A practical algorithm for distinguishing between uncontrolled asthma and severe asthma in primary care

A new practical definition of asthma

‘Asthma is a heterogeneous disease, usually characterized by chronic airway inflammation. It is defined by the history of respiratory symptoms such as wheeze, shortness of breath, chest tightness and cough that vary over time and in intensity, together with variable expiratory airflow limitation’. This clinical definition, focussing on the two key features needed for the diagnosis of asthma (variable respiratory symptoms and variable airflow limitation), replaces a previous lengthy description of pathological and physiological features of asthma. For the first time, asthma is also defined as a heterogeneous disease.

Practical advice for confirming and documenting the diagnosis of asthma, to minimise under- or over-treatment

Tools include tables summarising criteria for variable expiratory airflow limitation, prioritised by reliability and feasibility for clinical practice. Clinicians are strongly encouraged to document the basis for diagnosis of asthma in individual patients; this is invaluable if the patient fails to respond to treatment or the diagnosis is in doubt. Specific advice is provided about confirming the diagnosis in special populations, e.g., the elderly, or patients presenting only with cough, and about strategies for confirming the diagnosis of asthma in patients already prescribed controller treatment.

3. Assess two domains of asthma control—symptom control and risk factors for adverse outcomes (also called ‘future risk’)⁸

Past asthma control assessments have focussed on current symptom control (e.g., with the Royal College of Physicians ‘three questions’,⁹ Asthma Control Test¹⁰ or Asthma Control Questionnaire¹¹), but this is insufficient, as patients who report few symptoms may still be at risk of asthma exacerbations. Each patient’s risk factors for future exacerbations, fixed airflow limitation and side effects (also called their ‘future risk’) should also be assessed. Poor symptom control itself is a well-known risk factor for exacerbations; GINA also includes an expanded list of other risk factors that are independent of the level of symptom control, including incorrect inhaler technique, poor adherence and low lung function. A helpful table explains specific treatment for modifiable risk factors, as not all risk factors for exacerbations require a step-up in asthma treatment.

A practical algorithm for distinguishing between uncontrolled asthma and severe asthma in primary care

As above, asthma control relates both to symptom control and risk factors for future adverse outcomes such as exacerbations, and it can be quickly assessed at any time; whereas asthma severity (based on the level of treatment required to achieve good control) is a label that can only be applied retrospectively after the patient has been on treatment for at least several months. Of patients with poor symptom control and/or exacerbations despite treatment, few actually have severe refractory (i.e., treatment-resistant) asthma;¹² the latter are estimated to comprise 5–10% of the asthma population.¹³ The GINA report provides a practical algorithm that, for primary care, prioritises the investigations for the most common remediable causes of uncontrolled asthma. It starts first with checking inhaler technique, as this is incorrect in up to 70–80% of patients¹⁴ and can be corrected with appropriate skills training.¹⁵ Confirming the diagnosis of asthma is important, as up to 25–35% of people with asthma may have been misdiagnosed;^16–19 however, if symptoms and lung function improve substantially when inhaler technique or adherence are corrected, this may effectively confirm the diagnosis of asthma, avoiding the need for additional investigations. Patients whose asthma remains uncontrolled despite appropriate management should be referred promptly for specialist investigation and advice.

Control-based management

In the past, this concept was sometimes interpreted as prompting an automatic step-up in controller treatment if symptoms were not well controlled. Key changes for primary care in the GINA report emphasise that control-based management should include three components: