Lack of evidence to recommend routine screening for chronic kidney disease

Sep 4 2012

By Andrew Czyzewski, medwireNews Reporter

Currently there is insufficient evidence to recommend the routine screening of chronic kidney disease (CKD) in asymptomatic adults in the general population, according to a review by the US Preventive Services Task Force (USPSTF).

While there were no studies on the direct harms of screening, potential harms include adverse effects from venopuncture, psychologic effects of labeling, and false-positive results leading to unnecessary treatment and diagnostic interventions.

Chaired by Virginia Moyer (Baylor College of Medicine, Houston, Texas), the task force observes: "Approximately 11% of Americans have an early form of CKD. Most cases are asymptomatic; identified in early stages; and associated with diabetes, hypertension, or both."

The task force therefore performed a review of published randomized, controlled trials to assess the benefits and harms of screening, monitoring, and treatment of early-stage CKD in asymptomatic adults.

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 glomerular filtration rate (GFR).

However, no studies have evaluated the sensitivity and specificity of one-time testing with either or both tests for CKD, defined as decreased kidney function or kidney damage persisting for at least 3 months.

Indeed, intra-individual variability of urinary albumin is high with reported coefficients of variance estimates ranging from 30% to 50%.

The treatment of early-stage CKD is generally targeted to comorbid medical 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 modification.

Evidence shows that identification and treatment of CKD may affect 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.

Overall, the evidence on the harms of screening for CKD is currently inadequate. However, there is convincing evidence showing that the aforementioned medications used to treat early CKD may have adverse effects.

"Although undiagnosed CKD in its early stages is common and there are potential beneficial disease management interventions for persons with chronic diseases, the USPSTF found insufficient evidence on screening accuracy, benefits of early treatment in the general population (that is, persons without chronic disease), and harms of screening," the task force concludes in the Annals of Internal Medicine.

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