The 2016 updated BTS/SIGN guideline offers a pragmatic approach to the diagnosis, management, and treatment of people who may have asthma, says Professor Hilary Pinnock

pinnock hilary

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Read this article to learn more about:

  • updated recommendations on diagnosing asthma, and what the structured clinical assessment should include
  • diagnostic tests and when to use them
  • the management of asthma in adults and children.

Key points

GP commissioning messages

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A n estimated 3.6 million people in the UK were actively being treated for asthma in 2011/2012.1 Each year, asthma is responsible for over 6 million primary care consultations, almost 100,000 hospital admissions, and 37,000 disability living allowance claims.1 In the UK there are over 1000 deaths each year from asthma, of which 20 are in children aged under 14 years.2 Accurate diagnosis, appropriate prescription of effective medication, and supported self-management can reduce this morbidity and mortality.3

The BTS/SIGN asthma guidelines and the 2016 update

The first British Thoracic Society Guidelines for the management of asthma in adults, published in 1990, were motivated by the ‘unacceptably high’ levels of morbidity and mortality that were associated with asthma in Great Britain.4 The September 2016 update of the British Thoracic Society/ Scottish Intercollegiate Guideline Network (BTS/SIGN) British guideline on the management of asthma5 still has the overall objective of recommending best practice in asthma management, now in the shadow of the 2014 National review of asthma deaths, which highlighted key deficiencies in care.6 [NB Minor revisions were made to the guideline in November 2016 and are reflected in this article.]

NICE Accreditation Mark

NICE accreditation mark

SIGN Guideline 153, British guideline on the management of asthma, has been awarded the NICE Accreditation Mark.

The BTS/SIGN asthma guideline is a 'living guideline' that is updated biennially. Following a scoping exercise, key sections are selected for updating based on availability of new evidence. In 2016, the update focused on several topics relevant to primary care:5

  • a pragmatic approach to diagnosis
  • revising the summary of pharmacological management
  • addressing adherence
  • the role of telehealthcare in organisation of care.

Diagnosis of asthma

Recent studies have focused attention on the accuracy of the diagnosis of asthma, and suggested that there may be significant over-diagnosis.7,8 The BTS/SIGN 2016 guideline has reviewed the pragmatic evidence and offers a structured approach to suspecting and confirming a diagnosis.5

The diagnosis of asthma is a clinical one; there is no single diagnostic test. The diagnosis is based on a clinical assessment, supported by objective tests for variable airway obstruction or airway inflammation, and reinforced or refuted by monitored initiation of treatment.

Asthma status varies over time

Variability in airflow obstruction is the hallmark of asthma.5 Symptoms and signs are typically episodic with ‘attacks’ during which symptoms are troublesome, wheeze may be detected on examination, and lung function tests confirm reversible airflow obstruction. In contrast, there may be periods of minimal/no symptoms, when examination and tests are normal.

This variability has two implications for clinical practice:

  • a positive test can help to confirm a diagnosis of asthma; but normal lung function does not rule out the diagnosis. In a primary care population, where many patients have intermittent symptoms, bronchodilator reversibility could only be confirmed in 15–17% of patients5
  • time may be used to make the diagnosis. Lung function recorded when a patient is asymptomatic can be compared with a peak flow when they present weeks/months later, wheezing with a viral upper respiratory tract infection.

Initial structured clinical assessment

The updated guideline introduces the concept of a structured clinical assessment.5 This involves extending the clinical history by using all the information likely to be available to a primary care clinician to assess the probability of asthma (see Box 1, below, for details). Features that increase the probability of asthma include a history of episodic 'attacks' of symptoms, a record of wheeze heard by a professional, evidence of variability, a personal or family history of atopy, and the absence of symptoms suggesting an alternative diagnosis.

Box 1: An initial structured clinical assessment5

Episodic symptoms

More than one of the symptoms of wheeze, breathlessness, chest tightness and cough occurring in episodes with periods of no (or minimal) symptoms between episodes. Note that this excludes cough as an isolated symptoms in children. For example:

  • a documented history of acute attacks of wheeze, triggered by viral infection or allergen exposure with symptomatic and objective improvement with time and/or treatment
  • recurrent intermittent episodes of symptoms triggered by allergen exposure as well as viral infections and exacerbated by exercise and cold air, and emotion or laughter in children
  • in adults, symptoms triggered by taking non-steroidal anti-inflammatory medication or beta blockers.

