State dementia registries: Diverse methodologic approaches to a common public health goal

Abstract

A common goal of state dementia registries is public health disease surveillance for program planning service delivery, and research. Despite this similarity in perspective, methodologic differences involving coverage, diagnostic, and data coding issues distinguish the various registries. Some of these differences include the illnesses, geographic area(s), and population groups covered by dementia registries. Diagnostic differences center on the development and application of case definitions specific to the different types of dementing illness, the thoroughness of accessible sources of medical data, and the standardization of disease staging for the dementias. Competing coding systems for diagnoses exist, but fortunately the coding of procedures is already uniform. A critical step toward facilitating the production of regional or national aggregate statistics and engaging in multisite research studies would be the achievement of enhanced standardization of the data elements and coding systems of public health and other dementia registries. This article promotes such methodologic compatibility.