Reported asthma-related outcomes of included trials.

Abbreviations: NS, non-significant effect; FEV1, forced expiratory volume in 1 second; PEF, peak expiratory flow; ↑, intervention significantly increased outcome measure as compared to control (P<0.05); ↓ intervention significantly decreased outcome measure as compared to control (P<0.05). *Shows effect direction between intervention and control at the end of follow-up. †Asthma symptoms score based on different scoring systems. ‡As defined by asthma exacerbation attacks. Outcome based on two different units of measurement: number of children experiencing asthma exacerbation and number of asthma exacerbation during treatment period. Reported asthma-related outcomes of included trials.