RC1 – Biostatistics Core: Project Summary Since mid-2003, this OAIC Biostatistics Core (RC1) has dedicated critically needed resources toward the quantitative challenges of research on frailty. Partnering in OAIC leadership, and working closely with other OAIC resource cores, it has helped develop the careers of an interdisciplinary cohort of junior faculty supported by the Research Education Component (REC)—and beyond—and ensured expert design and analysis of pilot, external, and de novo studies needed to advance science on frailty. It now proposes to continue in these efforts, by providing: (1) mentorship for junior faculty supported by our REC, and our broader OAIC, in developing careers focused on frailty and aging; (2) new data and computing infrastructure and software, including web-based data housing and acquisition tools; (3) expertise for science on frailty, through support for the design, statistical analysis, and data management of research projects, and through making available new data analytic methodologies that are essential to studying the complex syndrome of frailty; and (4) leadership and visibility for frailty-related scientific and health promotion endeavors at Johns Hopkins, throughout the OAIC network, and in the broader gerontological community. Our support and leadership in these areas have been significant and wide-reaching, and could not be provided without the resources of this Core. The leadership is experienced, expert, deeply immersed in scholarship on aging, and visible in both gerontology and statistics. The Core will continue to support every REC and pilot-supported investigator as per their need. The Core synergizes actively with other OAIC resource cores, as evidenced by progress over the last cycle. Our team includes a statistical genomics expert to enhance our collaborations with the Biological Mechanisms Core (RC2). We also have engaged an internal consultant with expertise in signal intensive measurement to enhance our interactions with our new Technological Assessment and Solutions Core (RC4). We will continue to provide design and analytic expertise and support a Registry collaboratively with the Clinical Translation Core (RC3). Regarding new methodologies: research will develop approaches needed to better (i) assess prefrailty, hence identify at-risk persons early enough to intervene successfully; (ii) delineate heterogeneous etiology underlying frailty; (iii) design studies to assess frailty intervention; (iv) characterize attributable fraction of frailty risk factors over the lifecourse, and (v) address frailty disparities. By efforts along all these lines, this Core will contribute crucially to the success of this OAIC in answering a next generation of questions on frailty, and achieving findings' translation toward increased independence of older persons.