Cost and statistical efficiency of posture assessment by inclinometry and observation, exemplified by paper mill work.

Postures at work are paramount in ergonomics. They can be determined using observation and inclinometry in a variety of measurement scenarios that may differ both in costs associated with collecting and processing data, and in efficiency, i.e. the precision of the eventual outcome. The trade-off between cost and efficiency has rarely been addressed in research despite the obvious interest of obtaining precise data at low costs. Median trunk and upper arm inclination were determined for full shifts in 28 paper mill workers using both observation and inclinometry. Costs were estimated using comprehensive cost equations; and efficiency, i.e. the inverted standard deviation of the group mean, was assessed on basis of exposure variance components. Cost and efficiency were estimated in simulations of six sampling scenarios: two for inclinometry (sampling from one or three shifts) and four for observation (one or three observers rating one or three shifts). Each of the six scenarios was evaluated for 1 through 50 workers. Cost-efficiency relationships between the scenarios were intricate. As an example, inclinometry was always more cost-efficient than observation for trunk inclination, except for observation strategies involving only few workers; while for arm inclination, observation by three observers of one shift per worker outperformed inclinometry on three shifts up to a budget of €20000, after which inclinometry prevailed. At a budget of €10000, the best sampling scenario for arm inclination was 2.5 times more efficient than the worst. Arm inclination could be determined with better cost-efficiency than trunk inclination. Our study illustrates that the cost-efficiency of different posture measurement strategies can be assessed and compared using easily accessible diagrams. While the numeric examples in our study are specific to the investigated occupation, exposure variables, and sampling logistics, we believe that inclinometry will, in general, outperform observation. In any specific case, we recommend a thorough analysis, using the comparison procedure proposed in the present study, of feasible strategies for obtaining data, in order to arrive at an informed decision support.

Flexible Work: Opportunity and Challenge (FLOC) for individual, social and economic sustainability. Protocol for a prospective cohort study of non-standard employment and flexible work arrangements in Sweden.

INTRODUCTION: Flexibility in working life, including non-standard employment (NSE) and flexible work arrangements (FWAs), offers the organisation a better ability to adapt to changing conditions while also posing considerable challenges for organisations as well as workers. The aim of the Flexible Work: Opportunity and Challenge (FLOC) study is to investigate associations between NSE and FWA on the one hand, and individual, social and economic sustainability on the other. METHODS AND ANALYSIS: This prospective open cohort study targets approximately 8000 workers 18-65 years old in 8-10 public and private organisations in Sweden. We will use a comprehensive battery of measurement methods addressing financial performance, physical and psychosocial exposures, and physical and mental health, both at the organisational and the individual level. Methods include valid survey questionnaires and register data, and, in subpopulations, technical measurements, interviews and diaries. Main exposures are type of employment and type of work arrangement. Main outcomes are indicators of social and economic sustainability and, at the individual level, health and well-being. Data, collected over 54 months at approximately 18-month intervals, will be analysed using multivariate methods considering main effects as well as potential effect modifiers. The analyses will take into account that respondents are nested in organisations, divisions and/or have specific managers. ETHICS AND DISSEMINATION: FLOC is approved by the Swedish Ethical Review Authority (decision numbers 2019-06220, 2020-06094 and 2021-02725). Data will be published in peer-reviewed journals and presented at international conferences, and researchers will assist the organisations in improving policies and routines for employment and organisation of work.

A systematic review of the research on telework and organizational economic performance indicators.

Introduction: A systematic review is conducted in the study to investigate the relationship between telework and organizational economic performance indicators such as self-reported employee performance, organizational performance, actual employee turnover rates, or intentions. Methods: The databases Scopus, Business Source Premier, and Web of Science were used to conduct a literature search. Original articles published from 2000 and up to May 2021 were selected. Studies were screened for inclusion independently by review pairs and data were extracted. The Mixed Methods Appraisal Tool (MMAT) was used to evaluate the quality of the studies included. Results: Forty-three studies were included with some addressing multiple outcomes. Self-reported performance was higher for teleworking employees compared to those working in the ordinary workplace. The extent of the change in performance was dependent on individual characteristics and the extent of the teleworking practice in the organization. Telework was also associated with increased organizational performance, particularly in homogenous samples with unique work tasks. When telework is voluntary, it appears that both actual employee turnover rates and intentions to leave the organization are lower. Discussion: Further research with high-quality prospective designs is necessary to properly understand the contribution of telework to organizational economic performance indicators.

Uncertainty in monetary cost estimates for assessing working postures using inclinometry, observation or self-report.

