Global Strategy for Asthma Management and Prevention 2024
Publication Date: May 7, 2024
Last Updated: May 7, 2024
Key Changes to the 2024 Guidance
- Diagnosis of asthma: The diagnostic flowchart for clinical practice (Box 1-1) has been revised, recognizing that, globally, a large proportion of health professionals do not have access (or timely access) to spirometry in their clinical practice. Although peak expiratory flow (PEF) is less reliable than spirometry, it is better than relying on symptoms alone. The flowchart allows for selection of different initial lung function tests, depending on local resources. The criteria for identifying variable expiratory airflow limitation (Box 1-2) have also been clarified, and more details provided about bronchodilator withholding.
- GINA again reviewed, but has not adopted, the recommendation by the American Thoracic Society and European Respiratory Society Technical Standards Committee to change the criterion for bronchodilator responsiveness from an increase from baseline of ≥12% and 200 mL to an increase from baseline of >10% predicted. The Technical Standards Committee based this recommendation on data for survival, and had explicitly avoided making any recommendation about the use of this criterion for diagnostic decisions in clinical practice. This topic will be considered by GINA again when data from additional populations, and for other asthma outcomes, have been published, to inform the implications of the proposed new criterion for diagnosis of asthma in clinical practice.
- Cough variant asthma: more information has been added about this clinical phenotype of asthma, which is common in some countries. Cough variant asthma may be difficult to distinguish from other causes of chronic cough in clinical practice, as spirometry may be normal and variable airflow limitation may be identified only from bronchial provocation testing. Some patients may later also develop wheezing and bronchodilator responsiveness. The treatment of cough variant asthma is the same as for asthma in general; the cough may return if inhaled corticosteroids (ICSs) are stopped.
- Assessment of asthma control: We clarify that assessment of symptom control should not be limited to the most recent 4 weeks, but that there are no validated tools for assessing symptom control over longer periods than this, and that recall-error for symptoms is common. GINA continues to emphasize that assessing symptom control is not enough – the patient’s risk factors for exacerbations (including history of exacerbations), for accelerated decline in lung function and for medication adverse effects must also be assessed (Box 2-2). While ICS markedly reduce asthma exacerbations and, in patients not taking ICS, serious exacerbations are associated with greater decline in lung function, there is no clear evidence that use of ICS per se prevents long-term development of persistent airflow limitation. GINA goal of asthma treatment (Box 3-2): The goal of asthma treatment is to achieve the best possible longterm asthma outcomes for the individual patient, including both long-term symptom control and long-term minimization of risk of exacerbations, lung function decline and medication adverse effects (including long-term adverse effects of OCS). It is also important to elicit the patient/caregiver’s goals for asthma treatment, as these may differ from medical goals.
- Remission of asthma: There has been extensive recent discussion in the clinical and research community about asthma remission on treatment, in the context of biologic therapy for severe asthma. Several proposed definitions and criteria for their operationalization have been published. A new section of the GINA 2024 report outlines a framework for clinical practice and research about clinical and complete (pathophysiological) remission in children and in adults, both off-treatment and on-treatment. These perspectives should also be considered for discussions with patients and parents/caregivers. The concept of asthma remission on treatment is consistent with the GINA long-term goal of asthma treatment (Box 3-2), but individual patient goals should be achievable.
- Initial asthma treatment in adults and adolescents (Tracks 1 and 2): Key changes have been made to the recommendations about the choice of initial treatment step for adults and adolescents in both Tracks 1 and 2, with updating of Boxes 4-4 and 4-5 about choice of initial treatment step. The suggested criteria at each step for initial treatment are based on evidence (where available) and on consensus, so the thresholds are not precise. The new flowchart for initial asthma treatment (Box 4-5) includes the GINA cycle of asthma management as a reminder that asthma treatment is not just about medications.
- For Track 1, as-needed-only low-dose ICS-formoterol has been the preferred treatment option for both Step 1 and Step 2 since 2021, so together they are called ‘Steps 1–2’. Accordingly, the descriptions of evidence and other considerations are now also presented for Steps 1–2 together. A common question is which patients should instead start treatment at Step 3, i.e., with low-dose ICS-formoterol being taken as maintenance-and-reliever therapy (MART) rather than as-needed-only. There is no specific evidence to guide this choice, but clinical factors that are suggested for consideration of starting with MART (if permitted by local regulators) include symptoms every day, current smoking, low lung function, a recent severe exacerbation or a history of life-threatening exacerbation, impaired perception of bronchoconstriction (e.g. low initial lung function but few symptoms), severe airway hyperresponsiveness, or current exposure to a seasonal allergic trigger.
- For Track 2, the previous description of patients suitable for Step 1 treatment (having asthma symptoms less than twice a month and no risk factors for exacerbations) was introduced in GINA 2014 to limit the use of short-acting beta2 agonist (SABA)-only treatment, as its risks in asthma were already well known.13 This criterion for Step 1 treatment has now been replaced, since GINA has recommended against SABA-only treatment since 2019. Another consideration for choosing between Step 1 and Step 2 treatment is that, although maintenance ICS almost halved the risk of serious exacerbations in patients with symptoms ≤2 days/week in a clinical trial, such patients would be very unlikely to take daily ICS if it was prescribed in clinical practice. Therefore, for patients with such infrequentsymptoms, taking ICS whenever SABA is taken (Track 2, Step 1) is preferred over daily ICS plus as-needed SABA (Track 2, Step 2) to ensure that patients receive at least some ICS, rather than taking SABA alone.
- GINA 2024 treatment figure for adults and adolescents, Box 4-6,. There are no major changes from 2023 in the main treatment figure. In the arrowed circle (also Box 3-3), ‘asthma medications’ has been changed to ‘asthma medications including ICS’ as a reminder that all patients with asthma should receive ICS-containing therapy. New short versions of the main treatment figure are shown at the start of the sections of text about Steps 1–4 for Track 1 (Box 4-7) and Track 2 (Box 4-9) respectively.
- Medications and doses for Track 1 anti-inflammatory reliever (AIR) therapy: Following requests from clinicians, Box 4-8, has been expanded to show all the relevant ICS-formoterol devices (dry-powder inhalers [DPIs] and pressurized metered-dose inhalers [pMDIs]) and doses for AIR therapy by age-group and treatment step, with the corresponding dosing regimens and maximum number of inhalations in a single day. More devices and doses may become available in the future.
