Fig. 2

Results of the path analysis by structural equation models. Legend: Standardised coefficients estimated by centre from the structural equations models. Single-headed arrows represent regressions and double-headed arrows represent correlations between residuals. The standardised estimations are presented in bold for the initial model and between curly brackets for the multi-group model, as follows: {centre 1, centre 2, centre 3, centre 4, centre 5, centre 6}