Workplace Sitting and Height-Adjustable Workstations: A Randomized Controlled Trial

BackgroundDesk-based office employees sit for most of their working day. To address excessive sitting as a newly identified health risk, best practice frameworks suggest a multi-component approach. However, these approaches are resource intensive and knowledge about their impact is limited.PurposeTo compare the efficacy of a multi-component intervention to reduce workplace sitting time, to a height-adjustable workstations-only intervention, and to a comparison group (usual practice).DesignThree-arm quasi-randomized controlled trial in three separate administrative units of the University of Queensland, Brisbane, Australia. Data were collected between January and June 2012 and analyzed the same year.Setting/participantsDesk-based office workers aged 20-65 (multi-component intervention, n=16; workstations-only, n=14; comparison, n=14).InterventionThe multi-component intervention comprised installation of height-adjustable workstations and organizational-level (management consultation, staff education, manager e-mails to staff) and individual-level (face-to-face coaching, telephone support) elements.Main outcome measuresWorkplace sitting time (minutes/8-hour workday) assessed objectively via activPAL3 devices worn for 7 days at baseline and 3 months (end-of-intervention).ResultsAt baseline, the mean proportion of workplace sitting time was approximately 77% across all groups (multi-component group 366 minutes/8 hours [SD=49]; workstations-only group 373 minutes/8 hours [SD=36], comparison 365 minutes/8 hours [SD=54]). Following intervention and relative to the comparison group, workplace sitting time in the multi-component group was reduced by 89 minutes/8-hour workday (95% CI=−130, −47 minutes; p<0.001) and 33 minutes in the workstations-only group (95% CI=−74, 7 minutes, p=0.285).ConclusionsA multi-component intervention was successful in reducing workplace sitting. These findings may have important practical and financial implications for workplaces targeting sitting time reductions.Clinical Trial RegistrationAustralian New Zealand Clinical Trials Registry 00363297