Temporal changes in occupational sitting time in the Danish workforce and associations with all-cause mortality: results from the Danish work environment cohort study

A tool for assessing sex/gender bias in epidemiological studies of occupational health: Pilot testing on studies of sedentary behaviour at the workplace and cardiometabolic health

BACKGROUND

The perspective of sex/gender bias is often missing in tools used to assess study risk of bias in systematic reviews. The aim was to pilot a checklist using an aetiological occupational health research question regarding the impact of sedentary behaviour at the workplace and cardiometabolic health. The checklist examined whether the consideration of sex/gender was associated with different study characteristics.

METHODS

A sex/gender checklist developed based on a synopsis of existing instruments with input from the Cochrane Sex/Gender Methods Group was adapted for the present study. This checklist comprises four categories: 1. "Background and conceptual considerations" (3 items), 2. "Study design" (2 items), 3. "Study procedures of investigation or intervention and statistical analysis" (2 items), and 4. "Presentation and interpretation of findings" (3 items). Two independent reviewers evaluated all included studies. Bivariate and multivariable logistic regression analyses were used to examine the consideration of sex/gender across study designs, years of publication, and risk of bias levels (based on the Scottish Intercollegiate Guidelines Network [SIGN]).

RESULTS

Of the 49 studies evaluated with the checklist, none provided detailed information, 69% (n = 34) provided basic information and 31% (n = 15) no information for the consideration of sex/gender. No intervention study provided information for the first two categories. In the third category, all intervention studies (n = 17) and case-control studies (n = 5) provided basic information on sex/gender, while two of the 23 cohort studies did not. In the fourth category, detailed information was found for all study designs (n = 8). Bivariate analyses revealed no association between the consideration of sex/gender and the year of publication (OR per year = 0.89; 95% CI: 0.65, 1.23). A low risk of bias level was not associated with consideration of sex/gender (OR = 0.60; 95% CI: 0.14; 2.50). Compared to intervention studies the odds of considering sex/gender was increased by a factor of 3.6 (95% CI: 1.0, 12.8) in observational studies.

CONCLUSION

The adapted checklist was applicable to assess the consideration of sex/gender in all studies. None of the primary studies considered sex/gender perspectives in all of the four categories. Further optimisation of the sex/gender tool seems warranted, based on further research on weighting individual categories or items and application of the checklist for occupational epidemiology in general.

The impact of breaking up sitting during simulated nightshifts on musculoskeletal pain: A randomised controlled trial

OBJECTIVES

Prolonged sitting is associated with an increased risk of musculoskeletal pain, especially in nightshift workers. However, research investigating effects of breaking up sitting on musculoskeletal pain during nightshifts is lacking. This study evaluated effects of prolonged sitting or breaking up sitting with short bouts of light-intensity physical activity on pain in healthy adults during simulated nightshifts.

METHODS

An in-laboratory randomised controlled trial was undertaken with 52 healthy adults completing five simulated nightshifts. Participants were randomised to prolonged sitting (Sit9; n = 26) or breaking up prolonged sitting (Break9; n = 26). Break9 group completed 3-min walking every 30 min during nightshifts, while Sit9 group remained seated. Musculoskeletal pain intensity and sensory/affective pain experiences were assessed. Linear mixed models examined pain within nights (pre-to post-shift) and across nights (pre-shift-night-1 to pre-shift-night-5).

RESULTS

Musculoskeletal pain intensity increased within nights for both Sit9 (mean change [95%CI] points: 0.14 [0.05, 0.24]) and Break9 (0.09 [0.001, 0.19], but not across nights (Sit9: -0.13 [-0.33, 0.08]; Break9: 0.07 [-0.14, 0.29]). Sensory-pain experience improved across nights for Sit9 (-3.08 [-4.72, -1.45]), but not within nights (0.77 [-0.004, 1.55]). There was no change in affective-pain experience in either group. Between-group difference was observed favouring Sit9 for improving sensory-pain across nights (β: 3.71 [1.42, 5.99]). No other between-group difference was observed.

CONCLUSION

Both prolonged sitting and breaking up sitting were associated with a within-night increase in musculoskeletal pain intensity. Compared to prolonged sitting, breaking up sitting did not induce benefits on pain in healthy adults working simulated nightshifts.

TRIAL REGISTRATION

ACTRN12619001516178.

