Exhaled Nitric Oxide Levels to Guide Treatment for Children with Asthma

Summary

A Cochrane review [Abstract] 1 included 9 studies with a total of 1 426 children with asthma (1 329 completed). The studies differed in definition of asthma exacerbations, fractional exhaled nitric oxide (FeNO) cut-off levels used (12 parts per billion (ppb) to 30 ppb), the way in which FeNO was used to adjust therapy and duration of study (6 to 12 months).

The number of children having at least one asthma exacerbation over the study period was significantly lower in the FeNO group compared to control group (OR 0.58, 95% CI 0.45 to 0.75; 8 studies, n=1 279). The number needed to treat for an additional beneficial outcome (NNTB) over 52 weeks was 9 (95% CI 6 to 15). There was no difference between the groups when comparing exacerbation rates (MD -0.37, 95% CI -0.8 to 0.06, statistical heterogeneity I² = 67%; 4 studies, n=736). The number of children in the FeNO group requiring oral corticosteroid courses was lower in comparison to the children in the control group (OR 0.63, 95% CI 0.48 to 0.83; 7 studies, n=1 169). There was no statistically significant difference between the groups for exacerbations requiring hospitalisation (OR 0.75, 95% CI 0.41 to 1.36; 6 studies, n=1 110). There were no significant differences between the groups for any of the secondary outcomes (FEV₁, FeNO levels, symptom scores or inhaled corticosteroid doses at final visit). The included studies recorded no adverse events.