Nonadherence to antihypertensive drugs: A systematic review and meta-analysis

Effectiveness of a Patient-Tailored, Pharmacist-Led Intervention Program to Enhance Adherence to Antihypertensive Medication: The CATI Study

Introduction: Non-adherence to medication is a complex health care problem. In spite of substantial efforts, up till now little progress has been made to effectively tackle the problem with adherence-enhancing interventions. The aim of this study was to investigate the effectiveness of a patient-tailored, pharmacist-led and theory-driven intervention program aimed to enhance self-reported adherence to antihypertensive medication. Materials and Methods: A parallel-group randomized controlled trial in 20 community pharmacies with nine months follow-up was conducted. Patients (45-75 years) using antihypertensive medication and considered non-adherent based on both pharmacy dispensing data and a self-report questionnaire were eligible to participate. The intervention program consisted of two consultations with the pharmacist to identify participants' barriers to adhere to medication and to counsel participants in overcoming these barriers. The primary outcome was self-reported medication adherence. Secondary outcomes were beliefs about medicines, illness perceptions, quality of life and blood pressure. Mixed-model and generalized estimating equation (GEE) analyses were used to assess overall effects of the intervention program and effects per time point. Results: 170 patients were included. No significant differences between intervention and control groups were found in self-reported adherence, quality of life, illness perceptions, beliefs about medicines (concern scale), and blood pressure. After nine months, intervention participants had significantly stronger beliefs about the necessity of using their medicines as compared to control participants (mean difference 1.25 [95% CI: 0.27 to 2.24], p = 0.012). Discussion: We do not recommend to implement the intervention program in the current form for this study population. Future studies should focus on how to select eligible patient groups with appropriate measures in order to effectively target adherence-enhancing interventions. Trial Register: NTR5017 http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=5017.

Hypertension genomics and cardiovascular prevention

Hypertension continues to be a major risk factor for global mortality, and recent genome-wide association studies (GWAS) have expanded in size, leading to the identification of further genetic loci influencing blood pressure. In light of the new knowledge from the largest cardiovascular GWAS to date, we review the potential impact of genomics on discovering potential drug targets, risk stratification with genetic risk scores, drug selection with pharmacogenetics, and exploring insights provided by gene-environment interactions.

Non-adherence to antihypertensive pharmacotherapy in Buea, Cameroon: a cross-sectional community-based study

Background

Hypertension is a challenging public health problem with a huge burden in the developing countries. Non-adherence to antihypertensive treatment is a big obstacle in blood pressure (BP) control and favours disease progression to complications. Our objectives were to determine the rate of non-adherence to antihypertensive pharmacotherapy, investigate factors associated with non-adherence, and to assess the association between non-adherence and BP control in the Buea Health District (BHD), Cameroon.

Methods

A community-based cross-sectional study using stratified cluster sampling was conducted in the BHD from November 2013 – March 2014. Eligible consenting adult participants had their BP measured and classified using the Joint National Committee VII criteria. The Morisky medication adherence scale was used to assess adherence to BP lowering medication. Multivariable logistic regression models were used to predict non-adherence.

Results

One hundred and eighty-three participants were recruited with mean age of 55.9 years. Overall, 67.7% (95% CI: 59.8–73.6%) of participants were non-adherent to their medications. After adjusting for age, sex and other covariates, forgetfulness (aOR = 7.9, 95%CI: 3.0–20.8), multiple daily doses (aOR = 2.5, 95%CI: 1.2–5.6), financial constraints (aOR = 2.8, 95%CI: 1.1–6.9) and adverse drug effects (aOR = 7.6, 95%CI: 1.7–33.0) independently predicted non-adherence to anti-hypertensive medication. BP was controlled in only 21.3% of participants and was better in those who were adherent to medication (47.5% versus 8.2%, p <  0.01).

Conclusion

At least two of every three hypertensive patients in the Buea Health District are non-adherent to treatment. Forgetfulness, multiple daily doses of medication, financial constraints and medication adverse effects are the major predictors of non-adherence in hypertensive patients. These factors should be targeted to improve adherence and BP control, which will contribute to stem hypertension-related morbidity and mortality.

