CKD Awareness Towards Tracking HP2020 Goals
Prevalence of Awareness among People with CKD 1999–2004 vs. 2005–2010 vs. 2020 Target
The National Health and Nutrition Examination Survey (NHANES) is a nationally representative, cross-sectional survey that is currently conducted every 2 years by the Centers for Disease Control and Prevention's National Center for Health Statistics to examine disease prevalence and trends over time in noninstitutionalized U.S. civilian residents.

The survey consists of a standardized in-home interview and a physical examination and blood and urine collection at a mobile examination center (MEC). Here, we examined data from the 1999-2000, 2001-2002, 2003-2004, 2005-2006, 2007-2008, and 2009-2010 NHANES. eGFR was calculated according to the modified MDRD study formula for calibrated creatinine (Levey et al., 2005; Levey et al., 2006). Serum creatinine was calibrated for 1999-2000 and 2005-2006 participants; no correction was required for calibrated serum creatinine in participants in the 2001-2002, 2003-2004, 2007-2008, and 2009-2010 surveys (Selvin et al., 2007). Albuminuria was defined by urinary albumin-to-creatinine ratios of 30-299 mg/g (microalbuminuria) and >300 mg/g (macroalbuminuria); pregnant women were excluded. For comparisons across the 12-year period 1999-2012, albuminuria was corrected in 1999-2006 to account for differences in the instrumentation and method for urine creatinine starting in 2007. Prevalence of CKD is likely overestimated due to single measurements of albuminuria and kidney function, since chronic disease is defined as having albuminuria or reduced kidney function for ≥3 months. The question used to obtain the national baseline data (1999-2004) was from the National Health And Nutrition Examination Survey Codebook for Data Collection, Kidney Conditions of survey participant and MEC CAPI Questionnaire (KIQ) and asked "{Have you/Has survey participant} ever been told by a doctor or other health professional that {you/s/he} had weak or failing kidneys? Do not include kidney stones, bladder infections, or incontinence."

Description of MeasurePrevalence of CKD stage 1-4
Prevalence of CKD stage 1-4NCHS
Type of Data SourcePublic
Health Care Delivery System DataNo
Regional or National?National
Demographic GroupNon-institutionalized U.S. residents aged 20+ years
NumeratorNumber of adults 45 years or older among those with chronic kidney disease (CKD) stages 1-4, who answer "Yes" to the awareness question
DenominatorNumber with CKD stages 1-4 who answer the awareness question
Definition of CKDStage 1, eGFR ≥ 90 ml/min/1.73 m² and estimated persistent albuminuria; Stage 2, eGFR 60-89 ml/min/1.73 m² and estimated persistent albuminuria; Stage 3, eGFR 30-59 ml/min/1.73 m²; Stage 4, 15-29 ml/min/1.73 m²; Stage 5, excluded
Glomerular filtration rateEstimated using MDRD study formula for calibrated creatinine: eGFR=175 × [(calibrated serum creatinine in mg/dl)-1.154] × age-0.203 × (0.742 if female) × (1.210 if African-American) Schwartz formula for 12- to 17-year-olds: eGFR=k × (height in cm) × (serum creatinine in mg/dl), where k=0.55 for 1-13-year-olds and females 13-17; and k=0.65 for males 13-17
ProteinuriaUrinary albumin-to-creatinine ratios of 30-299 mg/g (microalbuminuria) and >300 mg/g (macroalbuminuria); pregnant/menstruating women excluded
Primary Data Source Indicatorlbxscr: Serum creatinine
Primary Indicator Method of MeasurementExamination/Laboratory
Secondary (1) Variableridageyr: Age in years
Secondary (1) Indicator Method of MeasurementQuestionnaire (interviewer-administered)
Secondary (2) Variableridgendr: Gender
Secondary (2) Indicator Method of MeasurementQuestionnaire (interviewer-administered)
Second (3) VariableNo
Secondary (3) Indicator Method of Measurementridreth1: Race/ethnicity
Secondary (3) from Medical Record?Questionnaire (interviewer-administered)
Secondary (4) Data Source Indicatorurxuma: Urine albumin
Secondary (4) Indicator Method of MeasurementExamination/lab
Secondary (5) Data Source Indicatorurxucr: Urine creatinine
Secondary (5) Indicator Method of MeasurementExamination/lab
Frequency of Measurement (Primary)Once (cross-sectional)
U.S. Region Covered by Primary VariableAll
Period Currently Available1999–2020
Pending Data2011-2016
Additional Data Items of InterestStage of CKD, year, other stratification variables of interest (diabetes by self-report, hypertension by self-report)
Limitations of IndicatorAlbuminuria and kidney function can only be assessed from a one-time cross-sectional measurement, leading to overestimation of prevalence; second measures of albuminuria are available for only 2009-2010 and were first-morning rather than spot urine samples; no second measures of creatinine
Analytic ConsiderationsAppropriate NHANES survey weights must be used for all analyses; creatinine measurements must be calibrated for NHANES III, 1999-2000 and 2005-2006; many variable names differ across surveys; if SE 30% or more of estimate, must report as “low precision”