DESCRITION: The Study Design and Statistical Analysis Core provides services in three general areas: Study Design, Data Management, and Statistical Analysis. Within each of these areas a variety of essential services are offered. These include services traditionally offered by a core of this type, such as assistance with power and sample size determination, development of case report forms, design of data bases, training investigators in the use of hardware and software, and varying levels of assistance with statistical analyses. In addition, the Core offers services related to bioethics to ensure that human subjects concerns are appropriately addressed prior to submission to IRS review.