Impact of missing value imputation on classification for DNA microarray gene expression data--a model-based study

Youting Sun1, Ulisses Braga-Neto, Edward R Dougherty

  • 1Department of Electrical and Computer Engineering, Texas A&M University, College Station, TX 77843, USA.

Insights

Missing value imputation in microarray data can improve classification accuracy under certain conditions, especially with high noise or strong correlations. However, imputation is not recommended for large amounts of missing data.

Area of Science:

  • Bioinformatics
  • Computational Biology
  • Genomics

Background:

  • Numerous missing-value (MV) imputation methods exist for microarray data.
  • Few studies have rigorously examined the impact of MV imputation on classification accuracy.
  • Previous research often suffers from flawed MV generation and error estimation.

Purpose of the Study:

  • To conduct a model-based investigation into the relationship between MV imputation and classification accuracy in microarray data.
  • To address fundamental issues identified in prior studies concerning MV handling and evaluation.

Main Methods:

  • Evaluation of six popular MV imputation algorithms.
  • Incorporation of two feature selection methods.
  • Assessment using three distinct classification rules.
  • Model-based simulation to control for MV generation and error estimation.

Main Results:

  • MV imputation is beneficial when noise levels are high, variance is low, or gene-cluster correlations are strong, particularly at small to moderate MV rates.
  • Data quality metrics can guide imputation by identifying poor-quality points for imputation.
  • Performance of imputation methods exhibits a peaking phenomenon, improving up to an optimal MV rate before deteriorating rapidly.

Conclusions:

  • MV imputation is recommended for specific data characteristics and moderate missingness rates.
  • Imputation methods are not advised for high missing value rates.
  • The optimal MV rate for imputation performance should be considered to avoid accuracy degradation.