Asthma Management Handbook

Assessing recent asthma symptom control and risk of adverse asthma outcomes in adults

Recommendations

Before starting treatment, document the patient’s:

  • baseline lung function
  • level of recent asthma symptom control
  • risk factors for flare-ups, life-threatening asthma, accelerated decline in lung function, or adverse effects of treatment.

Table. Definition of levels of recent asthma symptom control in adults and adolescents (regardless of current treatment regimen)

Good control

Partial control

Poor control

All of:

  • Daytime symptoms ≤2 days per week
  • Need for reliever ≤2 days per week
  • No limitation of activities
  • No symptoms during night or on waking

One or two of:

  • Daytime symptoms >2 days per week
  • Need for reliever >2 days per week
  • Any limitation of activities
  • Any symptoms during night or on waking

Three or more of:

  • Daytime symptoms >2 days per week
  • Need for reliever >2 days per week
  • Any limitation of activities
  • Any symptoms during night or on waking

† Not including SABA taken prophylactically before exercise. (Record this separately and take into account when assessing management.)

Note: Recent asthma symptom control is based on symptoms over the previous 4 weeks.

Adapted from:

Global Initiative for Asthma (GINA). Global strategy for asthma management and prevention. GINA, 2012. Available from: http://www.ginasthma.org/

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Table. Risk factors for adverse asthma outcomes in adults and adolescents Opens in a new window Please view and print this figure separately: https://www.asthmahandbook.org.au/table/show/40

Table. Management of risk factors for adverse asthma outcomes in adults

Risk factor

Clinical action †

Any risk factor for flare-ups

Check patient has an appropriate action plan

Carefully check inhaler technique and adherence, and identify any barriers to good adherence

Review frequently (e.g. every 3 months)

Hospitalisation or ED visit for asthma or any asthma flare-up during the previous 12 months

Ask about triggers for flare-ups, and lead time

History of intubation or intensive care unit admission for asthma

Ensure action plan recommends early medical review when asthma worsens

Hospitalisation or ED visit for asthma in the past month

Emphasise importance of maintaining regular ICS use after symptoms improve

Confirm that patient has resumed using SABA only when needed for symptoms

High SABA use (>2 canisters per month)

Check lung function

If SABA use appears to be habitual, investigate causes and consider alternative strategies, e.g. short-term substitution of ipratropium for SABA

Long-term high-dose ICS

Consider gradual reduction of ICS dose if symptoms stable

Monitor regularly (e.g. assessment of bone density, regular eye examinations)

For local side-effects, ensure inhaler technique is appropriate

Poor lung function (even if few symptoms)

Consider 3-month trial of higher ICS dose, then recheck lung function

Consider referral for detailed specialist investigation

Sensitivity to unavoidable allergens (e.g. Alternaria species of common moulds)

Refer for further investigation and management

Exposure to cigarette smoke (smoking or environmental exposure)

Emphasise the importance of avoiding smoke

Provide quitting strategies

Consider increasing ICS dose (higher dose of ICS likely to be necessary to control asthma)

Refer for assessment of asthma–COPD overlap

Difficulty perceiving airflow limitation or the severity of exacerbations

Regular PEF monitoring

Action plan should recommend early review and measurement of lung function

No current written asthma action plan

Provide and explain written asthma action plan

† In addition to actions applicable to all risk factors

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How this recommendation was developed

Adapted from existing guidance

Based on reliable clinical practice guideline(s) or position statement(s):

  • Global Initiative for Asthma, 20121

Measure lung function by spirometry to establish the patient’s baseline values.

Notes

If reliable equipment and appropriately trained staff are available, spirometry can be performed in primary care. If not, refer to an appropriate provider such as an accredited respiratory function laboratory.

Document if spirometry is pre- or post-bronchodilator.

How this recommendation was developed

Consensus

Based on clinical experience and expert opinion (informed by evidence, where available).

More information

Classification of asthma severity and recent asthma symptom control in adults

Recent asthma symptom control

Recent asthma symptom control in adults is defined by frequency of symptoms, the degree to which symptoms affect sleep and activity, and the need for reliever medication over the previous 4 weeks.

