The acute effects of working time patterns on fatigue and sleep quality using daily measurements of 6195 observations among 223 shift workers.

OBJECTIVES: This study aimed to estimate acute effects of roster characteristics on fatigue and sleep quality and investigated whether these effects differed by individual characteristics. METHODS: Using an ecological measurement assessment survey, fatigue and sleep quality were daily measured among 223 shift workers for up to eight weeks. A questionnaire assessed baseline characteristics, and roster data were retrieved from the company registers to determine roster parameters. The effects between each shift parameter on fatigue and sleep quality were estimated with random- and fixed-effects models. RESULTS: Compared to day shifts, night shifts were related to fatigue [ß=0.22; 95% confidence interval (CI) 0.05-0.39] and poorer sleep quality (ß=0.64; 95% CI 0.47-0.80), and more successive night shifts with more fatigue (up to ß=0.68; 95% CI 0.49-0.87 for ≥2 nights). Fatigue was increased after a quick return (<11 hours) (ß=1.94; 95% CI 1.57-2.31) or 11-16 hours (ß=0.43; 95% CI 0.26-0.61) compared to >16 hours between shifts. Compared to forward rotation, stable (ß=0.22; 95% CI 0.01-0.43) and backward rotation (ß=0.49; 95% CI 0.23-0.74) were also associated with more fatigue. Workers with a morning or intermediate chronotype had poorer sleep quality after a night shift, while workers with poor health reported poor sleep quality as well as more fatigue after a night shift. CONCLUSIONS: To alleviate acute effects of shift work on fatigue, shift schedules should be optimized by ensuring more time to recover and rotate forwards.

Promoting Employees' Recovery During Shift Work: Protocol for a Workplace Intervention Study.

BACKGROUND: Shift work can be demanding owing to disturbances in the biological and social rhythms. This can cause short-term negative effects in employees, such as increased fatigue and reduced alertness. A potential way to counteract these negative effects is to enhance employees' recovery from work during working hours. OBJECTIVE: The aim of this study is to develop and implement an intervention that focuses on promoting "on-job" recovery of shift workers. METHODS: This study is performed in 2 department units with shift workers at a multinational company in the steel industry. For each department, an intervention will be developed and implemented through an iterative process of user-centered design and evaluation. This approach consists of various sessions in which employees and a project group (ie, researchers, line managers, human resource managers, and occupational health experts) provide input on the intervention content and implementation. Intervention effects will be evaluated using pretest and posttest web-based surveys. Digital ecological momentary assessment will be performed to gain insight into the link between the intervention and daily within-person processes. The intervention process and participants' perception of the interventions will be assessed through a process evaluation. Intervention results will be analyzed by performing mixed model repeated measures analyses and multilevel analyses. RESULTS: This study is supported by the Netherlands Organization for Applied Scientific Research Work and Health Research Program, which is funded by the Ministry of Economic Affairs and supported by the Dutch Ministry of Social Affairs and Employment, program number 19.204.1-3. This study was approved by the institutional review board on February 7, 2019. From June to August 2019, baseline data were collected, and from November to December 2019, the first follow-up data were collected. The second follow-up data collection and data analysis are planned for the first two quarters of 2020. Dissemination of the results is planned for the last two quarters of 2020. CONCLUSIONS: A strength of this study design is the participatory action approach to enhance the stakeholder commitments, intervention adherence, and compliance. Moreover, since the target group will be participating in the development and implementation of the intervention, the proposed impact will be high. In addition, the short-term as well as the long-term effects will be evaluated. Finally, this study uses a unique combination of quantitative and qualitative evaluation methods. A limitation of this study is that it is impossible to randomly assign participants to an intervention or control group. Furthermore, the follow-up period (6 months) might be too short to establish health-related effects. Lastly, the results of this study might be specific to the department, organization, or sector, which limits the generalizability of the findings. However, as workplace intervention research for shift workers is scarce, this study might serve as a starting point for future research on shift work interventions.

The effect of speech recognition on working postures, productivity and the perception of user friendliness.

A comparative, experimental study with repeated measures has been conducted to evaluate the effect of the use of speech recognition on working postures, productivity and the perception of user friendliness. Fifteen subjects performed a standardised task, first with keyboard and mouse and, after a six week training period, with speech recognition. The use of speech recognition leads to improved postures of wrist, forearm, upper arm and shoulder and improvement of neck movements when compared to the use of keyboard and mouse. Although the observation method was basic, this study provides insight into the potential benefits speech recognition has for posture. However, productivity decreased for most subjects and speech recognition appears to be usable for specific tasks only. From the perspective of productivity and the perception of user friendliness further development of speech recognition software is necessary. Up to now, speech recognition seems especially beneficial for people with WMSD complaints.

