Cystatin C, mortality risk and clinical triage in US adults: threshold values and hierarchical importance

Nephrol Dial Transplant. 2011 Jun;26(6):1831-7. doi: 10.1093/ndt/gfq629. Epub 2010 Oct 20.


Background: It has been suggested that cystatin C may be a superior measure of estimated glomerular filtration rate (eGFR) than creatinine-based methods. We aimed to assess the utility of cystatin C for clinical triage in community-based settings.

Methods: We identified cystatin C thresholds that maximize sensitivity and specificity (Max(Sn + Sp)) for predicting death and subsequently applied classification tree methodology considering serum creatinine, creatinine-based eGFR, urinary albumin-creatinine ratio and conventional modifiable risk factors to define subgroups, interactions and hierarchical ranks in fasting US adults (National Health and Nutrition Examination Survey 1988-94, followed through 2006).

Results: A threshold cystatin C value of 0.94 mg/L exhibited the best maximum combined value of sensitivity and specificity for predicting death (Max(Sn + Sp), Sn 0.64/Sp 0.78). When all variables were considered jointly in a classification tree, cystatin C and albumin-creatinine ratio were the primary mortality discriminators in subgroups that added up to 41 and 14% of the study population, respectively; serum creatinine and creatinine-based eGFR were non-discriminatory.

Conclusion: Cystatin C may be useful for risk-based clinical triage in public health settings.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Aged
  • Cardiovascular Diseases / metabolism
  • Cardiovascular Diseases / mortality*
  • Creatinine / blood
  • Cross-Sectional Studies
  • Cystatin C / metabolism*
  • Diabetes Mellitus / metabolism
  • Diabetes Mellitus / mortality*
  • Female
  • Glomerular Filtration Rate
  • Humans
  • Kidney Failure, Chronic / metabolism
  • Kidney Failure, Chronic / mortality*
  • Kidney Function Tests
  • Male
  • Middle Aged
  • Prognosis
  • Risk Factors
  • Sensitivity and Specificity
  • Survival Rate
  • Triage


  • Cystatin C
  • Creatinine