Individual assessment of each study regarding suitability for inclusion in meta-analysis
| Outcome assessed | Study | Justification |
| Continuous outcomes | ||
| ACQ scores | Garcia-Cardenas et al. [19] | Lack of standard deviation of mean change for control group |
| Armour et al. [15] | Lack of control group | |
| Giraud et al. [20] | Lack of control group | |
| Smith et al. [25] | Lack of standard deviation of mean change for both study groups | |
| Lim et al. [33] | Appropriate for meta-analysis | |
| Toumas-Sehata et al. [26] | Lack of control group | |
| ACT scores | Mehuys et al. [22] | Appropriate for meta-analysis |
| Young et al. [34] | Lack of standard deviation of mean difference | |
| Bereznicki et al. [17] | Lack of baseline results for control group; lack of mean change and standard deviation of both study groups | |
| Asthma severity | Mangiapane et al. [21] | Lack of control group |
| Saini et al. [23] | Lack of standard deviation of mean for both groups | |
| Schulz et al. [24] | Lack of standard deviation of mean for both groups | |
| PEF | Mangiapane et al. [21] | Lack of control group |
| Saini et al. [23] | PEF values only in intervention group | |
| Mehuys et al. [22] | Appropriate for meta-analysis | |
| Abdelhamid et al. [29] | Lack of outcome values before and after in both study groups | |
| Petkova [18] | Lack of control group | |
| Schulz et al. [24] | Lack of standard deviation of mean change for both study groups | |
| Narhi et al. [30] | Lack of control group | |
| FEV1 | Mangiapane et al. [21] | Lack of control group |
| Anjan Kumar et al. [28] | Lack of standard deviation of mean change for both study groups | |
| Schulz et al. [24] | Appropriate for meta-analysis | |
| Armour et al. [14] | Appropriate for meta-analysis | |
| de Tullio and Corson [32] | Lack of standard deviation of mean change and p-value for both study groups | |
| Zanghelini et al. [27] | Lack of control group | |
| VC | Mangiapane et al. [21] | Appropriate for meta-analysis |
| FVC | de Tullio and Corson [32] | Results not reported |
| FEV1/FVC | Armour et al. [14] | Appropriate for meta-analysis |
| FEV1 % VC | Mangiapane et al. [21] | Appropriate for meta-analysis |
| Asthma symptoms | Barbanel et al. [16] | Appropriate for meta-analysis |
| Mehuys et al. [22] | Appropriate for meta-analysis | |
| Petkova [18] | Lack of control group | |
| Narhi et al. [30] | Lack of control group | |
| Odegard et al. [31] | Lack of control group | |
| Abdelhamid et al. [29] | Appropriate for meta-analysis | |
| Mangiapane et al. [21] | Lack of control group | |
| Schulz et al. [24] | Lack of standard deviation of mean change for both study groups | |
| Dichotomous outcomes | ||
| Asthma control | Mehuys et al. [22] | Appropriate for meta-analysis |
| Armour et al. [15] | Appropriate for meta-analysis | |
| Garcia-Cardenas et al. [19] | Appropriate for meta-analysis | |
| Zanghelini et al. [27] | Lack of control group | |
| Asthma severity | Armour et al. [14] | Appropriate for meta-analysis |
ACQ: Asthma Control Questionnaire; ACT: Asthma Control Test; PEF: peak expiratory flow; FEV1: forced expiratory volume in 1 s; VC: vital capacity; FVC: forced vital capacity.