications between T0 and T1 (primary outcome) and illness perceptions, medication beliefs, and self-efficacy. The illness perceptions, medication beliefs and self-efficacy variables showing a p-value below 0.2 in a univariate analysis were included in the multivariate model.

In both models no control variables (i.e. age, gender, level of education, ethnicity, co-morbidities, etc.) were included since no substantial change was expected in these variables during the study period. The odds ratios (OR), 95% confidence interval (CI) and p-values were reported.

To evaluate the association between change in SBP and DBP (between T0 and T1) and medication and behavioral adherence, two multivariable linear regression analyses were performed. Coefficients (in mmHg), 95% CI and p-values were reported and similar to the logistic regression models, no control variables were included in the analyses.

Endline measurements in QUICK-I were used to determine patients eligibility for QUICK-II (uncontrolled BP and/or non-adherence to medications). On average, there was a gap of 4.7 months between the endline QUICK-I assessment and the baseline QUICK-II assessment (T0). During this period, 33% (n = 49) of the eligible QUICK-II patients had improved in BP and/or medication adherence (see Additional file 2). The number of patients with a controlled BP at T0 was high (59.7%), resulting in a low power for the first multivariable regression analysis. In the original design of the study [30] , our definitions of the secondary outcome measure, BP improvement was very strict (a ≥ 10% decrease in SBP and/or DBP between T0 and T1 or having a controlled BP at both T0 and T1). We believe, however, that any BP decrease can be favorable in the studied participants. For this reason, the research group decided to measure the secondary outcome also by assessing the BP improvement continuously as the delta of SBP and DBP between T0 and T1 and to perform the two multivariable linear regression analyses mentioned above.

2.6. Ethics

Ethical approval for the study was obtained on 30th March, 2010 from the Ethics committee of the University of Ilorin Teaching Hospital, Kwara State (Ref: UITH/CAT/189/13/13). Patients were adequately informed about the study and informed consents were taken prior to commencement of study by signature or fingerprint.

3. Results

3.1. Patient Characteristics

The QUICK-II cohort consisted of 149 patients. Participant flow is shown in Figure 1.

Out of 323 patients who completed QUICK-I study 156 were referred to QUICK-II, 7 of whom were excluded because they had diabetes but not hypertension. The remaining 149 patients were included in QUICK-II. For different reasons, nine patients (6%) were lost to follow-up. Of those who completed the study (n = 140), 132 (94%) attended all three CHEP sessions.

Table 1 shows participants’ socio-demographic characteristics. The median age was 56.5 years (IQR: 49.4 - 65.5), 63 (42%) were males and 85 (57%) were not formally educated.

3.2. Changes in Adherence to Medication and Behavioral Recommendations, BP and BMI

As Table 2 shows, medication adherence improved during the study period (p < 0.001). As compared to T0, more patients reported a high level of medication adherence (MMAS-8 = 8) at T1: N = 70 (50%) versus N = 101 (72%). A similar pattern was observed for adherence to behavioral recommendations; the proportion of patients

Figure 1. Flow of QUICK-II study participants.

Table 1. Characteristics of study participants (N = 149).

*n = 147; Note: Characteristics are taken at baseline QUICK-I. Age is newly calculated using the date of QUICK-II baseline assessment and the date of birth recorded in QUICK-I; **Based on end-line QUICK-I assessment; ***n = 140.

Table 2. Changes in adherence to medications and behavioral advice, BP and BMI between baseline and endline.

BP, blood pressure; SBP, systolic blood pressure; DBP, diastolic blood pressure. *n = 139.

who reported to always adhere to behavioral advice increased from 106 (76%) at T0 to 126 (90%) at T1 (p < 0.001). Median SBP and DBP levels dropped significantly from 129.0 mmHg (IQR: 118.3 - 147.3) to 122.0 mmHg (IQR: 108.0 - 138.0) (p < 0.001) and from 80.0 mmHg (IQR: 71.3 - 87.8) to 73.5 mmHg (IQR: 65.0 - 85.0) (p < 0.001), respectively. No significant change was found for BMI (p = 0.444). However, more participants reported engaging in moderate physical activity for 30 or more minutes a day, on 3 or more days a week at T1: 124 (89%) versus 98 (70%) at T0 (p < 0.001). No statistically significant changes were observed in dietary salt intake, smoking or alcohol consumption between T0 and T1.

