From: Information bias of social gradients in sickness absence: a comparison of self-report data in the Norwegian Mother and Child Cohort Study (MoBa) and data in national registries
Self-report data
Not absent
Absent
Total
Register data
 Not absent
13,506 (0.478)
1164 (0.041)
14,670 (0.519)
 Absent
5938 (0.210)
7632 (0.270)
13,570 (0.481)
 Total
19,444 (0.689)
8796 (0.311)
28,240 (1.000)