Summary of outcomes and certainty of the evidence
| Outcome(s) | No of participants (studies) | Relative effect RR/MD (95% CI) | Anticipated absolute effect (95% CI) | Certainty of the evidence (GRADE) |
| Primary outcome: effect on asthma severity | ||||
| Composite Asthma Severity Score (assessed with different scores) | 1953 (6 RCTs) | SMD −0.1 (−0.2 to 0.02) | SMD 0.09 lower (0.2 lower to 0.02 higher) | ⨁⨁◯◯ Low* |
| Individual scores | ||||
| PRAM score | 981 (3 RCTs) | −0.07 (−0.42 to 0.28) | 0.07 lower (0.28 lower to 0.36 higher) | ⨁⨁◯◯ Low† |
| Asthma Severity Score | 872 (2 RCTs) | −0.14 (−0.29 to 0.00) | 0.14 lower (0.29 lower to 0) | ⨁⨁◯◯ Low† |
| Modified Pulmonary Index Score | 100 (1 RCT) | 0.38 (−0.25 to 1.01) | 0.38 higher (0.25 lower to 1.01 higher) | ⨁⨁◯◯ Low† |
| Secondary outcomes | ||||
| Need for hospitalisation | 978 (3 RCTs) | 0.92 (0.79 to 1.06) | 33 fewer per 1000 (86 fewer to 25 more) | ⨁⨁◯◯ Low* |
| Need for intensive care unit admission | 1037 (3 RCTs) | 1.29 (0.75 to 2.20) | 12 more per 1000 (11 fewer to 52 more) | ⨁⨁◯◯ Low* |
| Discharged by 24 hours | 365 (1 RCT) | 1.02 (0.95 to 1.10) | 18 more per 1000 (44 fewer to 89 more) | ⨁⨁◯◯ Low† |
| Length of hospital stay (hours) | 1070 (4 RCTs) | −4.6 (−10 to 0.8) | 4.59 lower (9.99 lower to 0.81 higher) | ⨁◯◯◯ Very low‡ |
| Pulmonary function tests | ||||
| Peak expiratory flow rate (% predicted) | 145 (2 RCTs) | 19.3 (8.9 to 29.8) | 19.34 higher (8.94 higher to 29.75 higher) | ⨁⨁◯◯ Low§ |
| FEV1 (% predicted) | 62 (1 RCT) | 8.1 (−3.0 to 19.2) | 8.1 higher (3.03 lower to 19.23 higher) | ⨁◯◯◯ Very low¶ |
| Vital parameters | ||||
| Heart rate (beats/min) | 372 (5 RCTs) | −2.7 (−8.2 to 2.7) | 2.71 lower (8.16 lower to 2.74 higher) | ⨁◯◯◯ Very low†‡ |
| Respiratory rate (breaths/min) | 1056 (5 RCTs) | −0.9 (−1.4 to −0.4) | 0.87 lower (1.38 lower to 0.36 lower) | ⨁⨁◯◯ Low§ |
| Oxygen saturation | 1071 (5 RCTs) | 1.2 (−3.5 to 5.8) | 1.16 higher (3.47 lower to 5.79 higher) | ⨁◯◯◯ Very low*‡ |
| Any adverse event | 2015 (7 RCTs) | 1.45 (0.63 to 3.34) | 32 more per 1000 (26 fewer to 165 more) | ⨁◯◯◯ Very low*‡ |
*Wide 95% CI crossing the threshold for benefit/harm.
†Wide 95% CI crossing null line and small sample size.
‡Substantial heterogeneity.
§Sample size is far less than optimal information size (OIS).
¶Sample size is far less than optimal information size (OIS) and 95% CI crossing the threshold of appreciable benefit/harm.
FEV1, forced expiratory volume in 1 s; GRADE, Grading of Recommendations, Assessment, Development, and Evaluations; MD, mean dfference; PRAM, Pediatric Respiratory Assessment Measure; RCTs, randomised controlled trials; RR, risk ratio; SMD, standardised mean difference.