Shift work statistics 2026

Soon's own research: what the staffing models show

Computed from the models Soon publishes, not from customer data. Each figure is recalculated from its inputs every time this page is built, and the assumptions sit next to the result.

1. 4.47 to 6.09

   full-time employees for one round-the-clock post

   One position staffed every hour of every day needs between 4.47 and 6.09 full-time employees across the 17 countries we model for 2027, once statutory leave, weekday public holidays, sickness absence and training are counted. The common shortcut of adding 25% to the raw hours misses by up to 17.4% in a single country.

   Inputs per country from 144 official sources: statutory leave, contracted weekly hours, weekday public holidays in 2027 and national sickness absence, plus 3 training days. The range is not a ranking: sickness absence is measured differently in each country.

   Relief factor by country →

2. 57 to 18.1

   short-staffed days a year, from a team of 7 to a team of 8

   A team of 7 that must keep 6 on shift is short on about 57 working days a year from leave and sickness alone. An eighth person, with the same minimum, cuts that to 18.1. Headroom moves only at whole-person boundaries, so small teams sit on a sawtooth rather than a smooth curve.

   25 leave days and 8 sickness days per person a year, binomial model over 261 working days. Absences are treated as independent, so real figures are higher: these are floors.

   Leave capacity by team size →

3. 33 to 4.2

   uncovered working days a year, one trained person against two

   When a role needs one qualified person on every working day, such as a first aider or a keyholder, training exactly one person leaves it uncovered on about 33 working days a year. Training a second brings that to about 4.2.

   25 leave days and 8 sickness days per holder a year, over 261 working days. Absences are treated as independent, so these are floors.

   Qualified cover →

Fatigue and safety

How shift length, consecutive nights, rest between shifts and time awake relate to injuries, accidents and errors.

1. RR 2.73

   injury risk on shifts over 12 hours, against 8

   Injury risk rose with consecutive nights (2nd RR 1.05, 3rd 1.16, 4th 1.36 vs the first) and with shift length versus an 8-hour baseline (10h RR 1.54, over 12h RR 2.73).

   Fischer et al. (2017). Updating the 'Risk Index': a systematic review and meta-analysis of occupational injuries and work schedule characteristics. Chronobiology International. https://pubmed.ncbi.nlm.nih.gov/29064297/

   Strong evidenceSystematic review and meta-analysis

2. 5%

   lower injury risk per extra hour of rest between shifts

   For each additional hour of rest between shifts, injury risk fell 5% (IRR 0.95, 95% CI 0.93-0.96).

   Nielsen et al. (2019). Short time between shifts and risk of injury among Danish hospital workers. Scandinavian Journal of Work, Environment & Health, 45 (2), 166–173. https://pubmed.ncbi.nlm.nih.gov/30264848/

   Strong evidenceRegister-based cohort (69,200 workers, 167,726 person-years)

3. 12 hours

   by which accident risk roughly doubles against 8

   Accident risk cumulates with time on task, roughly doubling by 12 hours versus 8; shift and night work including nights carries substantially elevated accident risk, while pure night work may allow partial resynchronization.

   Wagstaff, A. S., & Sigstad Lie, J.-A. (2011). Shift and night work and long working hours: a systematic review of safety implications. Scandinavian Journal of Work, Environment & Health, 37 (3), 173–185. https://www.sjweh.fi/article/3146

   Strong evidenceSystematic review (~7,000 articles screened, 443 evaluated)

4. 61%

   higher hazard of injury or illness with overtime

   Overtime was associated with a 61% higher hazard of injury or illness (HR 1.61, 95% CI 1.43 to 1.79) after adjustment for age, gender, occupation, industry, and region.

   Dembe, A. E., Erickson, J. B., Delbos, R. G., & Banks, S. M. (2005). The impact of overtime and long work hours on occupational injuries and illnesses: new evidence from the United States. Occupational and Environmental Medicine, 62 (9), 588–597. https://doi.org/10.1136/oem.2004.016667

   Moderate evidenceProspective observational cohort, secondary analysis of the US National Longitudinal Survey of Youth 1987-2000, with rates per 100 worker-years and Cox proportional hazards models

5. 0.05%

   blood alcohol equivalent after 17 to 19 hours awake

   After 17 to 19 hours without sleep, performance on some tests was equivalent to or worse than performance at a 0.05% blood alcohol concentration.

