Error Estimation in Linking Heterogeneous Data Sources Error Estimation in Linking Heterogeneous Data Sources

BACKGROUND Record linkage is the process of bringing together related records that have been compiled separately [1]. Many types of studies have been conducted that have used different methods and approaches to link medical records obtained from heterogeneous data sources. For example, the use of administrative data for research purposes has led to considerable interest in computerized methods for linking medical records [3]. Techniques for record linkage are also important because they help in expanding and correcting databases that may be used for studying various diseases such as AIDS or diabetes and a wide range of treatments and procedures [4]. These techniques have allowed researchers to study the long-term outcomes of exposure to hazards [5]. Epidemiologists have depended on record linkage to examine the effects of immunization on subsequent morbidity and mortality [3]. Notwithstanding the potential informational value of record linkage, it may be a source of two kinds of error: homonym errors and synonym errors. Homonym errors occur when identifiers are too similar in distinct patients. Synonym errors occur when there is a failure to link multiple notifications of the same patients. Even starting with perfect data, these two types of error may be introduced when records from different systems are linked. The error rate may be compounded, however, if there are errors in the data to begin with. The majority of these pre-existing errors are related to data entry problems in the original data sources [6]. METHODS Our general research agenda is to develop methods to estimate error rates, both false positive and false negative, for methods of record linkage. Our specific objective in this study was to determine the false negative error rate associated with a particular method of record linkage in an ongoing calculation of breast cancer screening indicators. The method for which the false negative error rate was to be estimated was called the 'reference method'. We based our estimate of error on samples of records from two systems: the IDX Registration and Scheduling System and Medical Archival System (MARS) used in the Department of Radiology. The IDX system collects data from routine registration of patients coming to the hospital for inpatient or outpatient visits. The MARS system collects information about patients for routine X-ray, MRI or mammo-There are many instances in an institution when there is a need to gather data from different departments. Record linkage is the technique used to bring together these …