Evidence-based Clinical Practice Guideline Essential hypertension: managing adult patients in primary care 1st August 2004 North of England Hypertension Guideline Development Group Centre for Health Services Research School of Population and Health Sciences University of Newcastle upon Tyne, 21 Claremont Place, Newcastle upon Tyne, NE2 4AA. Tel: +44 (0)191 222 7045 Fax: +44 (0)191 222 6043 North of England Hypertension Guideline Development Group Page 2 Centre for Health Services Research Report No 111. University of Newcastle upon Tyne 2004 © Crown Copyright ISBN: 0-9540161-6-5 North of England Hypertension Guideline Development Group Page 3 Summary Overview This national guideline provides recommendations and supporting evidence for the care of patients with persistent raised blood pressure but no obvious underlying disease (essential hypertension). The guideline recognises that successfully reducing blood pressure, and (more broadly) cardiovascular risk, involves a partnership and good communication between patients and healthcare professionals. Its objective is to decrease subsequent cardiovascular morbidity and mortality due to stroke and coronary heart disease. Guidance is provided on: establishing when a patient has persistent raised blood pressure; using cardiovascular risk assessments; providing lifestyle advice; managing the use of blood pressure lowering drugs; addressing adherence; and stopping treatment. The guideline has been developed for use by the National Health Service in England and Wales. NHS healthcare professionals, patient representatives and researchers developed this guideline, incorporating comments received from referees and from an extensive national stakeholder consultation. Using a threshold of 140/90 mmHg, about 40% of the adult population have raised blood pressure although the proportion increases with age. In 2001, the NHS funded 90 million prescriptions for drugs that lower blood pressure at a cost of £840 million - nearly 15% of the total annual cost of all primary care drugs. This accepted, hypertension may often be inadequately treated and is a contributory factor in cardiovascular diseases which account for 30% of all deaths, and 4 million bed days annually: 8% of the total capacity of the NHS. A guideline on hypertension may thus be expected to impact on the healthcare received by a substantial proportion of the population and have major resource implications for the NHS. This guideline emphasises the need for standardised measurement to establish the presence of persistent raised blood pressure (hypertension) in patients. Formal cardiovascular risk assessment is important for patients with hypertension who have not yet developed cardiovascular disease; it may identify underlying causes and important modifiable risk factors; it provides prognostic information; and it provides the clinician and patient with a context to discuss the value of blood pressure lowering drugs alongside other treatments for raised cardiovascular risk. In the long term a guideline integrating all aspects of cardiovascular protection is needed, including, for example, treatments for raised serum cholesterol and use of antiplatelet therapy. Lifestyle advice should be an initial and periodically revisited aspect of care for patients with hypertension. This advice includes smoking cessation, healthy eating, restricting sodium salt intake, regular exercise, and avoiding excessive amounts of caffeine or alcohol. At the outset, patients may North of England Hypertension Guideline Development Group Page 4 achieve worthwhile changes in lifestyle which can remove or delay the need to use drugs. In certain patients treated for some time, lifestyle changes may help to reduce or stop drug therapy. In most hypertensive patients, pharmacological intervention becomes necessary if blood pressure lowering is to be substantial and sustainable. Available evidence demonstrates firmly that a sustained reduction in blood pressure by drugs reduces the incidence of stroke, coronary heart disease and overall mortality. Trials indicate that drug therapy should be offered to patients with persistently raised blood pressure of 160/100 mmHg or more, or patients with blood pressure of 140/90 mmHg or more with either a raised risk of cardiovascular disease risk or target organ damage. Modelling the disease and the costs and consequences of treatment over the lifetime of patients suggests that this is a cost- effective use of NHS resources. The guideline development group have had to interpret new evidence that indicates the use of a combination of older drugs (thiazide-type diuretics and beta-blockers) may lead to a small increased risk of new onset type-II diabetes. The unanimous consensus of the group was that it would be judicious to restrict the use of this combination of drugs when beginning treatment in patients at raised risk of developing diabetes, although the combination may become necessary if hypertension progresses or cardiovascular disease develops. As further evidence becomes available this position should be reviewed. Using this guideline This document is intended to be relevant to the primary care team, including general practitioners, practice nurses and other primary health care professionals who have direct contact with patients. It does not consider the hospital setting but provides criteria for referral to secondary care. To promote continuity of care, it is important that clinicians initiating treatment in secondary care are aware of the recommendations of this guideline. Inevitably, parts of this document are technical but we have tried as much as possible to make this document accessible to patients, carers of patients and the public. The Summary (pages 1-17) can be used as a standalone document by those wanting to access the recommendations, supporting evidence and management charts. A table of contents for the full guideline is found on page 18. A description of the methods used to develop the guideline is found on page 25. The evidence review used in the guideline development process begins on page 40. This full version of the guideline is available to download free-of-charge from the National Electronic Library for Health website (http://www.nelh.nhs.uk/). A printed copy of this document can be purchased from the Centre for Health Services Research, University of Newcastle. The Institute makes available three summary versions developed from this document on its website (http://www.nice.org.uk/): a patient version, a healthcare professional version and a quick reference guide. North of England Hypertension Guideline Development Group Page 5 Using recommendations and supporting evidence The guideline development group have worked to understand and reflect the overall benefits, tolerability, harms, costs, feasibility and fairness of alternative patterns of care, as the evidence allows. However, healthcare professionals need to apply their general medical knowledge and clinical judgement when applying recommendations which may not be appropriate in all circumstances. Decisions to adopt any particular recommendation are made in the light of individual patients’ views and circumstances as well as available resources. To enable patients to participate in the process of decision making to the extent that they are able and willing, clinicians need to be able to communicate information provided in this guideline. To this end, recommendations are often supported by evidence statements which provide summary information to help clinicians and patients discuss care options. Recommendations about drug treatment assume that clinicians will take account both of the response of individual patients and of the indications, contra-indications and cautions listed in the British National Formulary (BNF) or Summary of Product Characteristics (see www.medicines.org.uk). Grading recommendations and evidence There is a belief among the community of guideline developers that the way recommendations and evidence statements are graded needs to be improved. Consequently a new grading system has been evaluated and applied when developing this guideline. Guideline Recommendation and Evidence Grading (GREG) Evidence Grade Interpretation of evidence I High The described effect is plausible, precisely quantified and not vulnerable to bias. II Intermediate The described effect is plausible but is not quantified precisely or may be vulnerable to bias. III Low Concerns about plausibility or vulnerability to bias severely limit the value of the effect being described and quantified. Recommendation Grade Interpretation of recommendation A Recommendation There is robust evidence to recommend a pattern of care. B Provisional Recommendation On balance of evidence, a pattern of care is recommended with caution. C Consensus Opinion Evidence being inadequate, a pattern of care is recommended by consensus. This new system grades evidence from ‘I’ (high) to ’III’ (low) for each type of study (evaluation of treatment, diagnosis or prognosis) according to a series of quality criteria. It also provides a flexible framework for assessing studies that address the process of care (such as patient surveys) and economic analyses. Research provides robust evidence when it has been conducted to exclude bias, to include suitable populations in adequate numbers, and to measure suitable outcomes. Recommendations reflect the evidence, importance and feasibility of defined steps in the provision of healthcare. Grade A recommendations indicate a clear basis and conditions