Academic registrar in general practice. Royal Free Hospital School of .... tion at having her cheap expectorant replaced by a more expensive, unidentified ...
Thus while the efforts of the guideline development group are helpful in opening up the debate on evidence based decision making, they have to be handled with care. They should be the vehicle for achieving better value for money in health care.
power and a consensus of practitioners is substituted for such trials in some cases, the finding that two thirds or more of interventions are evidence based is less a cause of satisfaction than a source of debate. JOANNA CHIKWE Second year clinical student
D A FlTZMAURICE
Lecturer C P BRADLEY Senior lecturer R SALTER
Research associate A E SLATER Health economist Department of General Practice, University of Birmingham, Medical School, Birmingham B 15 2TT 1 North of England Asthma Guidelines Development Group.
2 3
4
5
North of England evidence based guidelines development project: summary version of evidence based guideline for the primary care management of asthma in adults. BMY 1996;312:762-6. (23 March.) Drepaul BA, Dayler DK, Qualtrough JE, Perry U, Reeve FBA, Charlton SC. Becotide or Becodisk? A controlled study in general practice. Clinical Trials journal 1989;26:335-44. Agertoft L, Pedersen S. Importance of the inhalation device on the effect of budesonide. Arch Dis Child 1993;69:130-3. Van der Palen J, Klein JJ, Kerkhoff AHM, van Herwaarden CLA. Evaluation of the effectiveness of four different inhalers in patients with chronic obstructive pulmonary disease. Thorax 1995;50:1183-7. Dowie J. The research practice gap and the role of decision analysis in closing it. Health Care Analysis 1996;1:1-14.
Evidence based general practice Findings of study should prompt debate
ED1TOR,-P Gill and colleagues' adaptation to a general practice setting' of a study originally designed to assess interventions in an acute hospital medical firm2 encouraged me to apply their methodology to acute admissions (n=50) over four weeks in the paediatric departmnent of a district general hospital. My finding that, by Gill and colleagues' criteria, two thirds of primary interventions in this setting were evidence based is perhaps less interesting than the flaws in their study that were highlighted by my attempt to emulate it. Firstly, Gill and colleagues cite individual randomised controlled trials and state that they did not attempt to assess the methodological quality of the trials identified. In my study at least four diagnosis-intervention pairs could be supported or contraindicated depending on which of two conflicting randomised controlled trials one chose to quote. Differences in the date of publication were not great enough to dictate the choice; an accurate assessment of trial strength is vital in such cases. Ellis et a's solution to this problem was to use overviews in addition to randomised controlled trials.2 Secondly, the treatments that fell into Gill and colleagues' category (ii)-"intervention based on
convincing non-experimental evidence"-were decided by a consensus of practitioners. Because of the nature of interventions in the paediatric department that I studied, this was the criterion that I adopted. The inclusion criteria for this category were therefore vastly different from those of Ellis et al, whose category (ii) interventions, such as cardiopulmonary resuscitation, were those "whose face validity is so great that randomised trials were unanimously judged by the team to be both unnecessary and, if a placebo would have been involved, unethical."2 The general practice study, like mine, therefore included within the authors' definition of evidence based interventions a large number of treatments that proponents of evidence based medicine would call non-evidence based. Such studies are useful for assessing the scientific basis of treatment. When, however, randomised controlled trials are not examined for 114
Oxford University, St Peter's College, Oxford OXI 2DL 1 Gill P, Doweli AC, Neal RD, Smith N, Heywood P, Wilson AK. Evidence based general practice: a retrospective study of interventions in one training practice. BMJ 1996;312:819-21. (30 March.) 2 Ellis J, Mulligan I, Rowe J, Sackett D. Inpatient general medicine is evidence based. Lancer 1995;12:407-9.
