A digital intervention to reduce home-office workers’ sedentary behaviour: protocol for the evaluation of the Click2Move programme, a cluster randomised controlled trial

Companies having different units, with 50 or more employees, and applying home-office policies will be included in the study. The list of potential companies was provided by the European Network for Workplace Health Promotion, which is also involved in the C2M project. All those companies involved in other initiatives to reduce SB will be excluded from the study.

Participants must be adults aged 18–65 years old with a desk-based job, working from home at least two days per week. Furthermore, participants must be able to walk without the use of an assistive device or requiring assistance from another person. Participants who are unable to read and understand the language native to the country in which they are residing, or employees with an end date for employment prior to the study completion date, will be excluded from the study. Participants using other devices for activity tracking such as a smartwatch will be eligible for inclusion.

The C2M intervention has been developed from a participatory research approach, with academics working alongside other stakeholders [37]. The development process of the C2M intervention includes a systematic review [27], two qualitative studies, including employers and employees [38] and a Delphi study with experts on occupational health and PA promotion [31]. Moreover, C2M followed the new Medical Research Council (MRC) framework on the development of complex interventions to improve health [39, 40]. Firstly, a systematic review and meta-analysis was conducted to examine the effectiveness of digital workplace interventions to reduce time spent in SB in office workers [27]. Nineteen randomised controlled trials were included in the systematic review, eleven of which were used in the meta-analysis. A wide range of digital elements and working strategies were described among the included studies. Delivery of information and educational materials through text messages, e-newsletters, websites or videos for increasing knowledge and awareness were the most common digital workplace strategy. Scheduled prompts to break SB or participate in PA delivered via computer screens and mobile phone applications were the second most common digital workplace strategy. The results of the study indicated that multicomponent digital interventions, including elements at organisational, environmental, and at the individual level are effective to reduce workplace SB, presenting a reduction of 29.9 min/8 h workday [27].

In addition, the perspectives of managers (n = 20) and employees (n = 51) across three countries, namely Ireland, Spain and The Netherlands were gathered through semi-structured interviews, allowing for an in-depth perspective on a multinational basis and was guided by the COM-B model [38, 41]. The interviews were conducted online, and a reflexive thematic analysis approach was adopted to analyse the data and develop themes and sub-themes. Both employees and managers highlighted the need for a top-down approach to the intervention, whereby organisational support was provided to employees, which would create the freedom and opportunities to reduce SB and engage in PA during work. Employees highlighted the need for a flexible intervention, which catered for the wide range of fitness levels and interest that exist within an organisation, with the provision of a range of time-efficient exercises that employees can chose from identified as a viable approach to reduce and break up SB. The need for a multicomponent intervention, which incorporates an educational element on the health benefits of SB, was also highlighted by both employees and managers. Finally, managers highlighted the possibility of leveraging infrastructure put in place during the Covid-19 pandemic, such as online educational provision or the use of digital platforms such as mobile phones for supportive messaging, to further support those working from home.

Lastly, a modified Delphi study to reach experts’ consensus on the most feasible strategies and the most usable digital elements as a delivery method to reduce SB in home-office context was performed [31]. Work strategies and digital elements, which were selected from a scoping review of workplace PA strategies across Europe [42], the previous systematic review [27] and the needs assessment [38], were classified according to the Behaviour Change Wheel (BCW) and the Behavioural Intervention Technology (BIT) elements. Eighteen feasible work strategies were identified, with feedback on activity progress and goal achievement, creation of an action plan or giving information to increase awareness and knowledge being the highest ranked. An additional 16 digital elements were identified as useful for inclusion within the intervention, including the use of wrist-based activity trackers, app interface in mobile phones or gamification features.

To refine and improve the C2M intervention, we conducted a single-group pilot study over a one-week period. Twenty-one participants across the four countries involved in the C2M project participated in the study. The usage, usability, acceptability, perceived usefulness, and satisfaction of the C2M intervention were assessed through four 5-point Likert scales and three open ended questions. Participants used the C2M App for an average of 4 days for 8 h each day. The App was considered as acceptable, and easy to use. Additionally, the activity tracker was perceived to improve the App information. Participants perceived the contents of the programme as “quite a bit useful”, with the exception of cooperative challenges, considered not useful/not useless. Participants were satisfied with the programme, with the awareness about their own activity patterns being the most liked item, while connection issues between the activity tracker and the application were the largest issues identified. Consequently, post-test modifications were performed to address the reported major issues.

Figure 2 provides the logic model of the C2M intervention development. For each element of the intervention, the intervention type was identified according to the intervention functions from the BCW [43], the Behaviour Change Techniques (BCT) using the BCT’s Taxonomy v1 [44], and the digital elements applying the BIT classification [32].

