Table 5 Multiple regression models for performance tests (grip strength, gait speed and chair stand) by the composite age at first birth/ parity variable (N = 473)

Grip strength (Kgf)

β (95 % CI)

p value

β (95 % CI)

p value

β (95 % CI)

p value

First child before 18 and ≥3 children

−1.613 (-2.938 : -0.289)

0.017

−1.236 (-2.599 : 0.127)

0.076

−1.350 (-2.730 : 0.030)

0.055

First child before 18 and <3 children

1.438 (-1.533 : 4.409)

0.342

0.726 (-2.236 : 3.688)

0.630

0.993 (-2.083 : 4.070)

0.526

First child at 18y or more and ≥3 children

−0.924 (-2.007 : 0.160)

0.095

−0.504 (-1.602 : 0.594)

0.367

−0.478 (-1.591 : 0.635)

0.399

First child at 18y or more and <3 children

0

0

0

Gait speed (m/s)

First child before 18 and ≥3 children

−0.030 (-0.076 : 0.016)

0.194

−0.018 (-0.066 : 0.030)

0.471

−0.016 (-0.064 : 0.031)

0.495

First child before 18 and <3 children

0.067 (-0.036 : 0.170)

0.201

0.065 (-0.039 : 0.168)

0.221

0.064 (-0.041 : 0.169)

0.233

First child at 18y or more and ≥3 children

−0.018 (-0.055 : 0.020)

0.356

−0.010 (-0.048 : 0.029)

0.615

−0.003 (-0.041 : 0.035)

0.871

First child at 18y or more and <3 children

0

0

0

Chair stands (s)

First child before 18 and ≥3 children

0.672 (0.157 : 1.187)

0.011

0.618 (0.081 : 1.156)

0.024

0.655 (0.113 : 1.197)

0.018

First child before 18 and <3 children

0.396 (-0.739 : 1.532)

0.493

0.573 (-0.571 : 1.718)

0.326

0.829 (-0.356 : 2.014)

0.170

First child at 18y or more and ≥3 children

0.401 (-0.019 : 0.821)

0.061

0.324 (-0.107 : 0.756)

0.140

0.379 (-0.058 : 0.815)

0.089

First child at 18y or more and <3 children

0

0

0