Quality of intervention delivery

Four components were chosen to assess quality of intervention delivery (one in each phase). These were the parent assembly (phase 1), the Healthy Lifestyles Week (phase 2), the parent assembly (phase 3) and the class delivered assembly (phase 4). For each of the four components, a score between 1 and 10 was given for (i) delivery; (ii) child response; (iii) parent response and (iv) teacher response. The criteria used to assess the quality of delivery were enthusiasm, open body language, responsivity to child/school needs and clear and friendly communication. The criteria to assess participant response to the delivery were attentiveness, positive body language (e.g. smiling, open posture) and active involvement (when required). These criteria evolved from the extensive piloting of the programme and in discussion with the advisory group and were felt to encompass the ‘spirit’ of the Healthy Lifestyles Programme.

The Trial Manager and the Principal Investigator independently scored quality of intervention delivery for the parent assembly in phase 1, across three schools. No discrepancy in scoring was observed for either quality of delivery or participant response. Thereafter, the majority of the observations were carried out by the Trial Manager.

The HeLP Coordinators assessed all the five drama sessions in the Healthy Lifestyle Week components (phase 2), after having carried out initial assessments alongside the Trial Manager (see Additional file 2 for an example checklist). Again, in order to control for possible bias, the Director of Headbanger’s Theatre Company, who had developed the drama scripts with the Trial Manager, observed and scored quality of delivery for one drama session in each of the 16 schools independently of the HeLP Coordinator. Scores were then compared for discrepancies.

The four scores (quality of delivery and child, parent and teacher response) per observation in each school were averaged (mean score) to create a single summary score out of 10 for each of the four components observed. These four component scores were then averaged to produce a single mean delivery score per school. A score ≥ 8 was pre-specified to indicate that the intervention had been delivered in the ‘spirit’ in which it had been designed.