Temporal trends in the burden of chronic kidney disease in the United States.
OBJECTIVE
The public health importance of chronic kidney disease (CKD) has only recently come to be appreciated and careful examination of temporal trends is warranted. The purpose of the present review was to examine existing research on temporal trends for CKD and treated end-stage renal disease (ESRD) in the United States.


RESULTS
When the broadly representative National Health and Nutrition Examination Survey (NHANES) datasets were compared in 1988-1994 and 1999-2002, a pronounced increase in the prevalence of abnormally low glomerular filtration rate was observed when serum creatinine was used to estimate glomerular filtration rate. In contrast, glomerular filtration rate findings were almost identical when cystatin C levels were examined. Thus, although the community-wide burden of CKD is already high, uncertainty exists as to the growth rate of this problem. For treated ESRD a dramatic increase in incidence rate occurred in the 1980s and 1990s. Changing burdens of standard risk factors for CKD do not readily explain increased rates of treated ESRD, suggesting that selection criteria for dialysis and transplant programs may underlie these secular trends. If the hypothesis that nonbiological factors are major determinants of rates of treated ESRD is valid, the latter may be a poor surrogate for true ESRD and for understanding its causes and rates of progression.


CONCLUSIONS
Given its prevalence and prognostic implications, it makes intuitive sense to monitor the burden of CKD over time; the validity of the tools used to generate an answer, however, is at least as important as the direction of the answer.
Foley
Robert N
RN
Minnesota School of Medicine, University of Minnesota-Twin Cities, Minneapolis, Minnesota 55404, USA. rfoley@usrds.org
D017281:Cost of Illness; D005919:Glomerular Filtration Rate; D006801:Humans; D007676:Kidney Failure, Chronic / Q000453:epidemiology; D015995:Prevalence; D051436:Renal Insufficiency, Chronic / Q000453:epidemiology*; D014481:United States / Q000453:epidemiology