These are the author’s opinions on key similarities and differences between the UK asthma guidance documents: Scottish Intercollegiate Guideline Network (SIGN) / British Thoracic Society (BTS),1 National Institute of Health and Care Excellence (NICE)2 and the latest 2020 Global Initiative for Asthma (GINA) strategy documents.3

All three are evidence-based documents, but GINA is the only strategy document updated annually.3 The style and length of these documents vary; in my opinion, the GINA document is easier to digest.

Diagnosis

The BTS/SIGN and NICE guidelines and GINA strategy include the use of objective measurements to support diagnosis.

NICE2 mandates inclusion of fractional exhaled nitric oxide (FeNO) and spirometry as essential for initial consideration of asthma diagnosis, which some experts disagree on4,5 mainly due to the impracticality in demonstrating airflow obstruction in patients who may not be obstructed when consulting. In fact, the NICE feasibility assessment contradicts their own recommendation by demonstrating that fewer than a third of those diagnosed with asthma had spirometric evidence of obstruction.6

SIGN/BTS1 recommend use of the lower limit of normal (LLN) for determining obstructive airflow, while NICE advocates using forced expiratory volume (FEV1)/forced vital capacity (FVC) <70%, which may be misleading, particularly in young and old patients due to this being based on the average adult. GINA3 states that the ratio in patients without obstruction is usually >75–80% in adults and usually >90% in children.

Diagnosis flowcharts are included in all three; these appear extremely complex in the NICE2 guidelines, while in SIGN/BTS1 options are based on probability, and there is a single simpler chart, with links to more detailed charts in the GINA document.3

A major difference between the three documents is that GINA 2020 has incorporated the details from the severe and difficult to treat booklet into the main document. This provides comprehensive advice and recommendations on diagnosis and management of severe asthma.3 

Uniquely, GINA has recognised the difficulty general clinicians have in differentiating asthma from COPD and importantly recognising those with features of  both. The Asthma–COPD overlap chapter has been extensively revised with new tables. The importance being that COPD is treated mainly with bronchodilators, while people with asthma–COPD must be treated with inhaled corticosteroids.3 

Monitoring

For many years, GINA3 recommended inclusion of two domains of asthma control – symptom control and also identification of risk factors for poor outcome and optimisation of those modifiable factors.

While NICE2 does recommend use of validated instruments for assessing symptom control, it still mandates using the unvalidated Royal College of Physicians (RCP) 3 Questions in the GP Quality Outcome Framework.7

SIGN/BTS1 is inconsistent in its advice on monitoring – validated symptom questionnaires are recommended in Tables 7 and 8, whereas elsewhere (section 4.2) it suggests the RCP 3 Questions.

For the first time SIGN/BTS1 2019 has included assessment of risk (with some new tables); five years after recommendation in the National Review of Asthma Deaths (NRAD).8 However the SIGN/BTS lists of independent risk factors is not as comprehensive as in the GINA strategy and, more importantly in my view as a generalist, the classification by level of risk (Table 9)1 is unsafe, mainly because the factors all independently indicate risk of death, even in patients with mild asthma.8–12 GINA 2020 has also recommended earlier referral of patients for specialist assessment.3

Drug treatment

The key differences between the guidance relate to drug treatment.

NICE2 focusses on medication cost-effectiveness and, as a result, the cheapest medications predominate: short-acting bronchodilators (SABAs) and leukotriene receptor agonists (LTRAs) on initial diagnosis and when stepping up, respectively. Given the recent FDA warnings on serious mental health side effects to montelukast, perhaps NICE should urgently revise its guidance on LTRAs.13

SIGN/BTS1 continues to recommend ‘considering’ inhaled corticosteroids (ICS) at the time of diagnosis (Figures 2 and 3, which are used by most clinicians) and recommends that the criteria for initial ICS prescribing (section 7.2.1) are: asthma attack in the last two years, using SABAs more than twice a week and waking one night a week, and continues to advocate SABA for relief. This advice essentially delays initiation of ICS, despite evidence of risks of excess SABA use8,14,15 and benefits of even low-dose ICS,16–18 even in patients having symptoms less than once a week.19 This may possibly explain why the UK asthma death records differ so widely from the rest of the world.20,21  

In contrast, for reasons of safety,8–10, 22–24 GINA 20203 recommends ICS for all patients over 12, either regularly or intermittently, irrespective of severity, perceived or otherwise. In children aged 6-12, GINA recommends ICS if the child is having symptoms more than twice a month.3 Furthermore GINA 2020 no longer recommends SABA alone for as needed relief use. This is now replaced by as needed use of ICS in combination with formoterol (ICS-FORM), specifically because of its rapid action as well as duration of action.3 As needed ICS-FORM is now licensed in a number of countries world wide.

GINA 2020 has added a number of new figures and tables including two on initial treatment in newly diagnosed children, adolescents and adults.3

Evidence

The GINA3 2020 recommendations are underpinned by population based safety measures and direct evidence for step 2 and indirect evidence for step 1, supported by recent studies25–28 comparing as-needed SABA with regular ICS plus SABA when needed, and ICS-FORM used as needed for respiratory symptoms.29 These studies demonstrated a large reduction in severe exacerbations using ICS-FORM compared with SABA used as needed,25 non-inferiority for severe exacerbations for ICS-FORM compared with daily low dose ICS plus SABA as needed,25,26 and fewer severe exacerbations in ICS-FORM as needed compared with regular ICS plus SABA as needed.27

Other than one study,30 there is little evidence to support the new recommendations for children under 12 years of age with diagnosed asthma; therefore GINA 2020 recommends (off-label recommendation on the basis of safety) that these children are advised to use a low dose ICS whenever they use their SABA for relief.

In summary, in my view, the new GINA 2020 treatment recommendations may, on the basis of safety, reduce the burden of asthma in the UK.3

Dr Mark L Levy was Clinical Lead, National Review of Asthma Deaths (2011–2014) and is a sessional GP and member of the GINA a member of the GINA Board of Directors and Dissemination and Implementation Committee

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