Fig. 1.

Seven hypothesized models^a: a standard model, b physical health, mental health and QL, c physical burden, mental function and QL, d symptom burden, function and QL, e HRQL and QL, f formative symptom burden (free weights), function and QL, g formative symptom burden (fixed weights) function and QL. ^aModels are described in text. Item thresholds, means, (error) variances, and correlations between first-order latent variables (in the standard model) are not represented, for clarity’s sake