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Original Investigation |

Patient Awareness of Chronic Kidney Disease:  Trends and Predictors FREE

Laura C. Plantinga, ScM; L. Ebony Boulware, MD; Josef Coresh, MD, PhD; Lesley A. Stevens, MD; Edgar R. Miller III, MD; Rajiv Saran, MD; Kassandra L. Messer, BA; Andrew S. Levey, MD; Neil R. Powe, MD
[+] Author Affiliations

Author Affiliations: Departments of Epidemiology (Ms Plantinga and Drs Boulware, Coresh, and Powe), Biostatistics (Dr Coresh), and Health Policy and Management (Dr Powe), Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland; Department of Medicine, Johns Hopkins School of Medicine, Baltimore (Drs Boulware, Coresh, Miller, and Powe); Department of Medicine, Tufts–New England Medical Center, Boston, Massachusetts (Drs Stevens and Levey); and Departments of Medicine (Dr Saran) and Biostatistics, School of Public Health (Ms Messer), University of Michigan, Ann Arbor.


Arch Intern Med. 2008;168(20):2268-2275. doi:10.1001/archinte.168.20.2268.
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Published online

Background  The impact of recent guidelines for early detection and prevention of chronic kidney disease (CKD) on patient awareness of disease and factors that might be associated with awareness have not been well described.

Methods  Awareness rates were assessed in 2992 adults (age, ≥20 years) with CKD stages 1 to 4 from a nationally representative, cross-sectional survey (National Health and Nutrition Examination Survey 1999-2004). Awareness of CKD was defined by an answer of yes to “Have you ever been told you have weak or failing kidneys?” Potential predictors of awareness included demographics, access to care, and clinical and lifestyle factors, which were assessed by standardized interviewer-administered questionnaires and physical examinations. We examined independent associations of patient characteristics with awareness in those with CKD stage 3 (n = 1314) over 6 years using multivariable logistic regression.

Results  Awareness improved over time in those with CKD stage 3 only (4.7% [95% confidence interval {CI}, 2.6%-8.5%], 8.9% [95% CI, 7.1%-11.2%], and 9.2% [95% CI, 6.1%-13.8%] for 1999-2000, 2001-2002, and 2003-2004, respectively; P = .04, adjusted for age, sex, and race). Having proteinuria (odds ratio, 3.04 [95% CI, 1.62-5.70]), diabetes (OR, 2.19 [95% CI, 1.03-4.64]), and hypertension (OR, 2.92 [95% CI, 1.57-5.42]) and being male (OR, 2.06 [95% CI, 1.15-3.69]) were all statistically significantly associated with greater awareness among persons with CKD stage 3 after adjustment. Chronic kidney disease awareness increased almost 2-fold for those with CKD stage 3 over recent years but remains low. Persons with risk factors for CKD (proteinuria, diabetes, hypertension, and male sex) were more likely to be aware of their stage 3 disease.

Conclusion  Renewed and innovative efforts should be made to increase CKD awareness among patients and health care providers.

Figures in this Article

Chronic kidney disease (CKD) is a growing problem in the United States, with an estimated prevalence of 9% to 12% in 1999 to 2000.1,2 However, the majority of persons with CKD, especially those in early stages, may be unaware of their disease. Although there have been recent efforts to increase awareness among health care providers by the dissemination of guidelines for the definition and staging of severity of CKD3 and, more recently, among the public,4 there is a lack of evidence about whether awareness of CKD has increased over time.

Better management of CKD can slow the progression of CKD, prevent complications, and reduce cardiovascular-related outcomes.3,5,6 Early referral to a nephrologist has been shown to improve outcomes for those who progress to end-stage renal disease.7 Even if quality improvement initiatives are accepted and implemented by the medical community, patients must still seek timely treatment to be exposed to these initiatives. However, because CKD in its early stages is usually silent and without remarkable symptoms, patients may not be aware of their disease. Even persons who have been identified as having early-stage CKD by evidence of kidney damage or reduced kidney function through regular screening may not understand their diagnosis or recognize the importance of treatment.

Some patient characteristics may make screening more likely. For example, patients who are at high risk because of diabetes or hypertension may be screened more frequently. The likelihood of being aware could differ by age, sex, or race; for example, there is a greater prevalence of CKD among elderly patients,1,2 but older patients may also be less likely to be screened or CKD may not be recognized in older patients because of competing health issues. Whether the patient is insured or has a regular health care provider could also affect CKD awareness. Finally, a healthy lifestyle (as indicated by such factors as no smoking, low alcohol intake, and high physical activity) may make a person less likely to have CKD but also more attentive to the presence of disease and the practice of preventive behaviors, which modify risk.