OBJECTIVE: To assess uncertainty in cost estimates for collecting posture data by inclinometry, observations and self-report. METHOD: In a study addressing physical workloads at a paper mill, costs were calculated for measuring postures of twenty-eight workers during three shifts. Uncertainty in costs was assessed for all three methods as the range between an assumed best case (lowest cost) and worst case (highest cost) using scenario analysis. RESULTS: The cost for observation was larger, but also more uncertain (€16506 and €89552 in the best and worst case, respectively) than that of inclinometry (€7613 - €45896). Self-report costs were both lower and less uncertain (€3743 - €23368). CONCLUSIONS: The extent of uncertainty in cost estimates implies that observation could be less expensive than inclinometry, e.g., in a scenario where experienced observers could use existing software, while inclinometers would have to be purchased. We propose adding uncertainty assessments to cost estimates when selecting a method for measuring working postures, and offer guidance in how to proceed in a specific setting.

Observer variability in posture assessment from video recordings: The effect of partly visible periods.

Observers rank partly visible postures on video frames differently than fully visible postures, but it's not clear if this is due to differences in observer perception. This study investigated the effect of posture visibility on between-observer variability in assessments of trunk and arm posture. Trained observers assessed trunk and arm postures from video recordings of 84 pulp mill shifts using a work sampling approach; postures were also categorized as 'fully' or 'partly' visible. Between-worker, between-day, and between-observer variance components and corresponding confidence intervals were calculated. Although no consistent gradient was seen for the trunk, right upper arm posture showed smaller between-observer variance when all observers rated a posture as fully visible. This suggests that, partly-visible data, especially when observers disagree as to the level of visibility, introduces more between-observer variability when compared to fully visible data. Some previously-identified differences in daily posture summaries may be related to this phenomenon.

Data collection costs in industrial environments for three occupational posture exposure assessment methods.

BACKGROUND: Documentation of posture measurement costs is rare and cost models that do exist are generally naïve. This paper provides a comprehensive cost model for biomechanical exposure assessment in occupational studies, documents the monetary costs of three exposure assessment methods for different stakeholders in data collection, and uses simulations to evaluate the relative importance of cost components. METHODS: Trunk and shoulder posture variables were assessed for 27 aircraft baggage handlers for 3 full shifts each using three methods typical to ergonomic studies: self-report via questionnaire, observation via video film, and full-shift inclinometer registration. The cost model accounted for expenses related to meetings to plan the study, administration, recruitment, equipment, training of data collectors, travel, and onsite data collection. Sensitivity analyses were conducted using simulated study parameters and cost components to investigate the impact on total study cost. RESULTS: Inclinometry was the most expensive method (with a total study cost of € 66,657), followed by observation (€ 55,369) and then self report (€ 36,865). The majority of costs (90%) were borne by researchers. Study design parameters such as sample size, measurement scheduling and spacing, concurrent measurements, location and travel, and equipment acquisition were shown to have wide-ranging impacts on costs. CONCLUSIONS: This study provided a general cost modeling approach that can facilitate decision making and planning of data collection in future studies, as well as investigation into cost efficiency and cost efficient study design. Empirical cost data from a large field study demonstrated the usefulness of the proposed models.

The assessment of symptoms and functional limitations in low back pain patients: validity and reliability of a new questionnaire.

Many of the existing low back pain (LBP) questionnaires of function and symptoms have a content of different domains of disability presented as a single sum score, making it difficult to derive changes within a specific domain. The present study describes the development of a clinically derived back-specific questionnaire incorporating both a functional limitation and a symptom scale, with a further subdivision of the symptom scale in separate indices for severity and temporal aspects. The aims of the study were to assess the overall reliability and validity of the new questionnaire, named the Profile Fitness Mapping questionnaire (PFM). A total of 193 chronic LBP patients answered the PFM together with five validated criterion questionnaires. For the internal consistency of the questionnaires, the three indices of the PFM had the highest Cronbach's alpha (0.90-0.95) and all items had item-total correlations above 0.2. The correlation coefficients between the PFM and the back-specific criterion questionnaires ranged between 0.61 and 0.83, indicating good concurrent criterion validity. The best discriminative ability between patients with different pain severities was demonstrated by the functional limitation scale of the PFM. Well centered score distribution with no patient's score at the floor or the ceiling level indicates that the PFM has the potential to detect the improvement or worsening of symptoms and functional limitations in chronic LBP patients. Classification according to the International Classification of Functioning, Disability and health (ICF) of WHO revealed a high degree of homogeneous item content of the symptom scale to the domain of impairments, and of the functional limitation scale to the domain of activity limitations. The present study suggests that the PFM has a high internal consistency and is a valid indicator of symptoms and functional limitations of LBP patients. It offers the combination of a composite total score and the possibility of evaluations within specific domains of disability. Complementary evaluation of test-retest reliability and responsiveness to change is warranted.