Studies using more sophisticated methods are needed EDITOR,-P Gill and colleagues' to respond to the challenge posed by Ellis et as2 to assess the extent to which evidence forms the basis of practice in settings other than acute hospitals. They comment on the challenges of identifying the evidence and express concerns about its generalisability and applicability. It is not clear from their methodology, however, whether they assessed the quality of the evidence they identified, though they comment generally on issues related to quality. We think that several methodological issues are worth highlighting. As a result of the retrospective design of the study the authors assume that the diagnostic label recorded first in the patient's medical record was the primary reason for the patient's presentation. Is this a safe assumption? Many general practitioners have had the experience of patients expressing their main concern as they leave the consulting room. Also, the authors excluded 11 patients from their sample, for whom the "attempt to cure, alleviate, or care for the patient in respect of the primary diagnosis" was referral or investigation. Their reasons for this are not clear as these are valid interventions for which evidence of efficacy might be sought. The inclusion of follow up interventions in the sample may result in the inclusion of patients whose intervention is the result of decisions taken outside general practice. Two points arise from the results. Firstly, the fact that 76% of the interventions were drug interventions compared with the 66% reported by Fry3 casts further doubt on the representativeness of this sample. Also, although the authors report a similar proportion of evidence based interventions to that reported by Ellis et al,2 a higher proportion of these (50% compared with 29%) were substantiated by convincing nonexperimental evidence. This may reflect the fact that the interventions used in general practice are of a "low tech" nature and were often introduced before randomised controlled trials became commonly used. It means, however, that this evidence is qualitatively different from that in Ellis et al's study and calls into question the appropriateness of using this paradigm in this setting. In our view, the place of evidence based practice in primary care is an important issue and needs further investigation with more sophisticated methodologies. RICHARD MBEAYN Senior lecturer in general practice MARGARET LLOYD Reader in general practice SUE WARD Academic registrar in general practice Royal Free Hospital School of Medicine, Department of Primary Care and Population Sciences, London NW3 2PF 1 Gill P, Dowell AC, Neal RD, Smith N, Heywood P, Wilson AE. Evidence based general practice: a retrospective study of interventions in one training practice. BMY 1996;312:81921. (30 March.)
2 Ellis J, Mulligan I, Rowe J, Sackett DL Inpatient general medicine is evidence based. Lancet 1995;346:407-10. 3 Fry J. General practice: the facts. Oxford: Radcliffe Medical Press, 1993.
Drug treatment in general practice in Japan is evidence based EDITOR,-P Gill and colleagues report their study of the proportion of interventions in general practice that is evidence based.' We performed a similar study to evaluate the basis of such interventions in Japan and found that most (81 %) are evidence based. We estimated the proportion of drug treatments given to outpatients in general practice that was based on evidence from randomised controlled trials. The design was a retrospective review of case notes of patients treated between June and December 1995. Forty nine outpatients received 53 drugs prescribed by seven residents for 63 chronic diseases; 28 patients had hypertension. The setting was a training centre for general practice in Japan. New drug treatments, changes to treatment, and the addition of drugs to treatment were classed as subjective interventions. We classified levels of evidence supporting drugs as Ellis et al did2: (i) evidence from randomised controlled trials, (ii) convincing non-experimental evidence, and (iii) interventions without substantial evidence. We classified groups (i) and (ii) as the "evidence group" and group (iii) as the "non-evidence group." Each drug was evaluated by discussion with senior doctors. In discussion we used literature retrieved from Medline and personal files of the senior doctors. As a result the evidence group comprised 43 (81%) of the drug treatments. Thirty two of the 53 drugs were antihypertensive agents (calcium channel antagonists, angiotensin converting enzyme inhibitors, and a adrenergic antagonists) and oral hypoglycaemic drugs. For these drugs there are no randomised controlled trials with a true end point. These drugs were classified as belonging to group (ii) on the basis of certain guidelines. If these drugs had been classified as belonging to group (iii) the evidence group would have comprised 11 (21%) of the drug treatments. Our finding is similar to Gill and colleagues': in about 80% of cases we select drugs for chronic diseases in general practite on the basis of evidence from randomised controlled trials and guidelines. It was a problem that this evidence was not in Japanese. KOKI TSURUOKA(resident), YUKO TSURUOKA(resident), MANABU YOSHIMURA(chief resident), KOYU IMAI(resident), SATOKO SEKIGUCHI(resident), JUNICHI MISE(lecturer)YASUHIRO ASAIlecturer), NAOKI NAGO(lecturer), MASAHIRO IGARASHI(professor)
Departmnent of Community and Family Medicine, Jichi Medical School, Minamikawachi, Kawachi, Tochigi, Japan 1 Gill P, Dowel AC, Neal RD, Smith N, Heywood P, Wilson AE. Evidence based general practice: a retrospective study of interventions in one training practice. BMJ 1996;312:81921. (30 March.) 2 Ellis J, Mulligan I, Rowe J, Sackett DL. Inpatient general medicine is evidence based. Lancet 1995;346:407-10.