Previous studies have reported on static CKD awareness estimates in the US population in 1999-2000.1,8 To our knowledge, none have examined the trends in CKD awareness over time, with more recent data, nor have the associations of awareness with characteristics of persons with CKD been extensively explored. We sought to examine the prevalence of disease awareness among adults with CKD and the factors that may be associated with CKD awareness in a long-running, national survey of US citizens, the National Health and Nutrition Examination Survey (NHANES).

STUDY DESIGN

The NHANES is currently conducted every 2 years by the National Center for Health Statistics to examine disease prevalence and trends over time in different cross-sectional representative samples of noninstitutionalized US 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). Participants gave informed consent. The protocol was approved by an institutional review board.

We examined data from the 1999-2000, 2001-2002, and 2003-20049 NHANES. Our study was limited to NHANES participants from 1999 to 2004, who underwent the MEC examination; were at least 20 years old; had information on awareness, age, sex, race, creatinine level (to calculate estimated glomerular filtration rate [eGFR]), and proteinuria (if eGFR >60 mL/min/m2); had an eGFR of at least 15 mL/min/1.73 m2; and had CKD stages 1 to 4 (n = 930, n = 1046, and n = 1016 for the 3 surveys, respectively) (Figure 1).

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Figure 1.

National Health and Nutrition Examination Survey (NHANES) participants (1999-2004), who met inclusion criteria for this study. *Stages 1 and 2 defined by single measurement of albuminuria only; persistent albuminuria data not available. CKD indicates chronic kidney disease; eGFR, estimated glomerular filtration rate; MEC, mobile examination center.

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MEASUREMENTS

Self-reported demographic characteristics (age, sex, race, and educational level), access to care (insurance, routine health care site, and time since last physician visit), lifestyle factors (smoking, physical activity, and alcohol use), and diagnoses (CKD, diabetes, and hypertension) were obtained during the interview portions of the surveys. Blood pressure was measured during the MEC visit, and the mean of all available measurements (up to 4) was used. Height and weight, used in the calculation of body mass index (BMI), were also measured during this examination. Random spot urine samples were obtained, and urine albumin and creatinine levels were measured using frozen specimens. Urine albumin level was measured using solid-phase fluorescence immunoassay; urine creatinine level was measured using the modified Jaffe kinetic method in the same laboratory. Serum creatinine level was measured by the modified kinetic method of Jaffe using different analyzers in different survey years.

DEFINITIONS

The outcome variable was awareness of CKD. Participants who answered “yes” to the question “Have you ever been told you have weak or failing kidneys (excluding kidney stones, bladder infections, or incontinence)?” during the interview were defined as being aware of their CKD.

Estimated GFR was calculated according to the modified Modification of Diet in Renal Disease (MDRD) formula for calibrated serum creatinine level (CSCL):

eGFR = 175 × CSCL in mg/dL−1.154 × Age−0.203 × 0.742 if Female × 1.210 if African American.10,11

Serum creatinine level was calibrated for 1999-2000 participants using the following formula:

CSCL = 1.013 × Original Serum Creatinine Level in mg/dL + 0.147.

No correction was required for CSCL in participants in the 2001-2002 or 2003-2004 surveys.12 Proteinuria was considered to be present at urinary albumin to creatinine ratios of 17:250 mg/g (microalbuminuria) and greater than 250 mg/g (macroalbuminuria) for men and 25:355 mg/g (microalbuminuria) and greater than 355 mg/g (macroalbuminuria) for women.13 The independent variable of presence and stage of CKD in the participants was determined using eGFR and presence of proteinuria according to the Kidney Disease Outcomes Quality Initiative guidelines.3 Because urine protein measurements in NHANES are cross-sectional, we did not have data on persistent proteinuria, and the definitions of stages were therefore modified as stage 1 (eGFR, >90 mL/min/1.73 m2 and presence of proteinuria); stage 2 (eGFR, 60-89 mL/min/1.73 m2 and presence of proteinuria); stage 3 (eGFR, 30-59 mL/min/1.73 m2); stage 4 (eGFR, 15-29 mL/min/1.73 m2); and stage 5 (eGFR, <15 mL/min/1.73 m2).

Other independent variables included sex, diabetes, and hypertension. Diabetes was defined by answer of “yes” to the question “Have you ever been told by a doctor that you have diabetes or sugar diabetes?”; hypertension was defined by an answer of “yes” to “Have you ever been told by a doctor that you have hypertension, also called high blood pressure?,” a mean systolic blood pressure of 140 mm Hg or higher, or a mean diastolic blood pressure of 90 mm Hg or higher.

