Evidence map›Paper›PMID 31129586›Full record

ArticleBMJ open2019

Night shift work, long working hours and dementia: a longitudinal study of the Danish Work Environment Cohort Study.

Kirsten Nabe-Nielsen, Åse Marie Hansen, Kazi Ishtiak-Ahmed, Matias Brødsgaard Grynderup, Finn Gyntelberg, Sabrina Islamoska, Erik Lykke Mortensen, Thien Kieu Thi Phung, Naja Hulvej Rod, Gunhild Waldemar and 2 more

Open access · goldAbstract read
PubMed Full text at PMC Publisher
In one paragraph

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 9 papers, 4 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
9citing papers in PubMed, 4 pooled it
5.7field-weighted citation impact, top 4% of its field
1 · What the graph read from 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.

2 · The registry

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.

3 · Its place in the literature

Who cites it

9 citing papers in PubMed, 4 syntheses or guidelines pooled it, 34 citations in OpenAlex.

  1. Pooled it
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  5. Review
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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

12 authors at 2 institutions in 1 country.

Kirsten Nabe-NielsenDepartment of Public Health, University of Copenhagen, Copenhagen, Denmark.
Åse Marie HansenDepartment of Public Health, University of Copenhagen, Copenhagen, Denmark.
Kazi Ishtiak-AhmedDepartment of Public Health, University of Copenhagen, Copenhagen, Denmark.
Matias Brødsgaard GrynderupDepartment of Public Health, University of Copenhagen, Copenhagen, Denmark.
Finn GyntelbergNational Research Centre for the Working Environment, Copenhagen, Denmark.
Sabrina IslamoskaDepartment of Public Health, University of Copenhagen, Copenhagen, Denmark.
Erik Lykke MortensenDepartment of Public Health, University of Copenhagen, Copenhagen, Denmark.
Thien Kieu Thi PhungDanish Dementia Research Centre, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.
Naja Hulvej RodDepartment of Public Health, University of Copenhagen, Copenhagen, Denmark.
Gunhild WaldemarDanish Dementia Research Centre, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.
Rudi G J WestendorpDepartment of Public Health, University of Copenhagen, Copenhagen, Denmark.
Anne Helene GardeNational Research Centre for the Working Environment, Copenhagen, Denmark.
University of Copenhagen · DKNational Research Centre for the Working Environment · DK

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

objectiveShift work and long working hours are potential risk factors for dementia, but previous studies on shift work, long working hours and dementia are sparse and their findings are conflicting. Therefore, we investigated the effect of night shift work and long working hours on dementia.

designA longitudinal study.

settingDenmark.

participants3435 occupationally active men and women from the general working population.

methodsWork schedule covered day work (reference) and shift schedules without/with night work. Working hours covered <27, 28-36, 37 (reference), 38-44, and ≥45 hours/week. As the primary outcome, we used register-based information about dementia, and estimated incidence rate ratios (IRR) and 95% CI. Estimates were adjusted for gender, age, psychosocial work factors and cardiovascular risk factors.

resultsWe identified 85 dementia cases during a mean of 9.8 years of follow-up. We found a positive, but statistically insignificant association between night shift work and dementia (IRR=2.01; 95% CI: 0.87-4.65). Post hoc analyses indicated that this was only due to a higher risk in permanent night workers (IRR=3.25; 95% CI: 1.35-7.83). The dementia risk was also significantly higher among participants working 38-44 hours/week (IRR=2.08; 95% CI: 1.11-3.90) compared with those working 37 hours/week. We found no indications of a higher risk of dementia in participants working <37 hours/week or ≥45 hours/week.

conclusionWe did not find arguments that night shift work or long working hours increased dementia risk in general. However, we found a higher risk of dementia in specific subgroups, that is, permanent night workers and employees with moderately longer weekly working hours than the standard.

Indexed as

AdultAgedCohort StudiesDementiaDenmarkFemaleHumansLongitudinal StudiesMaleMiddle AgedRisk FactorsShift Work Scheduledementiaepidemiologypublic health

Identifiers

PMID31129586
PMCPMC6538206
OpenAlexW2946209974

What OpenQuestion holds

Textmetadata
LicenceCC BY-NC
Read underepoch 390

Registered trials

None linked

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.