Reducing sitting time in office workers: Short-term efficacy of a multicomponent intervention
Introduction
Excessive sitting time – a risk factor for cardiovascular disease, type 2 diabetes, and premature mortality (Thorp et al., 2011, Wilmot et al., 2012) – is prevalent within the office-based workplace. An estimated two-thirds of work hours is spent sitting, with much of this time accumulated in prolonged unbroken bouts of at least 20 to 30 min (Evans et al., 2012, Ryan et al., 2011, Thorp et al., 2012). However, as noted in two recent reviews (Chau et al., 2010, Healy et al., 2012), relatively few workplace intervention trials have specifically addressed this prevalent health risk behavior.
To date, the evidence relating to reducing and/or interrupting sitting time at work is predominantly from the ergonomic literature, with a focus on musculoskeletal health outcomes (Healy et al., 2012, Husemann et al., 2009, Roelofs and Straker, 2002). Key research gaps identified (Healy et al., 2012) include the need for controlled trials that specifically target, and objectively measure, workplace sitting time. Furthermore, such trials should include assessment of the cardio-metabolic biomarkers shown in epidemiological and experimental studies to be detrimentally related to prolonged, unbroken sitting (Dunstan et al., 2012, Healy et al., 2011) in order to evaluate the potential health benefits of reducing workplace sitting time (and increasing standing). Finally, and consistent with best practice workplace health promotion frameworks (Carnethon et al., 2009, Department of Health and Human Services, 2008, World Health Organization, 2010), interventions should target not only the individual, but also the organization and the work environment (Healy et al., 2012, Pronk, 2009). Although previous trials have incorporated one (e.g. Alkhajah et al., 2012, John et al., 2011, Kozey-Keadle et al., 2012), or some of these intervention elements (e.g. Ellegast et al., 2012, Pronk et al., 2012), none have integrated all components to specifically address and measure reductions in objectively-assessed workplace sitting.
The aim of this trial was to assess the short-term efficacy of an intervention integrating individual-, environmental-, and organizational-change elements to reduce workplace sitting. We examined whether participants receiving the multicomponent intervention, relative to control participants, would differ in overall objectively-measured workplace sitting time (primary outcome). We also assessed differences in sitting time accrued in prolonged bouts, in standing time, and in moving time, as well as health-related (cardio-metabolic biomarkers, anthropometric measures, musculoskeletal symptoms) and work-related (work-performance, absenteeism, and presenteeism) outcomes.
Section snippets
Study design
Data for this two-arm, non-randomized controlled trial were collected between July and September 2011 and analyzed May–August 2012. The study was approved by the Alfred Health Human Ethics Committee (Melbourne, Australia). Assessments occurred at baseline, and following the final contact of the individual element of the intervention (approximately 4 weeks; follow-up). Research staff, participants, and assessors were not blinded to group allocation.
Organization
A single workplace (Comcare: the government
Results
Of the 44 employees enrolled in the study, 18 in each group provided primary outcome data at both assessments (Fig. 1). The main difference between groups was the greater proportion of women in the intervention group (Table 1).
Discussion
This study demonstrated, for the first time, that a multicomponent workplace intervention, utilizing organizational, environmental, and individual elements, was achievable within an office context. It achieved sizeable (> 2-h per 8-h workday) reductions in workplace sitting. The intervention group's sitting reduction (− 26.5% of workplace time) is consistent with previous workplace interventions that have specifically targeted sitting (range − 0.1% to − 40%; (Alkhajah et al., 2012, Ellegast et al.,
Funding sources
This study was funded by an NHMRC project grant [#1002706] and the Victorian Health Promotion Foundation. Ergotron provided the height-adjustable workstations (www.ergotron.com). Support for researchers came from: NHMRC Training Fellowship [# 569861] (Healy); NHMRC Senior Research Fellowship [#511001] (Eakin); NHMRC Program Grant [#569940], Senior Principal Research Fellowship [NHMRC #1003960] and the Victorian Government's Operational Infrastructure Support Program (Owen); Australian
Conflict of interest statement
No financial disclosures were reported by the authors of this paper, and the authors declare that there are no conflicts of interest.
Acknowledgments
We thank Parneet Sethi for her assistance with the data cleaning and analyses, as well as the Comcare employees and management.
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