Senior Lecturer on Biostatistics
Dr. Williams divides her research between development of statistical methods for AIDS clinical trials observational studies and environmental risk assessment.
In the area of HIV/AIDS studies, Dr. Williams’ research has addressed statistical issues in the design, analysis, and sequential monitoring of both clinical trials and observational cohort studies conducted by the National AIDS Clinical Trial Group (ACTG) and the International Maternal Pediatric Adolescent AIDS Clinical Trials (IMPAACT) Group for prevention and treatment of opportunistic infections in HIV-infected children, adolescents, and adults. Dr. Williams serves as the senior statistician on a number of clinical trials and as a co-chair for a long-term follow-up study in HIV-infected children conducted by IMPAACT. Dr. Williams also heads the Core for Biostatistical and Epidemiologic Analysis Methods (C-BEAM) for the Pediatric HIV/AIDS Cohort Study (PHACS) at HSPH. PHACS is a network dedicated to long-term follow-up of infants, children and adolescents born to HIV-infected mothers in the United States. Along with these collaborative activities, Dr. Williams has developed statistical methods for monitoring clinical trials with multiple survival endpoints, and has investigated the use of both CD4 and HIV viral load as predictors of the risk of opportunistic infections. Dr. Williams is also actively involved in development and application of methods for control of confounding in observational studies, such as marginal structural models and propensity score methods.
In the area of environmental risk assessment, Dr. Williams’ research has focused on the development of statistical methods applicable to the design, analysis, and interpretation of animal bioassay studies for both cancer and developmental toxicity, and on statistical methods for evaluating effects of environmental exposures on reproductive and developmental outcomes in children. In particular, some of the research of Dr. Williams has dealt with the assessment of multiple outcomes in developmental toxicity studies, while accounting for both clustering of outcomes among littermates and potentially missing data. Dr. Williams collaborates actively with colleagues in the Environmental Health Department on studies evaluating effects of dioxins and other endocrine disruptors on sexual development, and on studies of effects of environmental exposures on fertility and reproductive outcomes.
BSPH, 1983, University of North Carolina at Chapel Hill
MS, Biostatistics, 1984, University of North Carolina at Chapel Hill
PhD, Biostatistics, 1990, University of North Carolina at Chapel Hill