Perspectives On Animal Research

Volume 1, Supplement

An Evaluation of Ten Randomly-Chosen Animal Models of Human Disease

Introduction

Funding agencies generally favor animal research on the assumption that animal studies benefit human health. However, the relationship between animal research and human health benefit is untested and unproven. Because Americans continue to invest billions of dollars developing animal models of human disease at a time when there is concurrent emphasis on cost-cutting and reduced spending for health care, the animal model must be assessed scientifically on a cost-benefit basis. Animal research has become an issue with important public health implications.

It is difficult to assess the value of the animal model because there is no single approach that provides all the relevant information. Past reviews have relied heavily on anecdotal and subjective data. While it is impossible to avoid subjectivity completely, there is a need for more objective criteria.

The fact that researchers might have discarded some animal models because they failed to resemble human disease should not indict all uses of animal models. Similarly, some researchers' continued use of inappropriate animal models does not prove that most animal models are ill-conceived. In an attempt to determine the value of animal models in general, this study evaluates in detail a representative group of animal models.

It was, of course, impossible to review all animal models; instead, the authors used a computer random number generator to select ten models from the Handbook Animal Models of Human Disease. (See Appendix B.) This annual publication of the Armed Forces Institute of Pathology highlights established animal models. The editors wrote, "It is not the objective of this series to be a section for rapid communication or the site of initial publication of new animal models, but rather to present a concise summary of animal models of human disease published in greater detail in peer-reviewed categorical journals."(1)

We evaluated the animal models on three parameters:

First, we compared the clinical manifestations and the pathophysiology of an animal disease with the analogous human disease.

We then searched the Science Citation Index for all English language citations in the medical and scientific literature of the key article(s) describing each animal model.(2) Following this, we focused on citations made by clinical investigators, and we took note of their assessment of the animal model's value.(3)

Finally, we evaluated the historical impact of the animal model in the management of the analogous human disease. We reviewed recent articles in the clinical literature to determine whether or not the animal model has provided any significant clinical insights or if it has made an impact on clinical practice.

1. Anon.: Guidelines for contributors of animal models. Am J Pathol 1983:111:i.

2. In the search for articles, all ten projects used at least two of the following three libraries: Columbia-Presbyterian Medical Center, New York University Medical Center, and New York Academy of Medicine.

3. Those papers that used human subjects and/or human tissues were defined as "clinical" research reports.