Reference intervals for serum creatinine concentrations: assessment of available data for global application

Area of Science:

• Clinical Chemistry
• Laboratory Medicine
• Renal Function Assessment

Background:

• Serum creatinine reference intervals remain crucial for renal function assessment, complementing estimated glomerular filtration rate (eGFR).
• Numerous studies on creatinine reference values have been published, necessitating a systematic approach to identify reliable intervals.
• This study aimed to establish universally applicable reference intervals for serum creatinine using established criteria.

Purpose of the Study:

• To systematically review existing literature on serum creatinine reference values.
• To identify universally applicable reference intervals for serum creatinine based on stringent criteria.
• To provide recommended reference intervals for white adults and children.

Main Methods:

• Systematic literature review adhering to IFCC (International Federation of Clinical Chemistry and Laboratory Medicine) criteria.
• Inclusion criteria: a priori selection of reference individuals, adequate description of preanalytical conditions, demonstrated traceability to isotope dilution-mass spectrometry (IDMS), and adequate statistical treatment.
• Exclusion of studies lacking adequate measurement traceability to IDMS.

Main Results:

• Out of 37 reports on serum creatinine reference values, only 6 met the inclusion criteria (1 pediatric, 5 adult).
• Inadequate demonstration of measurement traceability was the primary reason for excluding most studies.
• Recommended reference intervals for serum creatinine for white adults and children were collated from the selected studies.

Conclusions:

• Laboratories employing methods traceable to IDMS can confidently apply the derived reference intervals for serum creatinine.
• The identified reference intervals are applicable for evaluating renal function in white individuals.
• This work provides a reliable basis for serum creatinine reference intervals, emphasizing measurement traceability.