0000000000122564
AUTHOR
Mikko Härmä
showing 17 related works from this author
Trajectories of mobility limitations over 24 years and their characterization by shift work and leisure-time physical activity in midlife.
2019
Abstract Background We aimed to investigate trajectories of mobility limitations (MLs) over a period of 24 years. In addition, we aimed to study how shift work and leisure-time physical activity (LTPA) in midlife predict assignment to MLs trajectories separately for those retired on statutory pensions (SPs) and on disability pensions (DPs). Methods Subjects who responded MLs questionnaires (1985–2009, N = 3048) in Finnish Longitudinal Study on Aging Municipal Employees were included in this prospective cohort study. LTPA and shift work were measured during baseline. International Classification of Functioning was used to code MLs. Growth mixture modeling was used to identify the trajectorie…
Recurrent On-Duty Sleepiness and Alertness Management Strategies in Long-Haul Airline Pilots
2018
Introduction We examined whether long-haul airline pilots without recurrent on-duty sleepiness obtain more prior sleep and use more effective in-flight alertness management strategies than their colleagues with recurrent on-duty sleepiness. Methods There were 51 pilots who flew at least twice from Helsinki to Asia. Of them, 44 flew at least twice back to Helsinki following 1 local night. On-duty sleepiness was measured by the Karolinska Sleepiness Scale (KSS), alertness management strategies by a diary, and sleep by a diary and activity monitor. Pilots who rated KSS ≥ 7 on each, some, or none of the flights were classified as "regularly", "sometimes", and "never" sleepy, respectively. This …
Cognitive behavioural therapy interventions for insomnia among shift workers: RCT in an occupational health setting
2019
Abstract Introduction The aim of the study was to compare the effectiveness of cognitive behavioural therapy interventions for insomnia (CBT-I) to that of a sleep hygiene intervention in a randomized controlled design among shift workers. We also studied whether the features of shift work disorder (SWD) affected the results. Methods A total of 83 shift workers with insomnia disorder were partially randomized into a group-based CBT-I, self-help CBT-I, or sleep hygiene control intervention. The outcomes were assessed before and after the interventions and at 6-month follow-up using questionnaires, a sleep diary, and actigraphy. Results Perceived severity of insomnia, sleep-related dysfunction…
TRIB1 constitutes a molecular link between regulation of sleep and lipid metabolism in humans.
2012
Epidemiological studies show association between sleep duration and lipid metabolism. In addition, inactivation of circadian genes induces insulin resistance and hyperlipidemia. We hypothesized that sleep length and lipid metabolism are partially controlled by the same genes. We studied the association of total sleep time (TST) with 60 genetic variants that had previously been associated with lipids. The analyses were performed in a Finnish population-based sample (N = 6334) and replicated in 2189 twins. Finally, RNA expression from mononuclear leucocytes was measured in 10 healthy volunteers before and after sleep restriction. The genetic analysis identified two variants near TRIB1 gene th…
Sleep restriction for the duration of a work week impairs multitasking performance
2010
It is important to develop shift schedules that minimise the chance for sleep-related human error in safety-critical domains. Experimental data on the effects of sleep restriction (SR) play a key role in this development work. In order to provide such data, we conducted an experiment in which cognitively demanding and long-duration task performance, simulating task performance at work, was measured under SR and following recovery. Twenty healthy male volunteers, aged 19-29 years, participated in the study. Thirteen of them had first two baseline days (8-h sleep opportunity per day), then five SR days (4-h sleep) and finally two recovery days (8-h sleep). Seven controls were allowed to sleep…
The effects of using participatory working time scheduling software on sickness absence: A difference-in-differences study.
2020
Abstract Background Participatory working time scheduling is a collaborative approach to scheduling shift work. As a potential way of improving work time control, it may provide a means to reducing sickness absence in shift work. So far, experimental and quasi-experimental studies on the effects of increased work time control on sickness absence are lacking. Objective To investigate the effects of using digital participatory working time scheduling software on ward-level sickness absence among Finnish hospital employees. Participants and methods This quasi-experimental study compared the amount of sickness absence in hospital wards using a participatory working time scheduling software (n=1…
Prolonged sleep restriction induces changes in pathways involved in cholesterol metabolism and inflammatory responses
2016
Article
The Time-Varying Effect of Participatory Shift Scheduling on Working Hour Characteristics and Sickness Absence: Evidence from a Quasi-Experiment in H…
2022
Participatory shift scheduling for irregular working hours can influence shift schedules and sickness absence. We investigated the effects of using participatory shift scheduling and shift schedule evaluation tools on working hour characteristics and sickness absence. We utilized a panel data for 2015−2019 with 16,557 hospital employees (6143 in the intervention and 10,345 in the control group). Difference-in-differences regression with ward-level clustered standard errors was used to estimate the average treatment effect on the treated coefficients relative to timing of the intervention with 95% confidence intervals (CI). Using participatory scheduling tool increased long working hou…
Effects of cumulative sleep restriction on self-perceptions while multitasking
2012
Summary This study addressed a rarely studied question of self-perceptions of performance and overall functional state during cumulative sleep restriction and the ensuing recovery period. Twenty healthy male volunteers, aged 19–29 years, were divided into a sleep restriction group (n = 13) and a control group (n = 7). On the first 2 nights, the sleep restriction group had an 8-h sleep opportunity that was restricted to 4 h for the next 5 nights, and then restored to 8 h for the last 2 nights. The control group had an 8-h sleep opportunity each night. Each day participants accomplished 50-min multitask sessions and gave self-ratings in their connection. Similar to our previous findings on mu…
