Validity and Reliability of Portable Blood Lactate Analyzers: A Systematic Review with COSMIN and GRADE Assessment

Area of Science:

• Sports Medicine
• Biomedical Engineering
• Clinical Diagnostics

Background:

• Portable blood lactate analyzers (PBAs) are widely used in sports and clinical settings.
• Blood lactate is a key biomarker for performance and metabolic threshold assessment.
• Concerns exist regarding PBA accuracy, sampling, and calibration variability.

Purpose of the Study:

• Systematically review studies on the validity and reliability of commercial PBAs.
• Compare PBA performance against laboratory reference methods.
• Evaluate study quality and evidence certainty using COSMIN and GRADE frameworks.

Main Methods:

• Systematic literature search following PRISMA 2020 guidelines across major databases.
• Included 25 studies assessing PBA validity and reliability.
• Employed statistical measures (e.g., CCC, LoA, ICC, CV) and COSMIN/GRADE for quality assessment.

Main Results:

• PBAs demonstrated strong correlations (r=0.95-0.99) and high reliability (ICC>0.90).
• Systematic biases were noted at higher lactate concentrations.
• Thirteen studies exhibited high methodological quality.

Conclusions:

• PBAs offer strong reliability and moderate-to-high validity for lactate measurement.
• Standardized protocols and enhanced calibration are necessary for consistency with lab analyzers.