- Beclometasone-formoterol for MART (Box 4-7). There is evidence from randomized controlled trials and meta-analyses in approximately 40,000 patients for the long-term safety and efficacy of as-needed budesonideformoterol up to a maximum total of 72 mcg formoterol (54 mcg delivered dose) in a single day (total of as-needed and maintenance doses, if used) for adults and adolescents, together with data from earlier randomized controlled trials with as-needed formoterol. Based on this extensive evidence, GINA suggests that the same maximum total dose of formoterol (with ICS) in a single day (72 mcg metered dose) should also apply for adults and adolescents prescribed MART with beclometasone-formoterol 100/6 mcg, i.e. a maximum total of 12 inhalations in a single day. For children 6–11 years prescribed MART with budesonide-formoterol, the maximum recommended total dose of formoterol (with ICS) in a single day is 48 mcg metered dose (36 mcg delivered dose). Most patients need far fewer doses in any day than the maximum doses recommended.
- ICS-formoterol as reliever with other ICS-LABAs: GINA previously recommended against use of ICS-formoterol as the reliever for patients using maintenance treatment with a combination of ICS and long-acting beta2 agonist (LABA) with a non-formoterol LABA, because of lack of evidence for safety or efficacy with this approach (p.69). This recommendation is now supported by an analysis suggesting that taking two different LABAs in this way may be associated with increased adverse events.
- Leukotriene receptor antagonists: Wherever montelukast is mentioned throughout the report, there is a reminder to advise patients/parents/caregivers about the potential risk of neuropsychiatric adverse events associated with this medication. These include new-onset nightmares and behavioral problems and, in some cases, suicidal ideation. High-dose inhaled corticosteroids: Wherever this is suggested as a treatment option throughout the report for adults and adolescents, it is again stated that this is only for short-term use, e.g., 3–6 months, to minimize the potential for adverse effects.
- Add-on long-acting muscarinic antagonists (LAMA): Subgroup analyses suggest that the reduction in severe exacerbations requiring OCS associated with triple therapy (ICS+LABA+LAMA) was seen primarily in patients with a history of asthma exacerbations in the previous year.
- Severe asthma with good response to Type 2-targeted therapy: Advice about reduction in asthma therapy in patients who have had a good asthma response to therapy targeting Type 2 inflammation has been updated and clarified, with the highest priority to reduce and cease maintenance oral corticosteroids (OCS), if used. Some previous randomized controlled trials included a rapid ICS dose reduction in patients on biological therapies in order to induce loss of asthma control, but this is not relevant to clinical practice). A randomized controlled trial in adult patients with a good response to benralizumab found that, with randomization to MART, most could have their maintenance ICS-formoterol dose slowly reduced. However, the findings suggest that in patients with severe asthma, maintenance doses of ICS-formoterol should not be stopped. This study also provides support for use of MART in patients taking Step 5 treatment. Additional advice about stepping down treatment once asthma is well controlled is in Box 4-13.
- Initial asthma treatment in children 6–11 years: Boxes 4-10 and 4-11 about initial asthma treatment in children 6–11 years have been updated. These recommendations are based on evidence (where available) and on consensus. The flowchart includes the GINA cycle of asthma management, as a reminder that asthma treatment is not just about medications. Symptom levels and lung function prompting a particular starting treatment step are similar to those for adults and adolescents. In the text about treatment steps, additional details about studies, populations and outcomes in the 6–11 years age group have been added, including the ICS doses used in the studies of taking ICS whenever SABA is taken .
- Low, medium and high doses of inhaled corticosteroids. Box 4-2 lists low, medium and high doses of various ICS, alone or in combination with LABA. GINA has emphasized for many years that this table does not imply potency equivalence, but this continues to be assumed. For clarity, an example has been added: if you switch a patient’s treatment from a ‘medium’ dose of one ICS to a ‘medium’ dose of another ICS, this may represent a decrease (or increase) in potency, so the patient’s asthma may become unstable (or they may be at increased risk of adverse effects). After any change of treatment or inhaler device, patients should be monitored to ensure stability.
- Allergen immunotherapy. The section on allergen immunotherapy has been updated following a systematic review of publications about subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT) for asthma by a GINA Science Committee working group. Information is also included about the quality assurance, personnel, training, safety and administrative protocols that must be observed for preparation and safe delivery of SCIT. For patients with severe asthma, allergen immunotherapy may be considered as an add-on treatment, but only after asthma symptoms and exacerbations have been controlled.
Asthma Definition and Diagnosis
What is 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. One or more symptoms (e.g., cough) may predominate. Airflow limitation may later become persistent.
- Asthma is usually associated with airway hyperresponsiveness and airway inflammation, but these are not necessary or sufficient to make the diagnosis.
- Recognizable clusters of demographic and clinical characteristics are called ‘clinical asthma phenotypes’. In most instances, these do not correlate strongly with specific pathological processes or treatment responses. However, biomarkers reflecting pathophysiological processes are useful in the assessment of difficult-to-treat asthma and treatment of severe asthma.
How is asthma diagnosed?
- The diagnosis of asthma is based on the history of characteristic symptom patterns and evidence of variable expiratory airflow limitation. This should be documented from bronchodilator reversibility testing or other tests. More than one test may be needed to confirm asthma or exclude alternative causes of respiratory symptoms.
- Many health professionals do not have access to spirometry. If so, peak expiratory flow (PEF) should be used, rather than relying on symptoms alone.
- Test before treating, wherever possible, i.e., document the evidence for the diagnosis of asthma before starting inhaled corticosteroid (ICS)-containing treatment, as it is often more difficult to confirm the diagnosis once asthma control has improved.
- Additional or alternative strategies may be needed to confirm the diagnosis of asthma in particular populations, including patients already on ICS-containing treatment, the elderly, patients presenting with cough as the only symptom (including cough variant asthma), and patients in low-resource settings.
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.
Assessment of Asthma
Asthma control
- The level of asthma control is the extent to which the features of asthma can be observed in the patient, or have been reduced or removed by treatment.
- Asthma control is assessed in two domains: symptom control and risk of adverse outcomes. Poor symptom control is burdensome to patients and increases the risk of exacerbations, but patients with good symptom control can still have severe exacerbations.
Asthma severity
- The current definition of asthma severity is based on retrospective assessment, after at least 2–3 months of asthma treatment, from the intensity of treatment required to control symptoms and exacerbations.