The C2M intervention is a multicomponent program addressing multiple levels (i.e. the environmental, organisational and individual level) aiming to reduce sitting time during working hours. The intervention includes a mobile phone application (C2M App) available in five European languages: English, Spanish, Catalan, Dutch, and Slovenian, alongside an activity tracker (Fig. 3), comprising environmental, organisational, and individual implementation levels.

The C2M App is compatible with both Android and iOS platforms and connects to an activity tracker via Bluetooth. The App receives accelerometer data and interprets it using JS libraries within React Native. Furthermore, it communicates through an API hosted on a server within the C2M host institution. The activity tracker is a waterproof wristband (1810G Monitor Smart Band, Joint Chinese Ltd., Guangdong, CHN; dimensions = 42*19*11.2 mm main body; 204.6*16.8 mm). It operates using a durable 110mAh lithium battery with a built-in USB charger and is equipped with a triaxial accelerometer sensor.

The environmental level is comprised of a person’s situation or environment that encourages them to break their sitting time at work [45]. Activity tracker and App provision, sedentary reminders, cooperative challenges, and social chat are the environmental elements that will be part of this level.

The activity tracker, apart from tracking activities, provides sedentary reminders through vibrations and a message displayed on the screen of the wristband. Every uninterrupted hour without moving from the chair will result in the alert/message being displayed. After receiving the sedentary reminder on the activity tracker (Fig. 4a), the user will enter the C2M App, where a message will appear inviting them to perform a suggested active break (or strategy) (Fig. 4b). The user will be able to accept the strategy (by agreeing to complete the strategy) or to skip it.

The C2M App will offer monthly cooperative challenges for all participating company employees on the “Challenges” page. Examples include reaching a step goal or limiting the number of sedentary reminders received. Each challenge includes a title, description, and duration, as well as collective and individual achievement tracking. Each challenge will include a “social chat” where users will be able to share their experiences with other employees (Fig. 5).

The organisational level includes social pressure, social norms, social support, policies, rules, regulations, interaction with colleagues, and modelling that can cause individuals to change their behaviour [45, 46]. The C2M programme follows a top-down approach, involving the company in the dissemination, recruitment, and implementation phases. In addition, a monthly feedback survey and motivational messages are also strategies to be implemented at this level to provide further opportunities to break up prolonged SB.

Specific company actions include (a) internally communicating the C2M initiative (e.g., through face-to-face or virtual presentations), (b) sending invitation emails for participation to employees, and (c) leading by example in the social chat of the App to promote engagement (i.e., managers demonstrating to employees the active breaks they are engaging in). Additionally, the C2M program will feature a permanent suggestion box on the “Profile” page of the App (Fig. 6) and monthly short surveys to gather participant feedback. Participants will also receive motivational messages related to challenge achievements and for avoiding prolonged periods of sedentary time (Fig. 7).

The individual level considers elements to enhance the individual’s adoption and maintenance of the behaviour (e.g., knowledge, education) [47], such as self-monitoring and feedback provision, active break strategies together with demonstrative videos and educational material.

Users will self-monitor their working hours activity through the activity tracker and real-time feedback will be displayed on the “Home” of the C2M App. This includes metrics such as step count, time spent sedentary, status of sedentary reminders (accepted or declined), and completion status of additional strategies chosen by users without reminders. This data will also be visualized in a time continuous loop with each segment differentiated by color: green for activity time, yellow for sedentary time with bouts of less than one, and red for longer periods of sedentary time (> 1 hour). Furthermore, users can access their activity history through the “History” page (Fig. 8).

A list of general strategies (e.g., walk during the meetings) and active break strategies covering the following wide range of exercise types (i.e. walking, stretching, strengthening, mobility and stability) will be available on the “Strategies” page of the App (Fig. 9). Participants will be able to like them, and the more popular strategies will appear as preferred exercises. Each strategy will include a title, an image, a description, and a video demonstration on how to implement/complete them. Additionally, the active break strategies will be randomly suggested on the sedentary reminders message.

Finally, participants will receive monthly emails with educational material (i.e. infographics) with the aim of increasing participants’ knowledge and awareness for breaking prolonged periods of uninterrupted sedentary time. Moreover, in the description of each strategy, the benefits of implementing that strategy will be provided.

Participants from the intervention group will be invited to a face-to-face meeting to provide them with an activity tracker, and to provide a printed tutorial outlining how the App should be used. They will be asked to download the C2M App on their own mobile phone and wear the activity tracker during working hours for one year. Before the meeting, participants will be registered from the C2M App back office by the representative researchers in each country. During the meeting, the researchers will explain and demonstrate (a) how to initialise the App through the App wizard that will guide the user through the activity tracker synchronization, setting their work hours (Fig. 10), and (b) the wide range of App functionalities.

