Data analyses will be carried out in the LTRC for two main purposes. One is to monitor CC performance and the second is to perform appropriate analyses of all study data with particular emphasis on evaluation of comparisons among participant groups. It is anticipated that recruitment and status reports will be generated on a monthly schedule and monitoring reports providing more detailed information about data quality and performance of the CCs and CLs will be generated on quarterly performance reports that will be presented to the SC, the NHLBI and the OSMB. Analyses of study specific objectives will be performed on an "as needed basis." This will include support, as directed by the NHLBI and the OSMB, for discrete and collaborative studies between the LTRC and other investigators.