Biometry Research

The Biometry Unit of the Pathology Department, currently consisting of C. Alex McMahan, Ph.D., Professor, and Thomas J. Prihoda, Ph.D., Associate Professor, is involved in research, teaching, and service. Together they have over 50 years experience in application of biometrical techniques to many different types of projects.


Dr. McMahan and Dr. Prihoda participate in diverse research projects where they provide statistical expertise in experimental design, data management, data monitoring, preparation of data for bio-statistical analyses, performance of analyses, interpretation of results, and writing research reports, manuscripts, and proposals. They have extensive experience in NIH, foundation, state, and local grant writing, proposal planning, experimental design, power and sample size justification, and analysis of results. Methods and theory successfully employed in these bio-statistical activities include:

  • parametric and nonparametric analyses
  • multiple regression including parametric, logistic and survival analyses
  • factor analyses including descriptive and confirmatory
  • simple and multi-factorial analyses of variance with and without repeated measures
  • covariance structures are fit and assumptions are tested

The design and statistical analysis of epidemiological and experimental studies includes analysis of finite range random variables, particularly variables having a discrete probability mass at zero. Specific areas of research interest involving application of statistical methodology in the etiology and pathogenesis of atherosclerosis and aging. For instance, our faculty serve as the statistical coordinating center for a national multicenter cooperative study of atherosclerosis in individuals 15-34 years of age dying due to external causes. This project addresses the relationship of risk factors for adult coronary artery disease and genetics to early atherosclerosis, i.e., during the period of transition of the arterial fatty streak to the fibrous plaque. Separate studies are underway to examine nutritional influences on longevity.


The Biometry Unit also teaches introductory, graduate level biostatistics for students in the graduate programs leading to MS and PhD degrees in the basic sciences as well as to graduate students in the Advanced Dental Education program. Independent study in areas of biostatistics is also available for graduate students. Students are encouraged to engage in consultation in support of their individual research project.


The Biometry Unit provides consultation to members of UT Health’s research community as well as to researchers from outside the institution. Areas of consultation include study design, statistical analyses, interpretation of analyses, power and sample size justification, data management, data monitoring, and writing of grant applications. Consultation also is provided regarding statistical issues encountered by reviewers of research papers and funding proposals.

Pathology Faculty