Does routine repeat testing of critical laboratory values improve their accuracy?

Area of Science:

• Clinical Laboratory Science
• Medical Diagnostics

Background:

• Repeat testing of critical laboratory values is a common practice to ensure accuracy.
• The clinical utility and benefit of this routine repeat testing remain under investigation.

Purpose of the Study:

• To evaluate the benefits of routine repeat testing for critical laboratory values.
• To determine if repeat testing enhances the accuracy of critical results.

Main Methods:

• Analyzed 2233 repeated critical values across 13 hematology and chemistry tests.
• Calculated absolute and percentage differences between initial and repeat tests.
• Compared results against established allowable error limits (e.g., CAP/CLIA).

Main Results:

• 99.1% of repeat tests fell within allowable error margins.
• Few outliers were observed in specific tests like white blood cell, platelet, PTT, and INR.
• The vast majority of repeat tests confirmed the initial critical values within acceptable limits.

Conclusions:

• Routine repeat testing of critical values in hemoglobin, WBC, platelets, INR, PTT, glucose, and electrolytes offers no significant accuracy benefit.
• The practice does not appear to increase the reliability of these common critical laboratory results.
• Findings suggest re-evaluating the necessity of routine repeat testing for critical values.