Figure 2

Structural Equation Model exploring the basic paths of the ICF model for patients with OA prior to joint replacement. The underlying latent constructs (factors) are represented by the circles. The shaded squares represent the indicators of the underlying construct (i.e. the observed variables). The E's are the error terms of the indicators. The values on the structural paths between the latent constructs are the standardised path coefficients. The values between the latent construct and the indicators are the standardised factor loadings. The D's associated with each latent variable are the residual error in prediction of the unobserved latent construct. The elements marked * are estimated parameters. The path indicated by a dashed line is the path that was set to 1 for identification purposes and so not tested