   Williamson, A. M., & Feyer, A.-M. (2000). Moderate sleep deprivation produces impairments in cognitive and motor performance equivalent to legally prescribed levels of alcohol intoxication. Occupational and Environmental Medicine, 57 (10), 649–655. https://doi.org/10.1136/oem.57.10.649

   Moderate evidenceWithin-subjects laboratory experiment (39 subjects tested across 28 hours of sleep deprivation and after measured alcohol doses)

6. 2.3 times

   the odds of a crash after a 24-hour shift

   Extended shifts of 24 hours or more were associated with 2.3 times the odds of a motor vehicle crash (95% CI 1.6 to 3.3) and 5.9 times the odds of a near-miss incident (95% CI 5.4 to 6.3).

   Barger, L. K., Cade, B. E., Ayas, N. T., Cronin, J. W., Rosner, B., Speizer, F. E., & Czeisler, C. A. (2005). Extended work shifts and the risk of motor vehicle crashes among interns. New England Journal of Medicine, 352 (2), 125–134. https://doi.org/10.1056/NEJMoa041401

   Emerging evidenceProspective nationwide web-based cohort survey (2,737 US first-year residents, 17,003 monthly self-reports of work hours, crashes, near-misses, and involuntary sleep episodes)

7. 1.02 hours

   less sleep after a quick return

   Quick returns shortened measured sleep by 1.02 hours (95% CI -1.23 to -0.81) and reduced subjective sleep quality by half a scale point (-0.49, 95% CI -0.69 to -0.31) versus day-to-day transitions.

   Oster, K., Tucker, P., Soderstrom, M., & Dahlgren, A. (2024). Quick returns, sleep, sleepiness and stress: an intra-individual field study on objective sleep and diary data. Scandinavian Journal of Work, Environment & Health, 50 (6), 466–474. https://doi.org/10.5271/sjweh.4175

   Emerging evidenceIntra-individual actigraphy field study (90 nurses)

8. 5:07

   average sleep after a night shift

   Sleep averaged 5:07 after night shifts against 6:39 on recovery days (difference 1:32, P<0.001), and extra recovery days improved rated sleep quality without lengthening sleep (duration slope P=0.232).

   Garde, A. H., Nabe-Nielsen, K., Jensen, M. A., Kristiansen, J., Sorensen, J. K., & Hansen, A. M. (2020). The effects of the number of consecutive night shifts on sleep duration and quality. Scandinavian Journal of Work, Environment & Health, 46 (4), 446–453. https://doi.org/10.5271/sjweh.3885

   Moderate evidenceWithin-subject crossover field study (73 Danish police officers, actigraphy and Karolinska Sleep Diary across 2+2, 4+4 and 7+7 schedules)

Health

What meta-analyses and large cohorts report on night work, long weekly hours and long-term health.

1. RR 1.13

   cardiovascular events with night-shift work

   Night-shift work raised total CVD events RR 1.13 (95% CI 1.10-1.16), with each 5-year increment adding RR 1.07 for incidence and RR 1.05 for CVD mortality.

   Xi et al. (2025). Association between night shift work and cardiovascular disease: a systematic review and dose-response meta-analysis. Frontiers in Public Health, 13 1668848. https://pmc.ncbi.nlm.nih.gov/articles/PMC12506678/

   Strong evidenceDose-response meta-analysis of 23 cohort studies (3.34M participants)

2. ~30% excess

   hypertension, an established consequence of shift work

   Diabetes (~10% excess, pooled OR 1.08-1.15), overweight/obesity, and hypertension (~30% excess) are established consequences of shift work; other cardiovascular risk factors are not.

   Boini, Bourgkard, Ferrieres, Esquirol (2022). What do we know about the effect of night-shift work on cardiovascular risk factors? An umbrella review. Frontiers in Public Health. https://pmc.ncbi.nlm.nih.gov/articles/PMC9727235/

   Strong evidenceUmbrella review of 33 systematic reviews

3. RR 1.33

   stroke at 55 or more hours a week, against 35 to 40

   Working 55 hours or more per week was associated with stroke at RR 1.33 (95% CI 1.11-1.61) versus 35 to 40 hours, with a weaker coronary heart disease association at RR 1.13 (95% CI 1.02-1.26).

