Power analysis of longitudinal studies with piecewise linear growth and attrition.

ABSTRACT: In longitudinal research, the development of some outcome variable(s) over time (or age) is studied. Such relations are not necessarily smooth, and piecewise growth models may be used to account for differential growth rates before and after a turning point in time. Such models have been well developed, but the literature on power analysis for these models is scarce. This study investigates the power needed to detect differential growth for linear-linear piecewise growth models in further detail while taking into account the possibility of attrition. Attrition is modeled using the Weibull survival function, which allows for increasing, decreasing or constant attrition across time. Furthermore, this work takes into account the realistic situation where subjects do not necessarily have the s

SUBMITTER: Moerbeek M 

PROVIDER: S-EPMC9729151 | biostudies-literature | 2022 Dec

REPOSITORIES: biostudies-literature