The CHR Biostatistics Core provides technical expertise, programming support, and consultation to research projects on study design, data management, and data analysis. This group of investigators and researchers also assists with grant and manuscript preparation and helps others at the Center understand and interpret the results of our data analyses.

The Biostatistics Core offers:
  • Seminars on methods and statistics
  • Online and in-person consulting
  • Best practices guidelines, templates, and other statistical resources
  • Data analysis and statistical design support

Members of the Biostatistics Core

Nancy Perrin, PhD, Senior Investigator

Dr. Perrin is an expert in the application of multivariate statistical techniques to health outcomes. She uses a variety of designs and statistical methods in her research. Dr. Perrin came to CHR from Oregon Health & Science University, where she retains an adjunct professor appointment. A former professor and associate dean at Portland State University, she received her bachelor’s degree from University of California, Los Angeles, and her master’s and doctoral degrees from The Ohio State University.

Michael Leo, PhD, Investigator

As a consulting biostatistician, Dr. Leo uses a variety of research designs including quasi-experimental (longitudinal and cross-sectional), community-based participatory, and clinical trials. He is experienced with a variety of statistical techniques, such as general and generalized linear models, structural equation modeling, hierarchical linear modeling, and psychometrics. He received his PhD from Portland State University in systems science in the areas of industrial and organizational psychology and quantitative methods.

Ning Smith, PhD, Investigator

Dr. Smith is a consulting biostatistician. Her research areas include obesity in children and young adults and herpes zoster vaccination in an elderly population. She also studies the use of electronic medical and administrative records in research. She uses statistical methods such as multiple comparisons, multivariate analyses, logistic regression, longitudinal data analysis, mixed effects and generalized linear models, survival analysis, and factor analysis. She received a PhD and MS in biostatistics from the University of Michigan and a BS in economics from Nankai University in Tianjin, China.

Gabriela Rosales, MS, Biostatistician

Ms. Rosales provides statistical consultation, assists in proposal development, conducts statistical analyses, and helps organize a Biostatistics Seminar Series. She has a master's degree in statistics and was a biostatistician at the Mayo Clinic before joining CHR. She has expertise in a variety of statistical analyses including survival analysis, propensity scores, generalized estimating equations, and power analyses.

Mary Ann McBurnie, PhD, Investigator

Dr. McBurnie has designed, implemented, coordinated, and performed analysis for numerous multi-center epidemiologic studies and clinical trials. She has served on several national and international studies that relate to heart and lung disease, and provides scientific and statistical leadership for projects involving asthma, COPD, quality of care, obesity, nutrition, and comparative effectiveness research in community health centers. Dr. McBurnie received her PhD from the University of Washington Department of Biostatistics.

William Vollmer, PhD, Senior Investigator

Dr. Vollmer conducts research in the areas of blood pressure and weight, dental caries, the epidemiology and management of asthma and pulmonary disease, and numerous others. He also leads a number of coordinating centers for which he steers the direction of multi-site trials and works collaboratively with other trial investigators to resolve complex protocol-related issues. Dr. Vollmer received his PhD in biostatistics from the University of Washington.