Table 5
Relative risk ratio (RRR) of multiple spinal pain and daily-life consequences due to spinal pain, respectively, according to potential risk factors among the 46,726 children participated in the 11-year follow-up in the Danish National Birth Cohort
aReference category: not having reported in any of the spinal regions
Characteristics No. of cases (One-sited/Multi-sited) Multiple spinal painac No. of cases (1–2 times/More than two times) Daily-life consequencesbc One-sited
RRR (95% CI)Multi-sited
RRR (95% CI)1–2 times
RRR (95% CI)More than two times
RRR (95% CI)Sex, age Boys, 11 years 1377/376 Ref. Ref. 2714/863 Ref. Ref. Boys, 12 years 283/75 1.12 (0.98–1.28) 1.08 (0.84–1.39) 639/189 1.36 (1.23–1.50) 1.26 (1.07–1.48) Boys, 13+ years 45/18 1.02 (0.75–1.39) 1.47 (0.91–2.38) 118/22 1.44 (1.17–1.78) 0.83 (0.54–1.27) Girls, 11 years 1963/606 1.34 (1.25–1.45) 1.51 (1.33–1.73) 3176/1167 1.10 (1.04–1.16) 1.26 (1.15–1.39) Girls, 12 years 496/206 1.87 (1.67–2.09) 2.81 (2.36–3.35) 779/303 1.53 (1.40–1.67) 1.84 (1.60–2.11) Girls, 13+ years 102/46 2.60 (2.08–3.24) 4.21 (3.05-5.82) 135/69 1.79 (1.47–2.18) 2.81 (2.15–3.68) Sibling position Biological full siblings 3656/1140 Ref. Ref. 6598/2221 Ref. Ref. Biological only child 610/187 1.15 (1.04–1.26) 1.10 (0.93–1.31) 963/392 1.08 (1.00–1.17) 1.24 (1.10–1.40) Family type Child lives with both parents 3087/948 Ref. Ref. 5709/1918 Ref. Ref. Child not living with (both) parentsd 1179/379 1.31 (1.21–1.42) 1.32 (1.15–1.51) 1852/695 1.17 (1.10–1.25) 1.20 (1.09–1.33) Maternal educational level High 2308/652 Ref. Ref. 4415/1364 Ref. Ref. Medium 1636/570 1.07 (1.00–1.14) 1.30 (1.15–1.46) 2708/1035 0.92 (0.87–0.97) 1.13 (1.03–1.23) Low 322/105 1.33 (1.17–1.52) 1.47 (1.18–1.84) 438/214 0.96 (0.86–1.08) 1.47 (1.25–1.72) Equivalised household income 4th quartile (highest) 1398/416 Ref. Ref. 2566/884 Ref. Ref. 3rd quartile 1281/382 1.04 (0.96–1.13) 1.03 (0.89–1.18) 2357/736 1.09 (1.02–1.16) 0.96 (0.86–1.06) 2nd quartile 1015/321 1.06 (0.97–1.16) 1.08 (0.93–1.26) 1738/616 1.07 (1.00–1.15) 1.03 (0.92–1.15) 1st quartile (lowest) 572/208 1.15 (1.02–1.28) 1.32 (1.10–1.) 900/377 1.13 (1.03–1.24) 1.22 (1.06–1.40) Maternal age at childbirth ≤ 25 years 565/170 Ref. Ref. 945/320 Ref. Ref. 26–30 years 1833/564 0.95 (0.85–1.05) 1.01 (0.85–1.21) 3205/1107 0.93 (0.86–1.01) 1.02 (0.89–1.16) 31–35 years 1408/451 0.90 (0.81–1.00) 1.01 (0.84–1.22) 2560/890 0.92 (0.85–1.00) 1.02 (0.89–1.16) > 35 years 460/142 0.88 (0.77–1.00) 0.97 (0.76–1.22) 851/296 0.93 (0.84–1.03) 1.00 (0.85–1.19) bReference category: not having experienced daily-life consequences due to spinal pain
cAdjusted for additional variables in the model, as well as the interaction between child’s age and sex (P < 0.001)
dParents not living together due to divorce, separation, they never lived together, or only one parent alive