What is the difference between missing completely at random and missing at random?

Krishnan Bhaskaran; Liam Smeeth

doi:10.1093/ije/dyu080

What is the difference between missing completely at random and missing at random?

Int J Epidemiol. 2014 Aug;43(4):1336-9. doi: 10.1093/ije/dyu080. Epub 2014 Apr 4.

Authors

Krishnan Bhaskaran¹, Liam Smeeth²

Affiliations

¹ Department of Non-communicable Diseases Epidemiology, London School of Hygiene and Tropical Medicine, London, UK krishnan.bhaskaran@lshtm.ac.uk.
² Department of Non-communicable Diseases Epidemiology, London School of Hygiene and Tropical Medicine, London, UK.

Abstract

The terminology describing missingness mechanisms is confusing. In particular the meaning of 'missing at random' is often misunderstood, leading researchers faced with missing data problems away from multiple imputation, a method with considerable advantages. The purpose of this article is to clarify how 'missing at random' differs from 'missing completely at random' via an imagined dialogue between a clinical researcher and statistician.

Keywords: missing at random; missing data; multiple imputation.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Data Interpretation, Statistical*
Humans
Research Design*
Statistics as Topic

Abstract

Publication types

MeSH terms

Grants and funding