STATISTICAL METHODS

The proportion aware was calculated by CKD stage and survey year. Variance of proportions was estimated with Taylor series linearization. Exploration of factors associated with awareness was limited to CKD stage 3 because of small sample sizes for stage 4 and potential misclassification due to short-term variability in microalbuminuria in stages 1 and 2.14 Proportion aware was calculated by patient characteristics and by year, and those characteristics that were shown or thought a priori to be associated with awareness were examined in logistic models predicting awareness by year.

All analyses were performed using the “SVY” commands in Stata version 9.2 (StataCorp, College Station, Texas) to account study design weights, strata, and pseudostrata. Appropriate NHANES 2-year and 6-year MEC weights (WTMEC) were used; 6-year weights were calculated as the following:

6-Year WTMEC = ⅔ × 4-Year WTMEC (if Survey Year = 1999-2002), and

6-Year WTMEC = ⅓ × 2-Year WTMEC (if Survey Year = 2003-2004).15

PROPORTION OF PERSONS WITH CKD WHO ARE AWARE OF THEIR DISEASE

Overall, there were 2992 NHANES participants with CKD stages 1 to 4 who met the inclusion criteria (Figure 1) from 1999 to 2004 (675 with stage 1, 926 with stage 2, 1314 with stage 3, and 77 with stage 4 disease). Of these, only 6.0% reported being told that they had weak or failing kidneys (24 with stage 1, 36 with stage 2, 111 with stage 3, and 34 with stage 4 disease). The proportion aware differed substantially by CKD stage (Figure 2), with awareness in those with stages 1 and 2 being less than half that in those with stage 3, and awareness in those with stage 4 being nearly 6 times greater than that in those with stage 3 (P = .002). However, even at stage 4, fewer than half the subjects were aware that they had CKD.

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Figure 2.

Percentage of subjects with chronic kidney disease (CKD) who were aware of their disease by CKD stage (National Health and Nutrition Examination Survey 1999-2004). P value for trend across stage, adjusted for age, sex, and race. *Stages 1 and 2 defined by single measurement of albuminuria only; persistent albuminuria data not available. †No standard error estimates because of small sample size. Error bars indicate 95% confidence interval.

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Chronic kidney disease awareness did not change over time for participants with CKD overall (stages 1-4: 1999-2000, 5.2%; 2001-2002, 6.7%; and 2003-2004, 6.0%; P = .39). Awareness did increase for participants with CKD stage 3 (Figure 3), with proportion aware being greater in 2001-2004 than in 1999-2000 (P = .04). For stages 1 and 2, there were slight downward trends in awareness over time that were not statistically significant (P = .14 and .37, respectively); awareness in those with CKD stage 4 did not change significantly over time. Awareness in those with CKD stage 3 was similar to awareness in those with CKD stages 1 and 2 in 1999-2000, but in 2001-2004, awareness was higher in those with CKD stage 3 (Figure 3).

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Figure 3.

Percentage of subjects with chronic kidney disease (CKD) stages 1 to 4 who were aware of their disease by survey year (National Health and Nutrition Examination Survey 1999-2004). P value for trend across years, adjusted for age, sex, and race. *Stages 1 and 2 defined by single measurement of albuminuria only; persistent albuminuria data not available. †No standard error estimates because of small sample size. Error bars indicate 95% confidence interval.

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FACTORS ASSOCIATED WITH CKD AWARENESS IN THOSE WITH CKD STAGE 3

A total of 1314 participants had CKD stage 3 from 1999 to 2004; of these, 7.8% were aware of their CKD (Table). Participants with CKD stage 3 who were non-Hispanic black or Mexican American had higher rates of awareness than participants of non-Hispanic white or other races. A greater proportion of men were aware of their CKD compared with women. Chronic kidney disease awareness was far greater, but still less than one-fifth, among participants who had proteinuria, diabetes, hypertension, and obesity compared with those who did not. Those with less education and those with a routine site for health care were also more likely to be aware of their CKD, but these associations were not statistically significant. Within individual survey years, the associations of awareness with patient characteristics were generally similar to those seen in the overall study period (Table), although statistical significance was often lost in these small subgroups. For example, male sex was associated with increased awareness for all years, but the association was only statistically significant for 1999-2000. The association of CKD awareness with proteinuria in these stage 3 participants was statistically significant for all 3 survey year periods, with macroalbuminuria being far more predictive than microalbuminuria. Diabetes and hypertension were statistically significantly associated with CKD awareness in 2001-2002 and 2003-2004 only.

