Evaluating the impact of missing data imputation

This paper presents an impact assessment for the imputation of missing data. The assessment is performed by measuring the impacts of missing data on the statistical nature of the data, on a classifier, and on a logistic regression system. The data set used is HIV seroprevalence data from an antenatal clinic study survey performed in 2001. Data imputation is performed through the use of Random Forests, selected based on best imputation performance above five other techniques. Test sets are developed which consist of the original data and of imputed data with varying numbers of specifically selected missing variables imputed. Results indicate that, for this data set, the evaluated properties and tested paradigms are fairly immune to missing data imputation. The impact is not highly significant, with, for example, linear correlations of 96 % between HIV status probability prediction with a full set and with a set of two imputed variables using the logistic regression analysis.