Guidelines were developed for data collection from medical records for use in retrospective analyses

With guidelines for data collection, the quality of research data is enhanced. A well-designed case record form and a handbook for standardized data collection are essential for training the data collectors and for ensuring fastidious searching of the record; however, certain kinds of information are not always well documented in patient records. Consequently, it is essential to perform a pilot study to assess the study design and to use additional questionnaires. Correct interpretation of clinical outcomes documented in the medical records often necessitates an independent adjudication committee to prevent bias in outcome definition.