Prevalence of treatment-resistant hypertension after considering pseudo-resistance and morbidity: a cross-sectional study in Irish primary care

Supporting General Practitioners and people with hypertension to maximise medication use to control blood pressure: the contribution of Collective Intelligence to the development of the 'Maximising Adherence, Minimising Inertia' (MIAMI) intervention

Background

Hypertension remains one of the most important modifiable risk factors for stroke and heart disease. Anti-hypertensive medications are effective, but are often not used to maximum benefit. Sub-optimal dosing by prescribers and challenges with medication-taking for patients remain barriers to effective blood pressure control.

Objectives

We aimed to systematically develop a theory-based complex intervention to support General Practitioners (GPs) and people with hypertension to maximise medication use to control blood pressure.

Methods

We used the three-phase Behaviour Change Wheel (BCW) as the overarching intervention development framework. Collective Intelligence methodology was used to operationalise the stakeholder input to Phases 2 and 3 of the BCW. This took the form of a Collective Intelligence workshop with 19 stakeholders from diverse backgrounds including lived experience, general practice, nursing, pharmacy and health psychology. Techniques such as barrier identification, idea-writing and scenario-based design were used to generate possible intervention options. Intervention options were then selected and refined using the Acceptability, Practicability, Effectiveness, Affordability, Side-effects and Equity (APEASE) criteria and guidance from the MIAMI Public and Patient Involvement Panel.

Results

The finalised MIAMI intervention consists of both GP and patient supports. GP supports include a 30-minute online training, information booklet and consultation guide (drop-down menu) embedded within the patient electronic health system. Patient supports include a pre-consultation plan, website, and a structured GP consultation with results from an Ambulatory Blood Pressure Monitor and urine chemical adherence test. The intervention components have been mapped to the intervention functions of the BCW and Behaviour Change Technique Ontology.

Conclusion

Collective Intelligence offered a novel method to operationalise stakeholder input to Phases 2 and 3 of the BCW. The MIAMI intervention is now at pilot evaluation stage.

Characterizing apparent treatment resistant hypertension in the United States: insights from the All of Us Research Program

BACKGROUND

Hypertension (HTN) remains a significant public health concern and the primary modifiable risk factor for cardiovascular disease, which is the leading cause of death in the United States. We applied our validated HTN computable phenotypes within the All of Us Research Program to uncover prevalence and characteristics of HTN and apparent treatment-resistant hypertension (aTRH) in United States.

METHODS

Within the All of Us Researcher Workbench, we built a retrospective cohort (January 1, 2008-July 1, 2023), identifying all adults with available age data, at least one blood pressure (BP) measurement, prescribed at least one antihypertensive medication, and with at least one SNOMED "Essential hypertension" diagnosis code.

RESULTS

We identified 99 461 participants with HTN who met the eligibility criteria. Following the application of our computable phenotypes, an overall population of 81 462 were further categorized to aTRH (14.4%), stable-controlled HTN (SCH) (39.5%), and Other HTN (46.1%). Compared to participants with SCH, participants with aTRH were older, more likely to be of Black or African American race, had higher levels of social deprivation, and a heightened prevalence of comorbidities such as hyperlipidemia and diabetes. Heart failure, chronic kidney disease, and diabetes were the comorbidities most strongly associated with aTRH. β-blockers were the most prescribed antihypertensive medication. At index date, the overall BP control rate was 62%.

DISCUSSION AND CONCLUSION

All of Us provides a unique opportunity to characterize HTN in the United States. Consistent findings from this study with our prior research highlight the interoperability of our computable phenotypes.

A cost-analysis of managing secondary and apparent treatment-resistant hypertension in a specialist multidisciplinary hypertension clinic

OBJECTIVES

A knowledge gap exists around the costs and budget impact of specialist hypertension clinics. This study reports on the cost of providing care in a multidisciplinary hypertension clinic staffed by nephrologist, endocrinologist and cardiologist, which manages patients with suspected secondary hypertension and/or apparent treatment-resistant hypertension. The aim of this study is to provide the evidence required to inform policy and planning care pathways for this patient group.

METHODS

A cost analysis from a healthcare provider perspective using micro-costing techniques was conducted to estimate the direct implementation costs of existing standard practice for the care pathway of patients attending the multidisciplinary hypertension clinic. Sixty-five patients originally recruited for a study of medication adherence in hypertension were included in the sample.