An historical record of significantly lower FEV1 or PEF during symptomatic episodes compared to asymptomatic periods provides objective confirmation of the obstructive nature of the episodic symptoms.

Wheeze confirmed by a healthcare professional on auscultation

It is important to distinguish wheezing from other respiratory noises, such as stridor or rattly breathing.

Repeatedly normal examination of chest when symptomatic reduces the probability of asthma.

Evidence of diurnal variability

Symptoms which are worse at night or in the early morning.

Atopic history

Personal history of an atopic disorder (i.e. eczema or allergic rhinitis) or a family history of asthma and/or atopic disorders, potentially corroborated by a previous record of raised allergen-specific IgE levels, positive skin-prick tests to aeroallergens or blood eosinophilia.

Absence of symptoms, signs or clinical history to suggest alternative diagnoses

(including but not limited to COPD, dysfunctional breathing, obesity).

FEV1 =forced expiratory volume in 1 second; PEF=peak expiratory flow; IgE=immunoglobulin E; COPD=chronic obstructive pulmonary disease

British Thoracic Society/Scottish Intercollegiate Guidelines Network. British guideline on the management of asthma. SIGN 153. Edinburgh: 2016. Available at: sign.ac.uk/pdf/SIGN153.pdf
Reproduced with permission

High, intermediate, or low probability of asthma

On the basis of the assessment, it should be possible to decide the clinical (‘pre-test’) probability of asthma:

  • a young, non-smoking patient with a history of hay fever presenting acutely with audible wheeze and a peak flow of 250 l/min that improves to 500 l/min after a course of oral steroids fulfils all the criteria of the structured clinical assessment and has a ‘high’ probability of asthma. It is reasonable to commence a monitored initiation of treatment (see heading ‘Monitored initiation of treatment’ and text, below)
  • a middle-aged, obese patient with a history of acid reflux presents with a history of chronic cough and gradually increasing exertional dyspnoea. Her chest has been noted as ‘clear’ at previous consultations and a peak flow on three occasions in the previous year has been about 350 l/min. She is at ‘low’ probability of asthma and should be managed according to the more likely diagnoses of reflux-induced cough and obesity
  • a smoker presents with a short history of increasing dyspnoea. He had a ‘weak chest’ as a boy, problems with allergies as a teenager, and tends to be ‘chesty’ after colds. He is wheezing and has a peak flow of 300 l/min. Several diagnoses are possible and he will need further investigation (see heading ‘Diagnostic tests’ and text, below) to investigate his intermediate probability of asthma.

These three diagnostic probabilities are illustrated in the algorithm in Figure 1, below.

Figure 1: Diagnostic algorithm5
Diagnostic algorithm

* In children under 5 years of age and others unable to undertake spirometry in whom there is a high or intermediate probability of asthma, the options are monitored initiation of treatment or watchful waiting according to the assessed probability of asthma.

PEF=peak expiratory flow; FEV1 =forced expiratory volume in 1 second; IgE=immunoglobulin E; FeNO=fractional nitric oxide concentration in exhaled breath.

British Thoracic Society/Scottish Intercollegiate Guidelines Network. British guideline on the management of asthma. SIGN 153. Edinburgh: 2016. Available at: sign.ac.uk/pdf/SIGN153.pdf
Reproduced with permission

Diagnostic tests

Quality-assured spirometry is the pivotal test for demonstrating airway obstruction in adults and children old enough to perform the test (i.e. aged 5 years and over, with an operator trained and experienced in undertaking paediatric spirometry):5

  • the definition of obstruction is based on the FEV1/FVC ratio. This ratio varies with age; use of lower limit of normal (as opposed to a fixed ratio of 70%) will avoid under-diagnosis in children and over-diagnosis in elderly people.9,10
  • obstructive spirometry in children is usually due to asthma; in adults there are other causes (e.g. chronic obstructive pulmonary disease) that need to be considered. A bronchodilator reversibility test can detect the substantial improvement that suggests asthma5
  • normal spirometry does not exclude asthma, especially if the patient is asymptomatic at the time. Options include peak flow charting to detect variability in patients experiencing diurnal variation of symptoms, or repeating the test if the patient becomes symptomatic in the future. Another option is to refer the patient for a challenge test.5

An increase in fractional exhaled nitric oxide (FeNO) suggests eosinophilic inflammation and provides supportive (but not conclusive) evidence in favour of a diagnosis of asthma (see Box 2, below).5 Raised FeNO levels indicate steroid responsiveness, and levels fall after treatment with steroids. Blood eosinophilia, raised allergen-specific immunoglobulin E (IgE), and a positive skin-prick test indicate atopic status and are associated with asthma.

