Missing Data; Shared Parameter Mixture Models; Growth Models; Growth Mixture Models; Longitudinal Data
In longitudinal research, interest often centers on individual trajectories of change over time. When there is missing data, a concern is whether data are systematically missing as a function of the individual trajectories. Such a missing data process, termed random coefficient-dependent missingness, is statistically non-ignorable and can bias parameter estimates obtained from conventional growth models that assume missing data are missing at random. This paper describes a shared-parameter mixture model (SPMM) for testing the sensitivity of growth model parameter estimates to a random coefficient-dependent missingness mechanism. Simulations show that the SPMM recovers trajectory estimates as well as or better than a standard growth model across a range of missing data conditions. The paper concludes with practical advice for longitudinal data analysts
BYU ScholarsArchive Citation
Baldwin, Scott A.; Gottfredson, Nisha C.; and Bauer, Daniel J., "Modeling Change in the Presence of Non-Randomly Missing Data: Evaluating A Shared Parameter Mixture Model" (2014). Faculty Publications. 6067.
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