In a new clinical practice guideline, the American College of Physicians (ACP) recently recommended against screening for chronic kidney disease (CKD) in asymptomatic adults without risk factors (Ann Intern Med 2013;159:1–13). The guideline committee based this recommendation, rated as weak with low-quality evidence, on an extensive scientific literature review dating back to 1985.
"The potential harms of all the screening tests—false positives, disease label, and unnecessary treatment and associated adverse effects—outweigh the benefits," said ACP President Molly Cooke, MD, in a statement. "Ordering lab tests is not going to have any impact on clinical outcomes of asymptomatic patients with CKD without risk factors, but will add unnecessary costs to the healthcare system due to increased medical visits and unnecessary tests."
The evidence review, sponsored by the Agency for Healthcare Research and Quality and conducted by the Minnesota Evidence-Based Practice Center, sought to answer six key questions, including: what direct evidence is there that systematic CKD screening improves clinical outcomes; what harms result from CKD screening in asymptomatic adults; what direct evidence is there that monitoring kidney function or damage improves clinical outcomes in adults with stage 1–3 CKD; what harms result from monitoring stage 1–3 CKD patients for worsening kidney function or damage; what direct evidence substantiates that treatment improves clinical outcomes in stage 1–3 CKD patients; and what harms result from treating patients with stage 1–3 CKD.
The authors found indirect evidence in support of screening, such as adverse health consequences from CKD, and the prevalence of CKD. However, they found no direct evidence through randomized, controlled trials that compared the effect on clinical outcomes of systematic CKD screening versus not screening. Similarly the authors found no randomized, controlled trials that have evaluated the harms of systematic CKD screening. They said, however, that expert opinion suggests some of the harms include misclassifying patients due to false-positive results, negative effects from unnecessary testing, and psychological effects to patients from being labeled with CKD.
In 2012, both the American Academy of Family Practitioners and the U.S. Preventive Services Task Force concluded that there was insufficient evidence to assess the balance of benefits and harms from routine CKD screening in asymptomatic adults. However, the American Society of Nephrology (ASN) issued a sharply worded statement disagreeing with the ACP guideline.
"If detected early in its progression, kidney disease can be slowed and the transition to dialysis delayed. This evidence-based fact is why regular screening and early intervention by a nephrologist is so important to stemming the epidemic of kidney disease in the United States and why ASN strongly recommends it," said ASN President Bruce Molitoris, MD. He added that CKD increases the risk of experiencing acute kidney injury (AKI) from nephrotoxic medications, sepsis, surgery, or contrast dyes. AKI, in turn, worsens CKD. "This vicious cycle must be stopped," he contended.
Todd Ibrahim, ASN's executive director, called ACP's recommendation "irresponsible."
The guideline also recommended against testing for proteinuria in adults with or without diabetes who are taking an angiotensin-converting enzyme inhibitor or an angiotensin II-receptor blocker. In addition, the authors found no net benefit of routinely monitoring patients with stage 1 to 3 CKD, although individual monitoring could help some patients based on their risk level.