Evaluation of antihypertensive adherence and its determinants at primary healthcare facilities in rural South Africa

Aim: To evaluate adherence to antihypertensive treatment in rural South Africa and identify potential determinants given concerns with adherence and its impact in this priority disease area. Patients & methods: Face-to-face interviews with hypertensive patients and rating their adherence to treatment using defined categorized responses. Associations between adherence and patient characteristics assessed and sensitivity analyses performed. Results: 54.6% of patients were adherent to treatment. Controlled blood pressure (BP; odds ratios [OR] = 2.1; 95% CI: 1.1, 3.8; p = 0.019), comorbidity (OR = 2.0; 95% CI: 1.1, 3.6; p = 0.032) and smoking (OR = 0.3; 95% CI: 0.1, 0.8; p = 0.018) were associated with adherence. Conclusion: Adherence and BP control were suboptimal, only smoking was an independent risk factor for adherence. Adherent patients were twice as likely to have controlled BP, although results were sensitive to the definition of adherence. Initiatives are in place to improve adherence, which will be monitored.

Indexed plasma drug concentrations for drug adherence screening in hypertensive patients

AIM

Due to its high sensitivity, qualitative plasma drug screening by liquid chromatography/tandem mass spectrometry may not be able to distinguish same-day drug intake from drug use on preceding days and cause misclassifications of drug adherence in hypertensive patients. Analysis of plasma drug concentrations may provide more accurate results.

PATIENTS AND METHODS

We describe dose-dependent indexing of plasma drug concentrations for expected peak concentrations to define individual screening thresholds for same-day drug use. To explore its utility, plasma samples from 9 hypertensive patients without major comorbidity were prospectively analyzed on two occasions. All were on hydrochlorothiazide with either amlodipine (n=7) and/or valsartan (n=6) at different doses. Drugs were quantitated by mass spectrometry. Non-adherence was defined if an indexed drug concentration was below the expected trough level at 24-hour dosing interval.

RESULTS

All patients were adherent by qualitative plasma screening (spectrometric sensitivity). On the first visit (random sampling time), mean plasma concentrations of the drugs were 102±70, 15.4±6.7 and 2529±1608ng/mL, and mean indexes 84±57%, 85±35% and 60±38%, respectively. Using the study criterion, non-adherence was suspected in three. Intraindividual cross-checking retained two. On the second visit (fixed sampling time), amlodipine concentration was 15.6±8.5ng/mL (88±52% after indexing). Two patients were non-adherent according to the study criterion.

CONCLUSION

Indexing of plasma drug concentrations appears practicable and useful for drug adherence screening under clinical conditions. With this technique, same-day drug intake can be easily distinguished which reduces the risk of false positive results associated with qualitative drug screening.

Antihypertensive Effect of Ethanolic Extract from Acanthopanax sessiliflorus Fruits and Quality Control of Active Compounds

Acanthopanax sessiliflorus (Rupr. & Maxim.) Seem., which belongs to the Araliaceae family, mainly inhabits Korea, China, and Japan. Traditionally, Acanthopanax species have been used as treatment for several diseases such as diabetes, tumors, and rheumatoid arthritis. Especially, its fruits have many biological functions including antitumor, immunostimulating, antithrombosis, and antiplatelet activities. Recently, the extract of A. sessiliflorus fruit has been reported to have antithrombotic and antiplatelet activities related to the alleviation of hypertension. Therefore, we investigated the antihypertensive effect of ethanolic extract from A. sessiliflorus fruits (DHP1501) through in vivo, ex vivo, and in vitro studies. In this study, DHP1501 demonstrated free radical scavenging capacity, enhanced endothelial nitric oxide (NO) production, and inhibited angiotensin-converting enzyme (ACE) activity in spontaneously hypertensive rats (SHRs), resulting in the improvement of vascular relaxation and decrease in blood pressure in the hypertensive animal model. These results suggest that A. sessiliflorus fruit extract may be a promising functional material for the prevention and treatment of hypertension. Furthermore, this study demonstrated the utility of MS-based active compounds for the quality control of DHP1501.

Barriers to medication adherence and links to cardiovascular disease risk factor control: the Framingham Heart Study

BACKGROUND

In the elderly, impaired cognition may weaken medication adherence and compromise treatment for cardiovascular disease (CVD).

AIM

We examined risk factors for medication adherence and the relationship between adherence and levels of CVD risk factors among older participants with hypertension, dyslipidaemia and diabetes in the Framingham Heart Study.

METHODS

The four-item Morisky Medication Adherence Scale was administered to 1559 participants, median age 70 years, 53% women. We created an adherence score, ranging from 0 to 4, with low adherence defined as a score ≥2. CVD risk factors were assessed using standard protocols. Cognition was measured using the Mini-Mental State Examination (MMSE) and depressive symptoms were measured using the Center for Epidemiologic Studies of Depression (CES-D) scale.

