This article will help nurses to identify uncontrolled asthma in a primary care setting, and support the identification of people who may be at risk from asthma attack, hospital admission or death. Part two of this article will consider how to support and manage people with uncontrolled asthma, and people who may be at risk.
Asthma is a variable respiratory condition, characterised by bronchoconstriction and inflammation of the inside of the airway. The four main symptoms include cough (which is usually unproductive), wheeze (heard on auscultation), chest tightness and breathlessness. Most people with asthma have more than one symptom, which occur in the presence of known triggers (British Thoracic Society/Scottish Intercollegiate Guideline Network (BTS/SIGN), 2019; Global Initiative for Asthma (GINA), 2022). Nearly four people die from asthma every day in the UK, with many of these deaths being preventable (Royal College of Physicians, 2014; British Lung Foundation, 2022). Poor asthma control places a significant burden on health services as well as individuals with asthma, as it can lead to increased number of asthma attacks, hospitalisations and death (Peters et al, 2006).
Defining and measuring asthma control
The British Guideline on the Management of Asthma (BTS/SIGN, 2019) defines the aim of asthma management as being to gain control of the disease, while the guideline from the National Institute for Health and Care Excellence (NICE, 2021) focuses on defining uncontrolled asthma (Table 1). In addition, the international GINA (2022) guideline suggests that asthma control has two domains: symptom control and future risk of adverse outcomes.
Table 1. Guideline definitions of asthma control
| Complete control of asthma defined by SIGN/BTS (2019) | Uncontrolled asthma as defined by NICE (2021) |
|---|---|
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The definition of complete control adopted by the BTS/SIGN (2019) guideline derives from the landmark GOAL study, that showed complete control was achievable when people with asthma in the intervention arm of this randomised controlled trial took high doses of inhaled steroid and long-acting B2 agonist (Bateman et al, 2004). However, subsequent ‘real world’ studies have shown that 55% of people treated for asthma were not well controlled (Demoly et al, 2009) and 74% were using short-acting B2 agonists every day (Partridge et al, 2006). The reasons that people with asthma fail to achieve control in the real world are many and varied, as will be discussed.
There is no objective test that measures asthma control directly. Whereas control of hypertension can be assessed via objective tests of systolic and diastolic blood pressure, and diabetes control can measured via HbA1C serology, asthma has no such objective test. Although peak expiratory flow rate (PEFR) is an objective test, this does not always correlate closely with asthma control. Arguably the nearest and best measurement of asthma control comes in the form of validated questionnaires such as the Asthma Control Test (Thomas et al, 2009), or the Royal College of Physician's (RCP) Three Questions (Pinnock et al, 2012). Measuring asthma control using validated measures such as these is a requirement for the Quality Outcome Framework (NICE, 2022) and recommended by national and international guidelines (BTS/SIGN, 2019; NICE, 2021; GINA, 2022).
Risk of asthma attack
It is important to understand the differences between asthma severity, asthma control and risk of attack (or exacerbation) (Table 2). Although it may be assumed that the more severe an individual's asthma is, the poorer their control and the greater their risk of attack, this is not necessarily so.
Table 2. Key differences between severity, control and risk
| Asthma severity | Often measured by the amount or dosing of medication a person takes, ie the higher the dose of inhaled steroid needed, the more severe an individual's asthma |
| Asthma control | A measure of the impact that symptoms have on a person's life. Best measured using validated questionnaires such as the ACT |
| Risk of asthma attack | Risk of attack predicts what might happen to that person in the future |
Asthma severity is difficult to quantify and is a somewhat vague concept that is most often associated with the amount of medication an individual is taking (GINA, 2022). On the other hand, asthma control is measured on a composite score of different symptoms (Humbert et al, 2007). Therefore, one person may be taking high doses of inhaled medication, and be classified as having severe asthma, yet have no symptoms or limitations on activity and be classified as well-controlled. Conversely another person may be taking very little asthma medication and be classified as ‘mild severity’, yet be suffering greatly both day and night, and be classified as poorly controlled. Risk is a separate concept that aims to describe the likelihood that someone may have an asthma attack. When reviewing a person with asthma, it is important to be aware of the possibility that someone with severe asthma may be well controlled, and that someone with mild asthma could be poorly controlled.