Table Graphic Jump LocationTable. Chronic Kidney Disease (CKD) Awareness in NHANES Participants (1999-2004) (With Stage 3 Disease Only) by Patient Characteristics

In adjusted models, male sex, proteinuria, diabetes, and hypertension were all statistically significantly associated with greater odds of CKD awareness (Figure 4). Older age was associated with less awareness overall, and black race was associated with more awareness; however, the associations were not statistically significant. The increase in awareness over time can be seen in both the younger and older and white and black subgroups (Figure 4A and B). Similarly, awareness increased in men and women from 1999 to 2002, but men remained more likely to be aware in all 3 survey year periods (Figure 4C). Regardless of proteinuria subgroup (Figure 4D), awareness increased after 1999-2001, with macroalbuminuria being a greater predictor than microalbuminuria in all 3 survey year periods. The same trend was seen for diabetes (Figure 4E), with awareness increasing over time and diabetic individuals remaining more likely to be aware. Hypertensive participants were more likely to be aware, especially in the last 2 survey year periods, but it is unclear whether awareness increased in nonhypertensive participants (Figure 4F).

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Figure 4.

Association of chronic kidney disease (CKD) awareness over time with age (A), race (B), sex (C), proteinuria (micro indicates microalbuminuria; macro, macroalbuminuria) (D), diabetes (E), and hypertension (*no estimates—failure was predicted perfectly) (F) in National Health and Nutrition Examination Survey participants (1999-2004) (with stage 3 disease only). Odds ratios are adjusted for other patient characteristics shown plus education and health insurance. CI indicates confidence interval; Ref, reference.

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After adjustment for other factors, having a routine site for health care (adjusted OR for 1999-2004, 2.56; 95% confidence interval [CI], 0.63-10.3), having a high school education or greater (adjusted OR for 1999-2004, 0.70; 95% CI, 0.35-1.38), being uninsured (adjusted OR for 1999-2004, 0.92; 95% CI, 0.25-3.36), and being obese (adjusted OR for 1999-2004, 1.45; 95% CI, 0.83-2.54) were not associated with CKD awareness.

We found that disease awareness among US adults with CKD, as defined by Kidney Disease Outcomes Quality Initiative staging,3 was generally low. Even at CKD stage 4, fewer than half of the persons with CKD were aware of their disease. There were increases in CKD awareness after 2000, consistent across subgroups but seen only in those with CKD stage 3, which are arguably impressive for this short period; however, awareness among these persons was still fewer than 1 in 10. Substantial recent efforts to increase awareness among nephrologists (dissemination of Kidney Disease Outcomes Quality Initiative staging in 20023) and general physicians and persons in the general public (formation of the National Kidney Disease Education Program by the National Institutes of Health in 200116 and the initiation of a free screening program by the National Kidney Foundation, the Kidney Early Education Program, piloted in 1997-1999 and continuing today17) have not produced high levels of awareness among patients since their implementation several years ago. However, changes in guidelines,3 coupled with recent increased reporting of eGFR,16 may be at least partially responsible for differential increase in awareness for CKD stage 3 vs stages 1 and 2. Chronic kidney disease stages 1 and 2 are identified through the presence of proteinuria, which may not be as commonly, or consistently, detected.

Chronic kidney disease awareness rates, at lower than 10% for CKD stage 3 and lower than 50% for CKD stage 4, are still unacceptably low. The discrepancy between CKD awareness and awareness of other chronic diseases is large. Patients with hypertension and diabetes had awareness rates of 74% and 70%, respectively, in the same population during the same period.18,19 Both the National High Blood Pressure Education Program of the National Heart, Lung, and Blood Institute, founded in 1972,20 and the National Diabetes Education Program (through the combined efforts of the National Institutes of Health, Centers for Disease Control and Prevention, and more than 200 private organizations), founded in 1997,21 ran aggressive public awareness campaigns for many years. Similar long-term, broad-scale efforts in CKD might increase awareness dramatically in the United States, especially if they target both practitioners, who could identify and treat affected individuals,7,22 as well as high-risk individuals, who could present to practitioners based on their knowledge of CKD. Given that CKD not only can result in progression to end-stage renal disease and dependence on dialysis and transplantation but also is an independent risk factor for cardiovascular disease and mortality,23,24 the importance of increasing CKD awareness should not be underestimated.

