Primary Care Pharmacy June 2001 Vol 2 No 2 p53-54

Journal Club

What is in the medical press?

The rapidly changing situation in primary care means that it is often difficult to keep up to date with what is happening politically and clinically. This section of Primary Care Pharmacy picks out a few articles that may be useful in day-to-day practice or that are particularly relevant to the primary care role.

Prescribing

Prescribers prefer people: The sources of information used by doctors for prescribing suggest that the medium is more important than the message. McGettigan P, Golden J, Fryer J, Chan R, Feely J. Br J Clin Pharmacol 2001;51:184–9.

In this study, 200 general practitioners and 230 hospital physicians are asked to rate information sources by their importance when prescribing established and new drugs, and to name the source used to gain information about the most recent new drug they had prescribed. The Drug and Therapeutics Bulletin and a number of medical journals are the most frequently cited as important in gaining information, while pharmaceutical representatives are the most commonly used source of information on new products. The sources rated as important are not those most commonly used in practice, and the importance of pharmaceutical representatives was underestimated by the prescribers. Most importantly, sources involving personal contact to transfer the information are of greatest practical use.

High blood pressure

Diabetes, hypertension, and cardiovascular disease. Sowers JR, Epstein M, Frohlich ED. Hypertension 2001;37:1053.

This review article looks at the relationship between hypertension and diabetes. It provides an update on current knowledge of specific risk factors associated with diabetes and its treatment. It also examines the role of the renin-angiotensin system in the development of diabetes and in the increased risk of cardiovascular disease in patients with diabetes.

Patients’ responses to risk information about the benefits of treating hypertension. Misselbrook D, Armstrong D. Br J Gen Prac 2001;51:276–9.

This study examines patient choice of treatment of mild hypertension after being told about the risk associated with different types of treatment. Patients were asked whether they were likely to take medication on the basis of relative risk reduction, absolute risk reduction, number needed to treat (NNT) and personal probability of benefit. It appeared that 92 per cent, 75 per cent, 68 per cent and 44 per cent of patients, respectively, would accept the risk based on these models. This suggested that if GPs use the NNT model to convey benefits and risks to patients, a sizeable proportion might choose not to be treated for mild hypertension.

A series of five articles on evidence-based treatment of hypertension appeared recently in the BMJ.

Measurement of blood pressure: an evidence-based review. McAlister FA, Straus SE. BMJ 2001;322:908–11.

The first article in the series focuses on the need to measure blood pressure accurately. Accurate measurement helps avoid denying patients life-saving treatment, as well as avoiding inappropriate diagnosis and treatment, the authors say. A guideline for measuring blood pressure in adults is included in the article. The effect of routine activities on blood pressure and also of “white coat” hypertension, which can occur in up to 40 per cent of patients, is discussed. Factors that can interfere with the accuracy of blood pressure measurement are listed, together with the importance of regular calibration and maintenance of sphygmomanometers.

Cardiovascular risk factors and their effects on the decision to treat hypertension: an evidence-based review. Padwal R, Straus SE, McAlister F. BMJ 2001;322:977–80.

The second article discusses hypertension and cardiovascular risk, together with other risk factors that affect cardiovascular prognosis. It considers the advantages and disadvantages of various methods of calculating absolute cardiovascular risk for an individual. Recommendations based on arm circumference are made about the sphygmo-manometer bladder dimensions that are required to obtain accurate blood pressure readings.

What are the elements of good treatment for hypertension. Mulrow C, Pignone M. BMJ 2001;322:1107–9.

Number three in the series compares the classes of drugs that are prescribed for treating hypertension. The comparison is based on over 1,500 trials and systematic reviews. Adverse effects and tolerability of the drugs are also discussed.

Using cardiovascular risk profiles to individualise hypertensive treatment. Pignone M, Mulrow CD. BMJ 2001;322:1124–66.

The fourth article looks at individual patients and what support they require when they make informed choices about treatment. The authors recommend using the tools outlined in the second article to estimate the risk associated with the risk factors for each patient, and to tie this to the estimated benefit of a particular treatment. They recommend informing patients about risks and benefits associated with treatments.

What to do when blood pressure is difficult to control. O’Rorke JE, Richardson WS. BMJ 2001;322:1229–32.

The final article in the series assesses the causes and incidence of resistant high blood pressure. It considers categories of causes of resistant hypertension that can contribute to treatment failure. Although the authors do not recommend a strategy for management of resistant hypertension based on evidence beyond expert opinion , they do recommend that clinicians consider several options simultaneously and include a common sense approach.

Heart failure

Effect of carvedilol on outcome after myocardial infarction in patients with left-ventricular dysfunction: the CAPRICORN randomised trial. The CAPRICORN investigators. Lancet 2001;357:1385–90.

Treatment of patients with a left-ventricular ejection fraction of less than or equal to 40 per cent following acute myocardial infarction (MI) with carvedilol was compared with placebo in this multicentre, randomised, controlled trial. The results showed that carvedilol reduced the frequency of all-cause and cardiovascular mortality, and of recurrent, non-fatal MI. The benefit was additional to that achieved with other treatments for acute MI that the trial subjects were taking.

Diagnosis of heart failure in primary care: an assessment of international guidelines. Grimshaw GM, Khunti K, Baker R. Br J Gen Prac 2001;51:384–6.

The authors of this article searched Medline for guidelines published between 1993 and 1999 on the treatment of heart failure. Only seven of the 13 guidelines found referred to diagnosis. In addition, the quality of the guidelines found was variable. However, there appears to be consensus with regard to main symptoms and diagnostic tests. Only the Scottish Intercollegiate Guideline Network and the Agency for Health Care Policy and Research guidelines included mechanisms for updating information. Of most concern was the lack of primary care studies that addressed the reliability of signs and symptoms of heart failure, the authors say.

Executive summary of the third report of the National Cholesterol Education Programme (NCEP) Expert Panel on detection, evaluation, and treatment of high blood cholesterol in adults (adult treatment panel III) JAMA 2001;286:2486–97.

This report updates existing recommendations for clinical management of high cholesterol, but it also focuses on primary prevention in patients with multiple risk factors. It recommends that patients with diabetes who do not have coronary heart disease (CHD) should be assigned a risk level equivalent to CHD risk. This is because they have multiple risk factors and because patients with diabetes who have an MI have an unusually high death rate. Strategies for promoting adherence to lifestyle changes and to drug therapies are also suggested by the authors. (Because this is an American article, cholesterol levels are expressed as mg/dl but dividing all figures by 38.7 will give the conversion to mmol/L.)

Helicobacter pylori

Randomised controlled trial of Helicobacter pylori testing and endoscopy for dyspepsia in primary care. Delaney BC, Wilson S, Roalfe A, Roberts L, Redman V, Wearn A, et al. BMJ 2001;322:898.

This randomised, controlled trial determines the cost-effectiveness of a strategy of near-patient H pylori testing and endoscopy in the management of dyspepsia has shown that the extra cost is not associated with benefits in symptom relief or quality of life when compared with standard management. The increased cost and workload contrasts with studies carried out in secondary care, which suggested that testing would reduce the endoscopy workload by eliminating people with a negative test result. The authors suggest that near-patient testing in patients aged under 50 years is probably not warranted.