Dr. Walter’s research focuses on improving cancer screening decisions in older adults. Using novel methods in observational study design and decision-modeling, her research has provided the empiric basis for new approaches to cancer screening. Rather than using a one-size-fits-all approach that assumes screening is appropriate for everyone above or below a certain age, her research takes a patient-centered approach that determines the effect of life expectancy and patient preferences on appropriateness of screening. Her body of work began with her landmark 2001 JAMA publication which developed a novel method of juxtaposing the lag-time-to-benefit of preventive services and life expectancy to help clinicians make better screening decisions. This approach is now reflected in most national cancer screening guidelines (American Cancer Society, National Comprehensive Cancer Network, and U.S. Preventive Services Task Force) and has also been applied to the management of diabetes in elders. In addition, Dr. Walter has conducted a series of seminal studies demonstrating decisions to screen older patients for cancer are often dictated more by age than health such that many patients in poor health continue to undergo screening while many healthy older patients fail to get screened. Also, she discovered that cancer screening frequently leads to significant harms without benefit in elders in poor health and developed a taxonomy and quantification of screening harms. Her research has demonstrated the fundamental importance of life expectancy rather than age alone in determining potential benefits and harms of screening.