RESULTS

The total care-pathway cost per patient, taking into account clinic visits, clinical reviews, investigations and MDT discussion, was estimated to be €3277, on average. For the patient subgroups, the average cost was €5644 for patients diagnosed with primary aldosteronism and €1446 for patients diagnosed with essential hypertension.

CONCLUSION

There is significant cost associated with providing specialized hypertension care for patients with apparent treatment-resistant hypertension. Given the high rates of nonadherence in this population, it is likely that some of this cost could be avoided with better detection and management of medication adherence in this challenging population. Future studies should consider the cost-effectiveness of this or similar models of care by exploring the benefit to patients and the wider healthcare context of providing care of this type.

Prevalence and determinants of resistant hypertension in the delta region of Egypt: A prospective observational study

Background and Aims

Hypertension (HTN) is a leading cause of morbidity and mortality affecting about 30%-40% of the adult population in developed countries. Fewer data were published about the prevalence, sociodemographics, and clinical characteristics of the resistant hypertensive population in Egypt. Hence, our aim is to focus the attention on these determinants especially in the delta region of Egypt.

Methods

Data belonging to patients visiting our HTN clinic in the Cardiovascular Department, Tanta University Hospital, Gharbeyah Governorate, Egypt, were collected over 12 months, between January 1, 2022, and 31 December 31, 2022, and then carefully analyzed.

Results

We found that the prevalence of resistant hypertension (RHTN) in the delta region of Egypt was 18%. We noted more RHTN cases in older age, that is, mean ± Std. was 51.5 ± 13.24 and 62.1 ± 7.56 for non-RHTN and RHTN, respectively. Also, the prevalence was higher in women representing about 54.4% of cases. Sixty-two percent of the patients with RH were obese (mean ± Std. of body mass index was 30.7 ± 5.36 in HTN and 47.7 ± 30.3 in RHTN groups with p value <0.001). We found a significant relationship between chronic kidney disease, diabetes, and RHTN.

Conclusion

Control of HTN among the Egyptian population in the delta region was unsatisfactory and higher than rates published globally. RH was more obvious in women, elderly, obese population, and diabetic and chronic kidney disease patients. Excessive use of nonsteroidal anti-inflammatory drugs, smoking, and high salt intake were clearly observed.

Perspectives on improving blood pressure control to reduce the clinical and economic burden of hypertension

The clinical and economic burden of hypertension is high and continues to increase globally. Uncontrolled hypertension has severe but avoidable long-term consequences, including cardiovascular diseases, which are among the most burdensome and most preventable conditions in Europe. Yet, despite clear guidelines on screening, diagnosis and management of hypertension, a large proportion of patients remain undiagnosed or undertreated. Low adherence and persistence are common, exacerbating the issue of poor blood pressure (BP) control. Although current guidelines provide clear direction, implementation is hampered by barriers at the patient-, physician- and healthcare system levels. Underestimation of the impact of uncontrolled hypertension and limited health literacy lead to low adherence and persistence among patients, treatment inertia among physicians and a lack of decisive healthcare system action. Many options to improve BP control are available or under investigation. Patients would benefit from targeted health education, improved BP measurement, individualized treatment or simplified treatment regimens through single-pill combinations. For physicians, increasing awareness of the burden of hypertension, as well as offering training on monitoring and optimal management and provision of the necessary time to collaboratively engage with patients would be useful. Healthcare systems should establish nationwide strategies for hypertension screening and management. Furthermore, there is an unmet need to implement more comprehensive BP measurements to optimize management. In conclusion, an integrative, patient-focused, multimodal multidisciplinary approach to the management of hypertension by clinicians, payers and policymakers, involving patients, is required to achieve long-term improvements in population health and cost-efficiency for healthcare systems.