Recent asthma symptom control is a component of overall asthma control. The other component is the risk of future events (e.g. flare-ups, life-threatening asthma, accelerated decline in lung function, or adverse effects of treatment).

Any experience of flare-ups or night-time waking due to asthma symptoms, even if infrequent, usually indicates that the person needs regular preventer treatment.

Table. Definition of levels of recent asthma symptom control in adults and adolescents (regardless of current treatment regimen)

Good control

Partial control

Poor control

All of:

  • Daytime symptoms ≤2 days per week
  • Need for reliever ≤2 days per week
  • No limitation of activities
  • No symptoms during night or on waking

One or two of:

  • Daytime symptoms >2 days per week
  • Need for reliever >2 days per week
  • Any limitation of activities
  • Any symptoms during night or on waking

Three or more of:

  • Daytime symptoms >2 days per week
  • Need for reliever >2 days per week
  • Any limitation of activities
  • Any symptoms during night or on waking

† Not including SABA taken prophylactically before exercise. (Record this separately and take into account when assessing management.)

Note: Recent asthma symptom control is based on symptoms over the previous 4 weeks.

Adapted from:

Global Initiative for Asthma (GINA). Global strategy for asthma management and prevention. GINA, 2012. Available from: http://www.ginasthma.org/

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Severity

Severity of asthma in adults is defined by the type and amount of treatment needed to maintain good control, not by the severity of acute flare-ups.

For patients prescribed a preventer, asthma severity can only be determined after using a preventer for at least 8 weeks and after checking adherence and inhaler technique.

Table. Definitions of asthma severity in adults in treatment

Severity

Treatment required to achieve good control †

Mild

Good control can be achieved with (any of):

  • intermittent reliever
  • low-dose inhaled corticosteroid
  • leukotriene receptor antagonist
  • cromone.

Moderate ‡

 

Good control can be achieved with (either of):

  • low- to-moderate dose of inhaled corticosteroid plus long-acting beta2 agonist
  • moderate dose of inhaled corticosteroid.

Severe ‡

Good control requires (or cannot be achieved despite) regular high dose of inhaled corticosteroid plus long-acting beta2 agonist.

Difficult-to-treat

Good control cannot be achieved despite treatment§ because of disease severity, comorbidities, persistent poor adherence or persistent smoking.

Severe treatment-resistant asthma (severe refractory asthma)

Good control requires (or cannot be achieved despite) regular high dose of inhaled corticosteroid plus long-acting beta2 agonist, in a patient in whom factors such as poor adherence, poor inhaler technique and comorbidities have been excluded.

† Good control is defined as all of the following: daytime symptoms on ≤2 days per week, need for reliever on ≤2 days per week, no limitation of activities, and no symptoms during night or on waking.

‡ If good control has been achieved for 2–3 months, the dose of inhaled corticosteroid should be down-titrated, if possible, to avoid misclassification due to over-treatment.

§ Repeated attempts to treat with appropriate medicines and self-management strategies

Source: Global Initiative for Asthma (GINA). Global strategy for asthma management and prevention. GINA; 2012. Available from: http://www.ginasthma.org/

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Assessing risk factors for adverse asthma outcomes in adults

Predicting poor asthma outcomes

As well as assessing recent asthma symptom control, it is necessary to assess each patient’s risk of future asthma events or adverse treatment effects. (Recent asthma symptom control and risk of adverse events are both components of overall asthma control.)

Table. Risk factors for adverse asthma outcomes in adults and adolescents Opens in a new window Please view and print this figure separately: https://www.asthmahandbook.org.au/table/show/40

Table. Management of risk factors for adverse asthma outcomes in adults

Risk factor

Clinical action †

Any risk factor for flare-ups

Check patient has an appropriate action plan

Carefully check inhaler technique and adherence, and identify any barriers to good adherence

Review frequently (e.g. every 3 months)

Hospitalisation or ED visit for asthma or any asthma flare-up during the previous 12 months

Ask about triggers for flare-ups, and lead time

History of intubation or intensive care unit admission for asthma

Ensure action plan recommends early medical review when asthma worsens

Hospitalisation or ED visit for asthma in the past month

Emphasise importance of maintaining regular ICS use after symptoms improve

Confirm that patient has resumed using SABA only when needed for symptoms

High SABA use (>2 canisters per month)

