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
aVariables were analyzed with the chi-squared test of heterogeneity. Chi-squared tests were statistical significant for all variables
N Overall spinal painab No pain (%) Moderate pain (%) Severe pain (%) Total population 46,726 58.3 29.7 12.0 Sex Boys 22,287 61.3 28.9 9.8 Girls 24,439 55.6 30.4 14.0 Age 11 years 38,303 59.4 29.3 11.3 12 years 7226 54.0 31.3 14.7 13–14 yearsc 1197 49.7 32.9 17.6 Sibling position Biological full siblings 41,185 58.9 29.4 11.7 Only biological child 5541 53.9 31.7 14.4 Family type Child lives with both parents 36,533 59.9 29.1 11.0 Child not living with (both) parentsd 10,193 52.7 32.0 15.3 Maternal educational level High 26,886 59.3 29.7 11.0 Medium 17,217 57.6 29.6 12.8 Low 2623 54.0 29.7 16.3 Equivalised household income 4th quartile (highest) 16,698 60.3 28.9 10.9 3rd quartile 14,331 58.6 29.8 11.6 2nd quartile 10,542 57.0 30.3 12.7 1st quartile (lowest) 5,155 54.1 30.8 15.1 Maternal age at childbirth ≤ 25 years 5417 55.6 30.8 13.6 26–30 years 19,972 58.4 29.6 12.0 31–35 years 16,043 58.7 29.7 12.0 > 35 years 5294 59.8 28.8 11.4 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