Workload of window cleaners using ladders differing in rung separation.

The objective of the present study was to compare energetic workload, perceived exertion, perceived discomfort, safety, and mechanical load at lower limb joints among window cleaners during usage of extension ladders with 30 and 35 cm rung separation. Eleven healthy male professional window cleaners of short and tall stature participated in this study. No significant differences between 30 and 35 cm rung separation were observed for the energetic workload. Results concerning the perceived exertion, discomfort, and safety indicate that 35 cm rung separation is preferred. Based on the mechanical load at the hip, knee, and ankle during ascending and descending the ladder, 30 cm rung separation is preferable to 35 cm rung separation. It is advised to climb ladders with the knees inside the side rails of the ladder, but this seems only possible with 35 cm rung separation. Findings of the presents study suggest that overall, a 35 cm rung separation is marginally favourable while using extension ladders.

Effects of four types of non-obtrusive feedback on computer behaviour, task performance and comfort.

This study investigated the effects of non-obtrusive feedback on continuous lifted hand/finger behaviour, task performance and comfort. In an experiment with 24 participants the effects of two visual and two tactile feedback signals were compared to a no-feedback condition in a computer task. Results from the objective measures showed that all types of feedback were equally effective to reduce lifted hand/finger behaviour (effectiveness) compared to absence of feedback, while task performance was not affected (efficiency). In contrast to objective measures, subjective user experience was significantly different for the four types of feedback signals. Continuous tactile feedback appeared to be the best signal; not only the effectiveness and efficiency were rated reasonable, it also scored best on perceived match between signal and required action. This study shows the importance of including user experiences when investigating usability of feedback signals. Non-obtrusive feedback embedded in products and environments may successfully be used to support office workers to adopt healthy, productive and comfortable working behaviour.

The effect of a feedback signal in a computer mouse on hovering behaviour, productivity, comfort and usability in a field study.

The aim of this study was to determine the effect of a tactile feedback signal on hovering behaviour, productivity, usability and comfort after 1 week of using an experimental mouse. In a randomized controlled trial, a regular computer mouse was compared to a new developed mouse with a tactile, vibrating feedback signal to prevent unnecessary hovering above the computer mouse. According to this study, participants do decrease their hovering behaviour when using a mouse with tactile feedback. Furthermore, the mouse with tactile feedback did not influence productivity. Usability was rated somewhat mixed. The use of a mouse with a tactile vibrating feedback signal seems promising for preventing neck, shoulder and arm complaints. Further research is needed to study long-term effects on (prevention of) neck, shoulder and arm complaints and development of learning effects.

Loss of productivity due to neck/shoulder symptoms and hand/arm symptoms: results from the PROMO-study.

INTRODUCTION: The objective of the present study is to describe the extent of productivity loss among computer workers with neck/shoulder symptoms and hand/arm symptoms, and to examine associations between pain intensity, various physical and psychosocial factors and productivity loss in computer workers with neck/shoulder and hand/arm symptoms. METHODS: A cross-sectional design was used. The study population consisted of 654 computer workers with neck/shoulder or hand/arm symptoms from five different companies. Descriptive statistics were used to describe the occurrence of self-reported productivity loss. Logistic regression analyses were used to examine the associations. RESULTS: In 26% of all the cases reporting symptoms, productivity loss was involved, the most often in cases reporting both symptoms (36%). Productivity loss involved sickness absence in 11% of the arm/hand cases, 32% of the neck/shoulder cases and 43% of the cases reporting both symptoms. The multivariate analyses showed statistically significant odds ratios for pain intensity (OR: 1.26; CI: 1.12-1.41), for high effort/no low reward (OR: 2.26; CI: 1.24-4.12), for high effort/low reward (OR: 1.95; CI: 1.09-3.50), and for low job satisfaction (OR: 3.10; CI: 1.44-6.67). Physical activity in leisure time, full-time work and overcommitment were not associated with productivity loss. CONCLUSION: In most computer workers with neck/shoulder symptoms or hand/arm symptoms productivity loss derives from a decreased performance at work and not from sickness absence. Favorable psychosocial work characteristics might prevent productivity loss in symptomatic workers.