Draft Recommendation Statement
Note: This draft Recommendation Statement is not the final recommendation of the U.S. Preventive Services Task Force. This draft is distributed solely for the purpose of pre-release review. It has not been disseminated otherwise by AHRQ. It does not represent and should not be interpreted to represent an AHRQ determination or policy.
This draft Recommendation Statement is based on an evidence review that was published on April 17, 2012 (available at http://www.uspreventiveservicestaskforce.org/uspstf12/kidney/ckdart.htm).
The USPSTF makes recommendations about the effectiveness of specific clinical preventive services for patients without related signs or symptoms.
It bases its recommendations on the evidence of both the benefits and harms of the service, and an assessment of the balance. The USPSTF does not consider the costs of providing a service in this assessment.
The USPSTF recognizes that clinical decisions involve more considerations than evidence alone. Clinicians should understand the evidence but individualize decisionmaking to the specific patient or situation. Similarly, the USPSTF notes that policy and coverage decisions involve considerations in addition to the evidence of clinical benefits and harms.
This draft Recommendation Statement is available for comment from April 30 until May 29, 2012, at 5:00 PM ET. You may wish to read the entire Recommendation Statement before you comment. A fact sheet that explains the draft recommendations in plain language is available here.
Screening for Chronic Kidney Disease: U.S. Preventive Services Task Force Recommendation Statement
DRAFT
Summary of Recommendation and Evidence
The U.S. Preventive Services Task Force (USPSTF) concludes that the evidence is insufficient to assess the balance of benefits and harms for routine screening for chronic kidney disease (CKD) in asymptomatic adults. Common tests considered for CKD screening include creatinine–derived estimates of glomerular filtration rate (GFR) and urine testing for albumin.
This is an I statement.
Go to the Clinical Considerations section for suggestions for practice regarding the I statement.
Table 1 describes the USPSTF grades, and Table 2 describes the USPSTF classification of levels of certainty about net benefit.
Rationale
Importance
Approximately 11 percent of U.S. adults have CKD, many of whom are elderly. The condition is usually asymptomatic until its advanced stages. Most cases of CKD are associated with diabetes mellitus and/or hypertension.
Detection
CKD is defined as decreased kidney function and/or kidney damage that persists for at least 3 months. There are no studies that assess the sensitivity and specificity of screening for CKD with tests for estimated GFR, microalbuminuria, or macroalbuminuria.
Benefits of Detection and Early Intervention/Treatment
There is inadequate evidence that routine screening for CKD improves clinical outcomes for asymptomatic adults.
Harms of Detection and Early Intervention/Treatment
There is inadequate evidence that routine screening for CKD improves clinical outcomes for asymptomatic adults.
USPSTF Assessment
There is inadequate evidence on the harms of screening for CKD. However, there is convincing evidence that medications used to treat early CKD may have side effects.
Clinical Considerations
Patient Population Under Consideration
This recommendation applies to asymptomatic adults without diagnosed CKD. Testing and monitoring of CKD for the purposes of chronic disease management (for example, in patients with diabetes and/or hypertension) are not covered by this recommendation.
Suggestions for Practice Regarding the I Statement
Potential preventable burden and potential benefits. CKD is very prevalent; in 2011, 11 percent of the U.S. general population had the condition. However, most people affected have risk factors for CKD, particularly older age, diabetes, and hypertension. CKD is usually asymptomatic until its advanced stages. While there is no evidence on the benefits and harms of screening in the general population of asymptomatic adults, there is evidence that specific treatments for patients with diabetes reduce the risk for advanced CKD. The American Diabetes Association recommends screening for CKD in all patients with diabetes mellitus. The USPSTF found very limited evidence about whether the knowledge of CKD status in patients with isolated hypertension (i.e., without diabetes or cardiovascular disease) helps in making treatment decisions. However, several organizations recommend screening patients who are being treated for hypertension, including the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure.
Potential harms. For adults without diabetes or hypertension, the risks for CKD and subsequent adverse outcomes resulting from CKD are small. It is unknown how many people with a positive screening test for CKD will be confirmed to have CKD. There are no studies on the benefits of early treatment in individuals without diabetes or hypertension. People who have a positive screening test for CKD but do not have CKD may experience the harms associated with interventions and treatments without the potential for benefit.
