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Introduction

Ruth McBride and Stephen W. Singer

The papers in this special issue of Controlled Clinical Trials are the product of an effort that began almost 4 years ago. This effort emanated from a discussion about coverage of data management topics in the programs of the annual meetings of the Society for Clinical Trials, the paucity of publications about data manage- ment in clinical and epidemiologic research, and the absence of any “primer” for individuals entering the field. There has been little survey and reference material published on this topic. Books on clinical trials typically contain a short chapter that highlights selected issues related to data management. Groups of investigators occasionally have presented details about the data management techniques em- ployed by a particular study group. However, comparisons of alternative methods have been rare, and experimental data to support such comparisons have been even rarer. There is a dearth of survey literature to inform the novice of techniques that have been tried, limitations on methods that usually work well, and lessons that can be drawn from past mistakes.

In 1991, we met with the editors of Controlled Clinical Trials to discuss how we might stimulate more and better quality manuscripts about data management for publication in this journal. We concluded that the first requirement was a set of review papers to document current practices. Our intention was that such papers would establish consistent nomenclature, outline the functions encompassed by data management, and describe in broad terms the tools and organizations that had evolved to perform those functions. By providing a base for discussion and comparison, we hoped to stimulate other authors and to encourage research in this area.

More than 40 people, engaged in data management in a wide variety of settings, were invited to participate as authors or reviewers of a set of manuscripts. The volunteers include representatives from government, academia, and industry. Their professional training and background includes statistics, epidemiology, mathematics, and computer science. Their collective experience embraces many diseases and nearly every organ and system of the body.

Following our initial discussions with the editors of this journal, we proposed to the 1992 Program Committee of the Society for Clinical Trials that a review of the topics to be addressed in the manuscripts be presented in workshop sessions at the Society’s 1992 annual meeting in Philadelphia. The Program Committee accepted this proposal and the Society provided logistical and financial support for the telephone conferences required to develop the organization and format

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2s R. McBride and S.W. Singer

of the manuscripts and the workshop sessions. Because the organization of this monograph reflects the structure of the 1992 workshops, the division into topic areas is somewhat arbitrary. The first paper, by Blumenstein et al., sets the stage for the discussions that follow by describing approaches used to manage and coordinate multicenter studies and the structure of coordinating centers. The paper by McFadden et al. describes the process of designing a data management system for a multicenter study and some of the alternatives to be considered. The paper by Hosking et al. discusses issues regarding data collection, provides guidelines for design and layout of data forms, presents considerations for data coding, and adresses data entry software and methods. The paper by Gassman et al. focuses on quality assurance mechanisms and quality monitoring procedures. The paper by McBride and Singer discusses the types of interim reports required in many multicenter studies, particularly multiyear, multicenter clinical trials, and consid- erations for establishing study archives.

With financial support from the Johns Hopkins Center for Clinical Trials, the authors were able to meet in Minneapolis in March 1992 to review and critique the first drafts of the manuscripts and to discuss the workshop presentations. Following the presentations in May 1992, the writing efforts were resumed. A second working meeting of all authors was held in May 1993 to discuss the critiques of each paper received from the external reviewers (listed in Appendix C) and to agree on final nomenclature and revisions to the manuscripts.

Challenges to the writing teams have included achieving consensus regarding recommendations, representation of diverse points of view whenever there were several valid approaches to a particular aspect of data management and no consen- sus regarding the preferred option, and obtaining data to support recommenda- tions or alternative approaches. In preparing these manuscripts, the authors have attempted to adopt common terminology, as summarized in the Glossary (Appen- dix A). For each term, many candidates already in use were available and each had its proponents. Although we do not expect the authors of all future publica- tions about clinical trials and epidemiologic data management to adopt our termi- nology, we do encourage its use, or reference to the terms we have adopted when- ever alternative nomenclature is employed. The success of our efforts to achieve consensus or to present different points of view must be judged by the reader. In those instances in which we could find data on which to base recommendations, those data have been cited. Unfortunately, there were many more instances in which no data could be located.

We challenge our colleagues and sponsors of clinical trials and large epidemio- logic studies to take a more scientific approach to data management issues than has been taken in the past. For relatively little additional cost, randomized trials of alternative strategies could be evaluated during the conduct of a multicenter study. Candidates for evaluation in this way are many. Some that we have identi- fied are:

l Comparison of different formats for response fields on data collection forms with respect to accuracy and legibility of recording and speed and accuracy of transcription during data entry.

l Comparison of the cost and accuracy of single- vs. double-keying of data in a number of different settings.

l Comparison of cost and accuracy of key entry vs. optical scanning.

Introduction 3s

l Types of computerized checks of data that identify the greatest number of data recording and data entry errors.

l Timeliness of initial data entry and corrections in distributed data systems in comparison to central systems.

l Comparison of less frequent versus more frequent visits to field sites with respect to timeliness, completeness, and consistency of data.

l Comparison of more frequent vs. less frequent meetings of field site personnel with respect to data timeliness, completeness, and consistency.

Other candidates for evaluation may occur to the reader of these manuscripts. In closing, we note that nearly 20 years elapsed between the first of the meetings

that led to formation of the Society for Clinical Trials and the 1992 data manage- ment symposium which led to this special issue of Controlled Clinical Trials. That time interval represents at least five “generations” in computer technology. We believe that such a long delay in documenting the practices of a core research methodology is wasteful of human effort. We encourage the Society for Clinical Trials to schedule a data management symposium to review general progress in this area at least once every five years. We also encourage the editors and publisher of Controlled Clinical Trials to devote an issue of this journal to record the proceed- ings of each such symposium.

All of the authors very much appreciate the cooperation and support received from the Society for Clinical Trials and Controlled Clinical Trials, and from the Johns Hopkins Center for Clinical Trials which underwrote the cost of publishing this special issue.