An examination of Alzheimer's disease case definitions using Medicare claims and survey data

Different information sources yield widely varied prevalence and expenditure estimates. Although claims data provided a more objective means for identifying AD cases, survey report identified more cases, and pharmacy data also are an important source for case ascertainment. Using any single source will underestimate the prevalence and associated cost of AD. The wide range of AD cases identified by using different data sources demands caution interpreting cost-of-illness studies using single data sources.