Control group participants will not receive any device, nor will they have to download the mobile phone App. They will be asked to maintain they regular behaviours at work during the study period.

At baseline, participants will be asked for their age, gender, anthropometrical measures, educational level, general working conditions, home-working environment, mode of commute to and from work (on office working days), and behavioural habits (i.e. sleep conditions, and tabaco and alcohol consumption).

The activPAL^3TM will be used to measure and quantify the occupational and leisure PA and SB of employees, including sitting, standing, and stepping time, number and duration of sedentary bouts, sedentary to non-sedentary transitions, light Intensity PA and MVPA. The activPAL device is a valid measure to quantify body posture and activity patterns during free-living conditions in a range of populations, including healthy adults [48]. The device will be attached to the midline of the anterior aspect of the participants’ right thigh using a flexible nitrile sleeve and a transparent film (10 × 10 cm of hypoallergenic Tegaderm™ Foam Adhesive Dressing). Participants will wear the activPAL^3TM for 7 consecutive days, 24 h/day. Additional dressings and instructions on how to reattach the device will also be provided. Furthermore, participants will be asked to record their daily wake time, bedtime, working hours, working location (office vs. home-office), the mode of commute, PA context and any monitor removal time through the activPAL^3TM diary. Data will be processed using activPAL^3TM Professional Software™ (version 7.2.32), Microsoft Excel 2010 (Redmond, WA, USA), and MATLAB v8.4 (MathWorks^®, Natick, MA, USA), following previously published procedure for data reduction and cleaning [49, 50, 51].

PA will also be self-reported using the Global Physical Activity Questionnaire (GPAQ), a valid and reproducible questionnaire [52]. The GPAQ questionnaire contains fifteen questions regarding PA in three domains (occupational PA, PA for transportation to and from places and PA during recreational activities). Self-reported SB will be measured through the Workforce Sitting Questionnaire (WSQ), which has previously been demonstrated to have excellent test-retest reliability and acceptable validity [53]. Five items will assess sitting time on working and non-working days in a range of domains (a) traveling, (b) at work, (c) watching television, (d) using a computer at home (outside of work), and (e) other leisure activities (but not including watching television or using computer).

Health-related outcome will be operationalised by musculoskeletal symptomatology and pain intensity. Musculoskeletal symptomatology will be measured through the Standardised Nordic Questionnaire (SNQ), while pain intensity will be measured using the 11-point Numeric Rating Scale (NRS). The SNQ is an internationally self-administered questionnaire, designed for the exploration and identification of musculoskeletal symptoms, primarily in the working population. The general questionnaire consists of 8 questions with dichotomous and Likert scale (4 to 5 levels of response) responses. In all questions, it is necessary to specify for each of the 8 body parts included: neck, shoulders (differentiating between the right and left), back (differentiating between the upper and lower part), elbow-forearm (differentiating between the right and left), hand-wrist (differentiating between the right and left), hip/thigh, knees, and ankles/feet. The questions refer to the presence of discomfort, both in the last 12 months and in the last 7 days; the duration of discomfort and each episode of pain in the last 12 months; the duration of temporary disability derived from discomfort in the last 12 months; the need for treatment for the discomfort presented in the last 12 months; the intensity of discomfort present in the last 7 days; and finally, the cause of discomfort in the last 7 days. The SNQ has been demonstrated as a valid, reliable and feasible tool that enables the identification of musculoskeletal problems among different anatomical areas in epidemiological and ergonomic studies [54]. The NRS consist of a numeric version of the visual analogue scale, with a horizontal line labelled from zero to ten, with zero being an example of someone with no pain and ten being the worst pain possible. The NRS has shown high sensitivity, reliability, and validity to identify pain intensity [55].

Presenteeism and absenteeism will be assessed with seven questions from the Health and Work Performance Questionnaire (HPQ) [56]. The HPQ demonstrated good validity [57], while it has also demonstrated strong reliability and sensitivity to change [56]. Four open questions on the number of days and hours participants work the past 7 days, the number of hours the employer expects employees to work in the past 7 days or in a typical 7-day week, and the number of hours participants work in the past 4 weeks will be used to score the absolute presenteeism. The number of entire or partial days missed in the past 4 weeks for mental or physical health or for other reasons (e.g., vacations) will be used to score the relative absenteeism. A high score indicates a higher amount of absenteeism. These questions are followed by two questions that ask employers to rate working in their job on a 0–10 scale of work performance (worst to best) and rank themselves over the past 4 weeks. Absolute presenteeism will be calculated as the difference between the score for one participant the past 4 weeks and the score for the average worker in the same job. In this case, a higher score indicates lower amount of lost performance. A relative presenteeism score can be computed as the ratio of individual versus other scores.