Supporting GPs and people with hypertension to maximise medication use to control blood pressure: Protocol for a pilot cluster RCT of the MIAMI intervention

Background: Hypertension is one of the most important risk factors for stroke and heart disease. Recent international guidelines have stated that 'poor adherence to treatment - in addition to physician inertia - is the most important cause of poor blood pressure control'. The MaxImising Adherence, Minimising Inertia (MIAMI) intervention, which has been developed using a systematic, theoretical, user-centred approach, aims to support general practitioners (GPs) and people with hypertension to maximise medication use, through the facilitation of adequate information exchange within consultations about long-term antihypertensive medication use and adherence skill development. The aim of the MIAMI pilot cluster randomised controlled trial (RCT) is to gather and analyse feasibility data to allow us to (1) refine the intervention, and (2) determine the feasibility of a definitive RCT. Methods: GP practices (n = 6) will be recruited and randomised to the intervention arm (n = 3) or usual care control arm (n = 3). Each practice will recruit 10 patient participants. For a patient to be eligible they must have a diagnosis of hypertension, be on two or more anti-hypertensive medications, must not be achieving recommended blood pressure levels, and be over the age of 65 years. Participants in the intervention arm will meet their GP and receive the MIAMI intervention twice over three months. Quantitative data collection will take place at baseline and three month follow up. A pilot health economic analysis and a qualitative sub-study will also be incorporated into the study. Discussion: This pilot cluster RCT of the MIAMI intervention will allow us to gather valuable acceptability and feasibility data to further refine the intervention so it optimally designed for both GP and patient use. In particular, the qualitative component will provide an insight into GP and patient experiences of using the intervention.

Primary Aldosteronism and Drug Resistant Hypertension: A "Chicken-Egg" Story

Drug-resistant arterial hypertension (RH) is a major risk factor for cardiovascular disease, often due to overlooked underlying causes. Identification of such causes poses significant clinical challenges. In this setting, primary aldosteronism (PA) is a frequent cause of RH and its prevalence in RH patients is likely higher than 20%.The pathophysiological link between PA and the development and maintenance of RH involves target organ damage and the cellular and extracellular effects of aldosterone excess that promote pro-inflammatory and pro-fibrotic changes in the kidney and vasculature.The feasibility of adrenal vein sampling in PA patients with RH, and the clinical benefit achieved by adrenalectomy, further emphasize the need to implement systematic screening for this common form of secondary hypertension in the management of a high-risk population as RH patients.: We herein review the current knowledge of the factors that contribute to the RH phenotype with a focus on PA and discuss the issues regarding the screening for PA in this setting and the therapeutic approaches (surgical and medical) aimed at resolving RH caused by PA.

Supporting GPs and people with hypertension to maximise medication use to control blood pressure: Protocol for a pilot cluster RCT of the MIAMI intervention

Background: Hypertension is one of the most important risk factors for stroke and heart disease. Recent international guidelines have stated that 'poor adherence to treatment – in addition to physician inertia - is the most important cause of poor blood pressure control'. The MaxImising Adherence, Minimising Inertia (MIAMI) intervention, which has been developed using a systematic, theoretical, user-centred approach, aims to support general practitioners (GPs) and people with hypertension to maximise medication use, through the facilitation of adequate information exchange within consultations about long-term antihypertensive medication use and adherence skill development. The aim of the MIAMI pilot cluster randomised controlled trial (RCT) is to gather and analyse feasibility data to allow us to (1) refine the intervention, and (2) determine the feasibility of a definitive RCT. Methods: GP practices (n = 6) will be recruited and randomised to the intervention arm (n = 3) or usual care control arm (n = 3). Each practice will recruit 10 patient participants. For a patient to be eligible they must have a diagnosis of hypertension, be on two or more anti-hypertensive medications, must not be achieving recommended blood pressure levels,  and be over the age of 65 years. Participants in the intervention arm will meet their GP and receive the MIAMI intervention twice over three months. Quantitative data collection will take place at baseline and three month follow up. A pilot health economic analysis and a qualitative sub-study will also be incorporated into the study. Discussion: This pilot cluster RCT of the MIAMI intervention will allow us to gather valuable acceptability and feasibility data to further refine the intervention so it optimally designed for both GP and patient use. In particular, the qualitative component will provide an insight into GP and patient experiences of using the intervention.

Introducing Advanced Paramedics into the rural general practice team in Ireland – general practitioners attitudes

Introduction

As Ireland's population increases and chronic disease becomes more prevalent, demand on limited general practice services will increase. Nursing roles within general practice are now considered to be standard, yet alternative allied health professional roles are under explored within an Irish context. Allied health personnel such as Advanced Paramedics (APs) may have the capability to provide support to general practice.

Aim

To explore General Practitioners’ (GPs) attitudes and opinions of integrating Advanced Paramedics (APs) into rural general practice in Ireland.