Active Breaks Reduce Back Overload during Prolonged Sitting: Ergonomic Analysis with Infrared Thermography

Background: Prolonged sitting is a potential risk factor for musculoskeletal disorders in office workers. This study aims to evaluate the effect of active breaks on reducing muscle overload in subjects who sit for long periods using infrared thermography (IRT). Methods: A sample of 57 office workers participated in this study and were divided into two groups: active breaks (ABs) and no active breaks (NABs). The NAB group sat continuously for 90 min without standing up, while the AB group performed stretching and mobility exercises every 30 min. IRT measurements were taken every 30 min before the active breaks. Results: The results highlight that the skin temperature of the back increased significantly in both groups after 30 min of sitting; however, in the subsequent measurements, the AB group showed a decrease in temperature, while the NAB group maintained a high temperature. Exercise and time point of measurement all reported p-values < 0.001; there were no statistically significant differences between the Δt0-1 of the NAB and AB groups, while the Δt1-2 and Δt1-3 of the NAB and AB groups showed statistically significant differences for all back regions. Conclusions: The clinical relevance of this study confirms the negative effects of prolonged sitting on the health of the back, demonstrating that active breaks can reduce back strain, emphasizing the need for workplace interventions. In addition, IRT represents a non-invasive method to assess back muscle overload and monitor the effectiveness of interventions in all categories of workers who maintain a prolonged sitting position. The main limitation of this study is the absence of a questionnaire for the assessment of back pain, which does not allow a direct correlation between temperature changes and back pain outcomes.

Office job sitting demand scale: Evidence of construct and predictive validity

Drawing on sedentary behavior and Job Demands-Resources theory, we developed a new scale for assessing office job sitting demand, conceptualized as job demand, and validated it using two independent samples. In Study 1 (N = 252), we developed the items and tested the Office Job Sitting Demand scales' factor structure through exploratory factor analysis. In Study 2 (N = 248), we tested the scales' factorial validity through confirmatory factor analysis. Indicators of measurement invariance showed no differences between participants who engage in leisure-time sport and participants who do not. Moreover, we tested convergent, discriminant, and criterion validity. We found significant positive associations with exhaustion, work pressure, and musculoskeletal complaints. The construct was unrelated to proactive vitality management and relaxation. Our results illustrate the relation between this new job demand in the workplace with employee well-being. Based on our findings, this newly developed instrument is valid and reliable and can be used to assess office job sitting demand to prevent burnout and health complaints.

Alignment of the Sternum and Sacrum as a Marker of Sitting Body Posture in Children

An analysis of literature on the methods of assuming a sitting position and the results of our own research indicated the need to search for biomechanical parameters and existing relationships that would enable a description of sitting body posture. The purpose of this paper is to analyze the relationship between the alignment of the body of sternum and sacrum and the changes in the thoracic and lumbar spine curvatures in children. The study involved 113 subjects aged 9-13 years. A planned simultaneous measurement of the angle parameters of the alignment of the body of sternum and sacrum relative to the body's sagittal axis and the angle parameters of the thoracic and lumbar spine curvatures was performed during a single examination session. The proposed markers of alignment in the corrected sitting body posture are characterized by homogeneous results. A high measurement repeatability was observed when determining the corrected body posture in the study setting. It was noted that changes in the alignment of the body of sternum and sacrum resulted in changes in the thoracic kyphosis and lumbar lordosis angle values, which may be an important component of clinical observations of sitting body posture in children. Implementing the body of sternum alignment angle of about 64° relative to the body's sagittal axis in clinical practice as one of the objectives of postural education may be the target solution for sitting body posture correction in children.

Association of occupational sitting with cardiovascular outcomes and cardiometabolic risk factors: a systematic review with a sex-sensitive/gender-sensitive perspective

OBJECTIVES

Sedentary behaviour is a modifiable risk factor for cardiovascular health. Although long periods of sedentary behaviour take place at work, evidence of the relationship between such occupational sitting and cardiometabolic health risks remains limited. This systematic review aimed to update the evidence on the associations of occupational sitting with cardiovascular outcomes and cardiometabolic risk factors based on longitudinal studies.

DESIGN

Systematic review.

SETTING

Workplace.

POPULATION

Employees aged 18-65 years.

PRIMARY AND SECONDARY OUTCOMES

Primary outcomes were cardiovascular diseases and cardiometabolic risk markers. The secondary outcome was all-cause mortality.

DATA SOURCES

Ten databases, including PubMed, Web of Science and CINAHL (search January 2018, updated February 2019).

DATA EXTRACTION AND SYNTHESIS

Data were screened, extracted and appraised by three independent reviewers following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

RESULTS

Studies were markedly heterogeneous in terms of measurement of occupational sitting, cardiometabolic risk factors and cardiovascular morbidity and mortality, so that standards were hardly identifiable and limiting the value of the evidence. The review included 27 high or acceptable quality publications. Of the eight high-quality publications from seven cohorts, three cohort studies found significant associations of occupational sitting with primary outcomes. Additionally, one study described an association with the secondary outcome. Another high-quality publication found an association between occupational sitting and ischaemic heart disease in a subgroup already at risk due to hypertension. For sex/gender analysis, 11 of the 27 high and acceptable quality publications reported sex-stratified results. Five of these found sex differences.

