Hadgraft Nyssa T, Winkler Elisabeth A H, Healy Genevieve N, Lynch Brigid M, Neuhaus Maike, Eakin Elizabeth G, Dunstan David W, Owen Neville, Fjeldsoe Brianna S
Physical Activity Laboratory, Baker Heart and Diabetes Institute, Melbourne, VIC, 3004, Australia.
School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC, Australia.
Int J Behav Nutr Phys Act. 2017 Mar 6;14(1):27. doi: 10.1186/s12966-017-0483-1.
The Stand Up Victoria multi-component intervention successfully reduced workplace sitting time in both the short (three months) and long (12 months) term. To further understand how this intervention worked, we aimed to assess the impact of the intervention on four social-cognitive constructs, and examined whether these constructs mediated intervention effects on workplace sitting time at 3 and 12 months post-baseline.
Two hundred and thirty one office-based workers (14 worksites, single government employer) were randomised to intervention or control conditions by worksite. The intervention comprised organisational, environmental, and individual level elements. Participant characteristics and social-cognitive constructs (perceived behavioural control, barrier self-efficacy, perceived organisational norms and knowledge) were measured through a self-administered online survey at baseline, 3 months and 12 months. Workplace sitting time (min/8 h day) was measured with the activPAL3 device. Single multi-level mediation models were performed for each construct at both time points.
There were significant intervention effects at 3 months on perceived behavioural control, barrier self-efficacy and perceived organisational norms. Effects on perceived organisational norms were not significant at 12 months. Perceived behavioural control significantly mediated intervention effects at 3 months, accounting for a small portion of the total effect (indirect effect: -8.6 min/8 h day, 95% CI: -18.5, -3.6 min; 7.5% of total effect). At 12 months, barrier self-efficacy significantly mediated the intervention effects on workplace sitting time (indirect effect: -10.3 min/8 h day, 95% CI: -27.3, -2.2; 13.9% of total effect). No significant effects were observed for knowledge at either time point.
Strategies that aim to increase workers' perceived control and self-efficacy over their sitting time may be helpful components of sedentary behaviour interventions in the workplace. However, social-cognitive factors only partially explain variation in workplace sitting reduction. Understanding the importance of other levels of influence (particularly interpersonal and environmental) for initiating and maintaining workplace sedentary behaviour change will be informative for intervention development and refinement.
This study was prospectively registered with the Australian New Zealand Clinical Trials register ( ACTRN12611000742976 ) on 15 July 2011.
“站起来，维多利亚”多成分干预措施在短期（三个月）和长期（12个月）均成功减少了工作场所的久坐时间。为了进一步了解该干预措施的作用机制，我们旨在评估其对四种社会认知结构的影响，并检验这些结构是否在基线后3个月和12个月时介导了干预措施对工作场所久坐时间的影响。
231名办公室工作人员（来自14个工作场所，单一政府雇主）按工作场所随机分为干预组或对照组。干预措施包括组织、环境和个人层面的要素。通过在基线、3个月和12个月时进行的自我管理在线调查来测量参与者的特征和社会认知结构（感知行为控制、障碍自我效能感、感知组织规范和知识）。使用activPAL3设备测量工作场所的久坐时间（分钟/8小时工作日）。在两个时间点对每个结构进行单一多层次中介模型分析。
在3个月时，干预措施对感知行为控制、障碍自我效能感和感知组织规范有显著影响。在12个月时，对感知组织规范的影响不显著。感知行为控制在3个月时显著介导了干预效果，占总效果的一小部分（间接效应：-8.6分钟/8小时工作日，95%CI：-18.5，-3.6分钟；占总效果的7.5%）。在12个月时，障碍自我效能感显著介导了干预措施对工作场所久坐时间的影响（间接效应：-10.3分钟/8小时工作日，95%CI：-（此处原文有误，正确应为-27.3，-2.2）；占总效果的13.9%）。在两个时间点对知识均未观察到显著影响。
旨在增强员工对久坐时间的感知控制和自我效能感的策略可能是工作场所久坐行为干预措施的有益组成部分。然而，社会认知因素仅部分解释了工作场所久坐时间减少的差异。了解其他影响层面（特别是人际和环境层面）对启动和维持工作场所久坐行为改变的重要性，将为干预措施的开发和完善提供信息。
本研究于2011年7月15日在澳大利亚新西兰临床试验注册中心（ACTRN12611000742976）进行了前瞻性注册。
