Breathing exercises for children with asthma

  • Protocol
  • Intervention



This is the protocol for a review and there is no abstract. The objectives are as follows:

To assess the effects of breathing exercises in children with asthma.


Description of the condition

Asthma is a chronic inflammatory disorder of the lungs that can lead to structural and functional changes resulting from bronchial hyperresponsiveness and airflow obstruction (Allen 2012; Brightling 2012; Holgate 2009; Taylor 2008; Zhang 2010). Symptoms of asthma include recurrent episodes of wheeze, cough, breathlessness and chest tightness, together with episodes of marked worsening of symptoms known as exacerbations (Bateman 2008; Brightling 2012; Zhang 2010). The diagnosis of asthma is based on the individual's medical history, physical examination findings and lung function and laboratory test results (Sveum 2010).

Asthma is a serious public health problem and a major cause of disability and health resource utilisation among those affected (Bateman 2008; Eisner 2012; To 2012). Around 300 million individuals of all ages worldwide are affected by asthma (Bateman 2008; Bousquet 2010; Brightling 2012). Asthma is the most common chronic disease in childhood (Solé 2006). Increased morbidity, mortality and economic costs are associated with patients with severe or difficult to treat asthma, particularly in industrialised countries (Eisner 2012; Zhang 2010). In addition, psychological symptoms may interfere with the severity of respiratory symptoms and may influence patients’ quality of life (Juniper 2004; Rimington 2001). Such consequences affect not only the patient but the whole family universe (Nogueira 2009), especially when it comes to children.

Asthma is sometimes associated with symptomatic hyperventilation, which decreases carbon dioxide (CO2) levels, causing hypocapnia (Bruton 2005a; Laffey 2002; Thomas 2001). Hypocapnia resulting from hyperventilation may perpetuate the bronchospasm, culminating in a cycle of progressive hypocapnia and increasing bronchospasm (Laffey 2002). Thus, hypocapnia may contribute to increased airway resistance in patients with asthma (Laffey 2002; van den Elshout 1991). This fact has led to increasing interest in strategies that can be used to reduce hyperventilation.

Description of the intervention

The main objective of asthma treatment is to achieve and maintain its clinical control (GINA 2012). Although no cure for asthma is known, its symptoms are controllable in most patients (Taylor 2008). Asthma treatment can be pharmacological or non-pharmacological or a combination of these approaches; it includes strategies of symptom control (information on environmental triggers and asthma education) to reduce symptoms and improve quality of life related to health (Burgess 2011; Rimington 2001; Welsh 2011).

Pharmacological treatment of asthma consists of maintaining control of the disease with the least medication, thereby minimising risks of adverse effects (Sveum 2010).

Non-pharmacological treatments have been used widely by researchers and professionals in the search for complementary therapies for the treatment of asthma; their use is reported in approximately 42% of patients in some populations (Blanc 2001). Some patients are interested in non-pharmacological therapies because they may feel or hope that they will lead to improvement in overall health (Bishop 2008), and because they are keen to try to reduce the need for pharmacological treatment (Brien 2011). Complementary medicine includes breathing exercises, homeopathy, acupuncture, aromatherapy, reflexology, massage, inspiratory muscle training and the Alexander technique (Blanc 2001; Bruton 2005b; Cooper 2003; Dennis 2012; Grammatopoulou 2011; Holloway 2007; Lima 2008; McCarney 2003; McHugh 2003).

Breathing exercises have been used routinely by physiotherapists and other professionals to control the hyperventilation symptoms of asthma (Bruton 2005b) and can be provided in the form of the Papworth method, the Buteyko breathing technique, yoga or any similar intervention that manipulates the breathing pattern (Ram 2003). Even though breathing exercises are commonly used, there is not a consensus regarding the effectiveness of breathing exercises. It was previously reported that groups with the same baseline characteristics may show different responses to different breathing exercise techniques (Prem 2013). Also, the duration of the intervention may interfere with the response to treatment, as was suggested previously (Grammatopoulou 2011). A previous systematic review on breathing exercises for asthma included studies performed in participants with mild to severe asthma (Ernst 2000). However, meta-analysis was not provided to assess the impact of breathing exercises at different levels of asthma severity.

