Feb 2018
A patient registry is “an organized system that uses observational study methods to collect uniform data (clinical and other) to evaluate specified outcomes for a population defined by a particular disease, condition or exposure and that serves one or more predetermined scientific, clinical or policy purposes.”1 Registry-based studies, by definition, are observational in nature. Within the context of nonexperimental research, both descriptive and comparative, registries do not typically dictate patient visit schedules, mandate specific diagnostic or laboratory tests, or require patients to complete surveys and patient-reported outcome (PRO) measures at specific intervals.
Even during routine care, patients may miss a visit or decline to undergo a procedure or test, and providers may elect to forego expected tests for a few or a specific subset of their patients. Demographics, test results, and other key information may not be documented in the registry due to lack of availability, refusal to provide, or incorrect documentation (e.g., the values are inconsistent or out-of-range). These scenarios, among other potential issues, result in missing data in the registry database. In addition, incorporation of data into a registry from electronic health records, insurance claims, or external observational or experimental studies may introduce missing or disparate data in the registry database.