Check lung function

If SABA use appears to be habitual, investigate causes and consider alternative strategies, e.g. short-term substitution of ipratropium for SABA

Long-term high-dose ICS

Consider gradual reduction of ICS dose if symptoms stable

Monitor regularly (e.g. assessment of bone density, regular eye examinations)

For local side-effects, ensure inhaler technique is appropriate

Poor lung function (even if few symptoms)

Consider 3-month trial of higher ICS dose, then recheck lung function

Consider referral for detailed specialist investigation

Sensitivity to unavoidable allergens (e.g. Alternaria species of common moulds)

Refer for further investigation and management

Exposure to cigarette smoke (smoking or environmental exposure)

Emphasise the importance of avoiding smoke

Provide quitting strategies

Consider increasing ICS dose (higher dose of ICS likely to be necessary to control asthma)

Refer for assessment of asthma–COPD overlap

Difficulty perceiving airflow limitation or the severity of exacerbations

Regular PEF monitoring

Action plan should recommend early review and measurement of lung function

No current written asthma action plan

Provide and explain written asthma action plan

† In addition to actions applicable to all risk factors

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Poor clinical control, as indicated by frequent asthma symptoms and frequent reliever use, is a very strong predictor of the risk of flare-ups in the future. Any asthma flare-up during the previous 12 months indicates higher risk of flare-up over the next 12 months. A history  of artificial ventilation due to acute asthma, and admission to an intensive care unit due to acute asthma have been associated with increased risk of near-fatal asthma,2 but there is not enough evidence to indicate how long this risk may persist over a person’s lifetime. Other risk factors indicate increased probability of future flare-ups or accelerated decline in lung function, independent of the person’s level of recent asthma symptom control. 134

Other factors may increase a person’s risk of treatment-associated adverse effects. The most important of these are prescription of high dose treatment and frequent courses of oral steroids.

People with risk factors need more frequent asthma review, a carefully tailored written asthma action plan, and close attention to adherence and correct inhaler technique.

Inflammatory markers

Inflammatory markers, such as sputum eosinophil percentage or exhaled nitric oxide, are used in research and for managing severe asthma in patients attending secondary or tertiary care. Elevated sputum eosinophil levels and, to a lesser extent, elevated exhaled nitric oxide, are associated with increased risk of flare-ups. At present, treatment based on inflammatory markers is not recommended for routine use in primary care.

The value of inflammatory markers is being evaluated:

  • Adjusting asthma treatment by monitoring exhaled nitric oxide does not reduce the rate of flare-ups or improve asthma control in adults and children, compared with adjusting treatment according to clinical symptoms or spirometry, based on a meta-analysis of randomised controlled clinical trials.5 However, many of the studies were not optimally designed to answer this question,6 and some comparator regimens did not match current recommended treatment options.
  • In some studies, asthma treatment algorithms based on monitoring sputum eosinophil counts reduced flare-ups, compared with control-based management.7, 8 However, most studies assessing treatment guided by sputum eosinophilia have been conducted in selected populations in a few research centres, and therefore may not apply to the general community population. Assessment of sputum inflammatory cells is not generally available at present even in secondary care.
  • Limited evidence9 suggests that patients whose symptoms do not match their degree of eosinophilic inflammation may benefit more from treatment monitoring using sputum eosinophil count than other patients.
  • Monitoring inflammatory markers might enable safer down-titration of maintenance inhaled corticosteroid doses.
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Assessing recent asthma control in adults: symptoms

Questionnaires

Questionnaire-based tools can be used to standardise review of asthma symptoms, e.g.:

  • Primary care Asthma Control Screening tool (also known as Pharmacy Asthma Control Screening tool)10 – a quick screening test to detect poor asthma control, developed and validated for use with Australian patients attending primary care
  • UK Royal College of Physicians ‘3 Questions’11
  • Asthma Score (also known as Asthma Control Test).3
  • Asthma Control Questionnaire (ACQ)

The questionnaires can be completed on paper in the waiting room and scored by the practice nurse. They have also been administered via an application on hand-held personal electronic devices,1213 or by telephone.14

Note: Clinicians and researchers should only use the versions of the ACQ and Asthma Score that have been validated for use in the Australian population. The wording and layout of questionnaires must not be changed.
 

