Cross-lagged model. This model demonstrates bidirectional causal paths from one time-point to the following, from general health towards overall quality of life as well as from overall quality of life towards general health perceptions. One of these cross-lagged paths is statistically significant; the path from baseline gQOL towards 3 months' scores on the SF-36 General health subscale. Together with the cross-lagged paths, the model also includes strong serial associations over time within each variable except between 6 and 12 months general health perceptions. Straight and curved single arrows indicate the causal paths modeled. The corresponding decimals are standardized regression coefficients. Bold face coefficients indicate p < 0.05 while broken lines are used for paths with a corresponding p ≥ 0.05. The curved line between baseline variables represents a correlation; the number is the corresponding correlation coefficient. Model fit indices are summarized in Table 3. Figures 3 and 4 are available in more detailed versions as Additional files 1 (Additional file 1_xlagged_gQOL.pdf) and 2 (Additional file 2_simultaneous_gQOL.pdf) with this paper, including the unstandardized parameter estimates.