Workplace interventions for reducing sitting time at work

Why is the amount of time spent sitting at work important?

Physical inactivity at work, particularly sitting has increased in recent years. Long periods of sitting increase the risk for obesity, heart disease, and overall mortality. It is unclear whether interventions that aim to reduce sitting at workplaces are effective at reducing the amount of time spent sitting.

The purpose of this review

We wanted to find out the effects of interventions aimed at reducing sitting time at work. We searched the literature in various databases up to 2 June 2015.

What trials did the review find?

We found twenty studies with a total of 2174 participants from high income nations. Nine studies evaluated physical changes in the workplace, four evaluated changes in workplace policy, seven studies evaluated information and counselling interventions and one study evaluated both physical workplace changes and information and counselling components.

Effect of sit-stand desks

Sit-stand desks alone decreased workplace sitting with about half an hour to two hours per day. When combined with information and counselling sit-stand desks reduced sitting at work in the same range. Sit-stand desks also reduced total sitting time (both at work and outside work) and the duration of sitting episodes that last 30 minutes or longer.

Effect of active workstations

Treadmill desks combined with counselling reduced sitting time at work compared to no intervention. Pedalling workstations combined with information did not reduce sitting at work compared to information alone.

Effect of walking during breaks

The introduction of walking during breaks in two studies with 443 participants did not change sitting time.

Effect of information and counselling

In two studies counselling decreased sitting time with 28 minutes and in another study mindfulness training did not have any effect on sitting at work. There was no considerable increase in work engagement with counselling.

Computer prompting software did not reduce sitting time in two studies. In another study computer prompts reduced sitting time with 55 minutes compared to no intervention. One study found that prompts to stand reduced sitting 14 minutes more than prompts to step. Computer prompts did not change the number of sitting episodes that last 30 minutes or longer.

Interventions from multiple categories

When multiple categories of interventions were combined to decrease sitting, there was reduction in workplace sitting time at 12 weeks' and six months' follow-up but there was no considerable difference between intervention and control group at 12 months' follow-up.

Conclusions

The quality of evidence was very low to low for most interventions mainly because studies were very poorly designed and because they had very few participants. We conclude that at present there is very low quality evidence that sit-stand desks can reduce sitting at work at the short term. There is no evidence for other types of interventions. We need research to assess the effectiveness of different types of interventions for decreasing sitting at workplaces in the long term.

Authors' conclusions: 

At present there is very low to low quality evidence that sit-stand desks may decrease workplace sitting between thirty minutes to two hours per day without having adverse effects at the short or medium term. There is no evidence on the effects in the long term. There were no considerable or inconsistent effects of other interventions such as changing work organisation or information and counselling. There is a need for cluster-randomised trials with a sufficient sample size and long term follow-up to determine the effectiveness of different types of interventions to reduce objectively measured sitting time at work.

Read the full abstract...
Background: 

Office work has changed considerably over the previous couple of decades and has become sedentary in nature. Physical inactivity at workplaces and particularly increased sitting has been linked to increase in cardiovascular disease, obesity and overall mortality.

Objectives: 

To evaluate the effects of workplace interventions to reduce sitting at work compared to no intervention or alternative interventions.

Search strategy: 

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, CINAHL, OSH UPDATE, PsycINFO, Clinical trials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) search portal up to 2 June, 2015. We also screened reference lists of articles and contacted authors to find more studies to include.

Selection criteria: 

We included randomised controlled trials (RCTs), cluster-randomised controlled trials (cRCTs), and quasi-randomised controlled trials of interventions to reduce sitting at work. For changes of workplace arrangements, we also included controlled before-and-after studies (CBAs) with a concurrent control group. The primary outcome was time spent sitting at work per day, either self-reported or objectively measured by means of an accelerometer-inclinometer. We considered energy expenditure, duration and number of sitting episodes lasting 30 minutes or more, work productivity and adverse events as secondary outcomes.

Data collection and analysis: 

Two review authors independently screened titles, abstracts and full-text articles for study eligibility. Two review authors independently extracted data and assessed risk of bias. We contacted authors for additional data where required.

Main results: 

We included 20 studies, two cross-over RCTs, 11 RCTs, three cRCTs and four CBAs, with a total of 2180 participants from high income nations. The studies evaluated physical workplace changes (nine studies), policy changes (two studies), information and counselling (seven studies) and interventions from multiple categories (two studies). One study had both physical workplace changes and information and counselling components. We did not find any studies that had investigated the effect of periodic breaks or standing or walking meetings.

Physical workplace changes

A sit-stand desk alone compared to no intervention reduced sitting time at work per workday with between thirty minutes to two hours at short term (up to three months) follow-up (six studies, 218 participants, very low quality evidence). In two studies, sit-stand desks with additional counselling reduced sitting time at work in the same range at short-term follow-up (61 participants, very low quality evidence). One study found a reduction at six months' follow-up of -56 minutes (95% CI -101 to -12, very low quality evidence) compared to no intervention. Also total sitting time at work and outside work decreased with sit-stand desks compared to no intervention (MD -78 minutes, 95% CI -125 to -31, one study) as did the duration of sitting episodes lasting 30 minutes or more (MD -52 minutes, 95% CI -79 to -26, two studies). This is considerably less than the two to four hours recommended by experts. Sit-stand desks did not have a considerable effect on work performance, musculoskeletal symptoms or sick leave. It remains unclear if standing can repair the harms of sitting because there is hardly any extra energy expenditure.

The effects of active workstations were inconsistent. Treadmill desks combined with counselling reduced sitting time at work (MD -29 minutes, 95% CI -55 to -2, one study) compared to no intervention at 12 weeks' follow-up. Pedalling workstations combined with information did not reduce inactive sitting at work considerably (MD -12 minutes, 95% CI -24 to 1, one study) compared to information alone at 16 weeks' follow-up. The quality of evidence was low for active workstations.

Policy changes

Two studies with 443 participants provided low quality evidence that walking strategies did not have a considerable effect on workplace sitting time at 10 weeks' (MD -16 minutes, 95% CI -54 to 23) or 21 weeks' (MD -17 minutes, 95% CI -58 to 25) follow-up respectively.

Information and counselling

Counselling reduced sitting time at work (MD -28 minutes, 95% CI -52 to -5, two studies, low quality evidence) at medium term (three months to 12 months) follow-up. Mindfulness training did not considerably reduce workplace sitting time (MD -2 minutes, 95% CI -22 to 18) at six months' follow-up and at 12 months' follow-up (MD -16 minutes, 95% CI -45 to 12, one study, low quality evidence). There was no considerable increase in work engagement with counselling.

There was an inconsistent effect of computer prompting on sitting time at work. One study found no considerable effect on sitting at work (MD -17 minutes, 95% CI -48 to 14, low quality evidence) at 10 days' follow-up, while another study reported a significant reduction in sitting at work (MD -55 minutes, 95% CI -96 to -14, low quality evidence) at 13 weeks' follow-up. Computer prompts to stand reduced sitting at work by 14 minutes more (95% CI 10 to 19, one study) compared to computer prompts to step at six days' follow-up. Computer prompts did not change the number of sitting episodes that last 30 minutes or longer.

Interventions from multiple categories

Interventions combining multiple categories had an inconsistent effect on sitting time at work, with a reduction in sitting time at 12 weeks' (25 participants, very low quality evidence) and six months' (294 participants, low quality evidence) follow-up in two studies but no considerable effect at 12 months' follow-up in one study (MD -47.98, 95% CI -103 to 7, 294 participants, low quality evidence).