Fig. 1

Predicted disability for exemplary HRS participants with different MWI trajectories.

Abbreviations: MWI, Multimorbidity-Weighted Index.

Legend: This figure illustrates the long-term progression of disability over time according to the evolution of multimorbidity. Participant-specific predicted values of disability are based on negative binomial regression with random intercept and time-varying MWI as the predictor. Models were adjusted for all baseline covariates, and baseline disability was set at the mean. Green line indicates the association between MWI and disability for a constant MWI over the whole time period, i.e., without an increase in MWI over time or interaction between MWI and time. Blue line indicates the association between MWI and disability for an increasing MWI at one time point, as if there were no interaction between MWI and time (as compared to the red line). Red line indicates the association between MWI and disability for an increasing MWI at several time points, with an interaction between MWI and time. The worsening slope is due to the significant interaction between MWI and time