Scandinavian Journal of Work, Environment & Health (May 2018)

Long working hours and depressive symptoms: systematic review and meta-analysis of published studies and unpublished individual participant data

  • Marianna Virtanen,
  • Markus Jokela,
  • Ida EH Madsen,
  • Linda L Magnusson Hanson,
  • Tea Lallukka,
  • Solja T Nyberg,
  • Lars Alfredsson,
  • G David Batty,
  • Jakob Bue Bjorner,
  • Marianne Borritz,
  • Hermann Burr,
  • Nico Dragano,
  • Raimund Erbel,
  • Jane E Ferrie,
  • Katriina Heikkilä,
  • Anders Knutsson,
  • Markku Koskenvuo,
  • Eero Lahelma,
  • Martin Lindhardt Nielsen,
  • Tuula Oksanen,
  • Jan H Pejtersen,
  • Jaana Pentti,
  • Ossi Rahkonen,
  • Reiner Rugulies,
  • Paula Salo,
  • Jürgen Schupp,
  • Martin J Shipley,
  • Johannes Siegrist,
  • Archana Singh-Manoux,
  • Sakari B Suominen,
  • Töres Theorell,
  • Jussi Vahtera,
  • Gert G Wagner,
  • Jian Li Wang,
  • Vasoontara Yiengprugsawan,
  • Hugo Westerlund,
  • Mika Kivimäki

DOI
https://doi.org/10.5271/sjweh.3712
Journal volume & issue
Vol. 44, no. 3
pp. 239 – 250

Abstract

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OBJECTIVES: This systematic review and meta-analysis combined published study-level data and unpublished individual-participant data with the aim of quantifying the relation between long working hours and the onset of depressive symptoms. METHODS: We searched PubMed and Embase for published prospective cohort studies and included available cohorts with unpublished individual-participant data. We used a random-effects meta-analysis to calculate summary estimates across studies. RESULTS: We identified ten published cohort studies and included unpublished individual-participant data from 18 studies. In the majority of cohorts, long working hours was defined as working ≥55 hours per week. In multivariable-adjusted meta-analyses of 189 729 participants from 35 countries [96 275 men, 93 454 women, follow-up ranging from 1–5 years, 21 747 new-onset cases), there was an overall association of 1.14 (95% confidence interval (CI) 1.03–1.25] between long working hours and the onset of depressive symptoms, with significant evidence of heterogeneity (I^2=45.1%, P=0.004). A moderate association between working hours and depressive symptoms was found in Asian countries (1.50, 95% CI 1.13–2.01), a weaker association in Europe (1.11, 95% CI 1.00–1.22), and no association in North America (0.97, 95% CI 0.70–1.34) or Australia (0.95, 95% CI 0.70–1.29). Differences by other characteristics were small. CONCLUSIONS: This observational evidence suggests a moderate association between long working hours and onset of depressive symptoms in Asia and a small association in Europe.

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