Awareness was greater among some subgroups of patients. Black participants with CKD were more likely to be aware of their disease than white participants. This race differential in patient awareness may reflect patient and physician perception of black race as a risk factor for CKD25 or greater family history among these patients,26 which may result in more testing among these patients. Increased physician awareness of black race as a risk factor and greater communication of this risk to these patients may also have contributed to the greater CKD awareness seen in black patients. Although older patients are at increased risk for reduced kidney function and CKD, they were less likely to be aware of their disease. Whether this reflects less testing or acceptance of reduced kidney function on the part of the practitioners as a normal part of aging in this population is unknown. Also, although there is no evidence that men are at higher risk of developing CKD than women,27 men were far more likely to be aware of their CKD. Higher awareness among men may also be due to their higher serum creatinine levels, which physicians, especially those who are less aware of CKD and who use creatinine levels alone rather than age- and sex-adjusted eGFR, may recognize more readily as an abnormality. Physicians may also perceive men to be at higher risk than women and thus screen for CKD more often in these patients; or men's symptoms of CKD may be more pronounced or less likely to be attributed to other causes than women's symptoms.

Several clinical conditions made CKD awareness more likely as well. Those with hypertension and diabetes were far more likely to be aware of their disease. This greater likelihood may be because physicians recognize that these patients are at much greater risk for CKD. Patient awareness of their risk may also encourage patients to ask for CKD screening. In addition, these patients are more likely to be seen frequently and thus be subjected to urine and blood testing as part of their regular care, making it more likely for CKD to be detected.

We expected that better access to care might lead to higher rates of disease awareness. However, we found no association between having health insurance and CKD awareness. This suggests that, even when patients have access to care, physician communication of risk and/or patient uptake of the information presented may be inadequate. Having a routine site for health care was marginally associated with greater CKD awareness, after adjustment for other factors. This may be because those at greatest risk, including those with diabetes and hypertension, are more likely to have a routine site for health care because of the condition that puts them at risk for CKD. Given that having a routine site was associated with awareness after adjustment for these conditions, but that merely having health insurance was not, it is also possible that having an established relationship with a health care provider is more important for generating awareness than general access to care. Further efforts to enhance the patient-provider relationship, in the context of discussion of CKD, may improve awareness. Finally, we found that lifestyle factors, such as obesity, physical activity, smoking, and alcohol use, were not associated with CKD awareness.

The urgency of making patients aware of CKD could be questioned on the grounds that many patients die before they progress to a more severe stage of CKD and many are already being treated for diabetes and/or hypertension.28,29 However, there are still compelling reasons why patients would benefit from awareness of their CKD. First, they could be made aware of medication exposures that could influence progression, including over-the-counter nonsteroidal anti-inflammatory agents and contrast agents used in imaging tests. In addition, there is evidence that appropriate early treatment (with medications and hypertension control) could slow progression of CKD.29 Also, patients should be aware that current and future medications could require dose adjustment in the setting of CKD. Many conditions, such as heart disease and cognitive decline, may increase with severity of CKD, and awareness of disease may motivate patients to adopt preventive strategies for these conditions. Awareness might also make patients more vigilant with adherence to dietary recommendations for comorbid hypertension and diabetes, including lower salt, sugar, and fat intake, as well as other lifestyle changes.

There are several limitations to this study that deserve mention. First, the questionnaire item assessing awareness asked participants if they had ever been told they had weak or failing kidneys. Patients may not be told that their kidneys are weak or failing, especially in early-stage CKD; rather, they may be told that they have decreased kidney function or protein in the urine. Thus, there is the possibility of misinterpretation of the questionnaire item by the participants; 1% of respondents without kidney disease answered “yes” to this question, indicating a small amount of misclassification of participant awareness and/or of early-stage disease. Second, proteinuria was a single measurement with no follow-up in NHANES, and CKD in its early stages is defined as persistent proteinuria. This lack of a confirmatory urine protein sample may have led to misclassification of participants with CKD stages 1 and 2. In fact, only 63% of subjects with albuminuria at the first visit in NHANES III had albuminuria at the second visit.14 Misclassification of disease may have also occurred due to GFR estimation. In addition, we do not know the duration of reduced kidney function and/or proteinuria, nor do we know the duration of symptoms, if any, that may have led the participant to seek medical treatment. The small number of participants with CKD, especially in single surveys, was another limitation. Health care provider factors, especially provider knowledge of CKD, quality of patient-provider communication, and specialist referral, may play a significant role in CKD awareness but could not be assessed using these data.

