Table 2

Estimates from multilevel models showing mean differences in grip strength (kg) and mean differences in grip strength change (kg/year) for each childhood factor in the Medical Research Council National Survey of Health and Development

NReg. coeff.95% CIP value*NReg.
95% CIP value*
Physical growth
 A. Birth weight (kg)15281530
  Birth weight1.961.08 to 2.84<0.0011.070.25 to 1.880.01
  Birth weight×age (year)N/A−0.06−0.12 to 0.000.05
 B. Growth parameters15091505
  Height size (cm)−0.01−0.22 to 0.200.9−0.16−0.29 to −0.030.02
  Height tempo (%)0.160.06 to 0.260.001−0.02−0.04 to 0.070.5
  Height velocity (%)−0.02−0.10 to−0.04 to 0.040.9
  Weight size (kg)0.710.24 to 1.180.0030.410.57 to 0.770.02
  Weight tempo (%)−0.06−0.12 to 0.010.08−0.01−0.06 to 0.040.8
  Weight velocity (%)−0.07−0.14 to 0.000.06−0.06−0.11 to 0.000.04
Motor development (months)
 C. Age at sitting1414−0.25−0.57 to 0.060.11424−0.18−0.38 to 0.010.07
 D. Age at standing1416−0.27−0.47 to −0.070.0081419−0.21−0.34 to  −0.070.002
 E. Age at walking14241416
  Walking1.360.00 to 2.730.05−0.13−0.25 to −0.010.03
  Walking2 −0.06−0.10 to −0.010.01N/A
  F. Cognitive development (SD)14081410
   Cognition−0.46−1.10 to to 0.760.005
   Cognition2 −0.81−1.27 to −0.340.001N/A
   Cognition×age (year)0.070.02 to 0.110.003N/A
   Cognition2×age (year)0.030.00 to 0.060.08N/A
  G. Father’s occupational class14531443
   I and IIReference0.2Reference0.4
   III−0.51−1.64 to 0.62−0.24−1.15 to 0.67
 IV and V−1.29−2.58 to 0.000.38−0.66 to 1.42
 III×age (year)N/A−0.03−0.10 to 0.040.07
 IV and V×age (year)N/A−0.10−0.18 to −0.01
  • All models adjusted for age term and standardised adult height.

  • *P values are given for the overall tests of associations. P values for sex interactions: birth weight p=0.004; childhood height after adjustment for adult height p=0.07; height tempo p=0.006; age at first waking (quadratic term) p=0.02.

  • N/A, not available.