Current practice. Serum creatinine testing is widely performed for a variety of reasons in clinical practice, including chronic disease management for patients with hypertension and diabetes. Many patients with CKD stages 1–3 appear to be undergoing at least some testing in usual clinical care, likely as a result of care for other conditions or in response to guidelines from other organizations.
Assessment of Risk
There is no generally accepted risk assessment tool for CKD or risk for complications of CKD. Diabetes and hypertension are well established risk factors with a strong link to CKD. Other risk factors for CKD include older age, cardiovascular disease, obesity, and family history.
Screening Tests
While there is insufficient evidence to recommend routine screening, the tests often suggested for screening that are feasible in primary care include testing the urine for protein (microalbuminuria or macroalbuminuria) and testing the blood for serum creatinine to estimate GFR. No studies have evaluated the sensitivity and specificity of one-time testing with either or both tests for diagnosis of CKD, defined as decreased kidney function or kidney damage persisting for at least 3 months.
Treatment
Treatment for early stages of CKD is generally targeted to comorbid conditions, such as diabetes, hypertension, and cardiovascular disease, to reduce the risk for complications and progression of CKD. These treatments include blood pressure medications (particularly angiotensin-converting enzyme inhibitors and angiotensin II–receptor blockers), lipid-lowering agents, and diet.
Research Needs and Gaps
Future research to define the sensitivity and specificity of one-time tests for possible CKD would help to clarify the usefulness of these tests and interpretation of their results. More research is needed on the potential benefits and harms of screening and early treatment for CKD in people without diabetes and hypertension. Studies to evaluate the impact of screening for CKD in patients with hypertension but not diabetes would help to define the benefits and harms of screening in this risk group.
Discussion
Burden of Disease
Approximately 11 percent of Americans have an early form of CKD (1, 2). Most cases of CKD are asymptomatic, identified in early stages, and associated with diabetes, hypertension, or both. Medicare data shows that 48 percent of patients with CKD (excluding end-stage renal disease) have diabetes, 91 percent have hypertension, and 46 percent have atherosclerotic heart disease (1, 2). Other reported risk factors include older age, obesity, and family history. CKD prevalence is higher in women (12.6 percent) than in men (9.7 percent) and is similar in whites (11.6 percent) and blacks (11.2 percent) (1, 2). African Americans are 3 to 5 times more likely to have end-stage renal disease than white Americans (3, 4). CKD is associated with numerous adverse health outcomes in several studies; these outcomes include increased risk for mortality, cardiovascular disease, fractures, bone loss, infections, cognitive impairment, and frailty.
Scope of Review
This is a new topic for the USPSTF and was nominated for consideration by several organizations. The USPSTF reviewed evidence on screening for CKD, including evidence on screening, accuracy of screening, early treatment, and harms of screening and early treatment.
Accuracy of Screening Tests
While a one-time creatinine–derived estimate of GFR is highly correlated to a one-time direct measurement of GFR, the USPSTF could find no studies on the accuracy of screening (with serum creatinine or urine albumin) for CKD, defined as impaired GFR and/or albuminuria that lasts at least 3 months (1, 2). A few studies provide some information about reliability and false-positive results. Intra-individual variability of urinary albumin is high; reported coefficients of variance estimates range from 30 to 50 percent (5). Body position, exercise, and fever can all affect urinary albumin excretion (5). While many groups recommend the use of one-time urinary albumin testing and calculation of a protein–creatinine ratio, there is no standard for collection and measurement of urinary albumin or creatinine. A study using National Health and Nutrition Examination Survey data reported that 37 percent of individuals with microalbuminuria and a GFR of ≥60 mL/min per 1.73 m2 did not have microalbuminuria or macroalbuminuria on repeat testing 2 months later (6). Another study reported that 59 percent of subjects with diabetes and persistent microalbuminuria (defined by repeated abnormal protein–creatinine ratios over a 2-year period) regressed to normal over a subsequent 6-year period (7).
