Small Numbers, Disclosure Risk, Security, and Reliability Issues in Web-based Data Query Systems

Abstract

In Brief This article describes the process for developing consensus guidelines and tools for releasing public health data via the Web and highlights approaches leading agencies have taken to balance disclosure risk with public dissemination of reliable health statistics. An agency's choice of statistical methods for improving the reliability of released data for Web-based query systems is based upon a number of factors, including query system design (dynamic analysis vs preaggregated data and tables), population size, cell size, data use, and how data will be supplied to users. The article also describes those efforts that are necessary to reduce the risk of disclosure of an individual's protected health information. This article describes the process for developing consensus guidelines and tools for releasing public health data via the Web and provides guidance to states and counties implementing or managing a WDQS for reducing the risk of inappropriate disclosure of sensitive information; improving the provision of reliable statistics; and increasing the security of their data. The article also describes those efforts that are necessary to reduce the risk of disclosure of an individual's protected health information.