On being better kidney doctors: understanding trajectories, probabilities, predictability, and people.

I n the last decade, chronic kidney disease (CKD) has become recognized as a more common condition than previously appreciated in the medical field: as a multiplier of risk and as an important prognostic factor for a number of health outcomes, such as cardio-vascular disease, hospitalization, dialysis, and death. 1,2 Universally, it now is recognized as a public health problem, requiring attention from policy makers, administrators , primary care physicians, and specialists. The 2002 publication of the KDOQI (Kidney Disease Outcomes Quality Initiative) guidelines for the definition , classification, and evaluation of CKD was a catalyst for this increase in awareness, 3 giving some sensible structure and nomenclature to the condition. Since 2002, the number of publications and research studies describing improved understanding of the biology of the condition and the outcomes of people with CKD has increased exponentially. In this issue of the American Journal of Kidney Diseases, 3 important articles are presented that help inform both research and clinical care in this area. These reports focus on movement among CKD states: speed of the travel, shape of the path, and implications of uncertainty (lack of our understanding) of this journey. The main theme is the uncertainty and diversity evident in pathways to clinical outcomes of those with CKD, particularly with respect to progression of kidney disease. The authors all emphasize the need to better characterize and understand that heterogeneity. By so doing, we will not only be able to care better for patients, but will also be better able to design and execute clinical trials and generate evidence on which to base that clinical care. The report by O'Hare et al 4 describes the trajectories of more than 5,000 persons within the Veterans Affairs system who started dialysis therapy between 2001 and 2003 and had at least 2 years of data prior to that start. Using the integrated laboratory and administrative database available through the Veterans Affairs system, they were able to capture patient characteristics and care practices to explore not only the trajectories, but also potential influences on those trajectories. While recognizing that this study examines only those who ultimately ended up on dialysis therapy (ie, the results are limited by survivor bias), there are important lessons here. First, although most people who initiated dialysis therapy within the 2-year follow-up were those with an estimated glomerular filtration rate (eGFR) Ͻ30 mL/min/ 1.73 m 2 (63%) and had …