Patterns of functional decline in very old age: an application of latent transition analysis

There is a scarcity of longitudinal studies examining how functional decline develops among very old people. The aim of the current study was to detect and characterize typical patterns of functional decline in a sample of very old people. We utilized longitudinal data from a sample of people aged 80-89 at baseline from Sweden and Germany (N = 847). Three follow-up assessments were completed and 159 participants completed the last assessment 9 years after baseline. Death (45 %) and contact no longer possible (40 %) were main reasons for dropout. We used latent transition analysis (LTA) to estimate the probabilities of latent class membership at each measurement point, as well as the transition probabilities of moving from one class to another. Three latent classes were revealed, labeled Mobility Problem Stayers, Hearing Problem Advancers and Visual Problem Advancers. The first class had a low probability of additional problems throughout the study period, while the two latter had increased probabilities of additional limitations. In terms of class membership change, Mobility Problem Stayers moved either towards Hearing Problem Advancers or towards Visual Problem Advancers. The results suggest that mobility problems are most common when people reach the age of 80+. Further decline is typically characterized by the addition of either visual problems or hearing problems, which are both associated with an increased risk of limitations in upper extremities. These findings warrant further research to analyze the association between the detected typical patterns of functional decline and health-related outcomes.