Another way of considering this is that asthma control is an assessment of current symptoms, while risk assesses or predicts what may happen to that person in the future
Attack and oral steroid use
The BTS/SIGN (2019) guidelines define an acute severe asthma attack as being any one of:
- PEF 33-50% best or predicted
- Respiratory rate >25/min
- Heart rate >110/min
- Inability to complete sentences in one breath.
It is important for people with asthma to understand how to recognise signs of an asthma attack, and what to do in such an emergency.
History of previous asthma attacks are perhaps the greatest red flag for future risk of attack (Blakey et al, 2017; BTS/SIGN, 2019). It is good practice to ask about the number of attacks during the past year, and to record these as part of an asthma annual review. The recording of asthma attacks and hospitalisations may be variable and unreliable. Therefore, conducting medical records searches for asthma attacks and hospitalisations may not reveal all those who are at risk.
The number of courses of oral steroids are one of the strongest independent predictors of future asthma attack (Blakey et al, 2017). Although just one course of oral steroids is an indicator of increased risk of attack, the more courses of oral steroids a patient has per year, the greater their risk of future attack (Price et al, 2016).
Searching for acute prescriptions of oral steroids may be useful in identifying people with asthma who are at risk from attack. People requiring oral steroids for an asthma attack should be monitored frequently until they show signs of full control.
Asthma control
Poor asthma control is also a significant indicator of asthma attack (Sims et al, 2011). Using the Asthma Control Test (ACT), a score of 19 or lower suggests uncontrolled asthma (Nathan et al, 2004; Thomas et al, 2009). Using the Royal College of Physicians Three Questions (Pinnock et al, 2012), answering ‘Yes’ to two or more questions suggests uncontrolled asthma, although this test is not as predictive as the ACT (BTS/SIGN, 2019). The advantage to the ACT is that it provides consideration for short-acting b2 agonist (SABA) usage, which is especially important.
Short-acting B2 agonist usage
SABAs, such as salbutamol, provide symptom relief and improvements in lung function rapidly, within 3 minutes, and are often known as ‘relievers’ (Seberova and Andersson, 2000). However, they do not control the underlying inflammation associated with poor asthma control, asthma attack and death.
High usage of SABA is an indicator of increased risk of attack (BTS/SIGN, 2019). The National Review of Asthma Deaths revealed that 39% of people who died from asthma had been prescribed 12 or more SABA inhalers in the past year (Royal College of Physicians, 2014). However, more recent studies suggest that as little as three prescriptions a year indicate an over-reliance on SABA (Janson et al, 2020; Noorduyn et al, 2022).
The use of composite scores, such as the ACT, suggest that three or more uses of SABA per week is indicative of uncontrolled asthma. Furthermore, asthma guidelines suggest that patients taking SABA more than three times a week should be commenced on inhaled steroids (BTS/SIGN, 2019). The number of prescriptions of SABA that may constitute poor control and that should initiate an urgent review is controversial and remains a subject of debate. Although SABA usage is possibly the best single indicator of poor asthma control, it should be interpreted within the context of the wider clinical picture, which includes a full assessment of asthma control.
Adherence to inhaled steroid therapy
Poor adherence to inhaled steroid therapy is associated with poor asthma control and death from asthma (Royal College of Physicians, 2014; BTS/SIGN, 2019). Inhaled steroids are the mainstay of asthma treatment, as they reduce the underlying inflammation that causes the majority of symptoms (Juniper et al, 1990). However, inhaled steroids have their greatest benefit when taken every day, and when dosing is reduced without gaining control, asthma control can decrease even further, and the number of attacks can increase (Engelkes et al, 2015).
