Analysis of incomplete public health data

The problem of dealings with missing values is common throughout statistics and is very prominent with epidemiologic data in the broad sense. Not only do data collection procedures break down, but subjects may be lost to foll ow up, or simply withdraw their consent without further providing a reason fbr doing so, In this paper, we review a framework for handling incomplete studies, and then concentrate on a specific case. It comes from a complex h ealth interview survey, conducted in Belgium in 1997 where different types of missingness arise at various levels of the hierarchical sampling procedu re.