The overarching goals of the Biostatistics Core (BC), RC-2, are to provide design and analytical services to investigators conducting studies of multifactorial geriatric conditions; to develop and disseminate new design and analytical techniques for conducting studies with older persons; and to train a cadre of clinical investigators, biostatisticians, and epidemiologists in the skills necessary to design, conduct, and analyze gerontologic studies. The BC provides state-of-the-art research design and biostatistical expertise for the Yale OAIC with the following specific aims: 1) to collaborate with REC Scholars and other REC trainees, PES investigators, Operations Core (OC) colleagues, and investigators of External Projects to achieve the mission of the Yale OAIC in promoting the understanding and management of multifactorial geriatric conditions; 2) to develop new and rigorous methods that address the challenges of designing and analyzing studies in basic, translational, and clinical geriatric/aging research, with special emphasis on introducing rigorous statistical methods; and 3) to train the next generation of gerontologic biostatisticians, epidemiologists, and early-stage investigators in Gerontologic Biostatistical Methods specific to studies of multifactorial geriatric conditions. To achieve these aims and ensure that OAIC investigators continue to stay at the forefront of methodologically rigorous research, we have formalized a partnership with the Yale Center for Analytical Sciences (YCAS), a center for collaborative science that serves as the Biostatistics and Epidemiologic core of the Yale Clinical and Translational Sciences Award (CTSA). This partnership boosts the reach of the BC in two important ways. First, it expands the resources available to our REC trainees and other OAIC investigators by providing access to additional expertise and mentorship. Second, it brings a wealth of experience in newer approaches that complement the techniques previously available to OAIC investigators. Productivity of the BC during the current funding cycle has been high, as evidenced by nearly 200 peer-reviewed publications and collaboration on 73 successfully funded extramural grants (>$123.4 million total costs) and on 13 pending grant applications representing more than $13 million. The proposed Biostatistics Core’s Development Project (DP-2) focuses on designing pragmatic clinical trials with multivariate outcomes. The project is innovative because such trials, which are becoming increasingly common, often do not take the correlation between outcomes into account in the design and/or analysis, leading to less efficient designs and to estimates that fail to demonstrate the efficacy of treatments. This is especially important for trials that include multiple primary outcomes assessing various aspects of a multifactorial condition or intervention. The code from this and all novel methods developed by the BC will be made publicly available, including ...