Quality in diagnostic microbiology: experiential note to emphasize value of internal control programs

Area of Science:

• Diagnostic Microbiology
• Laboratory Quality Management

Background:

• Quality control (QC) is critical for accurate and timely reporting in diagnostic microbiology.
• Key areas susceptible to QC issues include organism identification and antibacterial susceptibility testing.

Purpose of the Study:

• To provide evidence for the value of internal QC programs.
• To evaluate the effectiveness and efficiency of standard operating procedures.
• To assess the competence of laboratory staff.

Main Methods:

• Evaluation of an internal QC program across four scenarios.
• Comparison of ciprofloxacin versus moxifloxacin susceptibility testing.
• Assessment of calibrated dichotomous susceptibility versus directed susceptibility testing.

Main Results:

• The internal QC program successfully identified sources of laboratory result discrepancies.
• Evidence was generated to support decisions on new methodologies and antibiotic testing.
• Calibrated dichotomous susceptibility testing showed a significantly greater annular radius than directed susceptibility testing (P < 0.01).

Conclusions:

• Internal QC programs remain vital for identifying discrepancies and validating new approaches.
• The study reaffirms the continuous necessity of internal QC in diagnostic laboratories.