CONCLUSIONS

Evidence regarding the association of occupational sitting with cardiometabolic health risks was limited because of the lack of standardised measurements for occupational sitting. Occupational sitting combined with an overall sedentary lifestyle was associated with an elevated relative risk for several cardiometabolic outcomes. There is an urgent need for standardised measurements of occupational sitting to facilitate meta-analysis. Sex/gender aspects of this relationship require further investigation.

Physical activity and sedentary behaviour over adulthood in relation to all-cause and cause-specific mortality: a systematic review of analytic strategies and study findings

BACKGROUND

Questions remain about the effect on mortality of physical activity and sedentary behaviour over time. We summarized the evidence from studies that assessed exposure from multiple time points and critiqued the analytic approaches used.

METHODS

A search was performed on MEDLINE, Embase, Emcare, Scopus and Web of Science up to January 2021 for studies of repeatedly assessed physical activity or sedentary behaviour in relation to all-cause or cause-specific mortality. Relative risks from individual studies were extracted. Each study was assessed for risk of bias from multiple domains.

RESULTS

We identified 64 eligible studies (57 on physical activity, 6 on sedentary behaviour, 1 on both). Cox regression with a time-fixed exposure history (n = 45) or time-varying covariates (n = 13) were the most frequently used methods. Only four studies used g-methods, which are designed to adjust for time-varying confounding. Risk of bias arose primarily from inadequate adjustment for time-varying confounders, participant selection, exposure classification and changes from measured exposure. Despite heterogeneity in methods, most studies found that being consistently or increasingly active over adulthood was associated with lower all-cause and cardiovascular-disease mortality compared with being always inactive. Few studies examined physical-activity changes and cancer mortality or effects of sedentary-behaviour changes on mortality outcomes.

CONCLUSIONS

Accumulating more evidence using longitudinal data while addressing the methodological challenges would provide greater insight into the health effects of initiating or maintaining a more active and less sedentary lifestyle.

Socioeconomic status relates to exercise habits and cardiorespiratory fitness among workers in the Tokyo area

OBJECTIVES

This survey aims to investigate consciousness regarding habitual exercise among workers in urban areas and to analyze the associations of workers' socioeconomic status with their habitual exercise and cardiorespiratory fitness (CRF).

METHODS

Ten thousand participants, who worked in the Tokyo area of Japan, were recruited for the questionnaire-based survey. The questionnaire elicited participant's characteristics, socioeconomic status (eg, employment status and annual income), habitual exercise status, and consciousness regarding exercising. After the data-cleaning procedure, 9406 participants were selected for analyses. CRF was estimated by a validated equation model.

RESULTS

Some (32.9%) participants had an exercise habit, and 93% recognized that exercise is good for health. Of the nonexercise habit group (n = 6308), 73% wanted to develop an exercise habit, and "spare time (40%)" and "financial capability (16%)" were the two most necessary conditions for habituating exercise. As socioeconomic statuses increased, the odds ratios (ORs) for engaging in habitual exercise increased among full-time (1.22) versus part-time (reference) employees and those having high (1.76) versus low (reference) incomes, whereas the ORs for low CRF risk decreased among full-time (0.78) versus part-time (reference) employees and those having high (0.53) versus low (reference) incomes.

CONCLUSIONS

Although most workers recognized the benefits of exercise, many were unable to develop exercise habits and believed that they could develop exercise habits if they had the time and financial capabilities. The survey suggests that workers with a higher socioeconomic status more likely to obtain favorable physical fitness, indicating a health disparity among workers in urban areas.

Confounding due to pre-existing diseases in epidemiologic studies on sedentary behavior and all-cause mortality: a meta-epidemiologic study

PURPOSE

We examined the influence of confounding due to pre-existing diseases in prospective studies on sedentary behavior and all-cause mortality.

METHODS

We analyzed 25 studies included in systematic reviews. The risk of confounding due to pre-existing diseases was assessed by five methodologic characteristics.

RESULTS

Sedentary behavior was associated with higher all-cause mortality. Studies with short average follow-up length had stronger magnitudes of association: 1 to less than 5 years (hazard ratio [HR], 1.58; 95% confidence interval [CI], 1.28-1.94), 5 to 9 years (HR, 1.24; 95% CI, 1.16-1.31), and 10 years or more of follow-up (HR, 1.20; 95% CI, 1.10-1.31). Studies that did not adjust for diseases at baseline, did not exclude deaths in the first years of follow-up, and did not exclude participants with diseases/conditions showed stronger associations. Studies with higher risk of confounding because of pre-existing diseases (HR, 1.40; 95% CI, 1.27-1.54) showed stronger association than lower risk studies (HR, 1.18; 95% CI, 1.10-1.27). Studies excluding participants with diseases at baseline had weaker associations compared with studies adjusting for diseases in models.

