Thecis the Clinical Information System

Abstract

Recent improvements in the SAS® software package have made it possible for us to develop a total SAS system for processing data from clinical trials. System features include: a program code builder, computer assisted data editing, an interactive full screen editor, automatic tape backups, and a dated database which easily can be restored to any previous date. The system uses SAS databases for both storing data and controlling the system. The control database contains the necessary information for creating the other databases—data set names, variable names, location on the case report form (CRF), and formats for both input and output. This database requires updating each time a new case report form is designed. Clinical trial data are stored at two levels. The first protocol database is organized similar to the CRFs in order to facilitate data editing and coding. The drug level database combines data over protocols and is structured to allow efficient generation of display tables and statistical analyses. This database is used for pooled safety and efficacy analyses as well as responding to questions, both from company personnel and regulatory agencies. It is also useful for data exploration in order to form objectives for future studies. Data are entered offline and loaded into a card image file before they are added to the protocol database. Data editing is assisted by computer checks on variable ranges as well as checks on the internal consistency of the data. Changes to the data are made to the protocol database using an interactive full screen editor. These changes prompt the system to update the drug database. The system automatically tracks changes to the data. This feature allows either database to be regenerated to a past date. During the initial data editing this dating feature makes it possible to quickly recover from incorrect edits. This feature also eliminates the need to archive entire data libraries. Additional data security is provided by a disk management system that automatically backs up to tape all modified databases.