New guidelines on asthma managementBMJ 1997; 314 doi: https://doi.org/10.1136/bmj.314.7077.315 (Published 01 February 1997) Cite this as: BMJ 1997;314:315
Aim to control symptoms rapidly, with higher initial doses of steroid and earlier use of ß agonists
The British guidelines on the management of asthma first appeared in 1990 in the BMJ.1 2 Two years later revised guidelines, extended to cover asthma in childhood, were distributed to all hospitals and general practitioners in Britain.3 They have come to be widely respected as a clear and practical statement of best practice in the management of asthma. This month sees the publication of a review and a position statement commenting on the guidelines in the light of recent evidence.4
The participants for the latest review were those from the 1993 paper, if they wished to continue, or replacements as needed. Background papers were produced and subsequently published.5 The summary statement was discussed and agreed in 1995, and it is disappointing that publication has been delayed until 1997. The summary statement should be read in conjunction with the 1993 guidelines.
Most of the 1993 advice remains valid, but there are important changes. The new guidelines reiterate the importance of a correct diagnosis and the dangers of escalation of treatment in other unresponsive conditions. They emphasise the need to gain initial control of asthma. This may mean starting with a higher dose of inhaled or oral corticosteroids and then stepping down the treatment, rather than gradually increasing the intensity of treatment until control is achieved. The aims are to control symptoms rapidly and win patients' confidence. Stepping down to avoid prolonged unnecessary treatment is important, but the optimal timing of such reductions remains uncertain.
The advice on long acting inhaled ß agonists has also changed. The 1993 guidelines advocated these as an addition to high dose inhaled corticosteroids or as an alternative in a few patients with particular problems. In the latest guidelines the threshold for using long acting ß agonists is lower. When lower dose inhaled corticosteroids do not give adequate control the alternatives of salmeterol and higher dose inhaled corticosteroids are given equal weighting.
In the section on childhood asthma, children under 5 years old are dealt with as a distinct group while older children and adults have similar treatment programmes. For children under 5, sodium cromoglycate and inhaled corticosteroids are now offered as alternatives for first line regular inhaled prophylactic treatment, rather than recommending sodium cromoglycate before inhaled corticosteroids.
The new guidelines contain useful practical information on inhaler devices, with a recognition that the range of devices now available may render nebulisers unnecessary in many clinical situations. Advice is given on the forthcoming change to non-chlorofluorocarbon propellants for metered dose inhalers, which will feel and taste different but have been shown to be safe and effective. As the range of inhaler devices increases, the information on their lung deposition and delivery does not seem to expand in parallel. Devices cannot be changed on the assumption that the same dose will be delivered to the patient's airways, and prescribers must be aware of the delivery characteristics of any device they prescribe.
The position on managing asthma in partnership with patients has changed, with definite evidence of benefit from patient education and the use of self management plans. Examples of a practical approach might have been helpful here. In one recent survey of general practitioners this was the commonest request for addition to the next guidelines.6
Increasingly it is accepted that guidelines should have a clear evidence base. The British guidelines represent an expert consensus with no formal account of how the literature was searched and assessed. Some statements in the guidelines suggest the existence of evidence without citing the appropriate references; examples include the link between passive smoking and childhood asthma and the use of once daily inhaled budesonide. This contrasts with the well defined methodology of the North of England group, which published its evidence based guidelines for the primary care management of asthma in this journal in 1996.7 8
In some areas there is a lack of reliable published evidence. The North of England guidelines state that “as there is no good evidence of clinically important differences between differing inhaled steroids, patients should be treated with the cheapest inhaled steroid that they can use and which controls their symptoms.” It seems entirely reasonable for guidelines to include considerations of cost. Prescriptions for inhaled corticosteroids cost over £200m in England alone in 1995 (Department of Health Statistics Division 1E, private communication), and different preparations vary widely in price.
When there is a lack of evidence rather than evidence of lack of benefit it can be helpful to have the opinion of experts, providing it is made clear that this is opinion and not evidence. In places the British guidelines do this clearly, as in their advice on doubling inhaled corticosteroid dose if there is deterioration of control or upper respiratory tract infection. The opinion and experience of experts will remain important in the development of guidelines, but the experts should take care to convince us that the evidence for their opinions has been systematically appraised. This should be clearer in the next full rewrite of the guidelines. The British asthma guidelines have been widely disseminated, probably more so than any other similar guidelines. They are highly regarded, and used widely for clinical audit. This latest review will help to maintain their important role in the promotion of better asthma care.