Table. Primary care Asthma Control Screening tool (PACS)

Have you experienced any of the following more than once a week in the last month? Yes No
Symptoms of asthma, cough, wheeze, shortness of breath
  •  
  •  
Waking at night because of asthma
  •  
  •  
Chest tightness on waking
  •  
  •  
Difficulty in performing vigorous activity like running, lifting heavy objects, exercise
  •  
  •  
Difficulty in performing moderate activities like vacuuming, climbing flights of stairs
  •  
  •  

Interpretation: ‘Yes’ to any question indicates that the person may have poorly controlled asthma, so more detailed assessment is needed.

Source: LeMay KS, Armour CL, Reddel HK. Performance of a brief asthma control screening tool in community pharmacy: a cross-sectional and prospective longitudinal analysis. Prim Care Respir J; 2014. Available from: http://dx.doi.org/10.4104/pcrj.2014.00011

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Table. UK Royal College of Physicians ‘3 Questions’ screening tool

In the last month: Yes No
Have you had difficulty sleeping because of your asthma symptoms (including cough)?
  •  
  •  
Have you had your usual asthma symptoms during the day (cough, wheeze, chest tightness or breathlessness)?
  •  
  •  
Has your asthma interfered with your usual activities (e.g. housework, work/school etc)?
  •  
  •  

Inerpetation:

No to all three questions indicates good control.

Yes to 2 or 3 questions indicates poor control.

Yes to 1 question indicates that more detailed questioning is needed to assess level of asthma control (using another validated questionnaire or by asking about frequency of daytime symptoms, reliever requirement, limitation of activities and symptoms at night or on waking during the previous month).

Note: This test provides a quick and easy way of confirming someone’s asthma control is good, or identifying those who need more assessments.

Sources

Thomas M, Gruffydd-Jones K, Stonham C et al. Assessing asthma control in routine clinical practice: use of the Royal College of Physicians ‘3 Questions’. Prim Care Respir J 2009; 18: 83-8. Available from: http://www.nature.com/articles/pcrj200845

Pinnock H, Burton C, Campbell S et al. Clinical implications of the Royal College of Physicians three questions in routine asthma care: a real-life validation study. Prim Care Respir J 2012; 21: 288-94. Available from: http://www.nature.com/articles/pcrj201252

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Symptom-guided management

Data from one UK study suggest that, for the majority of patients attending primary care, asthma symptoms are concordant with eosinophilic airway inflammation, and that symptoms can therefore be used as a guide to changing anti-inflammatory treatment.9

However, if symptoms do not improve as expected after a change in treatment, or if the person continues to experience flare-ups, it is necessary to measure lung function and consider other possible causes:

  • Respiratory symptoms in a person with asthma may be due to non-asthma factors (e.g. cough due to post-nasal drip, shortness of breath due to obesity). Increasing the preventer treatment in such patients could result in unnecessarily high doses. A careful history (with lung function measurement in some patients) is necessary to confirm that symptoms are due to asthma, before deciding to change a person’s treatment.
  • Patients vary in their ability to perceive airflow limitation, so symptoms may be an unreliable measure of asthma control in some patients. Spirometry can help identify if the person is a poor perceiver of airflow limitation (e.g. person is unable to feel the difference when FEV1 increases or decreases by 15%).
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Assessing asthma control in adults: spirometry

Spirometry is necessary when making the diagnosis of asthma and when establishing the patient’s baseline and personal best status.

In ongoing asthma management, spirometry is useful in the following clinical situations:

  • During a flare-up, spirometry provides objective evidence about the severity of bronchoconstriction.
  • After a dose adjustment (either an increase or a decrease), change in lung function measured by spirometry provides additional information about the response to treatment.
  • Spirometry can help identify if the person’s symptoms may be due to non-asthma conditions (e.g. for a patient with frequent respiratory symptoms, FEV1 above 80–90% predicted should prompt consideration of an alternative cause).
  • Spirometry can help identify if the person is a poor perceiver of airflow limitation (e.g. person is unable to feel the difference when FEV1 increases or decreases by 15%).
  • Repeating spirometry over time may identify lung function decline that is more rapid than expected decline due to ageing alone, so the person can be referred for specialist review. (Spirometry should be repeated approximately every 1–2 years in most patients but more frequently as indicated by individual needs.)