Despite substantial recent efforts, both nationally and locally, to increase awareness of CKD in the community, the majority of those with CKD, as defined by decreased renal function and/or evidence of kidney damage, do not recall having been told by a physician that they have CKD. Renewed and greater efforts and resources may need to be directed toward dissemination activities by the government (eg, Centers for Disease Control and Prevention and National Kidney Disease Education Program) and private organizations (eg, National Kidney Foundation, American Society of Nephrology, Renal Physicians Association, and American College of Physicians) to increase awareness of CKD among practitioners and in the general community. Not only those with risk factors (eg, diabetes and hypertension) but also those who are less likely to be aware, including older, female, and white patients, without diabetes or hypertension, and those without routine access to health care should be targeted more aggressively. Future studies of disease awareness among those with CKD should focus on intervention by examining patient, health care provider, and societal (eg, public relations campaigns) factors that lead to better CKD awareness.

Correspondence: Neil R. Powe, MD, Welch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins Medical Institutions, 2024 E Monument St, Ste 2-600, Baltimore, MD 21287 (npowe@jhmi.edu).

Accepted for Publication: May 1, 2008.

Author Contributions:Study concept and design: Plantinga, Coresh, Saran, Levey, and Powe. Acquisition of data: Plantinga and Levey. Analysis and interpretation of data: Plantinga, Boulware, Coresh, Stevens, Miller, Saran, Messer, Levey, and Powe. Drafting of the manuscript: Plantinga, Levey, and Powe. Critical revision of the manuscript for important intellectual content: Boulware, Coresh, Stevens, Miller, Saran, Messer, Levey, and Powe. Statistical analysis: Plantinga, Messer, and Powe. Obtained funding: Powe. Administrative, technical, and material support: Boulware, Coresh, Levey, and Powe. Study supervision: Powe.

Financial Disclosure: None reported.

Funding/Support: This project was supported by a cooperative agreement from the Centers for Disease Control and Prevention (CDC) through the Association of American Medical Colleges (AAMC) (grant U36/CCU319276, AAMC ID MM-0997-07/07). Dr Powe is partially supported by grant K24DK02643 from the National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland.

Disclaimer: The report contents are solely the responsibility of the authors and do not necessarily represent the official views of the AAMC or CDC.

Previous Presentation: This study was presented in part at the 2007 American Society of Nephrology annual meeting; November 2, 2007; San Francisco, California.

Additional Contributions: We thank the participants and staff of the National Health and Nutrition Examination Survey.

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Levey  ASBeto  JACoronado  BE  et al. National Kidney Foundation Task Force on Cardiovascular Disease, Controlling the epidemic of cardiovascular disease in chronic renal disease: what do we know? what do we need to learn? where do we go from here? Am J Kidney Dis 1998;32 (5) 853- 906
PubMed Link to Article
Collins  AJLi  SGilbertson  DTLiu  JChen  SCHerzog  CA Chronic kidney disease and cardiovascular disease in the Medicare population. Kidney Int Suppl 2003;87 (87) S24- S31
PubMed Link to Article
National Kidney Foundation, The facts about chronic kidney disease. 2008;http://www.kidney.org/kidneyDisease/ckd/index.cfm#facts. Accessed April 1, 2008
McClellan  WSpeckman  RMcClure  L  et al.  Prevalence and characteristics of a family history of end-stage renal disease among adults in the United States population: reasons for Geographic and Racial Differences in Stroke (REGARDS) renal cohort study. J Am Soc Nephrol 2007;18 (4) 1344- 1352
PubMed Link to Article
Haroun  MKJaar  BGHoffman  SCComstock  GWKlag  MJCoresh  J Risk factors for chronic kidney disease: a prospective study of 23,534 men and women in Washington County, Maryland. J Am Soc Nephrol 2003;14 (11) 2934- 2941
PubMed Link to Article
O'Hare  AMChoi  AIBertenthal  D  et al.  Age affects outcomes in chronic kidney disease. J Am Soc Nephrol 2007;18 (10) 2758- 2765
PubMed Link to Article
Appel  LJWright  JT  IIGreene  T  et al. AASK Collaborative Research Group, Long-term effects of renin-angiotensin system-blocking therapy and a low blood pressure goal on progression of hypertensive chronic kidney disease in African Americans. Arch Intern Med 2008;168 (8) 832- 839
PubMed Link to Article

Figures

Place holder to copy figure label and caption
Figure 1.

National Health and Nutrition Examination Survey (NHANES) participants (1999-2004), who met inclusion criteria for this study. *Stages 1 and 2 defined by single measurement of albuminuria only; persistent albuminuria data not available. CKD indicates chronic kidney disease; eGFR, estimated glomerular filtration rate; MEC, mobile examination center.

