Methodological issues in studying the epidemiology of mild to moderate chronic renal insufficiency  Chi-Yuan Hsu, M.D., M.Sc., Glenn M. Chertow, Gary C. Curhan  Kidney International  Volume 61, Issue 5, Pages 1567-1576 (May 2002) DOI: 10.1046/j.1523-1755.2002.00299.x Copyright © 2002 International Society of Nephrology Terms and Conditions

Figure 1 Effect of within-person measurement error on determining the percent of a population with serum creatinine (SCr) above a certain cutoff. Dashed line represents observed distribution, solid line represents true population distribution, and hatched area represents observed percent of population with elevated SCr (for example,>1.4 mg/dL); (shaded area) true population percent. Kidney International 2002 61, 1567-1576DOI: (10.1046/j.1523-1755.2002.00299.x) Copyright © 2002 International Society of Nephrology Terms and Conditions

Figure 2 Creatinine distribution in the United States by gender, according to the NHANES III Study, 1988 to 1994. Percent distribution is plotted separately for (▪) males and (□) females aged 12 years or older. Sample values were weighted to estimate the distribution of creatinine values in the U.S. population by age, ethnicity, and sex. Reproduced with permission from the National Kidney Foundation2. Kidney International 2002 61, 1567-1576DOI: (10.1046/j.1523-1755.2002.00299.x) Copyright © 2002 International Society of Nephrology Terms and Conditions