In a recent article published in BMC Public Health, researchers investigated the effects of six months of multi-level workplace interventions aimed at decreasing sedentary behavior (SED) or increasing moderate to vigorous physical activity (MVPA) on the mental health of office workers.
They tested two different multi-level interventions, the PA intervention (iPA) and the SED intervention (iSED), with the former targeting increasing MVPA and the latter on reducing SED in the current three-armed cluster randomized controlled trial (RCT) conducted among teams of 263 office workers working in either a retail or a finance company in Sweden.
Study: Improving movement behavior in office workers: effects of two multi-level cluster-RCT interventions on mental health. Image Credit: Summit Art Creations/Shutterstock.com
Background
Office workers are sedentary for up to 82% of their work time and remain sedentary even during non-work hours. Since PA and SED may affect mental well-being, this behavior frequently leads to depression or anxiety symptoms and stress among office workers.
While SED may be reduced, for instance, by engaging them in structured exercise, no reductions in SED less than 100 min per 8 h workday are clinically meaningful. Similarly, interventions can increase PA levels; however, the effects of the two on mental health remain obscure.
Systematic reviews of previous studies point to a lack of high-quality RCTs investigating the effects of multi-level workplace interventions on mental health outcomes in office workers.
Either they lacked adequate sample sizes or control conditions or relied on self-reported measures of movement behaviors by office workers rather than accelerometers.
In addition, studies have not shed light on biochemical mechanisms driving mental health outcomes via increased PA or reduced SED. Therefore, well-designed RCTs are needed to establish these effects.
About the study
The present RCT included 263 office workers aged 18–70 who could stand and move. They were randomly allocated to one of two intervention groups or a control group.
The first intervention group focused on increasing MVPA (iPA), and the other on reducing SED (iSED).
They received face-to-face professional health guidance and a detailed manual to help complete their respective interventions, manually track their PA or SED in a logbook, and complete cognitive behavioral therapy (CBT) assignments.
These interventions continued for six months, spread across different seasons for different teams. At the end, all participants completed a web-based survey, including questions on mental health and demographics.
While PA and SED were considered proximal outcomes expected to be directly impacted by iPA and iSED, mental health outcomes were considered distal outcomes.
The study participants had high levels of PA and SED at baseline despite efforts to recruit less active office workers.
Thus, researchers hypothesized that the interventions elicited changes in mental health outcomes via mechanisms other than intended changes in movement behavior, such as increased social support.
The team used a 14-item Hospital Anxiety and Depression Scale (HADS) to assess depression and anxiety symptoms and a World Health Organization-Five Well-Being Index (WHO-5) to assess mental well-being.
Likewise, they evaluated the third component of mental health, i.e., stress, using a single-item stress question.
Finally, the researchers used linear mixed effects models to analyze the effects of study interventions versus controls.
Results
Most study participants were female, with an average age of 42 years. They had favorable levels of mental health at baseline.
Immediately after six months of interventions, only mental well-being improved in the group that focused on reducing SED, compared to the control group.
Even though it also increased for the intervention group focusing on improving MVPA than the control group, these effects were statistically insignificant.
The authors, however, noted no significant effects of interventions on depression/anxiety symptoms or stress in office workers.
Discussion and conclusion
In this study, trained health coaches and the companies’ staff delivered both interventions. However, statistically significant intervention effects were found for the iSED group, most likely due to the following reasons.
Participants perceived fewer barriers to reducing their time spent in SED. They spent substantial amounts of time in SED at baseline.
Drop-out from the iSED group was larger than the iPA group; however, these people were highly motivated, and self-efficacy concerning their movement behavior likely helped them improve their mental well-being.
A potential placebo effect might have played a role as the interventions were not placebo-controlled.
Adult Swedish populations enjoy good mental well-being compared to other European populations. Even at baseline, barely a few study participants had depression/anxiety symptoms (2% and 6%); only their stress levels at baseline were a little higher than the general population (30% vs. 14%).
However, their higher-than-average MVPA levels (on average ~100 minutes daily) might have compensated for some of this stress. All of these factors might have led to null effects of study interventions on depression/ anxiety symptoms and stress.
Further research is needed to investigate whether workplace-delivered movement behavior interventions improve some or all mental health outcomes.
Moreover, research should attempt to decipher which individuals benefit more from such interventions and their drivers. It could facilitate the tailoring of these interventions to a broader population.
At the same time, future studies should consider including placebo control groups for insights into the mechanisms by which movement behavior interventions improve mental health.
Even universal interventions, generating small effect sizes, are favorable as they are less likely to stigmatize people.
Overall, this study confirmed the beneficial effects of multi-level workplace interventions on the mental well-being of healthy office workers.
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