Effectiveness of Early Detection and/or Treatment
There are no studies that directly evaluate the effectiveness of screening for CKD. Treatment of early stages of CKD is targeted to associated conditions, primarily using medications to control hypertension, diabetes, and cardiovascular disease. There are few studies on early treatment of CKD stages 1–3 in people without chronic diseases (i.e., hypertension, diabetes, and cardiovascular disease). There is evidence that the identification and treatment of CKD may have an impact on management decisions or health outcomes in patients with established chronic disease, including diabetes, cardiovascular disease, and hypertension, but there is insufficient evidence that identification and early treatment of CKD in asymptomatic adults without these conditions results in improved health outcomes.
Potential Harms of Screening and/or Treatment
The USPSTF found no studies on the direct harms of screening for CKD. Potential harms of screening include adverse effects from venopuncture and psychological effects of labeling a person with CKD. The USPSTF found no studies on these potential harms. The most important potential for harm could occur as a result of false-positive results. Patients could be falsely identified as having CKD and receive unnecessary treatment and diagnostic interventions, with their resultant harmful effects. The USPSTF found insufficient evidence to quantify the overall harms from false-positive results. As discussed previously, several studies provide limited information about the potential frequency of false-positive results.
There is convincing evidence that some harm occurs from medications used to treat comorbid conditions associated with early CKD, such as diabetes, hypertension, and cardiovascular disease. While studies inconsistently report withdrawals or adverse effects by treatment group, commonly reported adverse effects of medications reviewed include cough with angiotensin-converting enzyme inhibitors, hypotension with antihypertension medications, edema with calcium channel blockers, and hyperkalemia with angiotensin-converting enzyme inhibitors, angiotensin II–receptor blockers, and aldosterone (1, 2).
Estimate of Magnitude of Net Benefit
While undiagnosed CKD in its early stages is common and there are potential beneficial disease management interventions for people with chronic diseases, the USPSTF found insufficient evidence on screening accuracy, benefits of early treatment in the general population (i.e., people without chronic disease), and harms of screening. Therefore, there was insufficient evidence to assess the balance of benefits and harms of screening for CKD in the general asymptomatic adult population.
Recommendations of Others
We found no guidelines from primary care organizations that recommend screening all adults for CKD. The National Kidney Foundation recommends assessing risk for CKD in all patients and performing the following for those at increased risk: blood pressure measurement, serum creatinine testing, urine albumin testing, and examination of urine for red and white blood cells (8). The American Diabetes Association recommends annual screening of all people with diabetes with urine albumin and serum creatinine testing (9). The Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure recommends that all people diagnosed with hypertension should have an urinalysis and serum creatinine test; urine testing for albumin is optional (10).
Appendix: U.S. Preventive Services Task Force
Members of the U.S. Preventive Services Task Force* at the time this recommendation was finalized are Virginia A. Moyer, MD, MPH, Chair (Baylor College of Medicine, Houston, Texas); Michael L. LeFevre, MD, MSPH, Co-Vice Chair (University of Missouri School of Medicine, Columbia, Missouri); Albert L. Siu, MD, MSPH, Co-Vice Chair (Mount Sinai School of Medicine, New York, New York; James J. Peters Veterans Affairs Medical Center, Bronx, New York); Linda Ciofu Baumann, PhD, RN (University of Wisconsin, Madison, Wisconsin); Kirsten Bibbins-Domingo, PhD, MD (University of California, San Francisco, San Francisco, California); Susan J. Curry, PhD (University of Iowa College of Public Health, Iowa City, Iowa); Mark Ebell, MD, MS (University of Georgia, Athens, Georgia); Glenn Flores, MD (University of Texas Southwestern, Dallas, Texas); Adelita Gonzales Cantu, RN, PhD (University of Texas Health Science Center, San Antonio, Texas); David C. Grossman, MD, MPH (Group Health Cooperative, Seattle, Washington); Jessica Herzstein, MD, MPH (Air Products, Allentown, Pennsylvania); Joy Melnikow, MD, MPH (University of California Davis, Sacramento, California); Wanda K. Nicholson, MD, MPH, MBA (University of North Carolina School of Medicine, Chapel Hill, North Carolina); Douglas K. Owens, MD, MS (Stanford University, Stanford, California); Carolina Reyes, MD, MPH (Virginia Hospital Center, Arlington, Virginia); and Timothy J. Wilt, MD, MPH (University of Minnesota Department of Medicine and Minneapolis Veterans Affairs Medical Center, Minneapolis, Minnesota). Ned Calonge, MD, MPH, a former USPSTF member, also contributed to the development of this recommendation.
