Table 3

Distribution of potential confounders across levels of cumulated exposure

Cumulated angular velocityLevel 1*(lowest)Level 2*Level 3*Level 4*Level 5* (highest)Total
Person years4 051 0524 054 6834 052 9954 044 5774 032 03320 235 440
 Men, %47.950.851.753.466.253.4
 Women, %52.149.248.346.633.846.6
Mean age (IQR)31.8
(24.4–37.3)
36.6
(29.8–41.8)
41.4
(35.2–46.7)
46.9
(40.2–53.3)
51.2
(44.5–58.0)
41.6
(32.7–49.9)
Lumbar disc herniation, cases56728112965910 32310 43644 202
 Men, %49.553.453.854.868.256.8
 Women, %50.546.646.245.231.843.2
Lumbar disc herniation, IR14.020.023.825.525.921.8
  • Shown for angular velocity.

  • *Based on quintiles of cumulative exposure in the study population.

  • IR, incidence rate.