RESULTS

Among participants who self-reported taking antihypertensive, lipid-lowering and/or hyperglycaemic medication(s), 12% (n = 191) had low medication adherence. The risk of low adherence increased by 45% (95% confidence interval (CI): 25-68%, P < 0.001) per five-unit increase in CES-D score. In participants taking antihypertensive medication (n = 1017), low adherence was associated with higher mean diastolic blood pressure (73 mmHg, 95% CI: 71-75 vs 71 mmHg, 95% CI: 70-71; P = 0.04) after adjusting for covariates. Among participants taking lipid-lowering medication (n = 937), low adherence was associated with higher mean low-density lipoprotein cholesterol (92 mg/dL, 95% CI: 87-96 vs 86 mg/dL, 95% CI: 84-88; P = 0.03). Low adherence was not associated with fasting plasma glucose (P = 0.10) or haemoglobin A1c (P = 0.68) in the subgroup of participants (n = 192) taking hypoglycaemic medication.

CONCLUSIONS

Depressive symptoms might act as a barrier for medication adherence, which exacerbates CVD risk factors in older-aged adults.

Prevalence and factors associated with medication adherence among patients with hypertension in sub-Saharan Africa: protocol for a systematic review and meta-analysis

INTRODUCTION

Hypertension is the leading cardiovascular risk factor globally, associated with a high morbidity and mortality. The high prevalence of hypertension in sub-Saharan Africa (SSA) is associated with contrastingly low awareness, treatment and control rates. Adherence to medication remains a major determinant of optimal blood pressure control. This systematic review aims to determine the prevalence, and factors associated with adherence to antihypertensive pharmacotherapy among patients with hypertension in SSA.

METHODS AND ANALYSIS

We will include studies published in Africa up to 31 December 2017. The following databases will be searched: PubMed, Embase, SCOPUS and Web of Science to identify potential studies without language restriction. To minimise chances of missing studies, resources specific to African literature such as WHO AFROLIB, African Index Medicus and African Journals Online will also be searched. Two reviewers will independently screen studies, extract data and critically appraise included studies for risk of bias, and a third reviewer will resolve discrepancies. A random-effects meta-analysis is planned to pool study-specific estimates to obtain a summary measure presented in Forest plots. Heterogeneity of included studies will be assessed using the χ² test on Cochrane's Q statistic and quantified using I². Publication bias will be assessed using the Egger's test and funnel plots. This protocol has been prepared according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses for Protocols 2015 statement.

ETHICAL AND DISSEMINATION

An ethical approval is not required for the proposed study, as it will be based on already published data. The end report will be presented at conferences and published in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42017079838.

Pharmacogenomic studies of hypertension: paving the way for personalized antihypertensive treatment

Introduction

Increasing clinical evidence supports the implementation of genotyping for anti-hypertensive drug dosing and selection. Despite robust evidence gleaned from clinical trials, the translation of genotype guided therapy into clinical practice faces significant challenges. Challenges to implementation include the small effect size of individual variants and the polygenetic nature of antihypertensive drug response, a lack of expert consensus on dosing guidelines even without genetic information, and proper definition of major antihypertensive drug toxicities. Balancing clinical benefit with cost, while overcoming these challenges, remains crucial.

Areas covered

This review presents the most impactful clinical trials and cohorts which continue to inform and guide future investigation. Variants were selected from among those identified in the Pharmacogenomic Evaluation of Antihypertensive Responses (PEAR), the Genetic Epidemiology of Responses to Antihypertensives study (GERA), the Genetics of Drug Responsiveness in Essential Hypertension (GENRES) study, the SOPHIA study, the Milan Hypertension Pharmacogenomics of hydro-chlorothiazide (MIHYPHCTZ), the Campania Salute Network, the International Verapamil SR Trandolapril Study (INVEST), the Nordic Diltiazem (NORDIL) Study, GenHAT, and others.

Expert Commentary

The polygenic nature of antihypertensive drug response is a major barrier to clinical implementation. Further studies examining clinical effectiveness are required to support broad-based implementation of genotype-based prescribing in medical practice.

Effect of characteristics of pharmacotherapy on non-adherence in chronic cardiovascular disease: A systematic review and meta-analysis of observational studies

INTRODUCTION

Cardiovascular medications are effective in prevention of cardiovascular diseases (CVD); however, medication non-adherence contributes to morbidity and mortality.

OBJECTIVE

This systematic review and meta-analysis aims to summarise the evidence regarding the relationship between characteristics of drug therapy (pharmacotherapy) and medication non-adherence in the CVD population.

