Validation and interpretation of neurological registry data.

RELEVANT LITERATURE Methods of Validation Several methods can be used to assess completeness of registry data. Completeness of registration can serve as an indicator of registry effectiveness an ideal registry will capture all cases of a given disease within a defined population. Completeness is defined as the proportion of diagnosed cases that are registered. Possible methods for estimating completeness include: 1. Estimates based on cases confirmed through death certificates and the mortality to incidence ratio 2. The historic data method: comparing current rates of registration to appropriate numbers of cases from the past within the same registry 3. Comparison to a reference registry with complete ascertainment 4. Capture-recapture methodology 5. Independent case ascertainment (linking registry data to an independent database) 6. The flow method 7. Estimating completeness based on mortality/incidence ratios.222 Schmidtmann et al222 performed a survey of 195 cancer registries in Europe to determine which methods were most commonly applied to estimate data completeness. The survey found that the historic data method, comparison to a reference registry, estimates based on death certificates and the mortality to incidence ratio, and mortality/incidence ratio were the most Validation and Interpretation of Neurological Registry Data