CONCLUSIONS

Sedentary behavior was associated with increased all-cause mortality, although confounding due to pre-existing diseases may bias the magnitude of the association.

Reducing sitting at work: process evaluation of the SMArT Work (Stand More At Work) intervention

Background

Office-based workers accumulate high amounts of sitting time. Stand More At Work (SMArT Work) aimed to reduce occupational sitting time and a cluster randomised controlled trial demonstrated it was successful in achieving this aim. The purpose of this paper is to present the process evaluation of the SMArT Work intervention.

Methods

Questionnaire data were collected from intervention participants at 6 months (n = 58) and 12 months (n = 55). Questionnaires sought feedback on the different components of the intervention (education, height-adjustable desk, Darma cushion, behaviour feedback, progress chats (coaching) with research team, action planning/goal setting diary) and experiences of evaluation measures. Control participants (n = 37) were asked via questionnaire at 12-month follow-up about the impact of the study on their behaviour and any lifestyle changes made during the study. Participants from both arms were invited to focus groups to gain a deeper understanding of their experiences on completion of 12-month follow-up.

Results

Focus group and questionnaire data showed a positive attitude towards the height-adjustable workstation with a high proportion of participants using it every day (62%). Most participants (92%) felt the education seminar increased their awareness of the health consequences of too much sitting and motivated them to change their behaviour. Receiving feedback on their sitting time and support from the research team also encouraged behaviour change. The Darma cushion and action planning/goal setting diary were seen to be less helpful for behaviour change. Benefits experienced included fewer aches and pains, improved cognitive functioning, increased productivity, more energy and positive feelings about general health.

Conclusions

Key elements of the programme identified as facilitating behaviour change were the educational seminar, the height-adjustable workstation, behavioural feedback and regular contact with research staff through regular progress chats.

Trial registration

ISRCTN: ISRCTN10967042. Registered on 2 February 2015.

Workers' physical activity data contribute to estimating maximal oxygen consumption: a questionnaire study to concurrently assess workers' sedentary behavior and cardiorespiratory fitness

Background

Sedentary behavior (SB) and cardiorespiratory fitness (CRF) are important issues in occupational health. Developing a questionnaire to concurrently assess workers’ SB and CRF could fundamentally improve epidemiological research. The Worker’s Living Activity-time Questionnaire (WLAQ) was developed previously to assess workers’ sitting time. WLAQ can be modified to evaluate workers’ CRF if additional physical activity (PA) data such as PA frequency, duration, and intensity are collected.

Methods

A total of 198 working adults (93 women and 105 men; age, 30–60 years) completed anthropometric measurements, a treadmill exercise test for measuring maximal oxygen consumption (VO_2max), and modified WLAQ (m-WLAQ, which included questions about PA data additional to the original questions). Multiple regression analyses were performed to develop prediction equations for VO_2max. The generated models were cross-validated using the predicted residual error sum of squares method. Among the participants, the data of 97 participants who completed m-WLAQ twice after a 1-week interval were used to calculate intraclass correlation coefficient (ICC) for the test–retest reliability analyses.

Results

Age (r = − 0.29), sex (r = 0.48), body mass index (BMI, r = − 0.20), total sitting time (r = − 0.15), and PA score (total points for PA data, r = 0.47) were significantly correlated with VO_2max. The models that included age, sex, and BMI accounted for 43% of the variance in measured VO_2max [standard error of the estimate (SEE) = 5.04 ml·kg^− 1·min^− 1]. These percentages increased to 59% when the PA score was included in the models (SEE = 4.29 ml·kg^− 1·min^− 1). Cross-validation analyses demonstrated good stability of the VO_2max prediction models, while systematic underestimation and overestimation of VO_2max were observed in individuals with high and low fitness, respectively. The ICC of the PA score was 0.87 (0.82–0.91), indicating excellent reliability.

Conclusions

The PA score obtained using m-WLAQ, rather than sitting time, correlated well with measured VO_2max. The equation model that included the PA score as well as age, sex, and BMI had a favorable validity for estimating VO_2max. Thus, m-WLAQ can be a useful questionnaire to concurrently assess workers’ SB and CRF, which makes it a reasonable resource for future epidemiological surveys on occupational health.

Does objectively measured prolonged standing for desk work result in lower ratings of perceived low back pain than sitting? A systematic review and meta-analysis

BACKGROUND

Prolonged sitting has been shown to induce transient low back pain (LBP). Height adjustable office desks now present the opportunity to replace sitting with standing in the workplace. Since standing has also been associated with LBP, this may not be an advisable alternative.