There are limits to the amount of information that can be gained from spirometry alone:

  • For an individual, spirometry readings are not closely reproducible between visits, so only a change in FEV1 of greater than 0.2 L and 12% from baseline can be considered clinically meaningful in adults.15
  • Older people with long-standing asthma may develop fixed (irreversible or incompletely reversible) airflow limitation. Reliance solely on lung function expressed as percentage predicted value as a guide to adjusting preventer treatment would risk dose-escalation and over-treatment in these patients.
  • At the population level, spirometry correlates poorly with symptom-based measures of asthma control,16 so in individual patients it is not possible to predict lung function from symptoms or vice versa.

To obtain reliable, good-quality readings, the spirometer must be well maintained and correctly calibrated, and the operator must be adequately trained and experienced.

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Spirometry in diagnosis and monitoring

Spirometry is the best lung function test for diagnosing asthma and for measuring lung function when assessing asthma control. Spirometry can:

  • detect airflow limitation
  • measure the degree of airflow limitation compared with predicted normal airflow (or with personal best)
  • demonstrate whether airflow limitation is reversible.

It should be performed by well-trained operators with well-maintained and calibrated equipment.17, 18

Before performing spirometry, check if the person has any contraindications (e.g. myocardial infarction, angina, aneurysm, recent surgery, suspected pulmonary embolism, suspected pneumothorax, fractured ribs). Advise them to stop if they become dizzy.

Clearly explain and physically demonstrate correct spirometry technique: 19

  • Sit upright with legs uncrossed and feet flat on the floor and do not lean forward.
  • Breathe in rapidly until lungs feel absolutely full. (Coaching is essential to do this properly.)
  • Do not pause for more than 1 second.
  • Place mouthpiece in mouth and close lips to form a tight seal.
  • Blast air out as hard and fast as possible and for as long as possible, until the lungs are completely empty or you are unable to blow out any longer.
  • Remove mouthpiece.

Repeat the test until you obtain three acceptable tests and these meet repeatability criteria.

Acceptability of test

A test is acceptable if all the following apply:

  • forced expiration started immediately after full inspiration
  • expiration started rapidly
  • maximal expiratory effort was maintained throughout the test, with no stops
  • the patient did not cough during the test
  • the patient did not stop early (before 6 seconds for adults and children over 10 years, or before 3 seconds for children under 10 years).

Record the highest FEV1 and FVC result from the three acceptable tests, even if they come from separate blows.19

Repeatability criteria

Repeatability criteria for a set of acceptable tests are met if both of the following apply:17

  • the difference between the highest and second-highest values for FEV1 is less than 150 mL
  • the difference between the highest and second-highest values for FVC is less than 150 mL.

For most people, it is not practical to make more than eight attempts to meet acceptability and repeatability criteria.19

Testing bronchodilator response (reversibility of airflow limitation)

Repeat spirometry 10-15 minutes after giving 4 separate puffs of salbutamol (100 mcg/actuation) via a pressurised metered-dose inhaler and spacer.19 (For patients who have reported unacceptable side-effects with 400 mcg, 2 puffs can be used.)

For adults and adolescents, record a clinically important bronchodilator response if FEV1 increases by ≥ 200 mL and ≥ 12%.19

For children, record a clinically important bronchodilator response if FEV1 increases by
≥ 12%.19

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Psychosocial factors affecting asthma self-management

Psychosocial factors can affect asthma symptoms and outcomes in children and adults. These can include biological, individual, family and community-level factors, which can have synergistic effects in an individual with asthma.20 Mechanisms may include effects of stress on the immune system20 and effects of life circumstances on patients’ and families’ ability to manage asthma.

Relationships between psychosocial and cultural factors

Important influences on asthma outcomes include the person’s asthma knowledge and beliefs, confidence in ability to self-manage, perceived barriers to healthcare, socioeconomic status, and healthcare system navigation skills, and by the quality of interaction and communication between patient and healthcare provider.21 There is a complex interrelationship between:21

  • patient factors (e.g. health literacy, health beliefs, ethnicity, educational level, social support, cultural beliefs, comorbidities, mental health)
  • healthcare provider factors (e.g. communication skills, teaching abilities, available time, educational resources and skills in working with people from different backgrounds)
  • healthcare system factors (e.g. the complexity of the system, the healthcare delivery model, the degree to which the system is oriented towards chronic disease management or acute care, and the degree to which the system is sensitive to sociocultural needs).