* Members of the Task Force at the time this recommendation was finalized. For a list of current Task Force members, go to http://www.uspreventiveservicestaskforce.org/about.htm.
Table 1: What the Grades Mean and Suggestions for Practice
Table 2: Levels of Certainty Regarding Net Benefit
| Level of Certainty* | Description |
|---|---|
| High | The available evidence usually includes consistent results from well-designed, well-conducted studies in representative primary care populations. These studies assess the effects of the preventive service on health outcomes. This conclusion is therefore unlikely to be strongly affected by the results of future studies. |
| Moderate | The available evidence is sufficient to determine the effects of the preventive service on health outcomes, but confidence in the estimate is constrained by factors such as:
As more information becomes available, the magnitude or direction of the observed effect could change, and this change may be large enough to alter the conclusion. |
| Low | The available evidence is insufficient to assess effects on health outcomes. Evidence is insufficient because of:
More information may allow an estimation of effects on health outcomes. |
*The U.S. Preventive Services Task Force defines certainty as "likelihood that the USPSTF assessment of the net benefit of a preventive service is correct." The net benefit is defined as benefit minus harm of the preventive service as implemented in a general, primary care population. The USPSTF assigns a certainty level based on the nature of the overall evidence available to assess the net benefit of a preventive service.
References
1. Fink HA, Ishani A, Taylor BC, et al. Chronic Kidney Disease Stages 1–3: Screening, Monitoring, and Treatment. Comparative Effectiveness Review No. 37. AHRQ Publication No. 11(12)-EHC075-EF. Rockville, MD: Agency for Healthcare Research and Quality; 2012. Accessed at http://www.ncbi.nlm.nih.gov/books/NBK84564/ on 24 April 2012.
2. Fink HA, Ishani A, Taylor BC, et al. Screening for, monitoring, and treatment of chronic kidney disease stages 1 to 3: a systematic review for the U.S. Preventive Services Task Force and for an American College of Physicians Clinical Practice Guideline. Ann Intern Med. 2012;156(8):570-81.
3. Hsu CY, Lin F, Vittinghoff E, Shlipak MG. Racial differences in the progression from chronic renal insufficiency to end-stage renal disease in the United States. J Am Soc Nephrol. 2003;14(11):2902-7.
4. Xue JL, Eggers PW, Agodoa LY, et al. Longitudinal study of racial and ethnic differences in developing end-stage renal disease among aged Medicare beneficiaries. J Am Soc Nephrol. 2007;18(4):1299-306.
5. Miller WG, Bruns DE, Hortin GL, et al. Current issues in measurement and reporting of urinary albumin excretion. Clin Chem. 2009;55(1):24-38.
6. Coresh J, Astor BC, Greene T, et al. 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.
7. Perkins BA, Ficociello LH, Silva KH, et al. Regression of microalbuminuria in type 1 diabetes. N Engl J Med. 2003;348(23):2285-93.
8. National Kidney Foundation. Clinical Practice Guidelines for Chronic Kidney Disease: Evaluation, Classification, and Stratification. New York: National Kidney Foundation; 2002. Accessed at http://www.kidney.org/professionals/KDOQI/guidelines_ckd/p9_approach.htm on 24 April 2012. 
9. American Diabetes Association. Standards of medical care in diabetes. Diabetes Care. 2012;35(Suppl 1):S4-10.
10. Chobanian AV, Bakris GL, Black HR, et al. Seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. Hypertension. 2003;42(6):1206-52.
AHRQ Publication No. 12-05166-EF-2
Current as of April 2012
Internet Citation:
U.S. Preventive Services Task Force. Screening for Chronic Kidney Disease: Draft Recommendation Statement. AHRQ Publication No. 12-05166-EF-2. http://www.uspreventiveservicestaskforce.org/draftrec.htm
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