Despite this knowledge, it is difficult, but not impossible, to track adherence to inhaled steroids. This may be due to many people with asthma stopping or reducing their inhaled steroids when they are well controlled. Similarly, people may re-start or become more adherent when their asthma becomes uncontrolled (Blakey et al, 2017). In other words, some people with asthma increase and decrease their preventer medication according to their symptoms. Partridge (2006) discovered that some patients are able to tell when their asthma starts to deteriorate, and many alter their medication accordingly. However, some adjust it inappropriately. Therefore, identifying people who are non-adherent to inhaled corticosteroids may not necessarily identify those people who are poorly controlled or who are at risk.
Inhaler technique
Good inhaler technique is an essential element of respiratory care and prescribing. National and international guidelines recommend that patients should be involved with device selection, that they should be shown how to use their device, and that their technique should be checked before prescribing (BTS/SIGN, 2019; NICE, 2021; GINA, 2022) and during annual review.
Yet evidence remains that both patients (Sanchis et al, 2016) and health professionals (Plaza et al, 2018) are unable to use inhaler devices correctly even when shown. Poor inhaler technique has been shown to lead to poor asthma control (Melani et al, 2011), asthma attack and death (Royal College of Physicians, 2014). Therefore, identification of incorrect technique should remain at the forefront of clinical practice. Part two of this article will discuss this subject further.
Lung function
Reduced lung function, for example forced expired volume in 1 second (FEV1) of <60%, is a risk factor for poor asthma outcomes (GINA, 2022).
A reduced PEFR may be an indicator of increased risk. A reduction of approximately 20% from baseline, or day to day variations of 20% or more, may be indicative of elevated risk of attack (BTS/SIGN, 2019). Practice nurses should measure PEFR if there is evidence of poor control or increased risk. Sub-optimal lung function may require a medication review, especially if found in conjunction with poor asthma control.
Other predictive factors
Other factors that are associated with a slightly increased risk of asthma attack include female gender, older age, obesity, diabetes, gastro-oesophageal reflux disease, rhinitis, smoking, depression and reduced lung function (BTS/SIGN, 2019). It may be that those patients with several of these factors could be considered higher risk of attack. Consideration of the management of people with uncontrolled asthma, and of those who may be at risk from attack, will be discussed in part 2 of this article
Strategies for identifying people with asthma at risk
Searching
Possibly the easiest and quickest way of identifying people with uncontrolled asthma is to conduct searches for oral steroids, such as prednisolone, and SABA, such as salbutamol and terbutaline. Searching for people whose last ACT score was 19 or less may also reveal patients who are poorly controlled.
Digital interventions
The use of digital technologies has been beneficial to the heath service since the COVID-19 pandemic (Golinelli et al, 2020; Campbell et al, 2021).
Distribution of online symptom checkers and questionnaires may help the gathering of patient information before or during the annual review process, and support the identification of people at risk. Using technologies such as Accurx (Accurx, 2022), sending confidential text messages direct to individual patients, and receiving information back from them, may help this process. Experience from the author's own clinical practice of sending the Asthma Control Test via this system, suggests some positive benefits in terms of patient engagement and adherence to medication.
Asthma UK's ‘Asthma At Risk Checker’ seeks to identify high-risk individuals through a simple online questionnaire, that produces a composite score (Asthma UK, 2022). The higher the score, the higher the risk of attack. The questionnaire asks about eight factors that are considered to increase risk, including smoking, medication adherence and daily reliver usage (Broadbent et al, 2017). Published data on its effectiveness are limited, and further validation is required (Walker et al, 2014). However, this may be useful in highlighting potential risks to individual patients who may not have previously considered themselves to be at risk.
Box 1.Research into peak inspiratory flow rateTo take part in a short 5-minute survey being conducted at Edge Hill University, click the link or scan the QR code:
- https://leeds.onlinesurveys.ac.uk/peak-inspiratory-flow-rate-and-inhaler-technique
Annual review
The BTS asthma guidelines (2019) suggest that health professionals should ‘assess risk of future asthma attacks at every asthma review by asking about history of previous attacks, objectively assessing current asthma control, and reviewing reliever use’.