   Kivimäki, M., Jokela, M., Nyberg, S. T., Singh-Manoux, A., Fransson, E. I., Alfredsson, L., Bjorner, J. B., Borritz, M., Burr, H., Casini, A., Clays, E., De Bacquer, D., Dragano, N., Erbel, R., Geuskens, G. A., Hamer, M., Hooftman, W. E., Houtman, I. L., Jöckel, K. H., ... Virtanen, M. (2015). Long working hours and risk of coronary heart disease and stroke: A systematic review and meta-analysis of published and unpublished data for 603 838 individuals. The Lancet, 386 (10005), 1739–1746. https://doi.org/10.1016/S0140-6736(15)60295-1

   Strong evidenceSystematic review and cumulative random-effects meta-analysis of 25 prospective observational cohort studies from 24 cohorts, combining published literature with unpublished individual-participant data

4. 745,194

   deaths attributed to 55-hour weeks in 2016

   Attributed 745,194 deaths and 23.3 million DALYs in 2016 to working 55 or more hours per week, with stroke the larger half of the total.

   Pega, F., Náfrádi, B., Momen, N. C., Ujita, Y., Streicher, K. N., Prüss-Üstün, A. M., Descatha, A., Driscoll, T., Fischer, F. M., Godderis, L., Kiiver, H. M., Li, J., Magnusson Hanson, L. L., Rugulies, R., Sørensen, K., & Woodruff, T. J. (2021). Global, regional, and national burdens of ischemic heart disease and stroke attributable to exposure to long working hours for 194 countries, 2000-2016: A systematic analysis from the WHO/ILO Joint Estimates of the Work-related Burden of Disease and Injury. Environment International, 154 106595. https://doi.org/10.1016/j.envint.2021.106595

   Moderate evidenceComparative risk assessment and burden-of-disease modelling study; exposure modelled for 194 countries from 2,324 surveys and 1,742 quarterly datasets, attributable burden estimated for 183 countries

5. 26.5%

   pooled prevalence of shift work disorder

   Pooled prevalence of 26.5% across 29 studies, with very high heterogeneity and lower estimates in studies applying ICSD-3 criteria.

   Pallesen, S., Bjorvatn, B., Waage, S., Harris, A., & Sagoe, D. (2021). Prevalence of shift work disorder: A systematic review and meta-analysis. Frontiers in Psychology, 12 638252. https://doi.org/10.3389/fpsyg.2021.638252

   Moderate evidenceRandom-effects meta-analysis and meta-regression of 29 prevalence studies

6. 1.23

   pooled odds of obesity or overweight with night work

   Night shift work was associated with higher odds of obesity or overweight, pooled odds ratio 1.23 (95% CI 1.17-1.29), with a weaker estimate in cohort designs than in cross-sectional ones.

   Sun, M., Feng, W., Wang, F., Li, P., Li, Z., Li, M., Tse, G., Vlaanderen, J., Vermeulen, R., & Tse, L. A. (2018). Meta-analysis on shift work and risks of specific obesity types. Obesity Reviews, 19 (1), 28–40. https://doi.org/10.1111/obr.12621

   Moderate evidenceSystematic review and meta-analysis of 28 observational studies, PubMed searched to March 2017

7. 1.33

   effect size for depressive symptoms with shift work

   Shift work was associated with more depressive symptoms (ES = 1.33; 95% CI = 1.02, 1.74), with gender explaining more than 90% of the heterogeneity between studies

   Torquati, L., Mielke, G. I., Brown, W. J., Burton, N. W., & Kolbe-Alexander, T. L. (2019). Shift Work and Poor Mental Health: A Meta-Analysis of Longitudinal Studies. American Journal of Public Health, 109 (11), e13-e20. https://doi.org/10.2105/AJPH.2019.305278

   Moderate evidenceSystematic review and random-effects meta-analysis of 7 prospective cohort studies (28,431 participants, 14 adjusted risk estimates), MOOSE guidelines, literature searched to August 2018

8. Group 2A

   IARC classification of night shift work

   Classified night shift work as probably carcinogenic to humans (Group 2A) on limited human evidence and sufficient animal evidence.