How the intervention might work

Breathing exercise techniques focus on the use of an appropriate breathing pattern to reduce hyperventilation and hyperinflation, thereby increasing CO2 levels, which may reduce bronchospasm, normalise the breathing pattern and reduce breathlessness (Bruton 2005b; Burgess 2011). Such techniques may also be used to help reduce anxiety associated with asthma symptoms (Singh 1990). Therefore, breathing exercises in patients with asthma may provide psychological benefits by increasing patients' sense of control over their condition (Ram 2003).

Why it is important to do this review

The worldwide high prevalence of asthma became a public health problem because of the high healthcare costs resulting from hospitalisation and medication (Giavina-Bianchi 2010). Asthma promotes changes in the whole family context, not only because of the costs associated with health care, but also because of the impact of this condition on daily living, including patients’ quality of life (Ferreira 2010).

Asthma control is promoted by the correct use of medication and may be associated with other therapies, such as breathing exercises. Such techniques have been widely used as adjunct therapy in the treatment of asthmatic patients, generating considerable interest among researchers to develop studies that aim to provide evidence of this intervention. Recently, we published a Cochrane systematic review regarding the use of breathing exercises in adults with asthma (Freitas 2013). This review included studies that differed significantly in terms of intervention characteristics, such as types of breathing exercises, numbers of participants, numbers and duration of sessions, reported outcomes and statistical presentation of data. Such differences limited meta-analysis and attainment of conclusive results. On the other hand, this review indicated that breathing exercises are a safe and well-tolerated intervention for people with asthma. Similarly, no conclusive evidence was provided in two previous systematic reviews (Ernst 2000; Ram 2003), even though outcomes reported from individual trials showed that breathing exercises may have a role in the treatment and management of asthma.

It is important to synthesise the evidence obtained on such techniques, taking into account their effects in the paediatric population. To our knowledge, no systematic review on this topic has been published previously. Thus, within this review, we aim to summarise and assess evidence from randomised controlled trials regarding the effects of breathing exercises in children with asthma.


To assess the effects of breathing exercises in children with asthma.


Criteria for considering studies for this review

Types of studies

We will include randomised controlled trials (RCTs).

Types of participants

We will include children (younger than 18 years of age) with a diagnosis of asthma. We will exclude participants with other associated respiratory disease.

Types of interventions

We will include trials comparing breathing exercises versus asthma education or alternatively versus no active control group (e.g. waiting list control).

Types of outcome measures

Primary outcomes
  1. Quality of life (measured by any respiratory disease–specific or generic instrument).

  2. Asthma symptoms (measured by any respiratory disease–specific or generic instrument).

  3. Serious adverse events (any undesired outcomes due to the intervention).

Secondary outcomes
  1. Reduction in medication usage (e.g. inhaled or oral steroids or rescue bronchodilator).

  2. Number of acute exacerbations (mean number and number of participants experiencing one or more exacerbations).

  3. Physiological measures—lung function (especially low flow rates) and functional capacity.

  4. Days off school.

  5. Adverse events.

Reporting in the trial one of more of the outcomes listed here is not an inclusion criterion for the review.

Search methods for identification of studies

Electronic searches

We will identify trials from the Cochrane Airways Group Specialised Register (CAGR), which is maintained by the Trials Search Co-ordinator for the Group. The Register contains trial reports identified through systematic searches of bibliographic databases including the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, CINAHL, AMED and PsycINFO, and by handsearching of respiratory journals and meeting abstracts (see Appendix 1 for further details). We will search all records in the CAGR using the search strategy provided in Appendix 2.

We will also conduct a search of ( and the World Health Organization (WHO) trials portal ( We will search all databases from their inception to the present, and we will impose no restriction on language of publication.

