Alternatives for Measuring Sitting Accumulation in Workplace Surveys.

OBJECTIVES: To develop and assess the measurement properties of self-report measures of accumulation of sitting time. METHODS: Seven candidate measures were collected in 51 workers from three office environments (79% women) via online questionnaire administered immediately before and after 7-day monitoring periods (activPAL3 24-hour protocol with diary recorded work hours). RESULTS: Three measures had some validity (P < 0.05 vs activPAL): % of sitting in long bouts more than or equal to 30 minutes, sitting strategy frequency (0 to 100), and interruption rate (n/h sitting). Agreement was limited. Some reliability (intraclass correlation or kappa P < 0.05) was seen for these measures, strategy variety (0 to 100), typical day (five categories), and making a conscious effort to sit less (yes/no). CONCLUSIONS: Two brief and one longer option may suit workplace studies requiring self-report measures of sitting accumulation. Validity was weaker for sitting accumulation than sitting time.

Temporal features of sitting, standing and stepping changes in a cluster-randomised controlled trial of a workplace sitting-reduction intervention.

BACKGROUND: There is now a body of evidence on the effectiveness of interventions to reduce workplace sitting time. However, there has been limited reporting of how such interventions may impact behaviour both during and outside of work. Sitting, standing and stepping changes following a workplace intervention were examined across five timeframes (work time on work days; non-work time on work days; work days; non-work days; overall (i.e. work and non-work time on all days)), and the relationships between changes during and outside of work was assessed. METHODS: The cluster-randomised controlled trial, 'Stand Up Victoria', delivered a multi-component workplace-delivered intervention that successfully reduced workplace and overall sitting time (relative to controls). Separately, over the five timeframes, changes in device (activPAL3)-assessed outcomes - sitting; prolonged sitting (≥30 min bouts); standing; and, stepping - were compared between intervention (n = 114) and controls (n = 84), along with the time-course of sitting changes during work hours, using mixed models. The potential relationships of changes during work with changes outside of work were examined using compositional data analysis. RESULTS: On workdays, intervention participants significantly (p < 0.05) improved their activity profile relative to controls, with reduced sitting (- 117 min/8-h workday, 95% CI: - 141, - 93) and prolonged sitting (- 77 min/8 h workday, 95% CI: - 101, - 52); increased standing (114 min/8 h workday, 95% CI: 92, 136) and maintenance of stepping (3 min/8 h workday, 95% CI: - 7, 11, p = 0.576). Effects were nearly identical for time at work; similar but slightly weaker for overall; and, small and non-significant outside of work on workdays and non-work days. Improvements occurred at all times, but not equally, during work hours (p < 0.001). Correlations between changes during and outside of work on workdays were very weak in both the intervention group (r = - 0.07) and controls (r = - 0.09). CONCLUSIONS: Sitting time was reduced almost exclusively during work hours (via replacement with standing), with reductions evident during all working hours, to varying degrees. There was no evidence of compensation, with minimal change in activity outside of work, in response to changes in activity at work. Future interventions may benefit from exploring how best to elicit change throughout the whole day, and across work and non-work domains. TRIAL REGISTRATION: This trial was prospectively registered with the Australian New Zealand Clinical Trials register (ACTRN12611000742976) on 15 July 2011.

What strategies do desk-based workers choose to reduce sitting time and how well do they work? Findings from a cluster randomised controlled trial.

BACKGROUND: Large amounts of sitting at work have been identified as an emerging occupational health risk, and findings from intervention trials have been reported. However, few such reports have examined participant-selected strategies and their relationships with behaviour change. METHODS: The Stand Up Victoria cluster-randomised controlled trial was a workplace-delivered intervention comprising organisational, environmental and individual level behaviour change strategies aimed at reducing sitting time in desk-based workers. Sit-stand workstations were provided, and participants (n = 134; intervention group only) were guided by health coaches to identify strategies for the 'Stand Up', 'Sit Less', and 'Move More' intervention targets, including how long they would stand using the workstation. Three-month workplace sitting and activity changes (activPAL3-assessed total sitting, prolonged sitting (i.e., sitting ≥30 min continuously) and purposeful walking) were evaluated in relation to the number (regression analysis) and types of strategies (decision-tree analysis). RESULTS: Over 80 different strategies were nominated by participants. Each additional strategy nominated for the 'Stand Up' intervention target (i.e. number of strategies) was associated with a reduction in prolonged sitting of 27.6 min/8-h workday (95% CI: -53.1, - 2.1, p = 0.034). Types of strategies were categorised into 13 distinct categories. Strategies that were task-based and phone-based were common across all three targets. The decision tree models did not select any specific strategy category as predicting changes in prolonged sitting ('Stand Up'), however four strategy categories were identified as important for total sitting time ('Sit Less') and three strategy categories for purposeful walking ('Moving More'). The uppermost nodes (foremost predictors) were nominating > 3 h/day of workstation standing (reducing total workplace sitting) and choosing a 'Move More' task-based strategy (purposeful walking). CONCLUSIONS: Workers chose a wide range of strategies, with both strategy choice and strategy quantity appearing relevant to behavioural improvement. Findings support a tailored and pragmatic approach to encourage a change in sitting and activity in the workplace. Evaluating participant-selected strategies in the context of a successful intervention serves to highlight options that may prove feasible and effective in other desk-based workplace environments. TRIAL REGISTRATION: This trial was prospectively registered with the Australian New Zealand Clinical Trials register ( ACTRN12611000742976 ) on 15 July 2011.

