In 1999-2014, <7% of those with eGFR ≥60 ml/min/1.73 m² with albuminuria (single random measurement) were aware of having CKD. Reported awareness was estimated to be higher for those with stage 3B (eGFR 30-45) at 28% compared to those with CKD stage 3A (eGFR 45-59) at 10%. For stage 4 (eGFR 15-29), about half reported being aware of their disease.
Those with evidence of albuminuria, particularly an albumin:creatinine ratio ≥300 mg/g (macroalbuminuria), were generally more likely to be aware of their CKD condition (19% in 1999-2004 to 21% in 2011-2014).
Chart Explanation: For all study years combined (1999-2014), overall awareness of CKD was 6.4%. As expected, awareness increased with severity or stage of CKD. However, just over half of participants (52.5%) with stage 4 (- the most severe stage prior to end-stage renal disease - reported being told by their physician that they had weak or failing kidneys. Fewer than 30% of stage 3 participants were aware of their disease, although the proportion was substantially higher for those with eGFR 30-44 than those with eGFR 45-59 ml/min/1.73 m² (27.7% vs. 9.8%). Among those with eGFR <90 and >30 ml/min/1.73 m², macroalbuminuria versus microalbuminuria was associated with greater awareness. For example, among those with eGFR 30-44 ml/min/1.73 m², awareness was 21.5% among those with microalbuminuria, while 44.8% of those with macroalbuminuria reported being aware, respectively.
In observance of albuminuria over time, microalbuminuria remained low with 5.2% reporting awarenss in 1999-2004 to 6.5% in 2011-2014. As noted, awareness was more likely in those with micro albuminuria (19.2% in 1999-2004 to 20.7% in 2011-2014). The trends for reported awareness of CKD were not significant for either stages of microalbuminuria.
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, 2009-2010, 2011-2012, and 2013-2014 NHANES. Awareness of CKD was defined as a “yes” response to the question “Have you ever been told by a health care provider you have weak or failing kidneys (excluding kidney stones, bladder infections, or incontinence)?” during the interview. CKD was diagnosed by laboratory testing and defined as an eGFR of ≥60 ml/min/1.73 m² and the presence of albuminuria (first single measurement of albumin: creatinine ratio from random spot urine) or by eGFR alone for CKD stage 3 or 4 (stage 5 was excluded).
| Field | Data |
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| Description of Measure | Awareness of CKD among those with kidney disease diagnosed by laboratory testing |
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| Data Source | NCHS |
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| Type of Data Source | Public |
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| Data Set | NHANES |
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| Health Care System Data | No |
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| Regional or National? | National |
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| Demographic Group | Non-institutionalized U.S. residents aged 20+ years |
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| Numerator | Participants with CKD who have been told they have weak or failing kidneys |
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| Denominator | Participants with CKD |
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| Definition of CKD | Stage 1, eGFR > 90 ml/min/1.73 m² and presence of single albuminuria; Stage 2, eGFR 60-89 ml/min/1.73 m² and presence of single albuminuria; Stage 3, eGFR 30-59 ml/min/1.73 m²; Stage 4, 15-29 ml/min/1.73 m²; Stage 5, excluded |
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| Glomerular filtration rate | Estimated using CKD-EPI equation for calibrated creatinine: eGFR=141 x [min(calibrated serum creatinine in mg/dL) /κ, 1)]α x [max(calibrated serum creatinine in mg/dL/κ, 1)]κ x 0.993age x (1.018 if female) x (1.159 if NH Black)
κ = 0.7 if female, and 0.9 if male
α = -0.329 if female, and -0.411 if male |
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| Proteinuria | Urinary albumin-to-creatinine ratios of 30-299 mg/g (microalbuminuria) and >300 mg/g (macroalbuminuria); pregnant/menstruating women excluded |
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| Primary Data Source Indicator | kiq022/kiq010: “Have you ever been told by a doctor or health professional that you have weak or failing kidneys (excluding kidney stones, bladder infections, or incontinence)?” yes/no |
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| Primary Indicator Method of Measurement | Questionnaire (interviewer-administered) |
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| Secondary (1) Variable | lbxscr: Serum creatinine |
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| Secondary (1) Indicator Method of Measurement | Examination/Laboratory |
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| Secondary (2) Variable | ridageyr: Age in years |
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| Secondary (2) Indicator Method of Measurement | Questionnaire (interviewer-administered) |
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| Secondary (3) Variable | ridgendr: Gender |
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| Secondary (3) Indicator Method of Measurement | Questionnaire (interviewer-administered) |
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| Secondary (3) from Medical Record? | No |
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| Secondary (4) Data Source Indicator | ridreth1: Race/ethnicity |
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| Secondary (4) Indicator Method of Measurement | Questionnaire (interviewer-administered) |
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| Secondary (5) Data Source Indicator | urxuma: Urine albumin |
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| Secondary (5) Indicator Method of Measurement | Examination/lab |
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| Secondary (5) Data Source Indicator | urxucr: Urine creatinine |
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| Secondary (5) Indicator Method of Measurement | Examination/lab |
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| Frequency of Measurement (Primary) | Once (cross-sectional) |
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| U.S. Region Covered by Primary Variable | All |
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| Period Currently Available | 1999–2014 |
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| Pending Data | 2015-2016 |
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| Additional Data Items of Interest | Stage of CKD, year, other stratification variables of interest (diabetes by self-report, hypertension by self-report) |
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| Limitations of Indicator | Proteinuria can only be assessed from a one-time cross-sectional measurement in 1999-2008; two measurements only in 2009-2010, including first random and second first-morning void ~2 weeks after MEC exam; participants who have been told they have proteinuria may not answer yes |
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| Analytic Considerations | Appropriate NHANES survey weights must be used for all analyses; creatinine measurements must be calibrated for NHANES years 1999-2000 and 2005-2006; if 2007-2008 data are combined with 1999-2006 data, the earlier data on urinary creatinine must be corrected; many variable names differ across surveys; if SE 30% or more of estimate, must suppress estimates and report as “low precision”; second urine albumin and creatinine measurements only available in 2009-2010 and not for 2011+ |
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