Swimming training for asthma in children and adolescents aged 18 and under (review)
Beggs, S and Foong, Y and Le, HC and Mohammed Noor, WD and Wood-Baker, R and Walters, JAE, Swimming training for asthma in children and adolescents aged 18 and under (review), Cochrane Database of Systematic Reviews, 4 pp. CD009607. ISSN 1469-493X (2013) [Contribution to Refereed Journal]
Asthma is the most common chronic medical condition in children and a common reason for hospitalisation. Observational studies
have suggested that swimming, in particular, is an ideal form of physical activity to improve fitness and decrease the burden of disease
To determine the effectiveness and safety of swimming training as an intervention for asthma in children and adolescents aged 18 years
We searched theCochrane AirwaysGroup’s Specialised Register of trials (CENTRAL),MEDLINE , EMBASE, CINAHL, inNovember
2011, and repeated the search of CENTRAL in July 2012. We also handsearched ongoing Clinical Trials Registers.
We included all randomised controlled trials (RCTs) and quasi-RCTs of children and adolescents comparing swimming training with
usual care, a non-physical activity, or physical activity other than swimming.
Data collection and analysis
We used standard methods specified in the CochraneHandbook for Systematic reviews of Interventions.Two review authors used a standard
template to independently assess trials for inclusion and extract data on study characteristics, risk of bias elements and outcomes. We
contacted trial authors to request data if not published fully. When required, we calculated correlation coefficients from studies with
full outcome data to impute standard deviation of changes from baseline.
Eight studies involving 262 participants were included in the review. Participants had stable asthma, with severity ranging from mild
to severe. All studies were randomised trials, three studies had high withdrawal rates. Participants were between five to 18 years of
age, and in seven studies swimming training varied from 30 to 90 minutes, two to three times a week, over six to 12 weeks. The
programme in one study gave 30 minutes training six times per week. The comparison was usual care in seven studies and golf in one
study. Chlorination status of swimming pool was unknown for four studies. Two studies used non-chlorinated pools, one study used
an indoor chlorinated pool and one study used a chlorinated but well-ventilated pool.
No statistically significant effects were seen in studies comparing swimming training with usual care or another physical activity for
the primary outcomes; quality of life, asthma control, asthma exacerbations or use of corticosteroids for asthma. Swimming training
had a clinically meaningful effect on exercise capacity compared with usual care, measured as maximal oxygen consumption during
a maximum effort exercise test (VO2 max) (two studies, n = 32), with a mean increase of 9.67 mL/kg/min; 95% confidence interval
(CI) 5.84 to 13.51. A difference of equivalent magnitude was found when other measures of exercise capacity were also pooled (four
studies, n = 74), giving a standardised mean difference (SMD) 1.34; 95% CI 0.82 to 1.86. Swimming training was associated with
small increases in resting lung function parameters of varying statistical significance; mean difference (MD) for FEV1%predicted 8.07;
95% CI 3.59 to 12.54. In sensitivity analyses, by risk of attrition bias or use of imputed standard deviations, there were no important
changes on effect sizes. Unknown chlorination status of pools limited subgroup analyses.
Based on limited data, there were no adverse effects on asthma control or occurrence of exacerbations.
This review indicates that swimming training is well-tolerated in children and adolescents with stable asthma, and increases lung
function (moderate strength evidence) and cardio-pulmonary fitness (high strength evidence). There was no evidence that swimming
training caused adverse effects on asthma control in young people 18 years and under with stable asthma of any severity. However
whether swimming is better than other forms of physical activity cannot be determined from this review. Further