Utilization and Harmonization of Adult Accelerometry Data: Review and Expert Consensus.

PURPOSE: This study aimed to describe the scope of accelerometry data collected internationally in adults and to obtain a consensus from measurement experts regarding the optimal strategies to harmonize international accelerometry data. METHODS: In March 2014, a comprehensive review was undertaken to identify studies that collected accelerometry data in adults (sample size, n ≥ 400). In addition, 20 physical activity experts were invited to participate in a two-phase Delphi process to obtain consensus on the following: unique research opportunities available with such data, additional data required to address these opportunities, strategies for enabling comparisons between studies/countries, requirements for implementing/progressing such strategies, and value of a global repository of accelerometry data. RESULTS: The review identified accelerometry data from more than 275,000 adults from 76 studies across 36 countries. Consensus was achieved after two rounds of the Delphi process; 18 experts participated in one or both rounds. The key opportunities highlighted were the ability for cross-country/cross-population comparisons and the analytic options available with the larger heterogeneity and greater statistical power. Basic sociodemographic and anthropometric data were considered a prerequisite for this. Disclosure of monitor specifications and protocols for data collection and processing were deemed essential to enable comparison and data harmonization. There was strong consensus that standardization of data collection, processing, and analytical procedures was needed. To implement these strategies, communication and consensus among researchers, development of an online infrastructure, and methodological comparison work were required. There was consensus that a global accelerometry data repository would be beneficial and worthwhile. CONCLUSIONS: This foundational resource can lead to implementation of key priority areas and identification of future directions in physical activity epidemiology, population monitoring, and burden of disease estimates.

Intervening to reduce workplace sitting time: how and when do changes to sitting time occur?

OBJECTIVE: To investigate how and when changes in workplace sitting time occurred following a workplace intervention to inform evaluation of intervention success. METHOD: The 4-week Stand Up Comcare study (June-September 2011) aimed to reduce workplace sitting time via regularly interrupting and replacing sitting time throughout the day. Activity monitor (activPAL3) workplace data from control (n=22) and intervention participants (n=21) were analysed. Differences in the number and usual duration of sitting bouts were used to evaluate how change occurred. To examine when change occurred, intervention effects were compared by hour since starting work and hour of the workday. Change in workplace activity (sitting, standing, stepping) was examined to further inform alignment with intervention messages. Individual variability was examined in how and when the change occurred. RESULTS: Overall, behavioural changes aligned with intervention aims. All intervention participants reduced total workplace sitting time, though there was wide individual variability observed (range -29 to -262 min per 8 h workday). On average, intervention participants reduced number of sitting bouts (-4.6 bouts (95% CI -10.1 to 1.0), p=0.106) and usual sitting bout duration (-5.6 min (95% CI -9.8 to -1.4, p=0.011)) relative to controls. Sitting time reductions were observed across the workday, though intervention effects varied by hour of the day (p=0.015). The intervention group successfully adopted the Stand Up and Sit Less intervention messages across the day. CONCLUSION: These analyses confirmed that this workplace intervention successfully modified sitting behaviour as intended (ie, fewer and shorter sitting bouts, with changes occurring throughout the day).

Improving diet and physical activity to reduce population prevalence of overweight and obesity: an overview of current evidence.

OBJECTIVE: The aim of this study is to provide an overview of interventions to reduce or prevent overweight or obesity and improve diet or physical activity. METHODS: A review of meta-analyses and/or systematic reviews of these interventions in any setting or age group were conducted. Narrative systematic reviews were included for intervention categories with limited meta-analyses available. Summary measures including weighted mean difference, standardised mean difference, and I-squared, were examined. RESULTS: A total of 60 meta-analyses and 23 systematic reviews met the inclusion criteria. Dietary interventions and multi-component interventions targeting overweight and obesity appeared to have the greatest effects, particularly in comparison with workplace or technology or internet-based interventions. Pharmaceutical and surgical interventions produced favourable results for specific population sub-groups (i.e. morbidly obese). Population-wide strategies such as policy interventions have not been widely analysed. The effectiveness of the interventions to assist in maintaining behaviour or weight change remains unclear. CONCLUSIONS: Various individually targeted interventions were shown to reduce body weight, although effect sizes were typically modest, and the durability of effects has been questioned. New approaches to evaluating population-based interventions, such as taxes and regulation, are recommended. Future research modelling the long-term effects of interventions across the lifespan would also be beneficial.