Table 1 Summary of findings for children: multiple treatment of β2-agonist via spacer (chamber) compared with nebuliser for children with acute asthma
OutcomesIllustrative comparative risks# (95% CI)Relative effect (95% CI)No of Participants (studies)Quality of the evidence (GRADE)Comments
Assumed risk: nebuliserCorresponding risk: multiple treatment of β2-agonist via spacer (chamber)
Hospital admission110 per 100078 per 1000 (52 to 119)RR 0.71 (0.47 to 1.08)757 (9 studies)++ Low¶,§Large increases in the proportion of children admitted to hospital on spacer in comparison to nebuliser are ruled out by this 95% confidence interval.
Duration in emergency department minThe mean duration in emergency department (minutes) in the control groups was 103 minutesThe mean duration in emergency department (minutes) in the intervention groups was 33 minutes shorter (43 minutes shorter to 24 minutes shorter)396 (3 studies)+++ ModerateThere was a consistent direction of shortening of time in the emergency department in all three studies and, although the size of this effect varied between studies (I2 = 66%), we felt that the mean difference was important in all studies.
Final rise in FEV1 % predControl groups: 27% predicted at baselineIntervention groups: 0.92% higher (4.96% lower to 6.79% higher)48 (2 studies)++ Low¶,§
Mean rise in pulse rate % baselineControl groups: 7% rise from baselineIntervention groups: 5.62% lower (7.52% to 3.72% lower)670 (9 studies)+++ Moderate
Number of participants developing tremor142 per 100091 per 1000 (62 to 135)RR 0.64 (0.44 to 0.95)254 (4 studies)+++ Moderate
  • #: The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes, the corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI); : Mostly open label studies; §: Wide confidence intervals. Patient or population: children with acute asthma; settings: community or emergency department; intervention: multiple treatments with β2-agonist via spacer (chamber); comparison: multiple treatments with β2-agonist via nebuliser. GRADE Working Group grades of evidence are as follows: high quality: further research is very unlikely to change our confidence in the estimate of effect; moderate quality: further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate; low quality: further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate; very low quality: we are very uncertain about the estimate.