Table 4 Associations between average lifetime frequency of night shifts worked and the risk of incident COPD (n = 74,559)

Case/all subjects

805/56,698

49/2381

125/8919

166/6561

Model 1

1 [reference]

1.46 (1.09, 1.94)

0.99 (0.82, 1.19)

1.79 (1.51, 2.11)

 < 0.001

Model 2

1 [reference]

1.43 (1.07, 1.91)

1.08 (0.90, 1.31)

1.78 (1.50, 2.10)

 < 0.001

Model 3

1 [reference]

1.30 (0.97, 1.73)

0.98 (0.81, 1.18)

1.42 (1.20, 1.69)

0.001

Model 4

1 [reference]

1.29 (0.97, 1.73)

0.98 (0.81, 1.18)

1.41 (1.19, 1.68)

0.001