Box 2: Fractional exhaled nitric oxide (FeNO)

Although equipment is not yet widely available, fractional exhaled nitric oxide (FeNO) can be measured in primary care.11 The technique is simple, and can be performed by most patients including children as young as 5 years of age.

The patient inhales to total lung capacity and then exhales at a controlled rate of 50 ml/s for 6 seconds. The level of FeNO is measured in the exhaled breath in parts per billion (ppb).

Levels in people with atopic asthma and non-asthmatic populations overlap.11 In steroid naive adults, a FeNO level of >40 ppb is positive; in schoolchildren a FeNO level of >35 ppb is a positive test.12 A positive FeNO test suggests eosinophilic inflammation and increases the probability of asthma but a negative test does not exclude asthma.5

There are some important confounders.13

FeNO levels are increased by:

  • co-morbid allergic rhinitis even without any respiratory symptoms
  • rhinovirus infection in healthy subjects (effect is inconsistent in people with asthma)
  • male gender, being tall
  • consumption of dietary nitrates (e.g. spinach, lettuce).

FeNO levels are decreased by:

  • young age (children)
  • cigarette smoking
  • treatment with inhaled or oral steroids.

Monitored initiation of treatment

In patients with a high probability of asthma, commence a monitored initiation of treatment (see Box 3, below).5 Asthma status should be assessed with a validated symptom questionnaire corroborated by lung function tests (spirometry or peak flow) and a validated symptom questionnaire before starting treatment (typically 6 weeks of inhaled steroids). A good objective response confirms the diagnosis; a poor/equivocal response should lead to discussions about adherence and further investigations.

Box 3: A monitored initiation of treatment5

In patients with suspected asthma

1. Record the patient as having ‘suspected asthma’

2. Proceed to a carefully monitored initiation of treatment. The initial choice of treatment will be based on an assessment of the degree of asthma severity. Typically this will be 6 weeks of inhaled steroids through a device the patient can use, but in more acute clinical circumstances a course of oral steroids may be appropriate.

3. Assess the baseline status using a validated questionnaire (e.g. Asthma Control Questionnaire or Asthma Control Test) and/or lung function tests (spirometry or peak expiratory flow).

4. Arrange a follow-up appointment in 6–8 weeks in order to assess response to treatment.

5. At the follow-up appointment, symptomatic response may be assessed with a validated questionnaire. Lung function may be monitored with FEV1 at clinic visits or domiciliary serial peak flows.

If the objective response is good (i.e. clinically important improvement in symptoms and/or substantial increase in lung function)

6. Confirm the diagnosis of asthma and record the basis on which the diagnosis was made.

7. Adjust treatment according to response (for example, titrating down the dose of inhaled steroid) to the lowest dose that maintains the patient free of symptoms. Careful observation during a trial of withdrawing treatment will also identify patients whose improvement was due to spontaneous remission (this is particularly important in children).

8. Provide self-management education and a personalised asthma action plan before arranging repeat prescribing so that the patient is aware of the action to take if their control deteriorates.

If the objective response is poor or equivocal

9. Discuss adherence and recheck inhaler technique as possible causes of treatment failure.

10. If the response is poor, arrange further tests or consider alternative diagnoses. It will usually be appropriate to withdraw the treatment.

