The Hemodialysis Fistula Maturation Consortium (HFMC) will conduct a prospective multi-center observational cohort study investigating factors associated with the failure of arteriovenous fistulas (AVFs) to mature. The Data Coordinating Center (DCC) will coordinate, administer, and support all HFMC research activities including all scientific and operational aspects of the Consortium. The DCC will: 1) assist in protocol development and analytical approaches for the protocol, and provide statistical leadership for study design; 2) develop data forms, instructions, and manuals of operations; 3) develop a data management and data collection system including an electronic communication system; 4) develop and maintain two web sites, one public and one for the research team; 5) establish, maintain and provide appropriate oversight to subcontracts for any central core laboratories as required; 6) work with the NIDDK Biosamples Repository and the clinical sites to coordinate procedures for coding, shipping, processing, receipt and storage of study samples to be maintained by the Repository; prepare the study data and coordinate with the NIDDK Data Repository for archiving; 7) develop procedures for quality control and training; 8) monitor the quality and quantity of data received from the clinical centers; 9) schedule, organize and perform site visits to clinical sites; 10) prepare periodic reports and analyses on recruitment, quality control, study adherence, patient safety and study results to the Steering Committee, the NIDDK and the Data, Safety and Monitoring Board; 11) support and coordinate manuscript publications and professional meeting presentations through data analysis, statistical collaboration and editorial support; 12) develop new statistical methodology as needed to properly analyze the data being collected; 13) schedule and arrange for all meetings and conference calls of established committees and boards; 14) provide regulatory guidance; and,15) provide overall scientific leadership. The goal of the HFMC is to identify pre-peri- and post-operative factors for AVF maturation and usability. Identification of risk factors for maturation failure and establishment of a surrogate for usability would facilitate the design of interventional trials targeting modifiable factors and help guide the clinical practice of whether and when to place AVF, and monitoring and implementing corrective actions for the AVF, thus improving hemodialysis patient lives.