Quality control log with CUSUM and clinically useful limits criteria

Area of Science:

• Clinical Chemistry
• Analytical Science
• Quality Control

Background:

• Traditional quality control charts like Levey-Jennings and Shewart are widely used in clinical chemistry.
• These methods may have limitations in detecting specific types of analytic drift.
• There is a need for practical and effective QC systems in quantitative assays.

Purpose of the Study:

• To describe a novel quality control (QC) log system for quantitative assays in clinical chemistry.
• To highlight the advantages of this QC log over existing graphic charts.
• To provide a practical system for analytic quality control.

Main Methods:

• The QC log system utilizes cumulative sum (CUSUM) techniques to monitor acute analytic drift.
• Comparison of means is employed to detect chronic analytic drift.
• Clinically useful limits (CUL) criteria are integrated for QC decision-making.
• An algorithm is provided to aid in the description, training, and implementation of the system.

Main Results:

• The proposed QC log system offers practical advantages for analytic quality control.
• It effectively monitors both acute and chronic analytic drift.
• The use of CUL criteria enhances the reliability of QC decisions.
• The provided algorithm simplifies the adoption and use of the QC log.

Conclusions:

• The described QC log system is a practical and effective tool for analytic quality control in clinical chemistry.
• It provides superior monitoring capabilities for analytic drift compared to traditional charts.
• The system, incorporating CUSUM, mean comparison, and CUL criteria, improves the accuracy and utility of QC processes.