OBJECTIVE

To determine if objectively measured prolonged exposures to desk work while standing, compared to sitting, results in lower perceived LBP in healthy adults.

METHODS

A systematic search of several databases was conducted. Two independent reviewers screened titles/abstracts and conducted a quality assessment. The results of three studies were pooled using an inverse variance random-effects meta-analysis. Heterogeneity was tested using the Chi-squared test and I2 statistic.

RESULTS

Objectively measured prolonged standing postures during desk work did not induce significantly less perceived LBP compared to seated postures (standardized mean difference 0.60, 95% CI -0.68 to 1.87, p = 0.36.) There was significant heterogeneity, I2 = 90%).

CONCLUSIONS

It appears that replacing seated desk work postures with standing for prolonged periods of time would not be recommended. Larger studies, including a wider age range and health history, conducted in the field with objective measures is recommended to obtain more generalizable data on which to base ergonomic standards for work postures.

Time trends between 2002 and 2017 in correlates of self-reported sitting time in European adults

BACKGROUND

This study explores trends in the prevalence of high sitting time and its correlates among "high sitting" and "high sitting-least active" European adults from 2002 to 2017. Both groups have merit for future public health interventions to prevent development of a range of prevalent non-communicable diseases.

METHODS

Data collected in the 2002 (15 countries), 2005 (30 countries), 2013 (28 countries) and 2017 (28 countries) Eurobarometer surveys were used, including around 15,000 respondents in 2002 and >26,000 respondents in the other years. Sitting time and moderate to vigorous intensity physical activity were measured with the validated International Physical Activity Questionnaire-short. High sitting was defined as >7.5 hours per day. Respondents in the lowest quartile of total reported days of physical activity (i.e. days walking, days in moderate activity, and days in vigorous activity) were defined as least active. Multivariate odds ratios of high sitting, and high sitting-least active were assessed by country and socio-demographic characteristics for each survey year using binary logistic regression analyses.

RESULTS

Trends in sitting time were relatively stable over a 15-year period, although this time trend was limited by a change in the sitting question between 2005 and 2013. Men, higher educated people, students, retired people, white collar workers, people living in urban areas, people with lower physical activity levels, and people living in the Czech Republic, Denmark or the Netherlands were consistently more likely to be in the high sitting group across all four survey years. Similarly, men, students, retired people, unemployed people, white collar workers, and people living in the Czech Republic or Denmark were consistently more likely to be in the high sitting-least active group across all four surveys.

CONCLUSION

This study identified population sub-groups that need special attention in public health interventions to lower total sitting time.

Physical heaviness of work and sitting at work as predictors of mortality: a 26-year follow-up of the Helsinki Birth Cohort Study

OBJECTIVES

To examine the relationships of late-career physical heaviness of work and sitting at work with mortality. A national-level job exposure matrix was used to determine the occupation-specific level of physical heaviness and sitting.

DESIGN

Prospective cohort study between years 1990 and 2015.

SETTING

Community.

PARTICIPANTS

5210 men and 4725 women from the Helsinki Birth Cohort Study with an occupational code at baseline (ages 45-57 years).

PRIMARY AND SECONDARY OUTCOME MEASURES

Total, cardiovascular (International Classification of Diseases 10th Revision I00-I99), cancer (C00-C97) and external (S00-Y84) mortality.

RESULTS

The exposures, physical heaviness and sitting had a non-linear, inverse relationship. During the 26-year follow-up, 1536 men and 759 women died. Among men, physical heaviness of work was positively associated and sitting at work was negatively associated with all-cause, cardiovascular and external cause mortality but they were not associated with cancer mortality. The HRs for men in the highest quartile of physical heaviness of work compared with men in the lowest quartile were 1.54 (1.31-1.80) for all-cause mortality, 1.70 (1.30-2.23) for cardiovascular mortality and 3.18 (1.75-5.78) for external cause mortality (adjusted for age and years of education). Compared with the lowest quartile, the HRs for the highest quartile of sitting at work among men were 0.71 (0.61-0.82) for all-cause mortality, 0.59 (0.45-0.77) for cardiovascular mortality and 0.38 (0.22-0.66) for external cause mortality. In women, neither physical heaviness of work nor sitting at work was associated with mortality.

CONCLUSIONS

Men in physically heavy work at their late-work career are at higher risk of death than men in physically light work.

Association between physical activity, occupational sitting time and mortality in a general population: An 18-year prospective survey in Tanushimaru, Japan

AIMS

It is well known that a decline in physical activity is associated with an increase of all-cause death including cardiovascular events and cancer. Few studies have examined the association between occupational sitting time and mortality. Therefore, we investigated this issue in a general population.