Health literacy

‘Health literacy’ refers to the individual’s capacity to obtain, process, and understand basic health information and services they need to make appropriate health decisions.22 A person’s level of health literacy is influenced by various factors including skills in reading, writing, numeracy, speaking, listening, cultural and conceptual knowledge.21

Inadequate health literacy is recognised as a risk factor for poorer health outcomes and less effective use of health care services.21 Poor health literacy has been associated with poor asthma control,23 poor knowledge of medications,24 and incorrect inhaler technique.24 Aspects of health literacy that have been associated with poorer asthma outcomes in adults include reading skills, listening skills, numeracy skills, and combinations of these.21 Studies assessing the association between parents’ health literacy and children’s asthma have reported inconsistent findings.21 Overall, there is not enough evidence to prove that low health literacy causes poor asthma control or inadequate self-management.21

Australian research suggests that there are probably many Australians with limited health literacy.25 It may be possible to identify some groups of patients more likely to have inadequate health literacy, such as people living in regions with low socioeconomic status, and those with low English literacy (e.g. people with limited education, members of some ethnic minorities, immigrants, and the elderly).21 However, even well-educated patients might have trouble with basic health literacy skills.21

Attempting to assess every patient’s health literacy is impractical and may be embarrassing for the person and time-consuming for the health professional.21 Instead, it may be more effective for health professionals simply to assume that all patients have limited health literacy.21 Accordingly, all self-management skills need to be explained carefully, simply and repeatedly, and all written material should be clear and easy to read. Special consideration is needed for patients from culturally and linguistically diverse communities, including Aboriginal and Torres Strait Islander people.

Psychosocial support and improving health literacy

Psychosocial interventions that include asthma education may improve health-related quality of life for children and adolescents with asthma and their families.26 However, simply providing education might not improve a person’s health literacy, since it also depends on other factors like socioeconomic status, social support, and is influence by the provider and the healthcare system.21

Asthma Australia provides personal support and information for people with asthma and parents of children with asthma through the Asthma Australia Information line by telephone on 1800 Asthma (1800 278 462) or online.