3.3. Improvement in Treatment Adherence Associated with Improvement in BP

Although trends were positive, no statistically significant associations was observed between BP improvement and changes in medication adherence (OR = 1.55, p = 0.351) and adherence to behavioral recommendations (OR = 1.93, p = 0.327) during the study period (Table 3).

But when using our second definition of BP improvement (Table 4), improvement in medication adherence during the study was associated with a 9.2 mmHg (p = 0.038) reduction in SBP and a 6.1 mmHg (p = 0.027) reduction in DBP. The improvement in adherence to behavioral recommendations was not associated with decrease in BP (SBP: p = 0.214; DBP: p = 0.318). Included in the definition of improvements in medication adhe-

Table 3. Association between treatment adherence and improvement in BP at six months; multivariable logistic regression models.

*Improvement in blood pressure (BP) is defined as having BP on target at endline or a > 10% decline in BP at endline compared to baseline; **Improvement in adherence to medication/behavioral advice is defined as having moved to a higher category of adherence between T0 and T1, or as having remained in the highest category of adherence at both time points.

Table 4. Association between treatment adherence and improvement in BP at six months; multivariable linear regression model.

*Improved adherence to medication/behavioral advice is defined as having moved to a higher category of adherence between T0 and T1, or as having remained in the highest category of adherence at both time points.

rence are the patients that remained adherent at T0 and T1. In this subgroup we observed no association between medication adherence and decrease in SBP (p = 0.610) and DBP (p = 0.820) (results not shown).

3.4. Illness Perceptions, Medication Beliefs and Self-Efficacy and Medication Adherence

As intended by CHEP, statistically significant differences between T0 and T1 were observed in some of the illness perception variables, namely for the dimensions timeline chronic (p < 0.001), consequences (p < 0.001), timeline cyclical (p = 0.001) and emotional representations (p < 0.001) (Table 5). Similarly, statistically significant changes between T0 and T1 were observed with respect to participants’ medication self-efficacy (p < 0.001), beliefs about the necessity of medications (p < 0.001), and their concerns about adverse effects of medications (p = 0.002) (Table 5).

An improvement in medication adherence during the study period was associated with an increase in medication self-efficacy (OR = 5.99, p < 0.001) and a decrease in patients’ concerns about adverse effects of medications (OR = 2.57, p = 0.045) (Table 6).

The association between improved adherence to behavioral advice and illness perceptions, medication beliefs and self-efficacy could not be assessed because of the high number of participants who reported a high adherence to behavioral advice at T0 (76%) and T1 (89%), (Table 2).

Furthermore, in the multivariate analysis, the most important determinants of the improvements in medication adherence (directly), and BP control (indirectly) were changes in perceived medication self-efficacy (OR = 5.99, p < 0.001); concerns about medications (OR = 2.57, p = 0.045); and personal control (OR = 0.45, p = 0.092), although the latter association was not statistically significant.

Table 5. Changes in illness perceptions, medication self-efficacy and beliefs about medicines between baseline and endline.

*n = 139.

Table 6. Associations between changes in IPQ, MASES-R, BMQ, and improvement in medication adherence; multivariable logistic regression models.

4. Discussion

Our study demonstrated that a tailored group-based cardiovascular health education program strengthened guideline-based CVD prevention care among hypertensive patients from primary care clinic in a rural community in Nigeria. The patients in question did not adhere to treatment recommendations or had a blood pressure outside the normal range after they had received guideline-based care alone for one year. We observed that 89% of the patients completed all educational sessions. Studies of similar educational interventions in primary care settings in Europe and the USA recorded lower attendance rates, namely 79% and 58% [23] [41] . The high attendance rate in this study suggests that CHEP responded to patients’ needs, which is plausible in the light of a previous qualitative study that was conducted in the area [29] .