Graphic Jump Location
Place holder to copy figure label and caption
Figure 2.

Percentage of subjects with chronic kidney disease (CKD) who were aware of their disease by CKD stage (National Health and Nutrition Examination Survey 1999-2004). P value for trend across stage, adjusted for age, sex, and race. *Stages 1 and 2 defined by single measurement of albuminuria only; persistent albuminuria data not available. †No standard error estimates because of small sample size. Error bars indicate 95% confidence interval.

Graphic Jump Location
Place holder to copy figure label and caption
Figure 3.

Percentage of subjects with chronic kidney disease (CKD) stages 1 to 4 who were aware of their disease by survey year (National Health and Nutrition Examination Survey 1999-2004). P value for trend across years, adjusted for age, sex, and race. *Stages 1 and 2 defined by single measurement of albuminuria only; persistent albuminuria data not available. †No standard error estimates because of small sample size. Error bars indicate 95% confidence interval.

Graphic Jump Location
Place holder to copy figure label and caption
Figure 4.

Association of chronic kidney disease (CKD) awareness over time with age (A), race (B), sex (C), proteinuria (micro indicates microalbuminuria; macro, macroalbuminuria) (D), diabetes (E), and hypertension (*no estimates—failure was predicted perfectly) (F) in National Health and Nutrition Examination Survey participants (1999-2004) (with stage 3 disease only). Odds ratios are adjusted for other patient characteristics shown plus education and health insurance. CI indicates confidence interval; Ref, reference.

Graphic Jump Location

Tables

Table Graphic Jump LocationTable. Chronic Kidney Disease (CKD) Awareness in NHANES Participants (1999-2004) (With Stage 3 Disease Only) by Patient Characteristics

