Costs
Costs were estimated from the perspective of the UCS’ operating budget (primarily covering salaries of staff; excludes room hire)—hereafter referred to as the ‘UCS perspective’. Use of SAU UCS offerings were extracted from the UCS record system (consequently, there is no missing data on UCS service use) following participant agreements and strict confidentiality of access protocols.At the time of this evaluation, routine UCS services were categorised into three broad groups: ‘individual’ sessions providing support to one student (includes assessment sessions); ‘workshops’—one-off offerings that more than one student attends—and ‘groups’—a number of sessions attended by multiple students (where a student stops attending a group, their place cannot be used by another student). In consultation with the then UCS head (GD), who consulted the UCS senior management team, we determined the usual staff grade delivering each offering and the associated typical time taken to prepare, deliver and record (eg, completing notes) each of these session types. To calculate the cost to the UCS of a given offering, we multiplied the time taken to prepare, deliver and record it by the hourly rate of employing staff at the required grade. For workshops and groups, the cost per student (unit cost) of an offering is determined by dividing its total cost by the number of students typically attending each offering (details given in the 
The total cost of delivering a course of mindfulness (the intervention) to 30 students (maximum capacity of a course) was determined through consultation with the then UCS head (GD) and the course teacher. Accordingly, the activities involved in delivering a course were identified, along with the total time, and grade of staff, delivering each activity. Total times were multiplied by appropriate hourly rates of staff delivering each course activity and summed to give the total cost of delivering a mindfulness course. The cost per student (unit cost) of delivering the course was determined by dividing this total cost by the capacity of each class (n=30 students). This cost was ascribed to each of the students in the MSS+SAU arm (multiple courses were being delivered in parallel for each cohort of MSS+SAU). This cost was irrespective of student attendance: the nature of the mindfulness course is such that a student cannot join part way through, so a non-attending student cannot be ‘replaced’; this is in line with other UCS groups.Hourly cost of employing staff were taken from the UoC Human Resources website and include on-costs (such as pension and national insurance contribution—see 