Reliability of white blood cell counting

Area of Science:

• Clinical Laboratory Science
• Medical Diagnostics
• Quality Assurance in Healthcare

Background:

• The Laboratory Proficiency Testing Program in Ontario has operated for 13 years.
• Peer committees facilitate this voluntary, alternative to gubernatorial proficiency testing.
• Historical data from 1975 shows clinical expectations for white blood cell (WBC) counts exceeded laboratory capabilities.

Purpose of the Study:

• To evaluate the effectiveness of a peer-based laboratory proficiency testing program.
• To assess improvements in white blood cell (WBC) count accuracy and precision over time.
• To identify factors contributing to enhanced laboratory performance.

Main Methods:

• Utilized white blood cell (WBC) count determinations as a key performance indicator.
• Analyzed results from a mandatory, 13-year proficiency testing program in Ontario.
• Examined program details including testing materials, computer analysis, and reference results.

Main Results:

• 96% of participants achieved WBC count results within +/- 10% of the all-methods mean.
• 77% of participants attained results within +/- 5% of the all-methods mean.
• 96% of participants demonstrated satisfactory precision in their WBC count determinations.

Conclusions:

• The proficiency testing program significantly improved laboratory performance in WBC counting.
• The transition from manual to automated counting methods, driven by proficiency testing, was a key factor in improvement.
• By 1987, laboratories consistently produced reliable and clinically useful WBC count results.