As well as asking about the frequency of SABA usage, a check through the acute and repeat prescription lists will provide additional information. The number of prescriptions of SABA may be discordant with what the patient reports or is aware of. The Primary Care Respiratory Society's (PRCS) Asthma Slide Rule may support these conversations, and help to show individual patients that over-reliance on their SABA inhaler can be dangerous (Primary Care Respiratory Society, 2022).
Opportunistic identification
Receptionists and community pharmacists are useful in opportunistic identification of patients repeatedly obtaining SABA prescriptions, or attending for consultations with repeated respiratory symptoms. There is a limited but growing body of evidence for these interventions cited within the guidelines (BTS/SIGN, 2019), but currently the effectiveness is not yet clear.
Research on future care for people with uncontrolled asthma
Asthma at-risk registers
Keeping a register of those people who are at-risk from attack or acute admission may be beneficial. This strategy has been considered for some time, and initial studies have suggested that this may be a cost-effective way of reducing asthma morbidity (Noble et al, 2006; Stephenson and Shields, 2012). One study showed that asthma at-risk registers may be helpful to those at greatest risk (Smith et al, 2012). A further study is now underway by the same study team the ‘At-Risk Registers Integrated into primary care to Stop Asthma crises in the UK’ (ARRISA-UK) Group (Smith et al, 2018). The research is nearing completion, with 244 GP surgeries participating, with results expected in 2023 (University of East Anglia, 2022).
Inhaler technique
There is a need to standardise inhaler technique, and to make improvements in the understanding of how health professionals deliver training and prescribe inhaled therapy.
A study being conducted at Edge Hill University (see Box 1), aims to look at one element of the process of inhaler technique: peak inspiratory flow rate (PIFR) (Cardio Respiratory Research Centre, 2022). PIFR is the speed of inhalation, or how fast someone breathes in. Assessment of PIFR (not to be confused with peak expiratory flow rate) is one of the key steps needed when checking inhaler technique, but it is often overlooked by health professionals (Baverstock et al, 2010). It is important to understand PIFR, as dry powder inhalers require a high PIFR, and aerosol inhalers (such as metered dose inhalers) require a low PIFR.
The first part of this study asks health professionals about their own clinical practice. The second part of this research will aim to understand if it is possible to predict PIFR from patient information that is recorded routinely in primary care. Data such as height, gender, ethnicity, and previous lung function will be collected and measured against PIFR to see if a a composite of these measures can predict a person's PIFR, and therefore help to decide if they may be more suitable for a DPI or aerosol inhaler.
CPD reflective practice:
- Are you able to establish regular searches for people who overuse their reliever inhalers, or who have taken oral steroids in the last year, or who have low Asthma Control Test scores?
- Do you feel confident in talking to people with asthma about their short-acting B2 agonist (SABA) usage, and challenging them about their habits?
- Do you know all the steps involved in checking inhaler technique?
Key Points:
- A significant number of people in the UK have poorly controlled asthma and may be at risk of asthma attack
- Early identification of poor control or increased risk may reduce attacks, admission and death from asthma
- Overuse of short-acting B2 agonists is a significant clinical sign of poor control and increased risk
- Use of a validated measure of asthma control, such as the Asthma Control Test, is recommended by national guidelines
- Patients should be involved with the selection of inhaler devices, and their technique should be checked before prescribing and at annual review
Conclusion
Asthma control can be measured and recorded using validated scores such as the ACT. Identifying people who are at risk of asthma attack can be undertaken by searching for people overusing SABA (such as 12 or more prescriptions in the last year) and from acute oral steroid prescriptions.
Further identification of people who have poor control or are at risk or attack can be undertaken during annual review. Challenging over-reliance on SABA inhalers can be supported through the PCRS Asthma Slide Rule. Checking inhaler technique can improve delivery of drug to the lungs and subsequent asthma control.