METHODS

Systematic searches in PubMed, LILACS, Academic Search and CINAHL databases for observational studies that enrolled adults with CVD were performed, from January 1960 to December 2015. The meta-analysis tested the association between characteristics of pharmacotherapy and self-reported medication non-adherence outcome, using a random effects model. To investigate heterogeneity, we performed subgroup analysis and sensitivity analysis.

RESULTS

Twenty-four cross-sectional studies and 7 cohort studies were included in this review. Based on 31 studies including 27 441 participants, we performed meta-analyses for all the characteristics of drug therapy that at least 2 studies evaluated, with a total of fourteen meta-analyses. The pooled results showed that studies which evaluate whether participants have insurance or another program that assists with medication costs, but not full coverage (OR = 0.63; 95% CI: 0.53-0.74; P < .001; I²  = 0%, P = .938), and a dosing frequency of twice or more daily (OR = 1.38; 95% CI: 1.13-1.69; P < .001) were associated with non-adherence.

CONCLUSIONS AND RELEVANCE

The results of this review suggest that access to insurance or another program that assists with medication costs was a protection factor for non-adherence. On the other hand, a high frequency of dosing was a risk factor for non-adherence. Therefore, these characteristics of pharmacotherapy must be considered to improve medication adherence among CVD patients.

Psychometric evaluation of the Polish version of the Adherence to Refills and Medications Scale (ARMS) in adults with hypertension

BACKGROUND

Only 50%-75% of chronically ill patients take their medication as prescribed. The patient is found to adhere to treatment correctly and optimally if they accomplish 80% or more of the treatment plan. A questionnaire titled the Adherence to Refills and Medications Scale (ARMS) has been used in studies involving various populations and proved to be a simple instrument for measuring adherence, with good psychometric properties.

OBJECTIVE

The aim of this study was to develop a Polish version of the ARMS (ARMS-P), an instrument that identifies levels of adherence in the hypertensive population, and evaluate its psychometric properties.

METHODS

This cross-sectional study included 279 patients, including 166 females (mean age 66.5 years), hospitalized between September 2016 and March 2017 in the Department of Internal Medicine, Occupational Diseases, and Hypertension of Wrocław Medical University, Poland. The 12-item ARMS was translated from English into Polish. The 12 items included in the final questionnaire comprise two subscales: adherence to taking medications (eight items) and adherence to refilling prescriptions (four items).

RESULTS

Patients in the good-adherence group were younger (P=0.017; P=0.048), more likely to be professionally active (P=0.041), better educated (P=0.037), and more likely to have normal blood pressure (P<0.001). They also measured their blood pressure more often (P<0.001), and took fewer pills in a day (P<0.001). Adherent patients were also more likely to take their medication on their own (P=0.016) and read information leaflets on the medication (P<0.001). The study demonstrated that the ARMS-P questionnaire has good psychometric properties that enable its use for assessing adherence in chronically ill patients, including in particular, patients with hypertension.

CONCLUSION

The psychometric properties of the questionnaire are satisfactory (reliability measured by means of Cronbach's α). The ARMS-P questionnaire proved to be suitable for use in the Polish population. The use of this screening tool for the assessment of adherence to treatment is recommended in this population of hypertensive patients.

Treatment adherence among adult hypertensive patients: a cross-sectional retrospective study in primary care in Romania

PURPOSE

This study was performed to elucidate the level of adherence to antihypertensive treatment in adult subjects attending a family medicine clinic in a city in central Romania.

PATIENTS AND METHODS

A cross-sectional, retrospective study was performed on a cohort of hypertensive adults. A total of 525 participants were selected from 1,714 adults attending a single urban family medicine practice. Assessment of adherence to therapy was performed by a chart review of prescription and clinical records over a 4-year study period.

RESULTS

The results showed that 69.8% of the patients had high adherence (>80% with therapy); 20.3% had medium adherence (20%-79%); and 9.9% had low adherence (<20%). A positive association was found (p = 0.01) between low adherence and male gender. A significant positive association (p = 0.02) was found between total cardiovascular risk and level of adherence. We found that 54.7% of the high adherence subjects had well-controlled blood pressure, and chronic kidney disease was associated with high adherence to therapy (p = 0.03). Antihypertensive regimens administered as fixed-dose combinations were positively associated with high adherence (p = 0.001). Subjects who had their antihypertensive regimen adjusted to a new drug class during the study period showed enhanced adherence compared to subjects treated with an unchanged regimen (p = 0.001).