   International Agency for Research on Cancer (2020). Night shift work. IARC Monographs on the Identification of Carcinogenic Hazards to Humans, 124. https://www.ncbi.nlm.nih.gov/books/NBK568195/

   Strong evidenceExpert consensus hazard evaluation by a Working Group of 27 independent international experts from 16 countries, Lyon, 4 to 11 June 2019

9. 0.99

   pooled breast cancer relative risk across prospective studies

   Any night shift work was associated with a pooled breast cancer relative risk of 0.99 (95% CI 0.95 to 1.03) across 10 prospective studies.

   Travis, R. C., Balkwill, A., Fensom, G. K., Appleby, P. N., Reeves, G. K., Wang, X.-S., Roddam, A. W., Gathani, T., Peto, R., Green, J., Key, T. J., & Beral, V. (2016). Night shift work and breast cancer incidence: Three prospective studies and meta-analysis of published studies. Journal of the National Cancer Institute, 108 (12), djw169. https://doi.org/10.1093/jnci/djw169

   Strong evidencePooled analysis of three UK prospective cohorts (795,850 women) plus inverse-variance-weighted meta-analysis of all 10 prospective studies (1.4 million women)

Staffing levels and outcomes

What happens to patients and staff as each person carries more of the workload.

1. 7%

   higher odds of surgical mortality per extra patient per nurse

   Each additional patient per nurse was associated with 7% higher odds of 30-day surgical mortality (OR 1.068), and each 10 point rise in bachelor-degree nurses with 7% lower odds (OR 0.929), in the fully adjusted model.

   Aiken, L. H., Sloane, D. M., Bruyneel, L., Van den Heede, K., Griffiths, P., et al. (2014). Nurse staffing and education and hospital mortality in nine European countries: a retrospective observational study. The Lancet, 383 (9931), 1824–1830. https://pmc.ncbi.nlm.nih.gov/articles/PMC4035380/

   Moderate evidenceRetrospective cross-sectional observational study (422,730 surgical patients, 300 hospitals, 9 countries)

2. 23%

   higher odds of nurse burnout per extra patient

   Each additional patient per nurse was associated with 7% higher odds of 30-day mortality and failure-to-rescue, and with 23% higher odds of nurse burnout and 15% higher odds of job dissatisfaction.

   Aiken, L. H., Clarke, S. P., Sloane, D. M., Sochalski, J., & Silber, J. H. (2002). Hospital Nurse Staffing and Patient Mortality, Nurse Burnout, and Job Dissatisfaction. JAMA, 288 (16), 1987–1993. https://doi.org/10.1001/jama.288.16.1987

   Moderate evidenceCross-sectional analysis of survey and discharge data (Pennsylvania hospitals)

3. 0.98

   fewer patients per nurse after mandated ratios

   California's mandated ratios were followed by an average reduction of 0.98 patients per licensed nurse, showing a legislated floor moved real staffing; the authors state they could not determine the causal effect.

   McHugh, M. D., Brooks Carthon, M., Sloane, D. M., Wu, E., Kelly, L., & Aiken, L. H. (2012). Impact of Nurse Staffing Mandates on Safety-Net Hospitals: Lessons from California. The Milbank Quarterly, 90 (1), 160–186. https://pmc.ncbi.nlm.nih.gov/articles/PMC3371663/

   Moderate evidenceWithin-California pre/post fixed-effects time series (173 hospitals, 1998-2007)

4. 40%

   of logged nurse shifts that exceeded 12 hours

   Error risk was significantly higher when shifts exceeded 12 hours, nurses worked overtime, or weekly hours exceeded 40; roughly 40% of logged shifts exceeded 12 hours.

   Rogers, A. E., Hwang, W.-T., Scott, L. D., Aiken, L. H., & Dinges, D. F. (2004). The Working Hours of Hospital Staff Nurses and Patient Safety. Health Affairs, 23 (4), 202–212. https://doi.org/10.1377/hlthaff.23.4.202

   Moderate evidenceProspective logbook study (393 nurses, 5,317 shifts)

Schedule design that works

Interventions and consensus guidance on building rosters that people can sustain.

