Title: Stand Out in Class: Restructuring the classroom environment to reduce sedentary behaviour - a pilot cluster randomised controlled trial
Funder: Department of Health and Social Care

Abstract: Background: Sedentary behaviour (sitting and expending <1.5 METs) is an important and highly prevalent negative health behaviour, accounting for >70% of wake time (~10 hours/day) in samples of Bradford primary school children. Adverse associations between sedentary behaviour and cardio-metabolic health risk markers have been reported in children. As sedentary children are highly likely to become sedentary adults the reduction of sedentary time in young people is pertinent for the primary and secondary prevention of chronic diseases that result from excessive sitting in adulthood. Classrooms are conducive to high volumes of sitting, therefore changing the classroom environment through the provision of sit-stand desks appears to be a feasible way of reducing children’s sedentary time in the short term. Classroom-based interventions are accessible to all children, providing a suitable environment for targeting health inequalities. Feasibility study: We have demonstrated the feasibility of incorporating sit-stand desks in the classroom over a 9-week period in a sample of Bradford primary school children. A reduction of 80 mins/day in daily sitting time was achieved. Behavioural improvements in class and no perceived negative effects on teaching and learning were observed. However, the longer term acceptability of this intervention in UK primary schools is yet to be established. Aim: The aim of this study is to undertake a pilot cluster randomised controlled trial (RCT) of an 8-month sit-stand desk intervention in primary school classrooms to inform a future fully-powered trial. Research plan: Year 5 children from 8 participating Bradford schools (4 intervention and 4 control, stratified by ethnic mix of pupils) will be invited to participate. We estimate that at least 120 participants will enrol into the study, which will provide estimates of the variation in the outcome measures, informing a sample size calculation for a full trial. Sit-stand desks (provided via an in-kind donation from our industrial partners) will replace 6 to 8 standard desks in the intervention classrooms. In consultation with teachers, we will ensure all pupils are exposed to the sit-stand desks for at least 1 hour/day. An advantage of this intervention is the minimal human resources needed for successful implementation after desk installation. Schools assigned to the control arm will be asked to continue with their usual lesson delivery, no environmental changes will be made to their classrooms. Measurements will be taken at baseline (October/November 2016) before desk installation and at the end of the school’s academic year (June/July 2017). In this pilot study, the primary outcome will be the acceptability of the long-term use of sit-stand desks and outcome measures proposed for inclusion in a full RCT (objectively measured total daily sitting time, physical activity during and outside school hours, adiposity, blood pressure, cognitive function, academic progress, engagement and behaviour). Acceptability of the trial will be assessed by monitoring recruitment uptake, compliance and attrition rates. We will conduct a full process evaluation and an exploratory economic evaluation to further inform a full trial. Impact: The primary output of this pilot study will be acceptability data to inform the development of a full, multi-site RCT designed to examine the efficacy of this intervention on health and education related outcomes in UK primary school children.

Lay abstract: Advances in technology and changes to our environment and lifestyles have led to children and adults spending most of their waking hours sitting, and therefore expending low levels of energy. Our day to day environments (e.g. school classroom, workplace) promote prolonged sitting which has been shown to be bad for health. We have found that primary school age children in Bradford spend approximately 10 hours/day sitting. This is a concern as prolonged sitting is linked to obesity, high blood pressure and high cholesterol in children, while in adults prolonged sitting increases the risk of obesity, heart disease, diabetes and some cancers. Children who sit for long periods are likely to become adults who sit for long periods. Therefore, it is important to encourage reduced sitting time during childhood as this will reduce the risks of many diseases linked to prolonged sitting in adulthood. A typical school classroom encourages prolonged sitting; we have found that 70% of a child’s time in the classroom is spent sitting. This earlier research has shown desks which change height (sit-stand desks) which enable children to switch between sitting and standing in the classroom, are effective in the short term in reducing children’s sitting time at school and overall during the school day. However, the acceptability of the long term use of these desks in UK primary schools is unknown. The aim of this research is to assess the acceptability of installing sit-stand desks in primary school classrooms over an 8-month period. We will recruit 8 primary schools in Bradford for the study. In 4 of the schools (the intervention schools) we will replace standard desks sitting 6 to 8 children with 6 to 8 sit-stand desks in Year 5 classrooms. In these schools we will work with the teachers to ensure children have the opportunity to use the sit-stand desks for over 1 hour every day. The 4 schools who do not receive any sit-stand desks (the control schools) will be asked to continue with their usual practice, and children in their Year 5 classes will act as a comparison group. All children in the Year 5 classes from the 8 schools will be invited to take part in the evaluation of the study; we anticipate that at least 120 children from across the 8 schools will take part. We will examine whether it is acceptable to use the sit-stand desks in the intervention schools, and whether it is possible and acceptable to collect a range of measures from the children. Measurements will include children’s sitting, standing and walking time (measured using a small device attached to the thigh, worn for 7 days), indicators of health (including body weight and fat, blood pressure), memory and learning, academic progress, and children’s behaviour in class. We will take these measures early in Year 5 (October/November 2016), before the desks are installed in the classrooms of the intervention schools. The measurements will be repeated at the end of Year 5 (June/July 2017). Our earlier work, along with meetings with children, parents and teachers have shown there is a widespread acceptance and enthusiasm for the proposed study. The main purpose of the study will be to gather information on whether the intervention and measurements are possible and acceptable to all those involved. If that is the case then the information gained from this study will be used to design a larger study to fully evaluate the use of sit-stand desks on children’s health and learning.

Research activity codes: 3.1 PRIMARY PREVENTION INTERVENTIONS TO MODIFY BEHAVIOURS OR PROMOTE WELL-BEING
Health categories: CANCER AND NEOPLASMS;CARDIOVASCULAR;METABOLIC AND ENDOCRINE;ORAL AND GASTROINTESTINAL;STROKE