Missing Data in Disguise and Implications for Survey Data Analysis

Abstract

The phenomenon was observed that more “not applicable” (NA) responses occurred for the items near the end of a survey instrument than for those at the beginning. In this article, the authors present evidence that this phenomenon represents missing data in disguise in a survey study, especially when the survey is long. They explore the implications for survey data analysis in this situation. Practical recommendations are made for survey instrument construction and survey data analysis to minimize the potential adverse effect of such missing data in disguise. Limitations of the study are also discussed.