Total and domain-specific sitting time among employees in desk-based work settings in Australia

Abstract

Objective: To describe the total and domain-specific daily sitting time among a sample of Australian office-based employees. Methods:In April 2010, paper-based surveys were provided to desk-based employees (n=801) in Victoria, Australia. Total daily and domain-specific (work, leisure-time and transport-related) sitting time (minutes/day) were assessed by validated questionnaires. Differences in sitting time were examined across socio-demographic (age, sex, occupational status) and lifestyle characteristics (physical activity levels, body mass index [BMI]) using multiple linear regression analyses. Results:The median (95% confidence interval [CI]) of total daily sitting time was 540 (531-557) minutes/day. Insufficiently active adults (median=578 minutes/day, [95%CI: 564-602]), younger adults aged 18-29 years (median=561 minutes/day, [95%CI: 540-577]) reported the highest total daily sitting times. Occupational sitting time accounted for almost 60% of total daily sitting time. In multivariate analyses, total daily sitting time was negatively associated with age (unstandardised regression coefficient [B]=-1.58, p<0.001) and overall physical activity (minutes/week) (B=-0.03, p<0.001) and positively associated with BMI (B=1.53, p=0.038). Conclusions:Desk-based employees reported that more than half of their total daily sitting time was accrued in the work setting.Implications: Given the high contribution of occupational sitting to total daily sitting time among desk-based employees, interventions should focus on the work setting.

Prediction of objectively measured physical activity and sedentariness among blue-collar work using survey questionnaires

“…In our full model, age was observed to be negatively associated with sedentary time at work, which corroborates many previous studies (26,30,32). BMI also tended to be negatively associated with time spent sedentary, and this contradicts previous studies (26,29).…”

“…The performance of the full model based on age, job group, BMI, and self-reported OST and OPA was similar to the best performances of previous questionnaires on occupational sedentary and physical activity (45)(46)(47). The performance of our model was even better than previously developed models using a customized set of variables to predict self-reported OST or OPA (26,29,30). Also, these previous models produce estimates of self-reported OST or OPA, and thus do not adjust for the bias present in these self-reports, relative to objectively measured data.…”

“…The predictors used for modelling in this study were Gupta et al selected a priori from the questionnaire based on (i) whether they would likely predict time spent sedentary or in physical activity according to previous studies (26,29,30,32,(36)(37)(38), (ii) whether they are commonly available in large epidemiological studies and surveys, and (iii) whether they showed a large relative dispersion between workers in our material. Based on these criteria, we arrived at including self-reported information on age, gender, body mass index (BMI), job type, OST, and OPA.…”

“…Explicit prediction models have been proposed before to predict time spent sedentary and in physical activity (23)(24)(25), but these studies have not developed models for exposures at work, which may show associations with self-reported predictors other than leisure time exposures. A few previous studies have, indeed, developed prediction models for time spent sedentary and in physical activity specifically at work (26)(27)(28)(29)(30). However, they have mainly focused on predicting answers to some self-reported variables by another type of self-reported information.…”

Cardiovascular benefits and risks across the physical activity continuum

“…Hence, physical inactivity represents sedentary behavior that does not involve muscle contraction, which is most prevalent during sitting and lying. Recent studies revealed that accelerometermeasured mean daily sedentary time was 8.2 hrs/day among New York City adults [13], whereas Australian desk workers reported an average of 9.0 hrs/day of sitting time [14]. Physical inactivity is not restricted to the general population; it can be observed in (half-)marathon runners as they have reported sitting 10.75 hrs/day on workdays and 8 hrs/day on non-workdays [15].…”