Searching other resources

We will check reference lists of all primary studies and review articles for additional references. We will search relevant manufacturers' websites for trial information.

We will search for errata or retractions from included studies published in full text on PubMed ( and will report within the review the date this was done.

Data collection and analysis

Selection of studies

Two review authors (TMFM and DAF) will independently screen titles and abstracts for inclusion of all potential studies identified as a result of the search and will code them as 'retrieve' (eligible or potentially eligible/unclear) or 'do not retrieve'. We will retrieve the full-text study report/publication, and two review authors (TMFM and DAF) will independently screen the full text, identify studies for inclusion and identify and record reasons for exclusion of ineligible studies. We will resolve disagreement through discussion, or, if required, we will consult a third review author (KMPPM). We will identify and exclude duplicates and will collate multiple reports of the same study, so that each study rather than each report is the unit of interest in the review. We will record the selection process in sufficient detail to complete a PRISMA flow diagram and a 'Characteristics of excluded studies' table.

Data extraction and management

To record study characteristics and outcome data, we will use a data collection form that has been piloted on at least one study in the review. One review author (TMFM or DAF) will extract the following study characteristics from included studies.

  1. Methods: study design, total duration of study, method of randomisation, method of allocation concealment, outcome assessor blinding, number of study centres and locations, study setting, withdrawals and dropouts and dates of the study.

  2. Participants: N, mean age, age range, gender, severity of condition, diagnostic criteria, baseline lung function, smoking history, inclusion criteria and exclusion criteria.

  3. Interventions: types of breathing exercises, methods (including numbers and duration of sessions and methods used in control group comparisons).

  4. Outcomes: primary and secondary outcomes specified and collected, and time points reported.

  5. Notes: funding for trial and notable conflicts of interest of trial authors.

Two review authors (TMFM and DAF) will independently extract outcome data from included studies. We will note in the 'Characteristics of included studies' table whether outcome data were reported in a usable way. We will resolve disagreements by consensus or by involving a third review author (KMPPM). One review author (TMFM) will transfer data into the Review Manager (RevMan 2012) file. We will double-check that data have been entered correctly by comparing the data presented in the systematic review against the study reports. A second review author (DAF) will spot-check study characteristics against the trial report to confirm accuracy.

Assessment of risk of bias in included studies

Two review authors (TMFM and DAF) will independently assess risk of bias for each study using the criteria outlined in the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2011a). We will resolve disagreements by discussion or by involving another review author (KMPPM). We will assess the risk of bias according to the following domains.

  1. Random sequence generation.

  2. Allocation concealment.

  3. Blinding of participants and personnel.

  4. Blinding of outcome assessment.

  5. Incomplete outcome data.

  6. Selective outcome reporting.

  7. Other bias.

We will grade each potential source of bias as high, low or unclear and will provide a quote from the study report, together with justification for our judgement, in the 'Risk of bias' table. We will summarise the risk of bias judgements across different studies for each of the domains listed. We will consider blinding separately for different key outcomes when necessary (e.g. for an unblinded outcome assessment, risk of bias for all-cause mortality may be very different than for a patient-reported pain scale). When information on risk of bias relates to unpublished data or correspondence with a trialist, we will note this in the 'Risk of bias' table.

When considering treatment effects, we will take into account the risk of bias for studies that contribute to that outcome.

Assesment of bias in conducting the systematic review

We will conduct the review according to this published protocol and will report deviations from it in the 'Differences between protocol and review' section of the systematic review.

Measures of treatment effect

We will analyse dichotomous data as odds ratios, and continuous data as mean differences or standardised mean differences with 95% confidence intervals (CIs). We will enter data presented on a scale with a consistent direction of effect.

We will undertake meta-analyses only when this is meaningful (i.e. if treatments, participants and the underlying clinical question are similar enough for pooling to make sense).

We will narratively describe skewed data reported as medians and interquartile ranges.

