Ix JH, Biggs ML, Mukamal K, Djoussé L, Siscovick D, Tracy R, Katz R, Delaney JA, Chaves P, Rifkin DE, et al. Urine Collagen Fragments and CKD Progression-The Cardiovascular Health Study. J Am Soc Nephrol. 2015  ;26(10):2494-503.