Multiple imputation for ordinal longitudinal data with monotone missing data patterns

ABSTRACT

Missing data often complicate the analysis of scientific data. Multiple imputation is a general purpose technique for analysis of datasets with missing values. The approach is applicable to a variety of missing data patterns but often complicated by some restrictions like the type of variables to be imputed and the mechanism underlying the missing data. In this paper, the authors compare the performance of two multiple imputation methods, namely fully conditional specification and multivariate normal imputation in the presence of ordinal outcomes with monotone missing data patterns. Through a simulation study and an empirical example, the authors show that the two methods are indeed comparable meaning any of the two may be used when faced with scenarios, at least, as the ones presented here.

KEYWORDS:

• Longitudinal data
• ordinal outcome
• monotone missing data patterns
• fullyconditional specification
• multivariate normal imputation
• proportional odds model

Disclosure statement

No potential conflict of interest was reported by the authors.