When multiple trial arms are reported in a single trial, we will include only the relevant arms. If two comparisons (e.g. breathing exercise A vs control and breathing exercise B vs control) are combined in the same meta-analysis, we will halve the control group to avoid double-counting.

Unit of analysis issues

Cross-over trials

We will not include cross-over studies, as the design is not appropriate for this intervention.

Cluster-randomised trials

We will include data from cluster-randomised trials if the information is available. For cluster-randomised trials, we will adjust results when the unit of analysis in the trial is presented as the total number of individual participants instead of as the number of clusters. We will adjust the results using mean cluster size and the intracluster correlation co-efficient (ICC) (Higgins 2011b). For meta-analysis, we will combine data from individually randomised trials using the generic inverse-variance method, as described in Chapter 16.3 of the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2011b).

Dealing with missing data

We will contact investigators or study sponsors when possible to verify key study characteristics and to obtain missing numerical outcome data (e.g. when a study is identified as an abstract only). When this is not possible, and the missing data are thought to introduce serious bias, we will perform a sensitivity analysis to explore the impact of including such studies in the overall assessment of results. 

Assessment of heterogeneity

The review authors will assess heterogeneity in trial results by inspecting the forest plots to detect non-overlapping CIs and by applying the Chi2 test (with P value 0.10 indicating statistical significance). We will use the I² statistic to measure heterogeneity among trials in each analysis. If we identify substantial heterogeneity (> 50%) we will report this and will explore possible causes by prespecified subgroup analysis (Higgins 2011c). 

Assessment of reporting biases

If we are able to pool more than 10 trials, we will create and examine a funnel plot to explore possible small-study and publication biases (Higgins 2011d).

Data synthesis

The review authors will use RevMan 5.1 to combine outcomes when possible (RevMan 2012). The review authors will use a fixed-effect model unless substantial heterogeneity (I2 > 50%) is observed, in which case they will use a random-effects model.

Summary of findings table

We will create a 'Summary of findings' table using the following outcomes: quality of life, asthma symptoms, serious adverse events, reduction in medication usage, number of acute exacerbations, physiological measures and days off school. We will use the five GRADE considerations (study limitations, consistency of effect, imprecision, indirectness and publication bias) to assess the quality of a body of evidence as it relates to the studies contributing data to the meta-analyses for prespecified outcomes. We will apply methods and recommendations described in Section 8.5 and Chapter 12 of the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2011e) using GRADEpro software. We will justify all decisions to downgrade or upgrade the quality of studies by using footnotes, and we will make comments when necessary to aid readers' understanding of the review.

Subgroup analysis and investigation of heterogeneity

We plan to carry out the following subgroup analyses.

  1. Degree of asthma severity.

  2. Duration of treatment.

  3. Types of breathing exercises.

We will use the following outcomes in subgroup analyses.

  1. Quality of life.

  2. Reduction in medication usage.

We will use the formal test for subgroup interactions in Review Manager (RevMan 2012).

Sensitivity analysis

We plan to carry out the following sensitivity analyses.

  1. Trial quality (studies with overall high risk of bias versus overall low risk of bias).

Reaching conclusions

We will base our conclusions only on findings from the quantitative or narrative synthesis of included studies in this review. We will avoid making recommendations for practise, and our implications for research will suggest priorities for future studies and will outline remaining uncertainties in this area.


The authors would like to thank Emma Welsh (the Managing Editor of the Cochrane Airways Group) for assistance provided in beginning this review, Elizabeth Stovold (the Trials Search Co-ordinator/Information Specialist of the Cochrane Airways Group) for the search strategy used in the review and Emma Jackson (Editorial Assistant of the Cochrane Airways Group) for assistance provided.

Anne Holland was the Editor for this review and commented critically on the review.