Methods

A sequential explanatory mixed methodology was adopted. A questionnaire was designed and distributed to a purposeful sample of GPs attending a rural conference followed by semi-structured interviews. Data was recorded and transcribed verbatim and thematically analysed.

Results

In total n = 27 GPs responded to the survey and n = 13 GPs were interviewed. The majority of GPs were familiar with APs and were receptive to the concept of closely collaborating with APs within a variety of settings including out-of-hours services, home visits, nursing homes and even roles within the general practice surgery.

Conclusion

General Practitioner and Advanced Paramedic clinical practice dovetail within many facets of primary care and emergency care. GPs recognise that current rural models are unsustainable and realise the potential of integrating APs into the general practice team to help support and sustain the future of rural general practice services in Ireland. These interviews provided an exclusive, detailed insight into the world of general practice in Ireland that has not been previously documented in this way.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12875-022-01740-9.

Evidence of Nonadherence in Cases of Pseudoresistant Hypertension

Resistant hypertension (RH) is characterized by the use of three or more antihypertensive drugs without reaching the goal of controlling blood pressure (BP). For a definitive diagnosis of RH, it is necessary to exclude causes of pseudoresistance, including the white-coat effect, errors in BP measurement, secondary hypertension, therapeutic inertia, and poor adherence to lifestyle changes and pharmacological treatment. Herein, we report the history of a patient with long-standing uncontrolled BP, even when using seven antihypertensive drugs. Causes of secondary hypertension that justified the high BP levels were investigated, in addition to the other causes of pseudo-RH. In view of the difficult-to-control BP situation, it was decided to hospitalize the patient for better investigation. After 5 days, he had BP control with practically the same medications previously used. Finally, all factors related to the presence of pseudo-RH are discussed, especially poor adherence to treatment. Poor adherence to antihypertensive treatment is common in daily medical practice, and its investigation is of fundamental importance for better management of BP.

Renal Denervation for Resistant Hypertension: Where Do We Stand?

PURPOSE OF REVIEW

To review the data about the use of renal denervation (RDN), a minimally invasive surgery, for resistant hypertension (RH) and to provide practical guidance for practitioners who are establishing an RDN service.

RECENT FINDINGS

RDN can selectively ablate renal sympathetic nerve fibres, block the transmission of nerve impulses between central sympathetic nerve and kidney, to control blood pressure to as a novel promising non-drug treatment option for RH. At present, there are many researches on the treatment of RH by RDN, but there are some controversies. This review summarises and critically examines the evidence for RDN in the treatment of RH and identifies areas for future research. With the development of RDN, the continuous innovation of RDN technology and methods, the development about better evaluating the real-time success of RDN and the improvement for identifying individuals who are most likely to benefit from RDN will ultimately determine whether RDN represents a feasible way to manage RH in the future.

Blood pressure control in patients with a previous stroke/transient ischaemic attack in primary care in Ireland: a cross sectional study

BACKGROUND

Uncontrolled blood pressure (BP) is an important modifiable risk factor for recurrent stroke. Secondary prevention measures when implemented can reduce stroke re-occurrence by 80%. However, hypertension control rates remain sub-optimal, and little data is available from primary care where most management occurs. The aim of this study was to describe BP control in primary care-based patients with a previous stroke or transient ischaemic attack (TIA) in Ireland, and to concurrently examine antihypertensive medication-dosing.

METHODS

Study participants most recent office-based BP reading was compared with the NICE (NG136) and European Society of Hypertension/ European Society of Cardiology (ESH/ESC 2013) goal of BP < 140/90 mmHg. Optimal anti-hypertensive medication dosing was determined by benchmarking prescribed doses for each drug with the World Health Organisation-Defined Daily Dosing (WHO-DDD) recommendations.

RESULTS

We identified 328 patients with a previous stroke or TIA in 10 practices. Blood pressure was controlled in almost two thirds of patients when measured against the ESH/ESC and NICE guidelines (63.1%, n = 207). Of those with BP ≥140/90 (n = 116), just under half (n = 44, 47.3%) were adequately dosed in all anti-hypertensive medications when compared with the WHO-DDD recommendations.