- This definition is clinically useful for severe asthma, as it identifies patients whose asthma is relatively refractory to high intensity treatment with high-dose inhaled corticosteroids (ICS) and a long-acting beta2 agonist (LABA) and who may benefit from additional treatment such as biologic therapy. It is important to distinguish between severe asthma and asthma that is uncontrolled due to modifiable factors such as incorrect inhaler technique and/or poor adherence.
- However, the retrospective definition of mild asthma as ‘easy to treat’ is less useful, as patients with few interval symptoms can have exacerbations triggered by external factors such as viral infections or allergen exposure, and the treatment that was historically regarded as the lowest intensity – short-acting beta2 agonist (SABA) alone – actually increases the risk of exacerbations.
- ‘Mild asthma’ is a retrospective label, so it cannot be used to decide which patients are suitable to receive Step 1 or Step 2 treatment.
- In clinical practice and in the general community, the term ‘mild asthma’ is often used to mean infrequent or mild symptoms, and it is often assumed that these patients are not at risk and do not need ICS-containing treatment.
- For these reasons, GINA suggests that the term ‘mild asthma’ should generally be avoided in clinical practice if possible or, if used, qualified with a reminder that patients with infrequent symptoms can still have severe or fatal exacerbations, and that this risk is substantially reduced with ICS-containing treatment.
- GINA is continuing to engage in stakeholder discussions about the definition of mild asthma, to obtain agreement about the implications for clinical practice and clinical research of the changes in knowledge about asthma pathophysiology and treatment since the current definition of asthma severity was published.
How to assess a patient’s asthma
- Assess symptom control from the frequency of daytime and night-time asthma symptoms, night waking and activity limitation and, for patients using SABA reliever, their frequency of SABA use. Other tools for assessing recent symptom control include Asthma Control Test (ACT) and Asthma Control Questionnaire (ACQ). There are no validated tools for assessing symptom control over a longer period.
- Also, separately, assess the patient’s risk factors for exacerbations, even if their symptom control is good. Risk factors for exacerbations that are independent of symptom control include not only a history of ≥1 exacerbation in the previous year, but also SABA-only treatment (without any ICS), over-use of SABA, socioeconomic problems, poor adherence, incorrect inhaler technique, low forced expiratory volume in 1 second (FEV1), exposures such as smoking, and blood eosinophilia. To date, there are no suitable composite tools for assessing exacerbation risk.
- Also assess risk factors for persistent airflow limitation and medication side-effects (including from oral corticosteroids), treatment issues such as inhaler technique and adherence, and comorbidities, and ask the patient/caregiver about their asthma goals and treatment preferences.
- Once the diagnosis of asthma has been made, the main role of lung function testing is in the assessment of future risk. It should be recorded at diagnosis, 3–6 months after starting treatment, and periodically thereafter.
- Investigate for impaired perception of bronchoconstriction if there are few symptoms but low lung function, and investigate for alternative diagnoses if there are frequent symptoms despite good lung function.
Summary of assessment of asthma in adults, adolescents, and children 6–11 years
1. Assess asthma control = symptom control AND future risk of adverse outcomes
2. Assess treatment issues
3. Assess multimorbidity
- Assess symptom control over the last 4 weeks (Box 2-2A,) or longer.
- Identify any other risk factors for exacerbations, persistent airflow limitation or side-effects (Box 2-2B).
- Measure lung function at diagnosis/start of treatment, 3–6 months after starting ICS-containing treatment, then periodically, e.g., at least once every 1–2 years, but more often in at-risk patients and those with severe asthma.
2. Assess treatment issues
- Document the patient’s current treatment step (Box 4-6).
- Watch inhaler technique (Box 5-2, p.110), assess adherence (Box 5-3) and side-effects.
- Check that the patient has a written asthma action plan.
- Ask about the patient’s attitudes and goals for their asthma and medications.
3. Assess multimorbidity
- Rhinitis, rhinosinusitis, gastroesophageal reflux, obesity, obstructive sleep apnea, depression and anxiety can contribute to symptoms and poor quality of life, and sometimes to poor asthma control (see Section 6).
Principles of Asthma Management in Adults, Adolescents and Children 6–11 Years
The patient-health professional partnership
- Effective asthma management requires a partnership between the person with asthma (or the parent/caregiver) and their healthcare providers.
- Teaching communication skills to healthcare providers may lead to increased patient satisfaction, better health outcomes, and reduced use of healthcare resources.
- The patient’s ability to obtain, process and understand basic health information to make appropriate health decisions (‘health literacy’) should be considered.
Goals of asthma management
The GINA goal of asthma management is to achieve the best possible long-term outcomes for the individual patient. This may include good long-term symptom control (few/no asthma symptoms, no sleep disturbance due to asthma, and unimpaired physical activity), and minimized long-term risk of asthma-related mortality, exacerbations, persistent airflow limitation and side-effects of treatment. The patient’s own goals should also be identified.
Remission of asthma
- Remission of asthma can be identified in children and in adults, either clinical remission or complete remission, and either off-treatment or on-treatment. Definitions and criteria vary.
- The concept of clinical remission on treatment is consistent with the long-term goal of asthma management promoted by GINA, to achieve the best possible long-term asthma outcomes for each patient.
- Research among patients who have (or have not) experienced clinical or complete remission of asthma, either offtreatment or on-treatment, provides important opportunities for understanding underlying mechanisms of asthma, to develop new approaches to asthma prevention and management. This will be facilitated by using standardized criteria and assessment tools.
- Take care if using the term ‘remission’ in conversations with patients or parents/caregivers, as they may assume it means a cure, or may associate it with cancer or leukemia. Explain what you mean, and that if asthma symptoms have gone quiet for a while, they may recur.
Making decisions about asthma treatment
- Asthma treatment is adjusted in a continual cycle of assessment, treatment, and review of the patient’s response in both symptom control and future risk (of exacerbations and side-effects), and of patient preferences.
- For population-level decisions about asthma medications, e.g., national guidelines, insurers, health maintenance organizations or national formularies, the ‘preferred’ regimens in Steps 1–4 represent the best treatments for most patients, based on evidence from randomized controlled trials, meta-analyses and observational studies about safety, efficacy and effectiveness, with a particular emphasis on symptom burden and exacerbation risk. For Steps 1–5, there are different preferred population-level recommendations for different agegroups (adults/adolescents, children 6–11 years, children 5 years and younger). In Step 5, there are also different preferred population-level recommendations depending on the inflammatory phenotype, Type 2 or non-Type 2.