FEV1 =forced expiratory volume in 1 second

British Thoracic Society/Scottish Intercollegiate Guidelines Network. British guideline on the management of asthma. SIGN 153. Edinburgh: 2016. Available at: sign.ac.uk/pdf/SIGN153.pdf
Reproduced with permission

Implications for primary care

The following top tips may help practitioners when assessing and diagnosing patients with possible asthma:

  • use the wealth of information in the electronic health record. The structured clinical assessment is informed by records of previous consultations and tests as well the symptoms described by the patient.
  • use time as a diagnostic agent. The record of a consultation during an attack compared with an assessment when the patient is asymptomatic may confirm the diagnosis. On a practical level, this emphasises the importance of recording the clinical status at the time of an assessment.
  • code as 'suspected asthma' until the diagnosis is clear. It may be necessary to repeat investigations, or observe over time to confirm the diagnosis.
  • make a clear record of how the diagnosis was confirme d. Once treatment is commenced, or if the condition is in an asymptomatic (‘inactive’) phase, tests may be negative and doubt cast on the diagnosis.

Pharmacological management of asthma

There have been a number of updates to the summary of management diagrams (see Figures 2 and 3, below, respectively):5

Figure 2: Summary of management in adults5
Summary of management in adults

ICS=inhaled corticosteroids; LABA=long-acting beta agonists; LTRA=leukotriene receptor antagonists; SR=sustained release; LAMA=long-acting muscarinic antagonists.

British Thoracic Society/Scottish Intercollegiate Guidelines Network. British guideline on the management of asthma. SIGN 153. Edinburgh: 2016. Available at: sign.ac.uk/pdf/SIGN153.pdf
Reproduced with permission


Figure 3: Summary of management in children5
Summary of management in children

ICS=inhaled corticosteroid; LABA= long-acting beta agonist; LTRA=leukotriene receptor antagonist; SR=sustained release; LAMA=long-acting muscarinic antagonists.

British Thoracic Society/Scottish Intercollegiate Guidelines Network. British guideline on the management of asthma. SIGN 153. Edinburgh: 2016. Available at: sign.ac.uk/pdf/SIGN153.pdf
Reproduced with permission

  • short-acting beta2 agonists (SABA) are now illustrated as a rescue therapy applicable to all therapeutic regimens, with the option of SABA monotherapy reserved for the few patients who have infrequent, short-lived wheeze
  • the first management option is therefore low-dose inhaled corticosteroids (ICS) as regular preventer treatment. Doses of ICS are increasingly complex with different molecules, different devices, and different ways of expressing the dose. The guideline includes tables that categorise currently available inhalers as ‘very low’, ‘low’, ‘medium’, or ‘high’ dose ICS
  • Initial add-on therapy is the addition of a long-acting beta2 agonist (LABA) to the low-dose ICS, usually as a combination to prevent inadvertent LABA monotherapy. If this is ineffective, the LABA should be discontinued, diagnosis confirmed, and adherence and inhaler technique addressed before additional options are considered (e.g. increasing ICS dose, trials of alternative add-on therapy)
  • referral for specialist advice is recommended if maintenance with high-dose ICS, multiple additional therapies, or oral steroids are being considered. Some new therapies, which may benefit some patients under specialist care, include anti-IgE or anti-IL-5 monoclonal antibodies
  • in young children in whom the evidence for treatment with LABA is less clear, leukotriene receptor antagonists (LTRA) are early treatment options.

The management summary now illustrates the monitored initiation of treatment (see heading and text above and Box 3, above) as an early stage in the diagnostic process before instituting ongoing maintenance treatment. If initiated treatment with ICS is effective, the dose should be titrated to the lowest dose that prevents symptoms (or stopped if symptoms do not recur). Before authorising ICS as a repeat prescription, self-management education and a personalised asthma action plan should be provided so that the patient can take action if their control deteriorates.

Prescribing of inhaler devices

As well as the required drug, an appropriate inhaler will need to be selected. The choice of inhaler device will be influenced by patient preference and their ability to use the device. Reassessing inhaler technique is an integral part of a structured clinical review. The guideline advises that inhalers should not be prescribed generically to avoid patients being given an unfamiliar device that they cannot use properly.5

Adherence

Assessing adherence is an important component of asthma reviews, and non-adherence should always be considered as a cause of poor control before stepping up treatment.5 The following points may help practitioners to assess and address patient adherence:

  • patients usually over-estimate their adherence. Asking specific questions about use of treatment over a short time period (e.g. in the last week/month) can help elicit an accurate response14
  • use open questions, avoid potentially judgmental terminology, and acknowledge that poor adherence is the norm in order to stimulate an honest discussion.14 Remember that poor adherence may be intentional and/or unintentional14
  • the prescribing record provides an indication of adherence and may be useful for opening a discussion about suspected poor adherence14
  • strategies for improving adherence should be multifaceted15and sustained within the context of proactive asthma care.16 Effective approaches, tailored to the individual, include practical facilitators (e.g. reminders, integration into routines, dose counters), discussions about necessity and concerns,17 and behavioural support.