Secondly, we observed that patients who attended CHEP showed improvements in adherence to medication and behavioral recommendations. These improvements may, of course, simply be explained by the fact that patients knew that their hypertension management and adherence was monitored in this study (Hawthorn effect). However, our study provides several indications that the intervention itself has contributed to the improvement in medication adherence. The education program was specifically designed to address previously identified contextual or behavioral barriers to treatment adherence, including patients’ perceptions about hypertension and the treatment (see Additional File 1). We found that improved medication adherence after CHEP was positively associated with improved medication self-efficacy (MASES-R) and with a reduction of concerns about medications as measured by the BMQ. It is unlikely that changes in these underlying determinants of adherence to hypertension treatment [42] - [49] would have occurred without the educational intervention. More patients had begun to engage in moderate physical activity during the study period. This improvement may be explained by the fact that CHEP addressed cultural barriers to physical exercise in the community and suggested opportunities for exercise that are part of people’s usual everyday activities, such as yam pounding, drawing water from the well, walking, dancing, clapping, fishing or farming. However, for salt use and other behavioral risk factors for CVD no improvements were observed despite the fact that possibilities for changing these behaviors were also specifically addressed during CHEP. Anthropological studies have indicated that dietary practices are particularly difficult to change as they are an important component of one’s culture and cultural identity [50] . Changes in dietary behaviour may need more specific approaches than CHEP could offer in three sessions [51] - [53] .

Third, we did not find the expected >10% decline in SBP/DBD. However, we observed that the median SBP declined with 9.2 mmHg (p < 0.001) and the median DBP with 6.1 mmHg (p < 0.001). Moreover, after the study period, more patients could be classified as having a BP within the normal range according to the JNC7 hypertension classification system. These results are, as such, clinically relevant [54] . Moreover, we found that the decline of the median BP levels was associated with an improvement in medication adherence.

To our knowledge this is one of the first studies that analyzed the potential impact of hypertension education in the context of a CBHI program that aims to improve the quality of CVD prevention in low resource primary care setting in Africa. The study is also unique in its explicit description of the educational intervention and its potential replicability by healthcare providers and researchers in other settings (Additional File 1).

4.1. Limitations

Yet, this study has several limitations, the most important being the lack of a control group. Although, we observed significant improvements in outcome measures, the lack of a control group limits the possibility of drawing firm conclusions as to the causality of the measured effects. The link between CHEP and behavioral and clinical outcomes should be further tested in randomized controlled trials or prospective studies. Medication adherence (MMAS-8) and behavioral adherence were measured through self-report scales, and answers could have been influenced by social desirability. Nevertheless, MMAS-8 is a validated, reliable, simple, and low-cost instrument that has been successfully used to estimate medication adherence in many previous studies involving hypertensive patients [55] - [59] , including low-income patients of African origin [36] . Furthermore, due to the relatively small sample size, only a limited number of variables could be taken into consideration within our multivariate analysis. We have opted for the inclusion of variables that refer to behavioral determinants of adherence. The inclusion of additional variables such as the type or the number of medications used might have strengthened this study. In addition, the limited sample size also made it impossible to conduct sub-group analyses, for instance for patients with different levels of formal school education or for those with different levels of treatment adherence at the start of the study. Furthermore, to evaluate the long-term effect of CHEP longer follow-up studies are needed. Finally, a recent study from Nigeria reported that the adherence level was higher among hypertensive patients attending specialized clinics compared to those attending general outpatient clinics, despite the former’s use of more medications [60] . In future studies evaluating CHEP, attention should be given to the influence of the context in which care is provided and to the type and the number of medications patients are being prescribed.

CHEP was designed to meet the specific needs of the study population. Some of the culturally specific issues that were addressed by CHEP may not be relevant to patients who live in other socio-cultural settings. Yet the description of CHEP provides general outlines for structuring and providing patient education, which makes it possible to adapt the specific contents to the needs of other patient populations. It should be realized, however, that the patients in our study had access to free primary care through health insurance. The findings might therefore not automatically be generalizable to the broader group of (mostly uninsured) hypertensive patients in the larger hypertensive population in Africa or to those who are treated at secondary and tertiary levels of care. Finally, the study was conducted in a health care facility that had participated in a CVD quality improvement program (for over a year) that was subsidized by a CBHI program. It is likely that the usual care that was being provided in this facility is better than that in other facilities. Consequently, the effects of CHEP might have been greater if we had conducted the study in a common primary care setting in Nigeria or elsewhere in Africa.

4.2. Implication for Practice and Further Research

This study found that CHEP responds to patients’ needs and that it can be a useful component of the primary care management of hypertension in low resource communities in SSA, if it is combined with appropriate pharmaceutical treatment. Further (controlled) studies are needed to confirm or refute these findings. This type of health education can be delivered (efficiently) by nurses and other trained health workers, and not just by physicians. The modules of the cardiovascular health education program (CHEP) are well described (Additional File 1) and can serve as a (useful) framework for further development and evaluation of educational interventions for patients who are at risk of developing CVD, and particularly for those living in disadvantaged communities in SSA.