- For individual patients, shared decision-making about treatment should also consider any patient characteristics or phenotype or environmental exposures that predict the patient’s risk of exacerbations or other adverse outcomes, or their likely response to treatment, together with the patient’s goals or concerns and practical issues (inhaler technique, adherence, medication access and cost to the patient).
- Optimize asthma management, including inhaled therapy and non-pharmacologic strategies, to reduce the need for oral corticosteroids (OCS) and their multiple associated adverse effects.
Medications and Strategies for Adults, Adolescents and Children 6–11 Years
Overview
- For safety, GINA does not recommend treatment of asthma in adults, adolescents or children 6–11 years with short-acting beta2 agonist (SABA) alone. Instead, they should receive inhaled corticosteroid (ICS)-containing treatment to reduce their risk of serious exacerbations and to control symptoms.
- ICS-containing treatment can be delivered either with regular daily treatment or, in adults and adolescents who have asthma symptoms less than daily and normal or mildly reduced lung function, with as-needed low-dose ICSformoterol taken whenever needed for symptom relief. For children not likely to be adherent with maintenance ICS, the ICS can be taken whenever the child uses their SABA reliever.
- Reduction in severe exacerbations is a high priority across treatment steps, to reduce the risk and burden to patients and the burden to the health system, and to reduce the need for oral corticosteroids (OCS), which have cumulative long-term adverse effects.
- Tables of low, medium or high dose ICS do not represent equivalent potency. If a patient is switched from one medication to another, monitor them for stability.
- For all patients, use your own professional judgment, and always check local eligibility and payer criteria.
Treatment tracks for adults and adolescents
- For clarity, the treatment figure for adults and adolescents shows two ‘tracks’, largely based on the choice of reliever. Treatment may be stepped up or down within a track using the same reliever at each step, or treatment may be switched between tracks, according to the individual patient’s needs.
- Track 1, in which the reliever is low-dose ICS-formoterol, is the preferred approach recommended by GINA. When a patient at any step has asthma symptoms, they use low-dose ICS-formoterol as needed for symptom relief. In Steps 3–5, they also take ICS-formoterol as regular daily treatment. This approach is preferred because it reduces the risk of severe exacerbations compared with using a SABA reliever, with similar symptom control, and because of the simplicity for patients and clinicians of needing only a single medication across treatment Steps 1–4.
- Medications and doses for Track 1 are explained in Box 4-8, p.84, including the maximum recommended total formoterol (with ICS) dose in any day for each formulation. Based on extensive evidence with budesonideformoterol, GINA suggests that the same maximum total daily dose should apply for beclometasone-formoterol.
- Track 2, in which the reliever is an ICS-SABA or SABA, is an alternative if Track 1 is not possible, or if a patient is stable, with good adherence and no exacerbations in the past year on their current therapy. In Step 1, the patient takes a SABA and a low-dose ICS together for symptom relief (in combination if available, or with the ICS taken immediately after the SABA). In Steps 2–5, the reliever is a SABA or combination ICS-SABA. Before considering a SABA reliever, consider whether the patient is likely to be adherent with their ICS-containing treatment, as otherwise they would be at higher risk of exacerbations.
Steps 1 and 2 for adults and adolescents
- Track 1: (Steps 1–2 combined) In adults and adolescents who were considered by their clinician to have mild asthma, and were taking SABA alone or had controlled asthma on daily low-dose ICS or LTRA, treatment with asneeded- only low-dose ICS-formoterol reduced the risk of severe exacerbations and emergency department visits or hospitalizations by about two-thirds compared with SABA-only treatment. As-needed-only low-dose ICSformoterol reduced the risk of emergency department visits and hospitalizations compared with daily ICS, with no clinically important difference in symptom control. In patients previously using SABA alone, as-needed low-dose ICS-formoterol also significantly reduced the risk of severe exacerbations needing OCS, compared with daily ICS.
- Track 2: Treatment with regular daily low-dose ICS plus as-needed SABA (Step 2), if taken, is highly effective in reducing asthma symptoms and reducing the risk of asthma-related exacerbations, hospitalization and death. However, adherence with ICS in the community is poor, leaving patients taking SABA alone and at increased risk of exacerbations. For patients with infrequent symptoms, who are likely to have very poor adherence, as-neededonly ICS-SABA with separate or combination inhalers is the best option for Step 1, although current evidence is limited to small studies that were not powered to detect differences in exacerbation rates.
Consider step-up if asthma remains uncontrolled despite good adherence and inhaler technique
- Before considering any step up, first confirm that the symptoms are due to asthma and identify and address common problems such as inhaler technique, adherence, allergen exposure and multimorbidity; provide patient education.
- For adults and adolescents, the preferred Step 3 treatment is the Track 1 regimen with low-dose ICS-formoterol as maintenance-and-reliever therapy (MART). This reduces the risk of severe exacerbations, with similar or better symptom control, compared with maintenance treatment using a combination of an ICS and a long-acting beta2 agonist (LABA) as controller, plus as-needed SABA. If needed, the maintenance dose of ICS-formoterol can be increased to medium (i.e., Step 4) by increasing the number of maintenance inhalations. MART is also a preferred treatment option at Steps 3 and 4 for children 6–11 years, with a lower dose ICS-formoterol inhaler.
- ICS-formoterol should not be used as the reliever for patients taking a different ICS-LABA maintenance treatment, because clinical evidence for safety and efficacy is lacking.
- Other Step 3 options for adults and adolescents in Track 2, and in children, include maintenance ICS-LABA plus as-needed SABA or plus as-needed ICS-SABA (if available) or, for children 6–11 years, medium-dose ICS plus asneeded SABA. For children, try other controller options at the same step before stepping up.
Step down to find the minimum effective treatment
- Once good asthma control has been achieved and maintained for 2–3 months, consider stepping down gradually to find the patient’s lowest treatment that controls both symptoms and exacerbations.
- Provide the patient with a written asthma action plan, monitor closely, and schedule a follow-up visit.
- Do not completely withdraw ICS unless this is needed temporarily to confirm the diagnosis of asthma.