Telehealthcare: supporting self-management and delivery of care

Technology-enabled healthcare has the potential to contribute to the delivery of asthma care in a number of ways:5

  • supporting self-management by providing information, facilitating monitoring, enabling transfer of monitoring data, or using games to influence behaviour change
  • providing access to professional care in the form of remote consultations—typically telephone calls, but other options such as email are being explored
  • computerised decision support systems that target professionals are insufficiently integrated and so under-used. Web-based decision systems that support patient self-management may be more effective.

Technology-enabled interventions include many diverse components, and their impact on process and clinical outcomes varies, though overall outcomes are at least as good as with traditionally delivered care. They may, therefore, be considered as an option if they are clinically appropriate, preferred by the patient and clinician, and acceptable within the organisational context.5

Useful sources of information

Box 4 (below) lists some useful sources of information about asthma for both patients and practitioners.

Box 4: Useful resources for patients and practitioners

Asthma UK

Asthma UK provides a wide range of information and resources on their website, including downloadable asthma action plans. Bulk copies of printed information booklets are available for purchase by healthcare professionals.

British Lung Foundation

The British Lung Foundation provides information for people with a range of lung diseases and runs the Breathe Easy support network, which offers information, support, and friendship to anyone affected by lung disease.

Conclusion

This article highlights the key messages from the 2016 update of the BTS/SIGN British guideline on the management of asthma.5 The chapter on diagnosis provides a pragmatic, structured approach to suspecting and confirming a diagnosis of asthma. The management summaries have been revised to illustrate that rescue therapy is applicable to all therapeutic regimes and to clarify the increasing number of options for 'add-on' therapies. The advice about assessing and addressing the challenge of poor adherence has been enhanced, and the role of technological solutions as an option for supporting self̄management, facilitating remote reviews, and supporting clinical decisions, has been considered.

Key points

  • The diagnosis of asthma is a clinical one; there is no single diagnostic test
  • Undertake a structured clinical assessment to assess the probability of asthma
  • Obstructive spirometry with reversibility confirms the diagnosis, but normal spirometry does not exclude asthma
  • An increase in fractional exhaled nitric oxide suggests eosinophilic inflammation and supports (but does not prove) a diagnosis of asthma
  • It may be necessary to repeat investigations, or observe over time to confirm the diagnosis
  • Code as 'suspected asthma' until the diagnosis is clear. Make a clear record of how the diagnosis was confirmed
  • Short-acting beta2 agonists are a rescue therapy applicable to all therapeutic regimes, but should rarely be used as monotherapy
  • Inhalers should not be prescribed generically to avoid the situation of patients being given an unfamiliar device that they cannot use properly
  • Non-adherence should always be considered as a cause of poor control before treatment is stepped up
  • Technology-based interventions may be considered as an option for delivering care.

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GP commissioning messages

written by Dr David Jenner, GP, Cullompton, Devon

  • The 2016 update to the BTS/SIGN asthma guideline gives structured and pragmatic advice for primary care clinicians to help them effectively diagnose and treat asthma
  • Commissioners should consider educational events for primary care nurses and GPs to update them on this guidance and include this in local formularies
  • Local online formularies or ‘apps’ are a good way to impart and update this guidance, ensuring the latest guidance is always published
  • There are now many different inhaler devices, and there are significant price differences between products so formularies should identify cost-effective devices and their respective licensed indications:
    • it is important, however, that patients are given a choice of inhalers and prescribed those that they are comfortable with and find easy to use.

BTS=British Thoracic Society; SIGN=Scottish Intercollegiate Guidelines Network

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Read the Guidelines summaries of the 2016 BTS/SIGN British guideline on the management of asthma for more recommendations on the management of asthma in adults and in children

References

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