CONCLUSION

This is the first published study assessing adherence to antihypertensive therapy in family medicine practice in Romania. It presented data derived from a primarily urban setting and targeted a geographical area where the prevalence of hypertension has increased continuously. Female gender, age, presence of cardiovascular risk factors, defined cardiovascular disease, chronic renal impairment, and good control of hypertension were positively associated with high adherence. The results provide insights to guide further strategies to improve adherence and indirect methods for blood pressure management strategies.

The influence of quality of life on the level of adherence to therapeutic recommendations among elderly hypertensive patients

BACKGROUND

Hypertension is one of the most important risk factors for cardiovascular disease, which contributes to lowering the quality of life (QOL), especially in elderly patients. Recent data show that almost half of the hypertensive patients and one-third of patients with comorbidities were nonadherent to medication.

OBJECTIVE

To assess the association of QOL with the level of adherence and to examine the association with selected variables on the level of adherence.

DESIGN

A prospective, cross-sectional, and analytical study.

METHODS

This study involved 186 hypertensive elderly patients (mean age: 71.05±7.47 years). An analysis of medical records based on sociodemographic and clinical data was conducted. The World Health Organization Quality of Life Scale Brief version (WHOQOL-BREF) was used to assess the level of QOL, and the Hill-Bone Compliance to High Blood Pressure Therapy Scale (HBQ) was used to examine the level of adherence to therapeutic recommendations in hypertensive patients.

RESULTS

The average assessment of the QOL measured by the WHOQOL-BREF questionnaire was 3.36±0.84 points, which indicates a QOL at a level between average and good. The patients' average score on the HBQ questionnaire was 20.39±4.31 points. In the "reduced sodium intake" subscale, patients had an average of 4.75±1.33 points. In the "appointment keeping" subscale, the patients scored an average of 3.45±1.07 points. In the "medication taking" subscale, the patients had an average of 12.19±3.46 points. It was shown that the total score of the HBQ questionnaire was negatively correlated with all domains of QOL assessed with the WHOQOL-BREF questionnaire (P<0.05).

CONCLUSION

There is an association between QOL and adherence to therapeutic recommendations among hypertensive elderly patients. It has been concluded that with an increasing QOL, the level of adherence to therapeutic recommendations increases. The level of adherence is also negatively affected by: older age, longer duration of disease, worse marital status, lower education, living alone, and using polytherapy.

Ongoing Initiatives to Improve the Quality and Efficiency of Medicine Use within the Public Healthcare System in South Africa; A Preliminary Study

Introduction: South Africa has an appreciable burden of both communicable and non-communicable diseases as well as high maternal, neonatal, and child morbidity. In recent years there have been significant strides with improving the public health system, and addressing current inequalities, with the right to health a constitutional provision in South Africa. Initiatives include the introduction of National Health Insurance, programmes to enhance access to medicines for patients with chronic diseases, as well as activities to improve care in hospitals, including improving pharmacovigilance. Consequently, the objective of this paper is to review ongoing initiatives within the public healthcare sector in South Africa and their influence to provide future direction.

Method: Principally a structured review of current and planned activities.

Results: There have been a number of major activities and initiatives surrounding the availability and access to medicines in the public system in recent years in South Africa. This includes a National Surveillance Centre and an innovative early warning system for the supply of medicines as well as the development of a National Health Care Pricing Authority and initiatives to improve contracting. There have also been developments to improve the supply chain including instigating Medicine Procurement Units in the provinces and enhancing forecasting capabilities. Access to medicines is improving though the instigation of stable chronic disease management initiatives to increase the number of external pick-up points for medicines. There are also ongoing programmes to enhance adherence to medicines as well as enhance adherence to the Standard Treatment Guidelines and the Essential Medicines List with their increasing availability. In addition, there is a movement to enhance the role of health technology assessment in future decision making. Hospital initiatives include increased focus on reducing antimicrobial resistance through instigating stewardship programmes as well as improving adverse drug reaction reporting and associated activities.

Conclusion: Overall, there are an appreciable number of ongoing activities within the public healthcare system in South Africa attempting to ensure and sustain universal healthcare. It is too early to assess their impact, which will be the subject of future research.

Randomized controlled trial of honey versus mupirocin to decolonize patients with nasal colonization of meticillin-resistant Staphylococcus aureus

BACKGROUND

Mupirocin is used specifically for the eradication of nasal meticillin-resistant Staphylococcus aureus (MRSA), but increasing mupirocin resistance restricts its repeated use. The antibacterial effects of manuka honey have been established in vitro; antibacterial activity of other honeys has also been reported.