For all patients with asthma, provide asthma education and training in essential skills
- After choosing the right class of medication for the patient, the choice of inhaler device depends on which inhalers are available for the patient for that medication, which of these inhalers the patient can use correctly after training, and their relative environmental impact. Check inhaler technique frequently.
- Provide inhaler skills training: this is essential for medications to be effective, but technique is often incorrect.
- Encourage adherence with ICS-containing medication, even when symptoms are infrequent.
- Provide training in asthma self-management (self-monitoring of symptoms and/or peak expiratory flow (PEF), written asthma action plan and regular medical review) to control symptoms and minimize the risk of exacerbations.
For patients with one or more risk factors for exacerbations
- Prescribe ICS-containing medication, preferably from Track 1 options, i.e., with as-needed low-dose ICSformoterol as reliever; provide a written asthma action plan; and arrange review more frequently than for lower-risk patients.
- Identify and address modifiable risk factors (e.g., smoking, low lung function, over-use of SABA).
- Consider non-pharmacological strategies and interventions to assist with symptom control and risk reduction, (e.g., smoking cessation advice, breathing exercises, some avoidance strategies).
Difficult-to-treat and severe asthma
- Patients who have poor symptom control and/or exacerbations, despite medium- or high-dose ICS-LABA treatment, should be assessed for contributing factors, and asthma treatment optimized.
- If the problems continue or diagnosis is uncertain, refer to a specialist center for phenotypic assessment and consideration of add-on therapy including biologics.
Allergen immunotherapy
Allergen-specific immunotherapy may be considered as add-on therapy for patients with asthma who have clinically significant sensitization to aeroallergens.
Initial asthma treatment for adults and adolescents with a diagnosis of asthma
Having trouble viewing table?
Presenting symptoms | Preferred INITIAL treatment (Track 1) | Alternative INITIAL treatment (Track 2) |
Infrequent asthma symptoms, e.g., 1–2 days/week or less |
As-needed low-dose ICSformoterol (Evidence A) |
Low-dose ICS taken whenever SABA is taken, in combination or separate inhalers (Evidence B). Such patients are highly unlikely to be adherent with daily ICS. |
Asthma symptoms less than 3–5 days/week, with normal or mildly reduced lung function |
Low-dose ICS plus as-needed SABA (Evidence A). Before choosing this option, consider likely adherence with daily ICS. |
|
Asthma symptoms most days (e.g., 4–5 days/week or more); or waking due to asthma once a week or more, or low lung function. See p.80 for additional considerations for starting at Step 3. |
Low-dose ICS-formoterol maintenance-and-reliever therapy (MART) (Evidence A) |
Low-dose ICS-LABA plus as-needed SABA (Evidence A) or plus as-needed ICS-SABA (Evidence B), OR Medium-dose ICS plus as-needed SABA (Evidence A) or plus as-needed ICS-SABA (Evidence B). Consider likely adherence with daily maintenance treatment. |
Daily asthma symptoms, waking at night with asthma once a week or more, with low lung function |
Medium-dose ICS-formoterol maintenance-and-reliever therapy (MART) (Evidence D). |
Medium- or high-dose ICS-LABA (Evidence D) plus as-needed SABA or plus asneeded ICSSABA. Consider likely adherence with daily maintenance treatment. High-dose ICS plus as-needed SABA is another option (Evidence A) but adherence is worse than with combination ICS-LABA. |
Initial asthma presentation is during an acute exacerbation |
Treat as for exacerbation (Box 9- 4 and Box 9-6), including short course of OCS if severe; commence mediumdose MART (Evidence D). |
Treat as for exacerbation (Box 9-4, and Box 9-6,), including short course of OCS if severe; commence medium- or high-dose ICS-LABA plus as-needed SABA (Evidence D). |
Before starting initial controller treatment
After starting initial controller treatment
- Record evidence for the diagnosis of asthma.
- Record the patient’s level of symptom control and risk factors, including lung function (Box 2-2).
- Consider factors influencing choice between available treatment options (Box 3-4), including likely adherence with daily ICS-containing treatment, particularly if the reliever is SABA.
- Choose a suitable inhaler (Box 5-1) and ensure that the patient can use the inhaler correctly.
- Schedule an appointment for a follow-up visit.
After starting initial controller treatment
- Review patient’s response (Box 2-2) after 2–3 months, or earlier depending on clinical urgency.
- See Box 4-6 for recommendations for ongoing treatment and other key management issues.
- Check adherence and inhaler technique frequently.
- Step down treatment once good control has been maintained for 3 months (Box 4-13).
Guided Asthma Self-Management Education and Skills Training
As with other chronic diseases, people with asthma need education and skills training to manage it well. This is most effectively achieved through a partnership between the patient/carer and their healthcare providers. The essential components for this include:
should be considered.
- Choosing the most appropriate inhaler for the patient’s asthma treatment: consider available devices, cost, the ability of the patient to use the inhaler after training, environmental impact, and patient satisfaction
- Skills training to use inhaler devices effectively
- Encouraging adherence with medications, appointments and other advice, within an agreed management strategy
- Asthma information
- Training in guided self-management, with self-monitoring of symptoms or peak expiratory flow (PEF), a written asthma action plan to show how to recognize and respond to worsening asthma, and regular review by a healthcare provider or trained healthcare worker.
should be considered.
Managing Asthma with Multimorbidity and in Specific Populations
Multimorbidity is common in patients with chronic diseases such as asthma. It is important to identify and manage multimorbidity, as it contributes to impaired quality of life, increased healthcare utilization, and adverse effects of medications. In addition, comorbidities such as rhinosinusitis, obesity and gastro-esophageal reflux disease (GERD) may contribute to respiratory symptoms, and some contribute to poor asthma control.
For patients with dyspnea or wheezing on exertion:
All adolescents and adults with asthma should receive inhaled corticosteroid (ICS)-containing treatment to reduce their risk of severe exacerbations. It should be taken every day or, as an alternative in mild asthma, by as-needed ICSformoterol for symptom relief.
Refer patients with difficult-to-treat or severe asthma to a specialist or severe asthma service, after addressing common problems such as incorrect diagnosis, incorrect inhaler technique, ongoing environmental exposures, and poor adherence (see Section 8).
Women with asthma who are pregnant or planning pregnancy should be advised not to stop ICS-containing therapy, as
exacerbations increase the risk of adverse perinatal outcomes. The advantages of actively treating asthma in pregnancy
with ICS-containing therapy markedly outweigh any potential risks of these medications.