METHODS

Physical activity and occupational sitting time were measured using the Baecke physical activity questionnaire in 1999. The questionnaire generated indices in three physical activity categories: work, sport and leisure-time. A total physical activity index was calculated by adding these three indices. The Baecke physical activity questionnaire was able to evaluate occupational sitting time. Hazard ratios and 95% confidence intervals (CIs) were calculated using Cox's proportional hazard regression models.

RESULTS

We enrolled a total of 1680 participants, who were followed up for 15.9 ± 3.8 years. The final follow-up rate was 93%. During the follow-up period, 397 subjects died. A significant inverse association (p < 0.0001) was found between physical activity and mortality after adjustment for age and sex. Compared with lower levels of physical activity, the adjusted hazard ratio for mortality at higher levels of physical activity was 0.85 (95% CI: 0.78-0.92). Longer occupational sitting time was also significantly associated with higher mortality (p < 0.01). The adjusted hazard ratio for mortality at longer occupational sitting time was 1.16 (95% CI: 1.05-1.27). These findings were observed in males, but not in females.

CONCLUSIONS

Our data demonstrated that higher levels of physical activity are associated with a reduced risk of cancer and cardiovascular death. Further, longer occupational sitting time is associated with increased mortality.

Job-exposure matrices addressing lifestyle to be applied in register-based occupational health studies

Objectives

Information about lifestyle factors in register-based occupational health studies is often not available. The objective of this study was therefore to develop gender, age and calendar-time specific job-exposure matrices (JEMs) addressing five selected lifestyle characteristics across job groups as a tool for lifestyle adjustment in register-based studies.

Methods

We combined and harmonised questionnaire and interview data on lifestyle from several Danish surveys in the time period 1981–2013 for 264 054 employees registered with a DISCO-88 code (the Danish version of International Standard Classification of Occupations (ISCO)-88) in a nationwide register-based Danish Occupational Cohort. We modelled the probability of specified lifestyles in mixed models for each level of the four-digit DISCO code with age and sex as fixed effects and assessed variation in terms of intraclass correlation coefficients (ICCs) and exposure-level percentile ratios across jobs for six different time periods from 1981 through 2013.

Results

The ICCs were overall low (0.26%–7.05%) as the within-job group variation was large relative to the between job group variation, but across jobs the calendar period-specific ratios between highest and lowest predicted levels were ranging from 1.2 to 6.9, and for the 95%/1% and the 75%/5% percentile ratios ranges were 1.1–2.8 and 1.1–1.6, respectively, thus indicating substantial contrast for some lifestyle exposures and some occupations.

Conclusions

The lifestyle JEMs may prove a useful tool for control of lifestyle-related confounding in register-based occupational health studies where lacking information on individual lifestyle factors may compromise internal validity.

The Short Term Musculoskeletal and Cognitive Effects of Prolonged Sitting During Office Computer Work

Office workers are exposed to high levels of sedentary time. In addition to cardio-vascular and metabolic health risks, this sedentary time may have musculoskeletal and/or cognitive impacts on office workers. Participants (n = 20) undertook two hours of laboratory-based sitting computer work to investigate changes in discomfort and cognitive function (sustained attention and problem solving), along with muscle fatigue, movement and mental state. Over time, discomfort increased in all body areas (total body IRR [95% confidence interval]: 1.43 [1.33–1.53]) reaching clinically meaningful levels in the low back and hip/thigh/buttock areas. Creative problem solving errors increased (β = 0.25 [0.03–1.47]) while sustained attention did not change. There was no change in erector spinae, trapezius, rectus femoris, biceps femoris and external oblique median frequency or amplitude; low back angle changed towards less lordosis, pelvis movement increased, and mental state deteriorated. There were no substantial correlations between discomfort and cognitive function. The observed changes suggest prolonged sitting may have consequences for musculoskeletal discomfort and cognitive function and breaks to interrupt prolonged sitting are recommended.

Web-based KAP Intervention on Office Ergonomics: A Unique Technique for Prevention of Musculoskeletal Discomfort in Global Corporate Offices

Aims:

The purpose of this study was to evaluate web-based Knowledge, Attitude and Practice (KAP) intervention on office ergonomics – a unique method for prevention of musculoskeletal discomfort (MSD) – in corporate offices that influences behavior modification.

Background:

With the increasing use of computers, laptops and hand-held communication devices globally among office employees, creating awareness on office ergonomics has become a top priority. Emphasis needs to be given on maintaining ideal work postures, ergonomic arrangement of workstations, optimizing chair functions, as well as performing desk stretches to reduce MSD arising from the use of these equipment, thereby promoting safe work practices at offices and home, as in the current scenario many employees work from home with flexible work hours. Hence, this justifies the importance of our study.

Objective:

To promote safe working by exploring cost-effective communication methods to achieve behavior change at distant sites when an on-site visit may not be feasible.

