Chronic kidney disease controversy: how expanding definitions are unnecessarily labelling many people as diseased

Summary box

• Clinical context—Concern about the late presentation of kidney disease and missed opportunities for earlier intervention

• Diagnostic change—A novel framework defining and classifying “chronic kidney disease” (CKD) introduced in 2002 and modified in 2012, based largely on laboratory measurements of kidney function and damage

• Rationale for change—Identifying chronic kidney disease early would slow progression towards total kidney failure and provide an opportunity to prevent associated illness, particularly cardiovascular disease

• Leap of faith—Identifying, monitoring, and treating the newly described chronic kidney disease will improve survival and quality of life

• Increase in disease—The new definition labels over 1 in 8 adults (around 14%) as having chronic kidney disease. Before 2002 the lack of a consistent definition made prevalence estimates unreliable, but one US study suggested a figure of 1.7% of the population.

• Evidence of overdiagnosis—The combination of the large numbers now labelled as having chronic kidney disease with low rates of total kidney failure suggest many of those diagnosed will never progress to symptomatic forms of kidney disease

• Harms from overdiagnosis—Psychological effect of a disease label and the burden and costs of repeated assessment, testing, and potentially unnecessary treatment

• Limitations—Lack of prospective data evaluating the benefits and harms of testing for, monitoring, and treating the early stages of chronic kidney disease

• Conclusions—Clinicians should be sceptical about the current definition of chronic kidney disease and cautious about labelling patients, particularly older people