title: A systematic approach to initial data analysis is good research practice.
abstract: Initial data analysis is conducted independently of the analysis needed to address the research questions. Shortcomings in these first steps may result in inappropriate statistical methods or incorrect conclusions. We outline a framework for initial data analysis and illustrate the impact of initial data analysis on research studies. Examples of reporting of initial data analysis in publications are given. A systematic and careful approach to initial data analysis is needed as good research practice.
authors.affiliation: Department of Statistics and Probability, Michigan State University, East Lansing, Mich; Institute for Medical Biometry and Statistics, Medical Center, University of Freiburg, Freiburg, Germany. Electronic address: huebner@stt.msu.edu.
authors.forename: Marianne
authors.initials: M
authors.lastname: Huebner
authors.affiliation: Institute for Medical Biometry and Statistics, Medical Center, University of Freiburg, Freiburg, Germany.
authors.forename: Werner
authors.initials: W
authors.lastname: Vach
authors.affiliation: Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Saskia
authors.initials: S
authors.lastname: le Cessie
mesh_terms: D035843:Biomedical Research / Q000379:methods / Q000706:statistics & numerical data*; D003625:Data Collection / Q000706:statistics & numerical data*; D003627:Data Interpretation, Statistical; D006801:Humans; D015233:Models, Statistical; D015203:Reproducibility of Results; D012107:Research Design / Q000706:statistics & numerical data*
keywords: data cleaning; data screening; initial data analysis