For patients with dyspnea or wheezing on exertion:
- Distinguish between exercise-induced bronchoconstriction (EIB) and symptoms that result from obesity or a lack of fitness or are the result of alternative conditions such as inducible laryngeal obstruction.
- Provide advice about preventing and managing EIB.
All adolescents and adults with asthma should receive inhaled corticosteroid (ICS)-containing treatment to reduce their risk of severe exacerbations. It should be taken every day or, as an alternative in mild asthma, by as-needed ICSformoterol for symptom relief.
Refer patients with difficult-to-treat or severe asthma to a specialist or severe asthma service, after addressing common problems such as incorrect diagnosis, incorrect inhaler technique, ongoing environmental exposures, and poor adherence (see Section 8).
Women with asthma who are pregnant or planning pregnancy should be advised not to stop ICS-containing therapy, as
exacerbations increase the risk of adverse perinatal outcomes. The advantages of actively treating asthma in pregnancy
with ICS-containing therapy markedly outweigh any potential risks of these medications.
Diagnosis and Initial Treatment in Adults with Features of Asthma, COPD or Both
Asthma and chronic obstructive pulmonary disease (COPD) are heterogeneous and overlapping conditions
- ‘Asthma’ and ‘COPD’ are umbrella labels for heterogeneous conditions characterized by chronic airway and/or lung disease. Asthma and COPD each include several different clinical phenotypes, and are likely to have several different underlying mechanisms, some of which may be common to both asthma and COPD.
- Symptoms of asthma and COPD may be similar, and the diagnostic criteria overlap.
Why are the labels ‘asthma’ and ‘COPD’ still important?
- There are extremely important differences in evidence-based treatment recommendations for asthma and COPD. For example, treatment with a long-acting beta2 agonist (LABA) and/or long-acting muscarinic antagonist (LAMA) alone (i.e., without inhaled corticosteroids [ICS]) is recommended as initial treatment in COPD but contraindicated in asthma due to the risk of severe exacerbations and death.
- These risks are also seen in patients who have diagnoses of both asthma and COPD, making it important to identify adult patients who, for safety, should not be treated with long-acting bronchodilators alone. ICS reduce mortality and hospitalizations in patients with asthma, including in those with concomitant COPD.
Many patients have features of both asthma and COPD
- Distinguishing asthma from COPD can be difficult, particularly in smokers and older adults, and some patients may have features of both asthma and COPD.
- The terms ‘asthma-COPD overlap’ or ‘asthma+COPD’ are simple descriptors for patients who have features of both asthma and COPD.
- These terms do not refer to a single disease entity. They include patients with several clinical phenotypes that are likely caused by a range of different underlying mechanisms.
- More research is needed to better define these phenotypes and mechanisms, but in the meantime, safety of pharmacologic treatment is a high priority.
Diagnosis
- Diagnosis in patients with chronic respiratory symptoms involves a stepwise approach, first, is the patient likely to have chronic airways disease, then syndromic categorization as having typical asthma, typical COPD, features of both, and/or with other conditions such as bronchiectasis.
- Lung function testing is essential for confirming persistent airflow limitation, but variable airflow obstruction can be detected with serial peak flow measurements and/or measurements before and after bronchodilator.
Initial treatment for safety and clinical efficacy
- For asthma: ICS are essential, either alone or in combination with a LABA, to reduce the risk of severe exacerbations and death. Do not treat with LABA and/or LAMA alone, without ICS.
- For patients with features of both asthma and COPD, treat as asthma. ICS-containing therapy is important to reduce the risk of severe exacerbations and death. Do not give LABA and/or LAMA alone without ICS.
- For COPD: Treat according to current recommendations from the Global Initiative for Chronic Obstructive Lung Disease (GOLD),72 i.e., initial treatment with LAMA and LABA, plus as-needed SABA; add ICS for patients with hospitalizations, ≥2 exacerbations/year requiring oral corticosteroids (OCS), or blood eosinophils ≥300/μl. Avoid high dose ICS because of risk of pneumonia.
- All patients: provide structured education especially focusing on inhaler technique and adherence; assess for, and treat, other clinical problems, including advice about smoking cessation, immunizations, physical activity, and management of multimorbidity.
- Specialist referral for additional investigations in patients with asthma+COPD is encouraged, as they often have worse outcomes than patients with asthma or COPD alone.
Difficult-to-Treat and Severe Asthma in Adults and Adolescents
What are difficult-to-treat asthma and severe asthma?
- Difficult-to-treat asthma is asthma that is uncontrolled despite prescribing of medium or high-dose treatment with the combination of inhaled corticosteroid (ICS) and long-acting beta2 agonist (LABA), or that requires high-dose ICS-LABA treatment to maintain good symptom control and reduce exacerbations. It does not mean a ‘difficult patient’.
- Severe asthma is asthma that is uncontrolled despite adherence with optimized high-dose ICS-LABA therapy and treatment of contributory factors, or that worsens when high-dose treatment is decreased. Approximately 3–10% of people with asthma have severe asthma.
- Severe asthma places a large physical, mental, emotional, social and economic burden on patients. It is often associated with multimorbidity.
How should these patients be assessed?
- Assess all patients with difficult-to-treat asthma to confirm the diagnosis of asthma, and to identify and manage factors that may be contributing to symptoms, poor quality of life, or exacerbations.
- Refer for expert advice at any stage, or if asthma does not improve in response to optimizing treatment.
- For patients with persistent symptoms and/or exacerbations despite high-dose ICS-containing therapy (with good adherence and correct inhaler technique), the clinical or inflammatory phenotype should be assessed, as this may guide the selection of add-on treatment.
Management of severe asthma
- Depending on the inflammatory phenotype and other clinical features, add-on treatments for severe asthma include long-acting muscarinic antagonists (LAMA), leukotriene receptor antagonists (LTRAs), low-dose azithromycin (adults), and biologic agents for severe asthma.
- Low-dose maintenance oral corticosteroids (OCS) should be considered only as a last resort if no other options are available, because of their serious cumulative long-term side-effects.
- Assess the response to any add-on treatment, stop ineffective treatments, and consider other options.
- Utilize specialist multidisciplinary team care for severe asthma, if available.
- For patients with severe asthma, continue to optimize patient care in collaboration with the primary care clinician, and considering the patient’s social and emotional needs.