Author's reply ED1ToR,-Joanna Chikwe and Richard Meakin and colleagues share the concerns that my colleagues and I have about the quality of randomised controlled trials. I would draw their attention to two further points. Firstly, few randomised controlled trials have been carried out in general practice. Secondly, owing to BMJ voLuME 313
13 juLY 1996
difficulties with methodological rigour and interpreting the clinical findings for a primary care context, the results of randomised controlled trials may be of questionable validity.' Systematic reviews and meta-analyses may offer ways to address the problems of methodological quality, but such reviews cover only limited topics and may themselves lack rigour. Nor will there ever be evidence from randomised controlled trials, systematic reviews, and meta-analyses to support all but a minority of the many interventions of everyday primary care. Koki Tsuruoka and colleagues highlight our concerns about the use of appropriate end points of treatment in randomised controlled trials. Like them, we used a pragmatic method of defining end points. All antihypertensive drugs were allocated to group (i) even though a reduction in mortality and morbidity has been established with only relatively few drugs.2 Furthermore, Tsuruoka and colleagues' study raises issues about generalising results to countries where health systems and clinical practice may be very different. Meakin and colleagues iterate our concern about the diagnostic label recorded in patients' notes and draw attention to the exclusion of patients who were referred or investigated. We too were concerned about the use of the first recorded problem as a primary diagnosis. Our methodology related interventions to diagnostic labels. We deliberately excluded patients sent for investigation and referral because investigations may modify diagnostic labels and referral may modify either diagnostic labels or the treatment plan. In our paper we insisted that the results should not be generalised. Interestingly, however, if the referral and investigation group is added back into the sample the proportion of drug interventions (72%) compares favourably with that reported by Fry,3 given the small sample size. The main point of our study was not merely to
estimate the proportion of evidence based interventions in general practice but to debate the appropriateness of methods used to assess evidence based practice. We consider it misjudged to compare percentages of evidence based interventions in different disciplines. It is now appropriate, however, to shift the debate to
exploring alternative paradigms of evidence based care and consider how we can ensure that the increasing body of research evidence is made accessible to all practitioners.
counter prescribing of antibiotics by pharmacists.3 There is a danger, though, in concluding from her article that restricting antibiotics to prescription only would solve the problem. This is not the case, as prescribing records in Britain show. The answer is more likely to lie in making both medical and pharmaceutical practice evidence based, but this may not be easy.4 The pharmaceutical industry, pharmacists, and doctors have vested interests. To suggest, as Hollis-Triantafillou seems to, that any one group is more altruistic than another is perhaps disingenuous. If prescribing decisions were more transparent and evidence based all parties, not least our patients, would benefit. Hollis-Triantafillou also conveys her exasperation at having her cheap expectorant replaced by a more expensive, unidentified altemative remedy by the pharmacist. Perhaps the pharmacist was right, given that evidence for the efficacy of expectorants is so sparse.5 In writing this riposte, we are not trying to be defensive on behalf of pharmacists but wish to point out that there is poor prescribing by both doctors and pharmacists. The prescribing of depot cortisone in lieu of antihistamines for a minor allergy, described by Hollis-Triantafillou, is perhaps an example. However, there is no easy solution. The answer perhaps lies in reexamining methods of persuading both doctors and pharmacists to be better prescribers, reducing patients' expectations, toning down overenthusiastic advice by some pharmaceutical manufacturers, and providing more evidence based updated guidelines and advice (as is being done through initiatives such as the Cochrane Collaboration). A Ll WAN PO Professor of clinical pharmaceutics
x Y SU Postdoctoral fellow Centre for Evidence-Based Pharmacotherapy, School of Pharmacy, University of Nottingham,
Nottingham NG7 2RD 1 Wyatt TD, Passmore CM, Morrow N, Reilly PM. Antibiotic prescribing: the need a policy in general practice. BMJ
1990;300:441-4. 2 Little PS, Williamson I. Are antibiotics appropriate for sore throats? BMJ 1994;309:1010-2. 3 Hollis-Triantafillou J. Over the counter antibiotics. BMJY 1996;312:644. (9 March.) 4 Poses RM, Cebul RD, Wigton RS. You can lead a horse to water-improving physicians' knowledge of probabilities may not affect their decisions. Med Decws Making
1995;15:65-75. 5 Li Wan Po A. Non prescription drugs. 2nd ed. Oxford: Blackwell
Scientific, 1990.
