ArticleBMJ open2019
Sleepiness of day workers and watchkeepers on board at high seas: a cross-sectional study.
Article in BMJ open, 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 7 papers, 2 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
7 citing papers in PubMed, 2 syntheses or guidelines pooled it.
- Seafarer fatigue: a systematic review and narrative synthesis of concepts, risk factors, prediction methods, and risk management strategies.Frontiers in public health · 2026Pooled it
- Measurement Methods of Fatigue, Sleepiness, and Sleep Behaviour Aboard Ships: A Systematic Review.International journal of environmental research and public health · 2021Pooled it
- Well-being, physical activity and health promotion among officers and ratings on board cargo ships: A cross-sectional study.PloS one · 2025Article
- Sleep Architecture and Sleep-Related Breathing Disorders of Seafarers on Board Merchant Ships: A Polysomnographic Pilot Field Study on the High Seas.International journal of environmental research and public health · 2023Observational
- Psychosocial issues and sleep quality among seafarers: a mixed methods study.BMC public health · 2022Article
- Online survey among maritime pilots: job-related stress and strain and the effects on their work ability.Journal of occupational medicine and toxicology (London, England) · 2021Article
- Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
2 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
objectivesTo estimate the prevalence of sleepiness on duty among day workers and watchkeepers on board.
designCross-sectional survey in a maritime field study.
setting10 shipping companies with container vessels under German management.
participantsThe whole crew (75 day workers and 123 watchkeepers) during 18 voyages on 18 different container ships. OUTCOME MEASURES: Sleepiness on duty and efficiency of sleep using pupillometry (in a cross-shift design) and the SenseWear armband activity monitor.
resultsThe watchkeepers showed significantly shorter sleep periods than day workers (5.5 hours vs 5.8 hours). The average efficiency of sleep was 69.6% and significantly lower among watchkeepers (OR 0.48; 95% CI 0.26 to 0.88). 396 pupillometric examinations were carried out and revealed 88 study members (22.2%) with a pupillary unrest index (rPUI) in a range characterised as 'unfit for duty' and 110 seafarers (27.8%) categorised as 'particular attention required'. The average rPUI was similar between day workers and watchkeepers. The Epworth Sleepiness Scale revealed recent daytime sleepiness in 70 seafarers, which was similarly often stated by day workers and watchkeepers. Based on the Stanford Sleepiness Scale (SSS), a measurable cross-shift increase in the SSS value during the examined shift was observed, especially among watchkeepers. The amount of time already spent on the vessel at the time of the present examination was significantly associated with the rPUI (p=0.009).
conclusionSleep periods of both the day workers and the watchkeepers aboard vessels were alarmingly short and sleep efficiency was low. Sleepiness on duty is similarly prevalent among day workers and watchkeepers and seems to depend partly on the cumulative working period on the vessels. Preventive measures need to be taken by the shipping industry to counteract fatigue (eg, by enabling sufficient rest and sleep times).
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.