Table 1

Subgroup analyses of OR of diabetes mellitus according to shift work status

No of reports*OR(95% CI)I2 (%)p Value for heterogeneityp Value for interaction
 Women91.091.04 to 1.1454.300.0250.01
 Men151.371.20 to 1.560.000.547
 Combined41.061.04 to
Study design
 Cohort study161.121.06 to 1.1952.900.0070.35
 Cross-sectional study121.061.03 to 1.0910.900.339
 Asia161.071.03 to 1.1120.900.2160.13
 Europe41.361.05 to 1.7323.600.269
 USA81.091.03 to 1.1455.600.027
 Nurse81.091.03 to 1.1455.600.0270.86
 Other201.091.04 to 1.1536.200.054
Shift schedule
 Rotating shifts41.421.19 to 1.6913.400.3250.04
 Irregular or unspecific shifts61.061.04 to
 Night shifts151.091.04 to 1.1437.600.07
 Mixed21.40.84 to 2.330.000.715
 Evening shifts11.730.85 to 3.52NANA
Controlling BMI in models†
 Yes211.071.04 to 1.1034.500.0620.004
 No151.341.21 to 1.5086.40<0.001
Controlling physical activity in models
 Yes211.071.04 to 1.1034.500.0620.01
 No71.471.21 to 1.790.000.597
Controlling family history of DM in models
 Yes131.091.04 to 1.1543.100.0490.95
 No151.091.03 to 1.1442.500.042
  • *Two articles reported their results by duration of shift work, one article by sex group, two articles by age group and one article by type of work schedule; therefore, there are 28 reports from 11 articles (one article presented their results from two independent cohort) for diabetes mellitus.

  • †Study by Pan and colleagues reported results both controlling and not controlling for BMI.

  • BMI, body mass index; DM, diabetes mellitus; NA, not applicable.