Table 3

Results on the association between long working hours and identified health effects in physicians

Health outcomeMain resultsAdjustment by confoundersStudy ID
Percutaneous injuriesOR (95% CI) for injuries during extended (>20 h/day) vs non-extended periods (first 12 h at work): all percutaneous injuries: 1.61 (1.46 to 1.78); injuries reported to OH: 1.83 (1.48 to 2.28); injuries in the ICU: 1.87 (0.69 to 5.04); injuries in the operating room or labour and delivery: 1.77 (1.49 to 2.09); injuries in the ICU, non-ICU or ED: 2.17 (1.56 to 3.00)Time of day and circadian influencesAyas et al40
Percutaneous injuries Medical trainees vs other healthcare workers: total median working hours: 70 vs 40 h (p<0.001); median previous working hours at the time of injury: 6.5 vs 5 h (p<0.001).
OR (95% CI) for self-reported fatigue: work >40 h in the past week: 3.50 (2.06 to 5.92); work during more than 5d in past week: 4.20 (4.46 to 7.15); >12 h at work before injury: 8.58 (3.7 to 19.86).
Incidence rate ratio (95% CI) for association between fatigue and injuries: all workers: 1.40 (1.03 to 1.90); medical trainees: 2.94 (1.71 to 5.07); other HCWs: 0.97 (0.66 to 1.42; p=0.001 for heterogeneity)
Age and sexFisman et al43
Motor vehicle accidentsORs (95% CI), after extended shift (≥24 h) vs non-extended shift (<24 h):
Crashes=2.3 (1.6 to 3.3); near miss accidents=5.9 (5.4 to 6.3)
Age and sexBarger et al41
Motor vehicle accidentsIncidence rates of driving accidents on house visits:
Long hours (mean 58.36 h/week)=0.10 (0.31) vs short hours (mean 38.17 h/week)=0.02 (0.18). p<0.05
Not adjustedKirkcaldy et al45
Mood disorders, depressionHR (95% CI) hours/week intervals and redemption of antidepressive drug prescription(reference group: 37–40 h/week):
25–36 h: 0.83 (0.24 to 2.82); 41–44 h: 0.95 (0.50 to 1.77); 45–49 h: 0.88 (0.43 to 1.78); 50–54 h: 0.83 (0.32 to 2.14); 55–59 h: 0.67 (0.15 to 2.94); >60 h: 0.48 (0.06 to 3.68).
Cox regression analysis of work hours as a continuous variable: HR=0.93 (0.76 to 1.13)
Age, sex, marital status, medical specialty, decision authority at work, social support at work, quantitative work demands and previous redemption of AD drug prescriptionVarma et al49
Mood disorders, GHQ-30Prevalence of cases by working time (hours/week)
≤30 h: 35.7% (41/115); >30–40 h: 39.0% (39/100); >40–50 h: 37.7% (26/69); >50 h: 56.8% (46/81); p=0.0179
Stepwise multiple logistic regression, >50 vs ≤50 h/week: parameter 0.635 (p=0.0293)
Marital status, medical facility, position and night dutyHayasaka et al44
Mood disorders, GHQ-12 and SCLDSNo association was found between number of hours worked in a week and depressionNot adjustedFirth-Cozens42
Mood disorders, SF-36Scores when night float vs standard call at baseline and follow-up:
Mental health mean score (SD): baseline=57.33 (22.63) vs 65.71 (7.61); follow-up=52.00 (15.49) vs 60.80 (11.45); p=0.72
Mental health component summary (SD), baseline=34.84 (14.06) vs 40.21 (7.61); follow-up=30.15 (10.71) vs 42.40 (6.23); p=0.39
Regression analysis: increased number of hours in hospital correlated with significantly lower SF-36 scores in almost all domains
Not adjustedZahrai et al50
Mood disorders, SF-36 and BDIImprovement of levels before and after duty hours limitations from 90–110 to 78–80 h/week):
Mental health SF-36: no statistically significant improvement
Individual questions BDI before and after duty hours limitations, only energy level statistically significant
Not adjustedStamp et al47
Mood disorders, SF-36OR (95% CI)for working 47 h/week or more:
Impaired mental health, men: 1.59 (0.95 to 2.66); women: 1.86 (1.03 to 3.37)
Age and amount of time in practiceSundquist and Johansson 48
General health, SF-36SF-36:
Scores when night float vs standard call at baseline and follow-up:
General health mean score (SD): baseline=62.11 (17.47) vs 77.57 (24.25); follow-up=56.43 (24.89) vs 84.20 (16.50); p=0.41
Physical health component summary (SD): baseline=46.16 (13.15) vs 52.01 (13.33); follow-up=39.32 (9.80) vs 56.15 (2.18); p=0.015
Vitality mean score (SD): baseline=51.67 (14.58) vs 51.43 (15.74); follow-up=48.57 (14.92) vs 51.00 (10.84); p=0.20
Regression analysis demonstrated that the increased number of hours spent in hospital correlated with significantly lower general health, physical function, mental health, role emotional, social function and mental component summary scale scores (all p<0.05)
Not adjustedZahrai et al50
General health, SF-36SF-36, BDI:
Improvement of levels before and after duty hours limitations from 90–110 to 78–80 h/week:
Physical health: no statistically significant differences
Not adjustedStamp et al47
General health, SF-36SF-36:
OR (95% CI) adjusted for age and time in practice, for working 47 h/week or more:
Impaired general health: men=1.66 (1.00 to 2.77); women=1.59 (1.00 to 3.17)
Age and amount of time in practiceSundquist and Johansson 48
General healthSelf-rated health:
OR (95% CI) of good self-rated health (logistic regression):
Norwegian work time pattern*=1.35 (1.03 to 1.77); working in Norway=4.17 (3.02 to 5.73)
Age, sex and country of workRosta and Aasland 46
  • *Not working more than 9 h a day and having more than 60 h a month on-call.

  • AD, anti-depressive (Mood disorders, depression); BDI, Beck Depression Inventory II; ED, Emergency Department; GHQ-12, General Health Questionnaire-12 items; ICU, intensive care unit; OH, Occupational Health (Percutaneous Injuries); SCLDS, Symptom Checklist Depression Scale.