CONCLUSION

Blood pressure control in patients post stroke/TIA appears sub-optimal in over one third of patients. A comparison of drug doses with WHO-DDD recommendations suggests that 47% of patients may benefit from drug-dose improvements. Further work is required to assess how best to manage blood pressure in patients with a previous stroke or TIA in Primary Care, as most consultations for hypertension take place in this setting.

Improvement of Blood Pressure Control by Adherence Check in Patients With Apparent Treatment-Resistant Hypertension: A Case Series

Adherence to medications is an important challenge while treating chronic disease such as resistant hypertension, which is defined as uncontrolled blood pressure (BP) despite treatment with more than 3 antihypertensive drugs to achieve targets. It is possible that poor adherence is the most significant contributor to rates of pseudo-resistance among treated hypertensive patients. In this report, we describe 4 patients with apparent treatment-resistant hypertension, who received intervention to promote adherence by pharmacists who set the prescribed medicines in a weekly medication calendar and conducted a weekly pill count. The results showed that the intervention of pharmacists to medication adherence improved systolic BP in patients with apparent treatment-resistant hypertension; however, further controlled trials are required to strengthen supporting evidence.

Measuring adherence to therapy in apparent treatment-resistant hypertension: a feasibility study in Irish primary care

BACKGROUND

Apparent treatment-resistant hypertension (aTRH) is defined as uncontrolled blood pressure (BP) in patients taking three or more antihypertensive medications. Some patients will have true treatment-resistant hypertension, some undiagnosed secondary hypertension, while others have pseudo-resistance. Pseudo-resistance occurs when non-adherence to medication, white-coat hypertension (WCH), lifestyle, and inadequate drug dosing are responsible for the poorly controlled BP.

AIM

To examine the feasibility of establishing non-adherence to medication, for the first time in primary care, using mass spectrometry urine analysis. Operationalisation would be established by at least 50% of patients participating and 95% of samples being suitable for analysis. Clinical importance would be confirmed by >10% of patients being non-adherent.

DESIGN AND SETTING

Eligible patients with aTRH (n = 453) in 15 university research-affiliated Irish general practices were invited to participate.

METHOD

Participants underwent mass spectrometry urine analysis to test adherence and ambulatory BP monitoring (ABPM) to examine WCH.

RESULTS

Of the eligible patients invited, 52% (n = 235) participated. All 235 urine samples (100%) were suitable for analysis: 174 (74%) patients were fully adherent, 56 (24%) partially adherent, and five (2%) fully non-adherent to therapy. A total of 206 patients also had ABPM, and in total 92 (45%) were categorised as pseudo-resistant. No significant associations were found between adherence status and patient characteristics or drug class.

CONCLUSION

In patients with aTRH, the authors have established that it is feasible to examine non-adherence to medications using mass spectrometry urine analysis. One in four patients were found to be partially or fully non-adherent. Further research on how to incorporate this approach into individual patient consultations and its associated cost-effectiveness is now appropriate.

A qualitative comparison of high and low adherers with apparent treatment-resistant hypertension

Poor adherence is a leading cause of apparent resistance to antihypertensive treatment. Recent empirical research has investigated predictors of adherence for primary care patients who are apparently resistant to treatment; however, questions remain regarding the variability in adherence behaviour among this group. This study aimed to investigate factors that may elucidate medication adherence among patients with apparent treatment-resistant hypertension (aTRH) using qualitative methods. Fourteen semi-structured interviews were conducted with patients undergoing treatment for aTRH in primary care in the West of Ireland. Patients who self-reported both high and low adherence in a previous quantitative study were purposively sampled. Data were analysed using thematic analysis. A public and patient involvement research group were active partners in developing the study protocol and interview topic guide. Three major themes were identified: beliefs about treatment, habits and routine, and health and health systems. High adherers reported favourable beliefs about antihypertensive treatment that had been validated by experience with taking the treatment over time, described strong medication-taking habits and stable routines, and positive relations with their GP. Low adherers expressed less coherence in their beliefs and used less effective strategies to support their medication-taking in daily life. The current findings are consistent with qualitative studies of adherence in other chronic conditions. Results reflect the difficulty for healthcare practitioners in identifying adherent versus non-adherent patients via conversation, and highlight the importance of accurate adherence assessment. Inception studies may provide an opportunity to better understand adherence behaviour across the illness trajectory.

