Sedentary behaviour in office workers: correlates and interventions

2019-10-09T13:52:48Z (GMT) by Victoria Kettle
Background: The concept of sedentary behaviour has emerged since the turn of the millennium and research into this area is rapidly developing. Sedentary behaviours are activities that require very little energy expenditure whilst in a sitting or reclining posture thus are distinct from physical inactivity. Previous observational studies have demonstrated that high amounts of sedentary behaviour are associated with an increased risk of obesity, type 2 diabetes, metabolic syndrome, cardiovascular disease, cancer, depression and all-cause, cardiovascular and cancer mortality. Experimental studies suggest that prolonged sedentary time causes metabolic dysregulation and could be the explanation for the associated negative health effects. Breaks in prolonged sedentary time where standing or stepping occurs have shown beneficial effects on metabolic risk markers but the threshold for these effects is ambivalent and may depend on the population. The increasing prevalence of sedentary behaviours due to advances in technology are concerning but there is a lack of large-scale studies from the UK identifying the extent of sedentary behaviour prevalence and where the majority of sedentary time is accumulated in working-aged adults. A number of correlates are associated with sedentary behaviour including individual, social and environmental factors but the extent to which multiple other health behaviours correlate with specific sedentary behaviours is unknown. Interventions to reduce sedentary time have focused on the workplace where office workers spend large amounts of time sedentary. Multicomponent workplace interventions have reported reductions in sedentary time but there is limited research in the UK investigating the long-term effects of these interventions on working and non-working hours sedentary time. Additionally, the use of persuasive technology in the form of a wearable device to reduce sedentary time has rarely been explored as an intervention strategy.
Aims: Study One aimed to assess the prevalence of domain-specific sedentary behaviour in a large sample of office workers from the UK and links with multiple other health behaviours. Study Two aimed to investigate the effectiveness of a pilot multicomponent workplace intervention to reduce sedentary time over the short (3 months) and long-term (12 months). Study Three aimed to explore the feasibility of a self-monitoring and prompting device to reduce sedentary time in a sample of office workers who have sit-stand desks.
Methods: Study One performed a secondary data analysis on a large sample of office workers (n=7,170) who self-reported their domain-specific sitting time, physical activity level, smoking status, alcohol consumption, and fruit and vegetable intake in a 2012 and/or 2014 survey. Multiple logistic regression models explored the association between sedentary behaviours and multiple other health behaviours. A separate analysis was performed to investigate how these associations tracked over time (n=806). Study Two implemented a multicomponent workplace intervention in a sample of office workers (baseline n=30) and measured the effects 3 and 12-months post-baseline compared to a control group (baseline n=30). activPAL sedentary time was the primary outcome with accelerometer-determined physical activity and markers of health measured as secondary outcomes. Study Three provided a sample of office workers who had sit-stand desks (n=19 baseline, n=17 follow-up) with a wearable device to self-monitor their sedentary time through an application and prompt reductions in prolonged sedentary time through haptic feedback (LUMO). Feasibility and acceptability of the 4-week intervention were measured through wear time, engagement with application, questionnaire and interview feedback. The effect on sedentary time was measured with the LUMO and activPAL in addition to health and work-related measures.
Results: Study One found that 643±160 minutes on a workday and 491±210 minutes on a non-workday were spent sitting. The majority of workday sitting took place at work (383±95 minutes/day) and whilst TV viewing on a non-workday (173±101 minutes/day). ≥7 hours sitting at work and ≥2 hours TV viewing on a workday both more than doubled the odds of partaking in ≥3 unhealthy behaviours [Odds ratio, OR=2.03, 95% CI, (1.59-2.61); OR=2.19 (1.71-2.80)] and ≥3 hours of TV viewing on a non-workday nearly tripled the odds [OR= 2.96 (2.32-3.77)]. No associations between domain-specific sitting time at baseline and change in unhealthy behaviour score were found over two years with the majority of participants maintaining baseline levels of all behaviours. Study Two found a trend towards reduced sedentary time at work by -7.9±25.1% and -18.4±12.4% per day at 3- (n=25 intervention, n=18 control group) and 12-months (n=11 intervention, n=7 control group) post-baseline in addition to overall workday by -4.6±13.8% and -8.0±8.3%. The intervention group showed an increase in sedentary time outside of work on a workday (4.2±9.5%) and overall on a non-workday (3.5±10.8%) after 12 months compared to baseline. However, the results found at the 3-month follow-up were not statistically significant and no significant differences in physical activity or health measures between groups were observed. Furthermore, due to the reduced sample size at the 12-month follow-up, no statistical testing was performed. Study Three found that the LUMO was a feasible intervention device in the short-term demonstrating high wear time (mean=60.6% of measurement days) and application engagement (mean=26.2±33.2 sessions, 30.3±26.5 minutes per week) with sedentary time being the most engaged with aspect of the application. The acceptability of the LUMO depended on the task undertaken, experience of problems with the device and preference towards the application or the prompt but overall, it increased awareness of behaviour. A trend towards reductions in sedentary time (-4%) and prolonged bouts of sedentary time >60 mins (-3%) on a workday were observed. Improvements were found in fat percentage and mass, blood pressure, job performance, work engagement, need for recovery and job satisfaction. Non-workday sedentary time >60 min bouts increased (4.8%) and increases in non-working hours sedentary time were apparent in weeks 3 and 4.
Conclusions: Office workers are highly sedentary at work and whilst TV viewing which is associated with partaking in other multiple unhealthy behaviours. Multicomponent workplace interventions result in a trend towards reductions in occupational sedentary behaviour over the short and long-term. However, compensation during non-working hours could attenuate overall sedentary behaviour reductions resulting from workplace interventions. Wearable technology as an intervention strategy to reduce sedentary time shows promise and further research is needed in fully-powered studies. Future interventions should target multiple unhealthy behaviours in addition to sedentary time during work and non-working hours.