Changes in cardiorespiratory fitness at 6-month follow-up between participants randomised to usual practice (control) or the Burn 2 Learn intervention
| Primary outcome (6 months) | No of clusters (participants) | Mean change from baseline (95% CI) | Adjusted difference at follow-up* | |||
| Control | Intervention | Control | Intervention | Coefficient (95% CI) | P value | |
| Cardiorespiratory fitness: intention-to-treat† | 10 (310) | 10 (329) | −3.52 (−5.50 to −1.54) | 0.91 (−0.46 to 2.28) | 4.10 (1.78 to 6.42) | <0.001 |
| Cardiorespiratory fitness: complete case‡ | 10 (211) | 10 (234) | −3.52 (−5.50 to −1.54) | 0.91 (−0.46 to 2.28) | 4.43 (2.08 to 6.78) | <0.001 |
| Cardiorespiratory fitness: multiple imputation§ | 10 (310) | 10 (329) | −3.01 (−4.47 to −1.56) | 0.97 (−0.22 to 2.16) | 3.98 (1.61 to 6.36) | <0.001 |
| Cardiorespiratory fitness: per protocol (group)¶ | 10 (310) | 7 (226) | −3.52 (−5.50 to −1.54) | 1.55 (−0.13 to 3.23) | 4.61 (1.98 to 7.24) | <0.001 |
| Cardiorespiratory fitness: per protocol (individual)** | 10 (310) | 10 (133) | −3.52 (−5.50 to −1.54) | 1.20 (−0.69 to 3.09) | 4.23 (1.19 to 7.26) | 0.007 |
*Adjusted difference ((intervention post-test mean−intervention baseline mean)−(control post-test mean−control baseline mean)) in multi-stage fitness test laps. P value adjusted for clustering and randomisation pair.
†Intention-to-treat analysis included all participants who completed the multi-stage fitness test at baseline or follow-up.
‡Complete case analysis included participants who completed the multi-stage fitness test at baseline and follow-up.
§Multiple imputation analysis included all participants who completed the multi-stage fitness test at baseline or follow-up.
¶Class-level per-protocol analysis included students from classes in which at least 28 school-based sessions were delivered.
**Student-level per-protocol analysis included students who achieved an average peak heart rate (HR) of ≥80% HRmax during sessions.