1. 11 hours

   consensus minimum rest between shifts

   To limit health and safety risk, the consensus is no more than 3 consecutive night shifts, at least 11 hours between shifts, and no more than 9 hours per shift.

   Garde, A. H., Harma, M., Bjorvatn, B., Bonde, J. P., Hansen, J., Hansen, A. M., et al. (2020). How to schedule night shift work in order to reduce health and safety risks. Scandinavian Journal of Work, Environment & Health, 46 (6), 557–569. https://pmc.ncbi.nlm.nih.gov/articles/PMC7737811/

   Moderate evidenceExpert-consensus paper (workshop of 15 shift-work researchers)

2. 13.2 to 6.7

   quick returns per person, halved in a hospital trial

   Halving quick returns (from 13.2 to 6.7 per person over a study period) in a hospital roster reduced insomnia, sleepiness, and work-related fatigue versus the control arm.

   Djupedal et al. (2024). Effects of a work schedule with abated quick returns on insomnia, sleepiness, and work-related fatigue. SLEEP, 47 (7), zsae086. https://doi.org/10.1093/sleep/zsae086

   Strong evidenceTwo-armed cluster randomized controlled trial (66 hospital units, 1,314 workers)

3. 5.1%

   labor productivity gain from a bundle of responsible scheduling practices

   Intent-to-treat analysis found a bundle of responsible scheduling practices raised store labor productivity 5.1%, from a 3.3% sales increase and a 1.8% reduction in labor hours.

   Kesavan, S., Lambert, S. J., Williams, J. C., & Pendem, P. K. (2022). Doing Well by Doing Good: Improving Retail Store Performance with Responsible Scheduling Practices at the Gap, Inc. Management Science, 68 (11), 7818–7836. https://doi.org/10.1287/mnsc.2021.4291

   Strong evidenceRandomized controlled field experiment (28 stores, roughly 150,000 shifts, about 1,500 employees)

4. 20 percent

   of wages applicants would give up to avoid employer-set schedules

   Applicants were willing to give up 20 percent of wages to avoid an employer-set schedule, an aversion the authors trace to evening and weekend hours rather than to short notice, while most placed no value on scheduling flexibility.

   Mas, A., & Pallais, A. (2017). Valuing alternative work arrangements. American Economic Review, 107 (12), 3722–3759. https://doi.org/10.1257/aer.20161500

   Strong evidenceRandomized discrete choice field experiment embedded in a live national call center hiring process, with a nationally representative survey replication

5. RR 0.34

   low schedule control with participatory scheduling

   Participatory scheduling was associated with lower risk of low schedule control (RR 0.34), short sleep (RR 0.70), and poor workability (RR 0.74), but not every wellbeing measure improved.

   Shiri, R., Karhula, K., Turunen, J., Koskinen, A., Ropponen, A., Ervasti, J., Kivimäki, M., & Härmä, M. (2021). The Effect of Using Participatory Working Time Scheduling Software on Employee Well-Being and Workability: A Cohort Study Analysed as a Pseudo-Experiment. Healthcare, 9 (10), 1385. https://doi.org/10.3390/healthcare9101385

   Moderate evidenceTwo-year observational cohort analyzed as a propensity-weighted pseudo-experiment

6. 30-minute

   scheduled nap that lowered night-shift sleepiness

   A scheduled 30-minute nap at 04:00 lowered sleepiness from 05:00 through 07:00 and improved two cognitive performance measures compared with no-nap nights.

   Zion, N., & Shochat, T. (2019). Let them sleep: The effects of a scheduled nap during the night shift on sleepiness and cognition in hospital nurses. Journal of Advanced Nursing, 75 (11), 2603–2615. https://doi.org/10.1111/jan.14031

   Moderate evidenceProspective within-subjects counterbalanced field study (109 nurses)

Leave, absence and working hours by country

The inputs behind Soon's relief factor model, each checked against a national statistics office, a labour ministry or the text of the law. Sickness absence is measured differently in each country, so read each row on its own: the gaps between rows are partly gaps between statistical methods, and this table is not a ranking.

Each country name links to its full derivation and every source behind its figures.

How these statistics are selected and checked