Title: Workplace Sitting and Height-adjustable Workstations: a Randomized Controlled Trial

257 words; 300 max.) Background: Desk-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 multicomponent approach. However, these approaches are resource intensive and knowledge about their impact is limited. Purpose: To 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). Design: Three-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/ participants: Desk-based office workers aged 20-65 (multi-component intervention, n=16; workstations-only, n=14; comparison, n=14). Intervention: The multi-component intervention comprised installation of height-adjustable workstations, organizational-level (management consultation, staff education, manager emails to staff) and individual-level (face-to-face coaching, telephone support) and elements. Main outcome measures: Workplace sitting time (mins/8-hour workday) assessed objectively via activPAL3 devices worn for seven days at baseline and 3 months (end-of-intervention).