5. Conclusion

This study suggested that the evaluated education program (CHEP) improved adherence to medications, followed by an increase in BP control among insured hypertensive patients in rural Nigeria. At the end of the study, more participants reported high adherence to medications and behavioral advice than at baseline: respectively, 101 (72%) versus 70 (50%), (p < 0.001) and 126 (90%) versus 106 (76%), (p < 0.001). Participants with controlled BP doubled from 34 (24%) to 65 (46%), (p = 0.001). The median SBP and DBP decreased from 129.0 to 122.0 mmHg, (p = 0.002) and from 80.0 to 73.5 mmHg, (p < 0.001), respectively. BMI did not change (p = 0.444). Improved medication adherence was associated with a decrease in medication concerns (p = 0.045) and improved medication self-efficacy (p < 0.001). Making such programs available to affected populations in SSA has the potential to help reduce burden of cardiovascular diseases and associated mortality.

Competing Interests

A.O. Odusola received a grant (# CF7536/2011) from NUFFIC. The study was funded by Health Insurance Fund. The Fund was not involved in the study design, data collection, analysis, and interpretation or reporting of the data. The remaining authors declare that they have no competing interests.

Author Contributions

AOO drafted the manuscript, conducted the study and participated in the design, reporting, analysis and revision. JH, JL, KS and MH participated in the original study design. JH and KS made substantial revision of several drafts of the manuscript. HN conducted the statistical analyses with critical contributions from FW. AOO drafted the education program with critical contributions from JH. AO, CA, CS, FW, GO, HN, JH, KS, MH, OAB and TA reviewed the manuscript critically. KA and PA provided vital logistic supports. CS, JH and KS reviewed the data collection and management procedures. AO, TA, CS, JH, and KS are members of the supervisory board. All authors read and approved the final draft.

Acknowledgements

Special tributes go to late Prof. Joep Lange, who tragically passed away before the manuscript had been finished. He initiated and promoted an enabling environment for the study and related projects. We thank the Medical Director and staff of Ogo Oluwa hospital for facilitating a successful data collection. We are grateful to all participants for collaboration in the study. We thank HIF, Pharm Access Foundation, KSHI and NUFFIC for supporting the study.

Additional Files

Additional File 1: (1) CSV; Table; Cardiovascular Health Education Program (CHEP); Overview of group- based Cardiovascular Health Education Program used in QUICK-II study; (2) CSV; Table; Changes in inclusion characteristics of QUICK-II participants between endline QUICK-I and baseline QUICK-II assessments.

Cite this paper

Aina OlufemiOdusola,HeleenNelissen,MarleenHendriks,ConstanceSchultsz,FerdinandWit,Oladimeji AkeemBolarinwa,TanimolaAkande,CharlesAgyemang,GbengaOgedegbe,KayodeAgbede,PejuAdenusi,AkinOsibogun,KarienStronks,JokeHaafkens, (2015) How Group-Based Cardiovascular Health Education Affects Treatment Adherence and Blood Pressure Control among Insured Hypertensive Nigerians: A Pre-Test, Post-Test Study. World Journal of Cardiovascular Diseases,05,181-198. doi: 10.4236/wjcd.2015.57021

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Additional File 1

Table 1. Overview of group-based Cardiovascular Health Education Program (CHEP) used in QUICK-II study.

Additional information:

- Two instructors guided the sessions

- Sessions were held in English, Yoruba and Nupe with a translator

- All sessions included a 5 minute welcome

- Results of participants’ homework assignments were discussed with the trainers 15 minutes before the start of next sessions

- During breaks, patients viewed educational posters

*Power points are used; ** Posters are used.

Table 2. Changes in inclusion characteristics of QUICK-II participants between endline QUICK-I and baseline QUICK-II assessments.

List of Abbreviations

BMQ: Beliefs about Medicines Questionnaire

BP: Blood pressure

CHEP: Cardiovascular Health Education Program

DBP: Diastolic Blood Pressure

HIF: Health Insurance Fund

IPQ-R: Revised Illness Perception Questionnaire

KSHI: Kwara State Health Insurance

MASES-R: Revised Medication Adherence Self Efficacy Scale

MMAS: Morisky Medication Adherence Scale

NUFFIC: Netherlands organization for international cooperation in higher education

OOH: Ogo Oluwa Hospital

QUICK: Quality Improvement Cardiovascular Care Kwara

SBP: Systolic Blood Pressure

NOTES

*Corresponding author.