References

Coresh  JByrd-Holt  DAstor  BC  et al.  Chronic kidney disease awareness, prevalence, and trends among US adults, 1999 to 2000. J Am Soc Nephrol 2005;16 (1) 180- 188
PubMed Link to Article
Coresh  JSelvin  EStevens  LA  et al.  Prevalence of chronic kidney disease in the United States. JAMA 2007;298 (17) 2038- 2047
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National Kidney Foundation, Kidney Disease Outcomes Quality Initiative (K/DOQI). 2008;http://www.kidney.org/professionals/doqi. Accessed April 1, 2008
Levey  ASAndreoli  SPDuBose  TProvenzano  RCollins  AJ Chronic kidney disease: common, harmful and treatable—World Kidney Day 2007. Am J Nephrol 2007;27 (1) 108- 112
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Chobanian  AVBakris  GLBlack  HR  et al. National Heart, Lung, and Blood Institute Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure; National High Blood Pressure Education Program Coordinating Committee, The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure: the JNC 7 report. JAMA 2003;289 (19) 2560- 2572
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Sarnak  MJLevey  ASSchoolwerth  AC  et al. American Heart Association Councils on Kidney in Cardiovascular Disease, High Blood Pressure Research, Clinical Cardiology, and Epidemiology and Prevention, Kidney disease as a risk factor for development of cardiovascular disease: a statement from the American Heart Association Councils on Kidney in Cardiovascular Disease, High Blood Pressure Research, Clinical Cardiology, and Epidemiology and Prevention. Hypertension 2003;42 (5) 1050- 1065
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Kinchen  KSSadler  JFink  N  et al.  The timing of specialist evaluation in chronic kidney disease and mortality. Ann Intern Med 2002;137 (6) 479- 486
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Nickolas  TLFrisch  GDOpotowsky  ARArons  RRadhakrishnan  J Awareness of kidney disease in the US population: findings from the National Health and Nutrition Examination Survey (NHANES) 1999 to 2000. Am J Kidney Dis 2004;44 (2) 185- 197
PubMed Link to Article
Centers for Disease Control and Prevention, National Center for Health Statistics,National Health and Nutrition Examination Survey Data, 1999-2000, 2001-2002, and 2003-2004. Hyattsville, MD US Dept of Health and Human Services, Centers for Disease Control and Prevention2007;
Levey  ASCoresh  JGreene  T  et al.  Expressing the MDRD study equation for estimating GFR with IDMS traceable(gold standard) serum creatinine values [abstract]. J Am Soc Nephrol 2005;1669A
Levey  ASCoresh  JGreene  T  et al.  Using standardized serum creatinine values in the modification of diet in renal disease study equation for estimating glomerular filtration rate. Ann Intern Med 2006;145 (4) 247- 254
PubMed Link to Article
Selvin  EManzi  JStevens  LA  et al.  Calibration of serum creatinine in the National Health and Nutrition Examination Surveys (NHANES) 1988-1994, 1999-2004. Am J Kidney Dis 2007;50 (6) 918- 926
PubMed Link to Article
Mattix  HJHsu  CYShaykevich  SCurhan  G Use of the albumin/creatinine ratio to detect microalbuminuria: implications of sex and race. J Am Soc Nephrol 2002;13 (4) 1034- 1039
PubMed
Coresh  JAstor  BCGreene  TEknoyan  GLevey  AS Prevalence of chronic kidney disease and decreased kidney function in the adult US population: Third National Health and Nutrition Examination Survey. Am J Kidney Dis 2003;41 (1) 1- 12
PubMed Link to Article
National Center for Health Statistics, Analytic and reporting guidelines: the National Health and Nutrition Examination Survey (NHANES). Updated September 2006. http://www.cdc.gov/nchs/about/major/nhanes/nhanes2003-2004/analytical_guidelines.htm. Accessed September 15, 2007
National Kidney Disease Education Program, National Institutes of Health, Kidney disease: are you at risk?  November16 2007;http://nkdep.nih.gov/. Accessed April 1, 2008
National Kidney Foundation, Kidney Early Evaluation Program. 2008;http://www.kidney.org/news/keep/index.cfm. Accessed April 1, 2008
Ostchega  YDillon  CFHughes  JPCarroll  MYoon  S Trends in hypertension prevalence, awareness, treatment, and control in older US adults: data from the National Health and Nutrition Examination Survey 1988 to 2004. J Am Geriatr Soc 2007;55 (7) 1056- 1065
PubMed Link to Article
Cowie  CCRust  KFByrd-Holt  DD  et al.  Prevalence of diabetes and impaired fasting glucose in adults in the US population: National Health and Nutrition Examination Survey 1999-2002. Diabetes Care 2006;29 (6) 1263- 1268
PubMed Link to Article
National Heart Lung and Blood Institute, National High Blood Pressure Education Program. 2007;http://www.nhlbi.nih.gov/about/nhbpep/. Accessed April 1, 2008
National Institute of Diabetes & Digestive & Kidney Diseases, National Diabetes Education Program. 2007;http://ndep.nih.gov/. Accessed April 1, 2008
Lea  JPMcClellan  WMMelcher  CGladstone  EHostetter  T CKD risk factors reported by primary care physicians: do guidelines make a difference? Am J Kidney Dis 2006;47 (1) 72- 77
PubMed Link to Article
Levey  ASBeto  JACoronado  BE  et al. National Kidney Foundation Task Force on Cardiovascular Disease, Controlling the epidemic of cardiovascular disease in chronic renal disease: what do we know? what do we need to learn? where do we go from here? Am J Kidney Dis 1998;32 (5) 853- 906
PubMed Link to Article
Collins  AJLi  SGilbertson  DTLiu  JChen  SCHerzog  CA Chronic kidney disease and cardiovascular disease in the Medicare population. Kidney Int Suppl 2003;87 (87) S24- S31
PubMed Link to Article
National Kidney Foundation, The facts about chronic kidney disease. 2008;http://www.kidney.org/kidneyDisease/ckd/index.cfm#facts. Accessed April 1, 2008
McClellan  WSpeckman  RMcClure  L  et al.  Prevalence and characteristics of a family history of end-stage renal disease among adults in the United States population: reasons for Geographic and Racial Differences in Stroke (REGARDS) renal cohort study. J Am Soc Nephrol 2007;18 (4) 1344- 1352
PubMed Link to Article
Haroun  MKJaar  BGHoffman  SCComstock  GWKlag  MJCoresh  J Risk factors for chronic kidney disease: a prospective study of 23,534 men and women in Washington County, Maryland. J Am Soc Nephrol 2003;14 (11) 2934- 2941
PubMed Link to Article
O'Hare  AMChoi  AIBertenthal  D  et al.  Age affects outcomes in chronic kidney disease. J Am Soc Nephrol 2007;18 (10) 2758- 2765
PubMed Link to Article
Appel  LJWright  JT  IIGreene  T  et al. AASK Collaborative Research Group, Long-term effects of renin-angiotensin system-blocking therapy and a low blood pressure goal on progression of hypertensive chronic kidney disease in African Americans. Arch Intern Med 2008;168 (8) 832- 839
PubMed Link to Article

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