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References

  1. Global Initiative for Asthma (GINA). Global strategy for asthma management and prevention. GINA, 2012. Available from: http://www.ginasthma.org
  2. Turner MO, Noertjojo K, Vedal S, et al. Risk factors for near-fatal asthma. A case-control study in hospitalized patients with asthma. Am J Respir Crit Care Med. 1998; 157: 1804-9. Available from: http://www.ncbi.nlm.nih.gov/pubmed/9620909
  3. Thomas M, Kay S, Pike J, et al. The Asthma Control Test (ACT) as a predictor of GINA guideline-defined asthma control: analysis of a multinational cross-sectional survey. Prim Care Respir J. 2009; 18: 41-49. Available from: http://www.nature.com/articles/pcrj200910
  4. Osborne ML, Pedula KL, O'Hollaren M, et al. Assessing future need for acute care in adult asthmatics: the Profile of Asthma Risk Study: a prospective health maintenance organization-based study. Chest. 2007; 132: 1151-61. Available from: http://journal.publications.chestnet.org/article.aspx?articleid=1085456
  5. Petsky HL, Cates CJ, Li A, et al. Tailored interventions based on exhaled nitric oxide versus clinical symptoms for asthma in children and adults. Cochrane Database Syst Rev. 2009; Issue 4: CD006340. Available from: http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD006340.pub3/full
  6. Gibson PG. Using fractional exhaled nitric oxide to guide asthma therapy: design and methodological issues for asthma treatment algorithm studies. Clin Exp Allergy. 2009; 39: 478-490. Available from: http://www.ncbi.nlm.nih.gov/pubmed/19260871
  7. Taylor DR, Bateman ED, Boulet LP, et al. A new perspective on concepts of asthma severity and control. Eur Respir J. 2008; 32: 545-554. Available from: http://erj.ersjournals.com/content/32/3/545.long
  8. Petsky HL, Cates CJ, Lasserson TJ, et al. A systematic review and meta-analysis: tailoring asthma treatment on eosinophilic markers (exhaled nitric oxide or sputum eosinophils). Thorax. 2012; 67: 199-208. Available from: http://www.ncbi.nlm.nih.gov/pubmed/20937641
  9. Haldar P, Pavord ID, Shaw DE, et al. Cluster analysis and clinical asthma phenotypes. Am J Respir Crit Care Med. 2008; 178: 218-224. Available from: http://ajrccm.atsjournals.org/content/178/3/218.full
  10. LeMay KS, Armous CL, Reddel HK. Performance of a brief asthma control screening tool in community pharmacy: a cross-sectional and prospective longitudinal analysis. Prim Care Respir J. 2014; 23 (1): 79-84. Available from: http://www.nature.com/articles/pcrj201411
  11. British Thoracic Society (BTS), Scottish Intercollegiate Guidelines Network (SIGN). British Guideline on the Management of Asthma. A national clinical guideline. BTS, SIGN, Edinburgh, 2012. Available from: https://www.brit-thoracic.org.uk/guidelines-and-quality-standards/asthma-guideline/
  12. Peters SP, Jones CA, Haselkorn T, et al. Real-world Evaluation of Asthma Control and Treatment (REACT): Findings from a national Web-based survey. J Allergy Clin Immunol. 2007; 119: 1454-1461. Available from: http://www.jacionline.org/article/S0091-6749(07)00619-7/fulltext
  13. Juniper EF, Langlands JM, Juniper BA. Patients may respond differently to paper and electronic versions of the same questionnaires. Resp Med. 2009; 103: 932-934. Available from: http://www.resmedjournal.com/article/S0954-6111(08)00385-5/fulltext
  14. Kosinski M, Kite A, Yang M, et al. Comparability of the Asthma Control Test telephone interview administration format with self-administered mail-out mail-back format. Curr Med Res Opin. 2009; 25: 717-727. Available from: http://www.ncbi.nlm.nih.gov/pubmed/19196218
  15. Pellegrino R, Viegi G, Brusasco V, et al. Interpretative strategies for lung function tests. Eur Respir J. 2005; 26: 948-968. Available from: http://erj.ersjournals.com/content/26/5/948
  16. Schatz M, Sorkness CA, Li JT, et al. Asthma Control Test: Reliability, validity, and responsiveness in patients not previously followed by asthma specialists. J Allergy Clin Immunol. 2006; 117: 549-556. Available from: http://www.jacionline.org/article/S0091-6749(06)00174-6/fulltext
  17. Miller MR, Hankinson J, Brusasco V, et al. Standardisation of spirometry. Eur Respir J. 2005; 26: 319-338. Available from: http://erj.ersjournals.com/content/26/2/319
  18. Levy ML, Quanjer PH, Booker R, et al. Diagnostic Spirometry in Primary Care: Proposed standards for general practice compliant with American Thoracic Society and European Respiratory Society recommendations. Prim Care Respir J. 2009; 18: 130-147. Available from: http://www.ncbi.nlm.nih.gov/pubmed/19684995
  19. Johns DP, Pierce R. Pocket guide to spirometry. 3rd edn. McGraw Hill, North Ryde, 2011.
  20. Yonas MA, Lange NE, Celedon JC. Psychosocial stress and asthma morbidity. Curr Opin Allergy Clin Immunol. 2012; 12: 202-10. Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3320729/
  21. Rosas-Salazar C, Apter AJ, Canino G, Celedon JC. Health literacy and asthma. J Allergy Clin Immunol. 2012; 129: 935-42. Available from: http://www.jacionline.org/article/S0091-6749(12)00128-5/fulltext
  22. Ratzan S, Parker R. Introduction. In: Selden C, Zorn M, Ratzan S, Parker R, editors. National Library of Medicine Current Bibliographies in Medicine: Health Literacy. National Institutes of Health, US Department of Health and Human Services, Bethesda, Maryland, USA, 2000; v-vi. Available from: http://www.nlm.nih.gov/archive//20061214/pubs/cbm/hliteracy.html
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