- Invite patients with severe asthma to enroll in a registry or clinical trial, if available and relevant, to help fill evidence gaps.
- See Boxes 8-2 through 8-5 (starting on p.142) for the GINA severe asthma decision tree.
- Although the majority of patients can achieve the goal of long-term well controlled asthma, some patients’ asthma will not be well controlled even with optimal therapy. This section will also be published separately as a GINA short guide for health professionals: Difficult-to-Treat and Severe Asthma in Adolescent and Adult Patients. Diagnosis and Management. V5.0, 2024 (the Severe Asthma Guide), available to download or order from the GINA website (www.ginasthma.org).
- Other resources about severe asthma include an online toolkit published by the Australian Centre of Excellence in Severe Asthma (www.toolkit.severeasthma.org.au).
Management of Worsening Asthma and Exacerbations in Adults, Adolescents and Children 6–11 Years
Terminology
- Exacerbations represent an acute or sub-acute worsening in symptoms and lung function from the patient’s usual status, or in some cases, a patient may present for the first time during an exacerbation.
- The terms ‘episodes’, ‘attacks’ and ‘acute severe asthma’ are also often used, but they have variable meanings. The term ‘flare-up’ is preferable for use in discussions with most patients.
- Patients who are at increased risk of asthma-related death should be identified, and flagged for more frequent review.
Written asthma action plans
- All patients should be provided with a written (i.e., printed, digital or pictorial) asthma action plan appropriate for their age, their current treatment regimen and their reliever inhaler (short-acting beta2 agonist [SABA] or combination inhaled corticosteroids [ICS]-formoterol), their level of asthma control, and their health literacy, so they know how to recognize and respond to worsening asthma.
- On the action plan, state when and how to change reliever and/or maintenance medications, use oral corticosteroids (OCS) if needed, and access medical care if symptoms fail to respond to treatment.
- Advise patients who have a history of rapid deterioration to go to an acute care facility or see their doctor immediately their asthma starts to worsen.
- Base the action plan on changes in symptoms or (only in adults) peak expiratory flow (PEF).
Management of exacerbations in a primary care or acute care facility
- Assess exacerbation severity from the degree of dyspnea, respiratory rate, pulse rate, oxygen saturation and lung function, while starting SABA and oxygen therapy. Infection control procedures should be followed.
- Arrange immediate transfer to an acute care facility if there are signs of severe exacerbation, or to intensive care if the patient is drowsy, confused, or has a silent chest. During transfer, give inhaled SABA and ipratropium bromide, controlled oxygen and systemic corticosteroids.
- Start treatment with repeated administration of SABA (in most patients, by pressurized metered-dose inhaler [pMDI] and spacer), early introduction of oral corticosteroids, and controlled flow oxygen if available. Review response of symptoms, oxygen saturation and lung function after 1 hour. Give ipratropium bromide only for severe exacerbations. Consider intravenous magnesium sulfate for patients with severe exacerbations not responding to initial treatment.
- Do not routinely request a chest X-ray, and do not routinely prescribe antibiotics for asthma exacerbations.
- Decide about hospitalization based on the patient’s clinical status, lung function, response to treatment, recent and past history of exacerbations, and ability to manage at home.
Discharge management
- Arrange ongoing treatment before the patient goes home. This should include starting ICS-containing controller treatment or stepping up the dose of existing ICS-containing treatment for 2–4 weeks, and reducing reliever medication to as-needed use.
- If the patient was using an anti-inflammatory reliever (e.g., ICS-formoterol) before the exacerbation and this was replaced with SABA during an emergency department or hospital stay, they should resume taking as-needed antiinflammatory reliever instead of SABA reliever before or on discharge. If the patient was previously using maintenance-and-reliever therapy (MART) with ICS-formoterol, they should resume MART. If the patient was previously using as-needed-only ICS-formoterol as needed, they should start MART, i.e., add maintenance ICSformoterol. There is no need to prescribe or provide SABA for patients prescribed ICS-formoterol reliever.
- For adults and adolescents using SABA as reliever before the exacerbation, consider switching to maintenance-and reliever therapy with ICS-formoterol (MART, Track 1, p.77), to reduce the risk of future exacerbations.
Arrange early follow-up after any exacerbation, regardless of where it was managed. At follow-up:
- Review the patient’s symptom control and risk factors for further exacerbations.
- Prescribe ICS-containing controller therapy to reduce the risk of further exacerbations. If already taking ICS-containing therapy, continue increased doses for 2–4 weeks.
- Provide a written asthma action plan and, where relevant, advice about avoiding exacerbation triggers
- Check inhaler technique and adherence.
Diagnosis of Asthma in Children 5 Years and Younger
Recurrent wheezing occurs in a large proportion of children 5 years and younger, typically with viral upper respiratory tract infections. It is difficult to discern when this is the initial presentation of asthma.
Previous classifications of wheezing phenotypes (episodic wheeze and multiple-trigger wheeze; or transient wheeze, persistent wheeze and late-onset wheeze) do not appear to identify stable phenotypes, and their clinical usefulness is uncertain. However, emerging research suggest that more clinically relevant phenotypes will be described and phenotypedirected therapy possible.
A diagnosis of asthma in young children with a history of wheezing is more likely if they have:
Previous classifications of wheezing phenotypes (episodic wheeze and multiple-trigger wheeze; or transient wheeze, persistent wheeze and late-onset wheeze) do not appear to identify stable phenotypes, and their clinical usefulness is uncertain. However, emerging research suggest that more clinically relevant phenotypes will be described and phenotypedirected therapy possible.
A diagnosis of asthma in young children with a history of wheezing is more likely if they have:
- Wheezing or coughing that occurs with exercise, laughing or crying, or in the absence of an apparent respiratory infection
- A history of other allergic disease (eczema or allergic rhinitis), allergen sensitization or asthma in first-degree relatives
- Clinical improvement during 2–3 months of low-dose inhaled corticosteroid (ICS) treatment plus as-needed shortacting beta2 agonist (SABA) reliever, and worsening after cessation.
Assessment and Management of Asthma in Children 5 Years and Younger
- The goals of asthma management in young children are similar to those in older patients:
- To achieve best possible control of symptoms and maintain normal activity levels
- To minimize the risk of asthma flare-ups, impaired lung development and medication side-effects.