Medication adherence and treatment-resistant hypertension: a review

Nonadherence is a common reason for treatment failure and treatment resistance. No matter how it is defined, it is a major issue in the management of chronic illnesses. There are numerous methods to assess adherence, each with its own strengths and weaknesses; however, no single method is considered the best. Nonadherence is common in patients with hypertension, and it is present in a large proportion of patients with uncontrolled blood pressure taking three or more antihypertensive agents. Availability of procedure-based treatment options for these patients has shed further light on this important issue with development of new methods to assess adherence. There is, however, no consensus on the management of nonadherence, which reflects the complex interplay of factors responsible for it.

Medication adherence for resistant hypertension: Assessing theoretical predictors of adherence using direct and indirect adherence measures

OBJECTIVES

This study examined theoretical predictors of long-term medication adherence (i.e., treatment-related beliefs, coherence of beliefs from experience with medication, habit strength, and pill burden) for patients with apparent treatment-resistant hypertension in primary care, using a composite adherence score derived from direct and indirect measures (i.e., prescription refill, self-report, and bioanalytical assays of urine).

DESIGN

Cross-sectional study.

METHODS

Individual patient records were screened for prescription refill adherence. Patients provided a urine sample for adherence screening and completed a battery of psychometric scales, including two self-report adherence measures (N = 204). Convergence of adherence measures was assessed, a composite adherence score was calculated, and hierarchical multiple regression was used to examine the role of theoretical predictors of adherence.

RESULTS

Non-adherence estimates ranged from 20.3 to 41.1%, depending on the assessment method used. Associations among adherence measures were weak to moderate (ρ = .00-.53). Medication-taking habit strength was the strongest predictor of adherence, explaining 19% incremental variance in adherence beyond treatment-related beliefs. Beliefs and coherence did not predict adherence, even for patients with weaker habits. Pill burden was not associated with habit strength or adherence for this sample.

CONCLUSIONS

Associations among unique adherence measures were weak overall, providing further evidence that multiple measures are necessary to accurately assess adherence. Habit strength is a key predictor of adherence for chronic conditions. Both habit strength and pill burden represent important intervention targets for improving long-term medication adherence. Longitudinal inception studies are needed to properly test Common-Sense Model propositions and elucidate the role of beliefs, coherence, and habits in predicting adherence at various stages of the chronic illness trajectory. Statement of contribution What is already known on this subject? Non-adherence to antihypertensives is a leading cause of apparent treatment-resistant hypertension (aTRH). Behaviour maintenance (vs. initiation) factors may be more predictive of long-term adherence. What does this study add? Associations among direct and indirect measures of adherence are generally weak. Habit strength is the strongest predictor of long-term adherence for aTRH in primary care. Inception studies are needed to further validate Common-Sense Model propositions.

Prognosis of patients with apparent treatment-resistant hypertension-a feasibility study

BACKGROUND

Most cases of hypertension can be effectively treated with lifestyle changes together with medications, but within this population lies a group with more difficult to treat hypertension-those with apparent treatment-resistant hypertension (aTRH). The American Heart Association and the UK National Institute for Health and Care Excellence have both highlighted the need for further research into the prognosis of patients with resistant hypertension, both apparent and true.

METHODS

In 16 practices affiliated to a university research network, 646 patients had been identified with apparent treatment-resistant hypertension. To inform a planned full cohort study of these patients, we conducted a feasibility study within three practices to determine participation of practices and patients, availability of outcome measures and data collection times.

RESULTS

All three practices fully participated and 205/210 (98%) patients were followed up for a median of 23 months. Thirty-five outcome events of interest occurred-the most common was the new onset of retinopathy (9 cases). Eight percent (17/210) had the main composite outcome of death or serious incident cardiovascular event. Of the six patients who died, identification of cause of death was possible from practice records in five; the national General Register Office was successfully used for the final patient. There were 123 admissions, both day and overnight, recorded in 94 individual patients. Average manual systolic blood pressure measurements improved from baseline by 5 mmHg to 138 (SD 19) mmHg; diastolic remained the same at 75 (SD 12) mmHg. Average eGFR increased from 58.8 (SD17.4) to 66 (SD19.7) mls/min/1.73m2. The average time for data collection per patient was 12 mins.

CONCLUSIONS

This study demonstrates that the proposed methodology for a full cohort study within general practice of patients with apparent treatment hypertension is both acceptable to practices and feasible. An adequately powered subsequent follow-up study of the entire cohort appears possible.