Materials and Methods:

An invitation was sent by the Medical and Occupational Health Team of a multinational corporation to all employees at their offices in Sri Lanka, Singapore, and Malaysia to take up an online Nordic questionnaire, a screening tool for musculoskeletal symptoms, shared in local languages on two occasions – baseline evaluation (n = 240) and a follow-up evaluation after 3 months (n = 203). After completing the baseline questionnaire, employees were immediately trained on correct postures and office ergonomics with animation graphics. The same questionnaire was sent again after a 12-week gap only to those employees who responded to the baseline questionnaire on initial assessment.

Statistical Analysis Used:

Data collected were analyzed using the Statistical Package for the Social Sciences (SPSS) version 20.0 software and variables were compared using odds ratio as well as Chi-square test.

Results:

Of the 203 employees who responded, 47.35% had some musculoskeletal symptoms. Among them 58.7% had lower back pain, 46.9% had upper back pain, 44.1% had wrist pain, 39.5% had shoulder pain, and 37% had knee pain. The percentages are high as some participants had multiple complaints i.e. 2 or 3 complaints. However, only 40% of these employees had ongoing symptoms at the time of evaluation (past 7 days). A subsequent 3-month evaluation after web-based intervention showed a significant 41–50% decline in ongoing symptoms.

Conclusions:

We conclude that newer technology using web-based animation graphics is a highly efficient technique to create office ergonomics awareness and has the potential to become a best practice in countries where language is a communication barrier and an on-site visit may not be feasible due to meagre resources.

Monitoring sedentary patterns in office employees: validity of an m-health tool (Walk@Work-App) for occupational health

OBJECTIVE

This study validated the Walk@Work-Application (W@W-App) for measuring occupational sitting and stepping.

METHODS

The W@W-App was installed on the smartphones of office-based employees (n=17; 10 women; 26±3 years). A prescribed 1-hour laboratory protocol plus two continuous hours of occupational free-living activities were performed. Intra-class correlation coefficients (ICC) compared mean differences of sitting time and step count measurements between the W@W-App and criterion measures (ActivPAL3TM and SW200Yamax Digi-Walker).

RESULTS

During the protocol, agreement between self-paced walking (ICC=0.85) and active working tasks step counts (ICC=0.80) was good. The smallest median difference was for sitting time (1.5seconds). During free-living conditions, sitting time (ICC=0.99) and stepping (ICC=0.92) showed excellent agreement, with a difference of 0.5minutes and 18 steps respectively.

CONCLUSIONS

The W@W-App provided valid measures for monitoring occupational sedentary patterns in real life conditions; a key issue for increasing awareness and changing occupational sedentariness.

A practical guidance for assessments of sedentary behavior at work: A PEROSH initiative

Sedentary behavior is defined as sitting or lying with low energy expenditure. Humans in industrialized societies spend an increasing amount of time in sedentary behaviors every day. This has been associated with detrimental health outcomes. Despite a growing interest in the health effects of sedentary behavior at work, associations remain unclear, plausibly due to poor and diverse methods for assessing sedentary behavior. Thus, good practice guidance for researchers and practitioners on how to assess occupational sedentary behavior are needed. The aim of this paper is to provide a practical guidance for practitioners and researchers on how to assess occupational sedentary behavior. Ambulatory systems for use in field applications (wearables) are a promising approach for sedentary behavior assessment. Many different small-size consumer wearables, with long battery life and high data storage capacity are commercially available today. However, no stand-alone commercial system is able to assess sedentary behavior in accordance with its definition. The present paper offers decision support for practitioners and researchers in selecting wearables and data collection strategies for their purpose of study on sedentary behavior. Valid and reliable assessment of occupational sedentary behavior is currently not easy. Several aspects need to be considered in the decision process on how to assess sedentary behavior. There is a need for development of a cheap and easily useable wearable for assessment of occupational sedentary behavior by researchers and practitioners.

Does a dynamic chair increase office workers' movements? - Results from a combined laboratory and field study

PURPOSE

Dynamic chairs have the potential to facilitate movements that could counteract health problems associated with sedentary office work. This study aimed to evaluate whether a dynamic chair can increase movements during desk-based office work.

METHODS

Fifteen healthy subjects performed desk-based office work using a dynamic office chair and compared to three other conditions in a movement laboratory. In a field study, the dynamic office chair was studied during three working days using accelerometry.

RESULTS

Equivocal results showed that the dynamic chair increased upper body and chair movements as compared to the conventional chair, but lesser movements were found compared to standing. No differences were found between the conditions in the field study.

CONCLUSIONS

A dynamic chair may facilitate movements in static desk-based office tasks, but the results were not consistent for all outcome measures. Validation of measuring protocols for assessing movements during desk-based office work is warranted.

