Letters Chronic kidney disease definition

An alternative classification system for chronic kidney disease

BMJ 2013; 347 doi: https://doi.org/10.1136/bmj.f5566 (Published 18 September 2013) Cite this as: BMJ 2013;347:f5566
  1. G Van Pottelbergh, general practitioner and researcher1,
  2. J M Degryse, general practitioner and researcher2
  1. 1Department of Public Health and Primary Care, KU Leuven, Belgium
  2. 2IRSS, UC Louvain, Belgium
  1. gijs.vanpottelbergh{at}med.kuleuven.be

We have several comments on Moynihan and colleagues’ excellent article about the overdiagnosis of chronic kidney disease (CKD).1

Firstly, two large cohort studies with long follow-up have shown that the chance of developing adverse outcomes (mortality or need for renal replacement therapy) is much lower in older age groups.2 3 This finding was confirmed in a large meta-analysis of the CKD consortium.4

Secondly, the current classification of CKD doesn’t take into account the evolution of estimated glomerular filtration rate over time, although it has been shown in several studies,5 including in the oldest old,6 that a rapid decline in this measure is a good predictor of adverse outcomes.

In 2012 the Belgian guideline for general practitioners on CKD incorporated these factors (age and rapid decline in estimated glomerular filtration rate over time) into an alternative CKD classification. This alternative classification (box) distinguishes two groups of CKD patients: high risk patients who should be in a shared care programme and those with intermediate risk who should be referred for diagnostic investigations.

Proposed classification criteria for chronic kidney disease

High risk patients
  • Patients with eGFR chronically <30 ml/min/1.73m2

  • Patients with eGFR 30-45 ml/min/1.73m2 and ACR >300 mg/g or PCR >1000 mg/g

Intermediate risk patients
  • Patients <75 years with eGFR 30-45 ml/min/1.73m2 and ACR of 30-300 mg/g

  • Patients with eGFR 30-45 ml/min/1.73m2 and a decrease in eGFR of >10 ml/min/1.73m2 in the past five years

  • Patients with eGFR >45 ml/min and ACR >300 mg/g or PCR >1000 mg/g

  • ACR=albumin to creatinine ratio; eGFR=estimated glomerular filtration rate; PCR=protein to creatinine ratio.

Use of this alternative classification avoids patients unnecessarily being labelled as having a chronic disease and reduces the prevalence of people with “real CKD” from 14% to about 2% of the population.

Notes

Cite this as: BMJ 2013;347:f5566

Footnotes

References

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