Table 3

Distribution of spinal pain according to selected characteristics of the 46,726 children participating in the 11-year follow-up in the Danish National Birth Cohort

N Overall spinal painab
No pain (%)Moderate pain (%)Severe pain (%)
Total population46,72658.329.712.0
 11 years38,30359.429.311.3
 12 years722654.031.314.7
 13–14 yearsc119749.732.917.6
Sibling position
 Biological full siblings41,18558.929.411.7
 Only biological child554153.931.714.4
Family type
 Child lives with both parents36,53359.929.111.0
 Child not living with (both) parentsd10,19352.732.015.3
Maternal educational level
Equivalised household income
 4th quartile (highest)16,69860.328.910.9
 3rd quartile14,33158.629.811.6
 2nd quartile10,54257.030.312.7
 1st quartile (lowest)5,15554.130.815.1
Maternal age at childbirth
 ≤ 25 years541755.630.813.6
 26–30 years19,97258.429.612.0
 31–35 years16,04358.729.712.0
 > 35 years529459.828.811.4
aVariables were analyzed with the chi-squared test of heterogeneity. Chi-squared tests were statistical significant for all variables

bFor inverse probability weighted estimates see Supplementary File 3

c130 individuals were 14 years old, most of them just turned 14 years at time of follow-up

dParents not living together due to divorce, separation, they never lived together, or only one parent alive