Dr. Landrum's primary research focus is on the development and application of statistical methodology for health services research. This research has several related themes including the development of medical guidelines, the profiling of health care providers, and methods for causal inference with observational data. Dr. Landrum has developed and applied methodology for profiling health care providers - in particular methods for assessing providers on more than one dimension of care. Dr. Landrum is also involved in a number of studies examining patterns and quality of care and their subsequent impac on patient outcomes. Some areas here include: differences in the use of procedures, medications, and preventive services between heart attack patients with HMO and fee-for-service insurance; quality of HIV care and changes in care subsequent to quality training; effect of managed care on the quality of care provided to patients with hypertension, diabetes and cancer; physician and patient characteristics related to the use of adjuvant tamoxifen therapy in elderly breast cancer patients; the impact of primary and specialty care on the diagnosis, treatment, and surveillance of elderly patients with breast cancer; and the development of quality indicators for advanced cancer care.