Sleep and alertness in shift work disorder: findings of a field study
2018
Purpose Although shift work disorder (SWD) affects a major part of the shift working population, little is known about its manifestation in real life. This observational field study aimed to provide a detailed picture of sleep and alertness among shift workers with a questionnaire-based SWD, by comparing them to shift workers without SWD during work shifts and free time. Methods SWD was determined by a questionnaire. Questionnaires and 3-week field monitoring, including sleep diaries, actigraphy, the Karolinska Sleepiness Scale (KSS), EEG-based sleep recordings, and Psychomotor Vigilance Tasks (PVT), were used to study 22 SWD cases and 9 non-SWD workers. Results The SWD group had a shorter …
The effects of using participatory working time scheduling software on working hour characteristics and wellbeing : a quasi-experimental study of irr…
2020
Background: Studies in the health care sector indicate that good work time control is associated with better perceived wellbeing but also with non-ergonomic work schedules, such as compressed work schedules. Participatory working time scheduling is a collaborative approach to scheduling shift work. Currently, there is a lack of information on whether working hour characteristics and employees' wellbeing in irregular shift work change after implementing participatory working time scheduling. Objective: To investigate the effects of using digital participatory working time scheduling software on working hour characteristics and well-being among Finnish hospital employees. Participants and met…
Combined effects of shiftwork and individual working time control on long-term sickness absence: a prospective study of finnish employees
2014
Objective To investigate whether the effects of shiftwork on long-term sickness absence vary according to the level of individual working time control (WTC). Methods A representative sample of Finnish employees (1447 men and 1624 women) was combined with a register-based follow-up. A negative binomial model was used in the analysis of long-term sickness absence days. The results were adjusted for various background and work-related factors. Results Individual WTC decreased long-term sickness absence. The higher rate of sickness absences in shiftwork was mainly due to the lower level of WTC. Working time control decreased sickness absence equally in day work and shiftwork. Conclusions The ne…
Sleep, alertness and alertness management among commercial airline pilots on short-haul and long-haul flights
2016
Item does not contain fulltext Airline pilots' sleep and on-duty alertness are important focus areas in commercial aviation. Until now, studies pertaining to this topic have mainly focused on specific characteristics of flights and thus a comprehensive picture of the matter is not well established. In addition, research knowledge of what airline pilots actually do to maintain their alertness while being on duty is scarce. To address these gaps in research knowledge, we conducted a field study on a representative sample of the airline pilots of a medium-sized airline. The sample consisted of 90 pilots, of whom 30 flew long-haul (LH) routes, 30 short-haul (SH) routes, and 30 flew both. A tota…
Working hours – tracking the current and future trends
2021
It is important to track the trends of future working hours, since working hours have strong associations to everyday life and work-life interaction, but also to health. In this paper we aim to track the current and future trends in working hours. We discuss the trends through the key dimensions of working hours: the length, timing, tempo and autonomy. We also consider the role of current trends of spatial changes of work. Changes in working time patterns are fostered by several driving factors: globalization and business restructuring challenging the current work organizations, new information technologies, demographic and climate change and the current and future pandemics. The past and c…
Partial Sleep Restriction Activates Immune Response-Related Gene Expression Pathways: Experimental and Epidemiological Studies in Humans
2013
Epidemiological studies have shown that short or insufficient sleep is associated with increased risk for metabolic diseases and mortality. To elucidate mechanisms behind this connection, we aimed to identify genes and pathways affected by experimentally induced, partial sleep restriction and to verify their connection to insufficient sleep at population level. The experimental design simulated sleep restriction during a working week: sleep of healthy men (N = 9) was restricted to 4 h/night for five nights. The control subjects (N = 4) spent 8 h/night in bed. Leukocyte RNA expression was analyzed at baseline, after sleep restriction, and after recovery using whole genome microarrays complem…
Physiological and autonomic stress responses after prolonged sleep restriction and subsequent recovery sleep in healthy young men
2018
Purpose Sleep restriction is increasingly common and associated with the development of health problems. We investigated how the neuroendocrine stress systems respond to prolonged sleep restriction and subsequent recovery sleep in healthy young men. Methods After two baseline (BL) nights of 8 h time in bed (TIB), TIB was restricted to 4 h per night for five nights (sleep restriction, SR, n = 15), followed by three recovery nights (REC) of 8 h TIB, representing a busy workweek and a recovery weekend. The control group (n = 8) had 8 h TIB throughout the experiment. A variety of autonomic cardiovascular parameters, together with salivary neuropeptide Y (NPY) and cortisol levels, were assessed.…
Trajectories of mobility limitations over 24 years and their characterization by shift work and leisure-time physical activity in midlife
2019
Background We aimed to investigate trajectories of mobility limitations (MLs) over a period of 24 years. In addition, we aimed to study how shift work and leisure-time physical activity (LTPA) in midlife predict assignment to MLs trajectories separately for those retired on statutory pensions (SPs) and on disability pensions (DPs). Methods Subjects who responded MLs questionnaires (1985–2009, N = 3048) in Finnish Longitudinal Study on Aging Municipal Employees were included in this prospective cohort study. LTPA and shift work were measured during baseline. International Classification of Functioning was used to code MLs. Growth mixture modeling was used to identify the trajectories of MLs.…