Participants
Sixty-seven managers across four divisions of the DVLA, stratified by division [Information Technology Services (ITS), the Contact Centre (CC), Casework and Enforcement Group (CAEG), and Input Services Group (ISG)] were chosen for the study. These were then randomised (using a random number sequence) into the two arms (active vs. control) with stratification to ensure equal numbers of managers from each division and similar gender profile being assigned to each group. These procedures were implemented by staff within the Human Resources department of the DVLA. The “random” split did not achieve a perfectly even split and 59% of the staff were allocated to the active arm of the study.The numbers in each phase of the study varied due to issues such as staff moving from the DVLA during the study, staff moving between teams/divisions within the DVLA, or not agreeing to consent to the study, etc. Numbers at each stage are illustrated in Fig. 
Consort Representation of Study