AIM

To describe the learning experience from a randomized controlled trial (RCT) comparing the efficacy of medical-grade honey (MGH) with mupirocin 2% for the eradication of nasal MRSA.

METHODS

Patients colonized in the nose with MRSA and age ≥18 years were recruited. Participants received either one or two courses of MGH or mupirocin 2%, three times per day for five consecutive days.

FINDINGS

The proportion of patients who were decolonized after one or two courses of treatment was not significantly different between MGH [18/42; 42.8%; 95% confidence interval (CI): 27.7-59.0] and mupirocin 2% (25/44; 56.8%; 95% CI: 41.0-71.7). Non-nasal MRSA colonization was significantly associated with persistent nasal colonization (odds ratio: 5.186; 95% CI: 1.736-5.489; P = 0.003). The rate of new acquisition of mupirocin resistance was 9.75%.

CONCLUSION

Although not significant, a decolonization rate of 42.8% for MGH was impressive. Our findings suggest that this strategy, which has the potential to combat antimicrobial resistance, should be assessed in similar but larger studies.

Post-discharge evaluation of medication adherence and knowledge of hypertension among hypertensive stroke patients in northwestern China

OBJECTIVES

The aims of this study were to assess the knowledge of hypertension (HTN) and investigate risk factors associated with medication adherence among hypertensive stroke patients after discharge in northwestern China.

PATIENTS AND METHODS

A cross-sectional study involving 440 Chinese hypertensive stroke patients was conducted in a tertiary hospital in Xi'an, China. Data were collected by telephone interviews and patients' medical records.

RESULTS

It was found that 35.23% of patients were compliant with their antihypertensive drug treatments, and 42.95%, 52.27% and 4.77% of patients had poor, moderate and adequate knowledge of HTN, respectively. Gender, blood pressure (BP) categories, BP monitoring and HTN knowledge were independently associated with antihypertensive medication adherence.

CONCLUSION

The medication adherence among hypertensive stroke patients in northwestern China was poor. Knowledge of HTN was suboptimal. More attention and effective strategies should be designed to the factors affecting medication adherence. As knowledge positively affects medication adherence, clinical pharmacists should play an important role in patients' medication education.

Roselle for hypertension in adults

BACKGROUND

Hypertension is considered a serious health problem worldwide. Controlling and lowering blood pressure have a significant benefit to the hypertensive patients because hypertension is a risk factor for stroke, heart disease and cardiovascular disease. A tropical plant called Roselle, or Red Sorrel in English-speaking countries, has been used both as a thirst-quenching drink and for medical purposes.

OBJECTIVES

To explore the effect of Roselle on blood pressure in hypertensive adult patients.

SEARCH STRATEGY

The following databases were searched (Date of most recent search was September 2009): - Cochrane Database of Systematic Reviews (2nd Quarter 2009) - DARE (2nd Quarter 2009) - Ovid MEDLINE (1950 to Present with Daily Update) - EMBASE (1980 to 2009 Week 22) - AMED (1985 to May 2009) - EBSCO CINAHL - BIOSIS (1969 to 2008) - AGRICOLA (1970 to May 2009) - Food Science and Technology Abstract (1969 to 2009 June Week 1) - International Pharmaceutical Abstracts - International Bibliographic Information on Dietary Supplements - Clinical Trials.gov and Current Controlled Trials - OpenSIGLE - Hand searching of journals - ISI Web of Knowledge

SELECTION CRITERIA

We sought randomised control trials (RCTs) evaluating use of any forms of Roselle with placebo or no treatment in hypertensive patients. Change in trough and/or peak systolic and diastolic blood pressure were primary outcomes. Secondary outcomes were withdrawals due to adverse effects, change of pulse pressure and change of heart rate.

DATA COLLECTION AND ANALYSIS

Two review authors (C Ngamjarus, CN and P Pattanittum, PP) independently scanned titles and abstracts, as well as independently screened the full reports of the potentially relevant studies. At each stage, the results were compared and disagreements were solved by discussion.

MAIN RESULTS

No studies were identified that met the inclusion criteria. However, one abstract of an ongoing study is likely to meet the inclusion criteria, when completed.

AUTHORS' CONCLUSIONS

There is insufficient evidence to support the benefit of Roselle for either controlling or lowering blood pressure in patients with hypertension. Based on the information of this review, there is a clear need to develop well-designed studies to assess the efficacy of Roselle on hypertensive patients.