Abstract

Life course functional trajectories are a dynamic way of studying lifetime influences on health and ageing. Gaining a better understanding of trajectories of physical and cognitive capability permits the identification of critical or sensitive periods of development and decline, and of the relative impact of early and later life exposures on these changes. A wide range of analytical tools are available for the description of longitudinal data. The choice of analytical method is based on a match between the method and the question asked, and the decision should be made in the context of study design, the nature of the outcome variable to be modelled, features of the exposure, and the extent of missing observations. This chapter presents a series of statistical models to evaluate specific questions regarding change in single and multiple outcomes, and discusses considerations that affect inferences made when these methods are employed.