Utilising an app-based behavioural intervention to increase the light exposure of office workers: A pilot randomised controlled trial

INTERVENTION: Randomisation/allocation: sequence generation The researchers will perform the assignment of individuals to treatment groups and the allocation of groups to intervention and placebo independently. First, using an optimal non‐bipartite matching and matched randomization algorithm (Lu, Greevy, Xu, & Beck, 2012) (Greevy, et al., 2012) the researchers will create matched pairs based on age and gender. Second, using a true random number generator (sampling atmospheric noise), they will then assign group 1 and 2 arising from the matching to be either intervention or placebo on a 1:1 basis. Sequences will be generated randomly by using a computerised coin flip. The algorithm will choose the order of participants and the researchers will truncate after n places. Allocation: concealment Researcher 2 will recruit participants and score their online screening questionnaires. Researcher 2 will be the only individual with access to the screening data. The age, gender and name of prospective participants who screen into the study and have agreed to take part in data collection will be passed onto Researcher 1. Researcher 1 will act as the equivalent of a central randomised service, matching participants into pairs and randomly allocating individuals within those pairs to either the intervention or placebo group. Researcher 1 will have no contact with the participants and will not be involved with recruitment, screening, or data collection. Allocation concealment will be achieved as Researcher 2 who will be enrolling participants will not be able to anticipate which groups participants will be allocated to. Participants will be unaware of the allocation sequence. Educational poster For t CONDITION: Modifying the behaviour of office workers working from home ; Not Applicable PRIMARY OUTCOME: ; Feasibility:; 1. Feasibility of the intervention will be measured using an app and quiz and the feasibility section of the custom feasibility and acceptability questionnaire at the end of the trial; 2. Feasibility of the design and procedures will be measured using a screening survey, custom allocation/randomisation script consent forms, a follow‐up questionnaire, the feasibility section of the custom feasibility and acceptability questionnaire and a self‐report question at the end of the trial; 3. Feasibility of the design and procedures in terms of completeness will be assessed by calculating the average percentage of daily questionnaires completed with valid data (GoodBarber), the average percentage of repeat questionnaires completed with valid data (REDCap), and the average percentage of actigraphs worn with valid data at the end of the trial (added 20/07/2021); ; Acceptability:; 1. Acceptability of the intervention will be measured using the acceptability section of the custom feasibility and acceptability questionnaire at the end of the trial; 2. Acceptability of the placebo will be measured using the acceptability section of the custom feasibility and acceptability questionnaire at the end of the trial; 3. Acceptability of the study procedures will be measured using the acceptability section of the custom feasibility and acceptability questionnaire at the end of the trial; ; Sample size calculation:; 1. Sample size for a definitive main trial calculated using a non‐central t‐distribution (NCT) approach at the end of the trial; SECONDARY OUTCOME: Three secondary outcome domain‐specific measures will be assessed INCLUSION CRITERIA: 1. Aged 25‐45 years 2. Healthy 3. Office worker (work sitting at a desk indoors for working day) 4. Living within the Oxford Ring Road, full‐time (Monday‐Sunday), in August/September 2021 5. Working within the Oxford Ring Road, full‐time (“9‐5”, Monday‐Friday), in August/September 2021 6. Working from home, full‐time (“9‐5”, Monday‐Friday), in August/September 2021 7. Android smartphone user (with a consistent internet connection indoors and outdoors) 8. Able to read and understand English