Appendix 1. Sources and search methods for the Cochrane Airways Group Specialised Register (CAGR)

Electronic searches: core databases

Database Frequency of search
MEDLINE (Ovid)Weekly
EMBASE (Ovid)Weekly
PsycINFO (Ovid)Monthly


Handsearches: core respiratory conference abstracts

Conference Years searched
American Academy of Allergy, Asthma and Immunology (AAAAI)2001 onwards
American Thoracic Society (ATS)2001 onwards
Asia Pacific Society of Respirology (APSR)2004 onwards
British Thoracic Society Winter Meeting (BTS)2000 onwards
Chest Meeting2003 onwards
European Respiratory Society (ERS)1992, 1994, 2000 onwards
International Primary Care Respiratory Group Congress (IPCRG)2002 onwards
Thoracic Society of Australia and New Zealand (TSANZ)1999 onwards


MEDLINE search strategy used to identify trials for the CAGR

Asthma search

1. exp Asthma/

2. asthma$.mp.

3. (antiasthma$ or anti-asthma$).mp.

4. Respiratory Sounds/

5. wheez$.mp.

6. Bronchial Spasm/

7. bronchospas$.mp.

8. (bronch$ adj3 spasm$).mp.

9. bronchoconstrict$.mp.

10. exp Bronchoconstriction/

11. (bronch$ adj3 constrict$).mp.

12. Bronchial Hyperreactivity/

13. Respiratory Hypersensitivity/

14. ((bronchial$ or respiratory or airway$ or lung$) adj3 (hypersensitiv$ or hyperreactiv$ or allerg$ or insufficiency)).mp.

15. ((dust or mite$) adj3 (allerg$ or hypersensitiv$)).mp.

16. or/1-15

Filter to identify RCTs

1. exp "clinical trial [publication type]"/

2. (randomised or randomised).ab,ti.

3. placebo.ab,ti.

4. dt.fs.

5. randomly.ab,ti.

6. trial.ab,ti.

7. groups.ab,ti.

8. or/1-7

9. Animals/

10. Humans/

11. 9 not (9 and 10)

12. 8 not 11

The MEDLINE strategy and the RCT filter are adapted to identify trials in other electronic databases.

Appendix 2. Search strategy to identify relevant trials from the CAGR


#2 MeSH DESCRIPTOR Asthma Explode All

#3 asthma*:ti,ab

#4 #1 or #2 or #3

#5 MeSH DESCRIPTOR Breathing Exercises

#6 (breath*) NEAR5 (technique* or exercise* or re-train* or train* or re-educat* or educat* or physiotherap* or "physical therapy" or "respiratory therapy")

#7 buteyko or "qigong yangsheng" or pranayama* OR yoga*

#8 "breathing control"

#9 #5 or #6 or #7 or #8

#10 #4 and #9

#11 child* or paediat* or pediat* or adolesc* or infan* or toddler* or bab* or young* or preschool* or "pre school*" or pre-school* or newborn* or "new born*" or new-born* or neo-nat* or neonat*

#12 MeSH DESCRIPTOR Child Explode All

#13 MeSH DESCRIPTOR Pediatrics Explode All

#14 MeSH DESCRIPTOR Infant Explode All

#15 MeSH DESCRIPTOR Adolescent Explode All

#16 #11 or #12 or #13 or #14 or #15

#17 #10 and #16

[Note: in search line #1, MISC1 refers to the field in the record where the reference has been coded for condition, in this case, asthma]

Contributions of authors

Thalita Macêdo: developed and advised on the protocol; completed the first draft of the protocol; made an intellectual contribution to the protocol; approved the final version of the protocol before submission.

Diana Freitas: developed and advised on the protocol; completed the first draft of the protocol; made an intellectual contribution to the protocol; approved the final version of the protocol before submission.

Gabriela Chaves: completed the first draft of the protocol; made an intellectual contribution to the protocol; approved the final version of the protocol before submission.

Elizabeth Holloway: contributed clinical expertise; approved the final version of the protocol before submission.

Karla Mendonça: developed and co-ordinated the protocol; completed part of the first draft of the protocol; made an intellectual contribution to the protocol; approved the final version of the protocol before submission.

Declarations of interest

None known.