Intra-individual variability in day-to-day and month-to-month measurements of physical activity and sedentary behaviour at work and in leisure-time among Danish adults

Background

Accelerometers can obtain precise measurements of movements during the day. However, the individual activity pattern varies from day-to-day and there is limited evidence on measurement days needed to obtain sufficient reliability. The aim of this study was to examine variability in accelerometer derived data on sedentary behaviour and physical activity at work and in leisure-time during week days among Danish office employees.

Methods

We included control participants (n = 135) from the Take a Stand! Intervention; a cluster randomized controlled trial conducted in 19 offices. Sitting time and physical activity were measured using an ActiGraph GT3X+ fixed on the thigh and data were processed using Acti4 software. Variability was examined for sitting time, standing time, steps and time spent in moderate-to-vigorous physical activity (MVPA) per day by multilevel mixed linear regression modelling.

Results

Results of this study showed that the number of days needed to obtain a reliability of 80% when measuring sitting time was 4.7 days for work and 5.5 days for leisure time. For physical activity at work, 4.0 days and 4.2 days were required to measure steps and MVPA, respectively. During leisure time, more monitoring time was needed to reliably estimate physical activity (6.8 days for steps and 5.8 days for MVPA).

Conclusions

The number of measurement days needed to reliably estimate activity patterns was greater for leisure time than for work time. The domain specific variability is of great importance to researchers and health promotion workers planning to use objective measures of sedentary behaviour and physical activity.

Trial registration

Clinical trials NCT01996176.

Time kinetics of physical activity, sitting, and quality of life measures within a regional workplace: a cross-sectional analysis

Background

Interventions to increase physical activity and reduce sedentary behaviours within the workplace have been previously investigated. However, the evolution of these constructs without intervention has not been well documented. This retrospective study explored the natural progression or time kinetics of physical activity, sedentary behaviours and quality of life in a professional skilled workplace where focussed interventions were lacking.

Methods

Participants (n = 346) employed as full-time staff members at a regional university completed an online survey in 2013 assessing physical activity and sedentary behaviours via the International Physical Activity Questionnaire, and quality of life via the Short-Form 36v2 questionnaire. Differences between that cohort of participants and an initial sample of similar participants (2009, n = 297), accounting for gender and staff categories (academic vs. professional), were examined using ANCOVAs with working hours as a co-variate.

Results

In comparison to the initial cohort, the follow-up cohort reported significantly less leisure-time, total walking, total vigorous and total physical activity levels, and lower overall physical health for quality of life (p < 0.05). In contrast, the follow-up cohort reported a significantly greater weekly sitting time, greater mental health scores for quality of life and greater total moderate physical activity levels (p < 0.05) compared to the initial cohort.

Conclusions

Over a 4-year timeframe and without focussed workplace interventions, total physical activity levels were lower with sedentary behaviours greater at a rate twice that reported previously. Continuation of these undesirable health behaviours may impact negatively on worker productivity and health at a greater rate than that currently reported. Workplace interventions targeting sedentary behaviours and physical activity should be actively incorporated into organisations to counteract the alarming behavioural trends found in this study to maintain and/or enhance employee health and productivity.

Where to Sit? Type of Sitting Matters for the Framingham Cardiovascular Risk Score

Background

Current evidence on associations of type-specific sedentary behavior with cardiovascular disease (CVD) is limited to mainly screen-time sedentary behavior (SB). We aimed to study the associations of type-specific and total time spent sitting with the Framingham 10-year cardiovascular disease risk score (Framingham score) in Finnish adults.

Methods

Data comprise the National FINRISK 2007 and 2012 health examination surveys with 10,185 participants aged 25–74 years, apparently free of CVD. Participants reported average daily time spent sitting in different locations: work-related sitting, at home in front of television (TV), at home in front of computer, in a vehicle, and elsewhere. Total SB time was calculated from these context-specific self-reports. Accelerometer-based sedentary time was assessed in 988 FINRISK 2012 participants. Framingham score was calculated using information on blood pressure and its medication, cholesterol levels, age, diabetes status, and smoking. Analyses were adjusted for age, study year, education, employment status, leisure time physical activity, and body mass index.

Results

Out of several type-specific sitting behaviors, only TV sitting showed systematic associations with the Framingham score in both genders. The lowest Framingham risk was found for TV sitting from 6 minutes to less than 1 hour daily. Of other types of sitting, computer sitting was inversely associated with the Framingham risk in men only. Total self-reported sitting time did not show significant associations with the Framingham score, but instead higher objectively assessed sedentary time showed higher Framingham risk in men.

Conclusions

TV sitting showed most systematic associations with CVD risk score. This suggests that of all types of SB, reducing TV sitting should be targeted for reducing CVD risk.