PARAMJrr S GILL Senior lecturer Department of Primary Care and Population Sciences,
Whittington Hospital,
Working party will see whether antimicrobials should be available
London N19 5NF 1 Pringle M, Churchill R. Randomised controlled trials in
general practice. BMY 1995;311:382-3. 2 Medical Research Council Working Party. MRC trial of mild
hypertension: principal results. BMJ 1985;291:97-104. 3 Fry J. General practice: the facts. Oxford: Radcliffe Medical Press, 1993.
Over the counter drugs
ED1TOR,-The series of articles on the availability of over the counter of drugs that were previously available only on prescription' is important in
BMJ VOLUME 313
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Hollis-Triantafillou.3 In response to the possible availability of antimicrobials over the counter, the society has set up a working party with the remit of producing recommendations on the desirability or otherwise of such a change and on the conditions under which it might occur. As joint convenors of the working party we would be interested to hear from any readers who have opinions on this matter. R G FINCH Professor of infectious diseases
City Hospital, Nottingham NG5 1PB D S REEVES Professor of medical microbiology
Southmead Hospital, Bristol BS1O 5NB 1 Blenkinsopp A, Bradley C. Patients, society, and the increase in self medication. BMJ 1996;312:629-32. (9 March.) 2 Reeves DS, Lewis DA. Over the counter anti-infectives-of benefit to whom? JAntmicrob Chemother 1995;36:579-84. 3 Hollis-Triantafillou J. Over the counter antibiotics. BMY 1996;312:644. (9 March.)
GPs' rate of recommending over the counter drugs varies ED1TOR,-In recent years the number and range of drugs available over the counter has increased dramatically. Limited evidence suggests that the general public may respond to this by increasing self treatment.' 2 Much less evidence exists, however, about how doctors are responding to the new scenario created by the deregulation of many medicines. It has been suggested that doctors ought at least to start making more systematic inquiries about patients' prior use of over the counter drugs.3 In a preliminary study of general practitioners' current practice we selected six general practitioners working in practices in the west midlands, which contrasted in terms of their location (rural, suburban, or inner city) and fundholding status. At the end of 3030 consecutive consultations (505 each) the general practitioners recorded whether the patient had used over the counter drugs before the consultation, whether they had recommended an over the counter drug, and whether they had issued a prescription (table 1). They also collected data
Table 1-Frequency with which patients admitted to prior use of over the counter (OTC) drugs and general practitioners recommended OTC drugs or issued prescriptions. Figures are numbers (percentages) of consultations*
Both doctors and pharmacists should prescribe better
ED1TOR,-The prescribing of antibiotics is a complex issue. There is increasing agreement that this class of drugs is overprescribed and that the development of antibiotic resistance is a major clinical problem, particularly in hospitals.' In general practice a concern is the prescribing of antibiotics for patients with a sore throat. Given that microbial cultures are difficult to undertake, however, some prescribers recommend the use of antibiotics under well defined conditions.2 Judith Hollis-Triantafillou's comments highlight the same problems in the context of over the
view of the increasing number of drugs licensed in this way. The British Society for Antimicrobial Chemotherapy has taken a keen interest in the fact that people now have easier access to antimicrobials because, unlike any other class of drugs, antimicrobials have an ecological dimension. While formal proof of a causal link between use of antimicrobials and antimicrobial resistance of microbes remains elusive,2 many professionals concerned with infection are convinced about the connection-as is Judith
Practice 1 2 3 4 5 6
Total
Consuitations for which data were returned
Prescription
(n.505)
Patient admitted to prior use of OTC drug
OTC drug recommended
444 (87.9) 463 (91.7) 464 (91.9) 496 (98.2) 459 (90.9) 477 (94.5)
50/258 (19.4) 130/375 (34.7) 179/448 (40.0) 208/495 (42.0) 77/449 (17.1) 13/473 (2.7)
10/444 (2.3) 118/463 (25.5) 80/464 (17.2) 186/496 (37.5) 35/459 (7.6) 15/477 (3.1)
315/406 (77.6) 113/369 (30.6) 247/445 (55.5) 387/495 (78.2) 268/449 (59.7) 250/453 (55.2)
5/406 (1.2) 106/369 (28.7) 44/445 (9.9) 147/495 (29.7) 16/449 (3.6) 6/453 (1.3)
2803 (92.5)
657/2498 (26.3)
444/2803 (15.8)
1580/2617 (60.4)
324/2617 (12.4)
Prescription
issued
issued and OTC drug
recommended
*Some responses were missing.
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