- Wheezing episodes in young children should be treated initially with inhaled short-acting beta2 agonist (SABA), regardless of whether the diagnosis of asthma has been made. However, for initial episodes of wheeze in children <1
- year in the setting of infectious bronchiolitis, SABAs are generally ineffective.
- A trial of low-dose inhaled corticosteroid (ICS) treatment should be given if the symptom pattern suggests asthma, alternative diagnoses have been excluded and respiratory symptoms are uncontrolled and/or wheezing episodes are frequent or severe.
- Response to treatment should be reviewed before deciding whether to continue it. If the response is absent or incomplete, reconsider alternative diagnoses.
- The choice of inhaler device should be based on the child’s age and capability. The preferred device is a pressurized metered-dose inhaler (pMDI) and spacer, with face mask for <3 years and mouthpiece for most children aged 3–5 years. Children should be switched from a face mask to mouthpiece as soon as they are able to demonstrate good technique.
- Review the need for asthma treatment frequently, as asthma-like symptoms remit in many young children. Advise parents/caregivers that asthma symptoms will often return later in life.
Management of Worsening Asthma and Exacerbations in Children 5 Years and Younger
Symptoms of exacerbation in young children
- Early symptoms of exacerbations in young children may include increased symptoms; increased coughing, especially at night; lethargy or reduced exercise tolerance; impaired daily activities including feeding; and a poor response to reliever medication.
Home management in a written asthma action plan
- Give a written asthma action plan to parents/caregivers of young children with asthma so they can recognize an impending severe attack, start treatment, and identify when urgent hospital treatment is required.
- Initial treatment at home is with inhaled short-acting beta2 agonist (SABA), with review after 1 hour or earlier.
- Parents/caregivers should seek urgent medical care if the child is acutely distressed, lethargic, fails to respond to initial bronchodilator therapy, or is worsening, especially in children <1 year of age.
- Medical attention should be sought on the same day if inhaled SABA is needed more often than 3-hourly or for more than 24 hours.
- There is no compelling evidence to support parent/caregiver-initiated oral corticosteroids.
Management of exacerbations in primary care or acute care facility
- Assess severity of the exacerbation while initiating treatment with SABA (2–6 puffs every 20 minutes for first hour) and oxygen (to maintain saturation 94–98%).
- Recommend immediate transfer to hospital if there is no response to inhaled SABA within 1–2 hours; if the child is unable to speak or drink, has a respiratory rate >40/minute or is cyanosed, if resources are lacking in the home, or if oxygen saturation is <92% on room air.
- Consider oral prednisone/prednisolone 1–2 mg/kg/day for children attending an Emergency Department (ED) or admitted to hospital, up to a maximum of 20 mg/day for children aged 0–2 years, and 30 mg/day for children aged 3–5 years, for up to 5 days; or dexamethasone 0.6 mg/kg/day for 2 days. If there is failure of resolution, or relapse of symptoms with dexamethasone, consideration should be given to switching to prednisolone.
- Be aware that oxygen saturation by pulse oximetry may be overestimated in people with dark skin color.
Arrange early follow-up after an exacerbation
- Children who have experienced an asthma exacerbation are at risk of further exacerbations. Arrange follow-up within 1–2 days of an exacerbation and again 1–2 months later to plan ongoing asthma management.
Primary Prevention of Asthma
The development and persistence of asthma are driven by gene–environment interactions. For children, a ‘window of opportunity’ to prevent asthma exists in utero and in early life, but intervention studies are limited.
With regard to allergen avoidance strategies aimed at preventing asthma in children:
Breast-feeding is advised, not for prevention of allergy and asthma, but for its other positive health benefits).
In patients with adult-onset asthma, always ask about occupational or domestic exposures, as these exposures may explain 5–20% of new cases of asthma.
In adults and adolescents, the early identification and elimination of occupational sensitizers and the removal of sensitized patients from any further exposure are important aspects of the prevention and management of occupational asthma.
With regard to allergen avoidance strategies aimed at preventing asthma in children:
- Strategies directed at a single allergen have not been effective in reducing the incidence of asthma
- Multifaceted strategies may be effective, but the essential components have not been identified.
- Avoid exposure to environmental tobacco smoke during pregnancy and the first year of life.
- Encourage vaginal delivery where possible.
- Where possible, avoid use of broad-spectrum antibiotics during the first year of life.
Breast-feeding is advised, not for prevention of allergy and asthma, but for its other positive health benefits).
In patients with adult-onset asthma, always ask about occupational or domestic exposures, as these exposures may explain 5–20% of new cases of asthma.
In adults and adolescents, the early identification and elimination of occupational sensitizers and the removal of sensitized patients from any further exposure are important aspects of the prevention and management of occupational asthma.
Implementing Asthma Management Strategies into Health Systems
- To improve asthma care and patient outcomes, evidence-based recommendations must not only be developed, but also disseminated and implemented at a national and local level, and integrated into clinical practice.
- Recommendations for implementing asthma care strategies are based on many successful programs worldwide.
- Implementation requires an evidence-based strategy involving professional groups and stakeholders, and should take into account local cultural and socioeconomic conditions.
- Cost-effectiveness of implementation programs should be assessed so a decision can be made to pursue or modify them.
- Local adaptation and implementation of asthma care strategies is aided by the use of tools developed for this purpose.
Recommendation Grading
Overview
Title
Global Strategy for Asthma Management and Prevention
Authoring Organization
Global Initiative for Asthma
Publication Month/Year
May 7, 2024
Last Updated Month/Year
May 29, 2024
Supplemental Implementation Tools
Document Type
Guideline
External Publication Status
Published
Country of Publication
Global
Inclusion Criteria
Male, Female, Adolescent, Adult, Child, Older adult
Health Care Settings
Ambulatory, Childcare center
Intended Users
Nurse, nurse practitioner, physician, physician assistant
Scope
Diagnosis, Assessment and screening, Treatment, Management, Prevention
Diseases/Conditions (MeSH)
D029424 - Pulmonary Disease, Chronic Obstructive, D001249 - Asthma
Keywords
chronic obstructive pulmonary disease (COPD), asthma, severe asthma, Exacerbations
Source Citation
Global Initiative for Asthma. Global Strategy for Asthma Management and Prevention, 2024.
Updated May 2024. Available from: www.ginasthma.org
Methodology
Number of Source Documents
943
Literature Search Start Date
January 1, 2018
Literature Search End Date
October 28, 2023