Visuospatial Reasoning Trajectories and Death in a Study of the Oldest Old: A Formal Evaluation of Their Association

OBJECTIVES: To model trajectories of visuospatial reasoning measured using Kohs Block Design test under realistic missing data assumptions and evaluate their association with hazard of death.

METHODS: A joint longitudinal-survival model was used to estimate trajectories of visuospatial reasoning under a missing not at random assumption of participants from the Origins of Variance in the Old-Old: Octogenarian Twins study. Sensitivity analyses to missing data assumptions were conducted.

RESULTS: Visuospatial reasoning declined at constant rate. Baseline age, dementia status, education, and history of stroke were associated with visuospatial reasoning performance, but only dementia was associated with its rate of decline. Importantly, our results demonstrated an association between poorer visuospatial reasoning and increased hazard of death. Baseline age and sex were associated with risk of death.

DISCUSSION: We confirmed an association between visuospatial reasoning and death under plausible missing data assumptions.