The Need for Recovery scale has demonstrated good and consistent validity to measure occupational fatigue [58]. Additionally, the Need for Recovery scale has shown favourable test-retest reliability and sensitivity to detect change [59]. The Need for Recovery comprises of eleven items with yes/no responses. A score is calculated by adding all the scores of the individual items and transforming these into a scale from 0 to 100. Higher scores indicate a higher need for recovery after work.

Job satisfaction will be measured using a single-item 5-point Likert scale [60], where 1 is extremely dissatisfied and 5 extremely satisfied. The standard satisfaction scale ranging from 1 to 5 will be converted into 0 to 100 scales using the formula: AdjSS = 100 x [stsSS-1] / [5 − 1], where adjSS and stdSS will be “adjusted satisfaction score” and “standard satisfaction score”, respectively. With the new scoring method, job satisfaction falls into 5 categories: “extremely dissatisfied” ([adjSS: 10–29], “dissatisfied” [30–49], “generally satisfied or not” [50–59], “satisfied” [70–89], and “extremely satisfied” [90–100] [61].

The process evaluation will be performed to understand the intervention groups’ experiences, as well as to check if the intervention has been implemented as expected. The process evaluation will include a range of evaluation approaches, including checklists, engagement data, questionnaires, and focus groups. The process evaluation of the C2M project will follow the guidance on “Process evaluation of complex interventions” from the MRC guidance [62]. This framework emphasises the dynamic nature of relationships between implementation, mechanisms of impact and contextual factors.

The implementation will lead to capture the programme fidelity (whether the intervention is delivered as intended), dose (the quantity of intervention implemented), and reach (whether the intended audience meets the intervention, and how). The national coordinators will assess the fidelity and dose of the intervention through two checklists (Additional File). The fidelity checklist will contain all the intervention elements with a brief explanation of each one, and team members will have to complete whether each of the elements has been implemented as expected and any changes that have been made. The dose checklist will include the list of all strategies, challenges and educational material delivered, the data and duration of which it is intended to be delivered. The reach will be assessed through the back office of the C2M App, in which we will be able to see the number of steps, the sedentary reminders received, the sedentary time, the completed and skipped strategies, the additional strategies performed, the ongoing challenges, and the accomplish or failed challenges. 1

The mechanisms through which the C2M programme bring about change will be assessed to understand how the effects of the specific intervention elements occur and how these effects might be replicated by similar future interventions. To evaluate the programme mechanisms of impact and the contextual factors, the intervention group participants will be asked to complete self-reported questionnaires and to participate in a focus group on their experiences with the different intervention components and the behavioural change adoption and adherence for impeding or enhancing employees’ behavioural change.

The self-reported questionnaire will be delivered through the REDCap platform at 3 months, assessing the programme usage, usability, acceptability, perceived usefulness, and satisfaction through 5-point Likert scales (Additional File 2). In addition, at 6- and 12-months programme usage, perceived usefulness and satisfaction of the intervention components will be assessed. The usage of the activity tracker and C2M App will be measured through three questions with responses scoring from ‘always’ to ‘never’. Usability will be measured by the 10-item System Usability Scale [63], from ‘strongly agree’ to ‘strongly disagree’. The acceptability questions includes if the information is a) interesting, b) credible, c) easy to understand, d) new acknowledgment, e) relevant, f) excessive information provided, g) met expectations, h) social support consequences, i) behavioural change consequences, and j) self-awareness. The items will be assessed with the 5-point Likert scale ranging from ‘strongly agree’ to ‘strongly disagree’. Activity tracker acceptability, in addition to the C2M App information, will include questions related to the value, credibility personal relevance of the App information, awareness of own PA behaviour and ease of use of the tracker data and the App. The perceived usefulness will be measured by asking participants how useful they found each specific element/strategy with response option from ‘very useful’ to ‘not at all useful’. Finally, participants’ satisfaction will be measured through two 5-point Likert scale questions, one for the C2M App and the other for the activity tracker, ranging from ‘very satisfied’ to ‘very unsatisfied’.

Focus groups will be conducted at the end of the intervention. The mechanisms of impact of the intervention will be assessed through questions about the perceived effects of the intervention on SB, PA, health, work or social relationships, the components that worked and did not work and factors that have made it work or not, if intervention had any unintended consequences and if the participants would recommend the intervention. The contextual factors will be examined through questions about whether it was easier to implement the intervention at home or in the office, if the same components for reducing SB worked differently in the two contexts, how contextual factors (i.e., setting, colleagues, housemates or other aspects) effect implementation and outcomes, and to what extent participants changed their occupational behaviour while working from home and in the office. Sessions at each cluster will be facilitated by the national team using a semi-structured guide, with 6–10 participants per group.