Use of postal codes and addresses in the analysis of health data.

This article describes various ways of using postal codes and addresses to analyze health data. It gives examples of files that contain data suitable for coding to small areas, explains how the coding can be done efficiently using the Postal Code Conversion File (PCCF), and shows various ways of analyzing the resulting data. It also points out limitations of the data and methods, and suggests ways of avoiding or working around some of the problems frequently encountered. Examples are given of several types of analytical studies based on data coded to local area through use of postal codes and addresses. Examples are also given of simpler types of analysis not requiring recourse to the PCCF, which are based on only the first three characters of the postal code.