Kotses et al20 | 33 [7–16 years] | Two parallel groups | | Biofeedback for facial relaxation (FD) (n=17) | Biofeedback for maintaining face tension at a stable level (FS) (n=16) | 2 DO from each group | 2 | i) Lung function tests incl. FEV1/FVC, PEFR | i) NSD |
| Yes | a) no | d) unclear | | | | | ii) Scores | ii) NSD |
| | b) yes | e) 2 months | | | | | a) Asthma severity | |
| | c) no | f) 5.5 months | | | | | b) Medicine | |
| | | | | | | | c) Frequency of attacks | |
| | | | | | | | | |
Coen et al21 | 20 [12–22 years] | Two parallel groups | | Relaxation techniques aided by biofeedback 15 mins twice daily (n=10) | Telephone contact (n=10) | Not stated although only sporadic data on PEFR because of compliance | 1 | i) Lung function tests | i) NSD |
| No | a) no | d) daily ×2 | | | | | ii) Symptom/medication score | ii) NSD |
| | b) yes | e) 8 weeks | | | | | | |
| | c) no | f) 14 days | | | | | | |