Exploring the links between quality assurance and laboratory resources. An audit-based study.

Area of Science:

• Medical Laboratory Science
• Microbiology
• Cytopathology

Background:

• Ziehl-Neelsen (Z-N) staining is crucial for diagnosing tuberculosis (TB) in cytology.
• Quality assurance is essential to maintain the accuracy of Z-N staining.
• Previous laboratory practices may have led to suboptimal diagnostic yields.

Purpose of the Study:

• To identify and resolve issues affecting Ziehl-Neelsen (Z-N) staining quality.
• To improve the accuracy of acid-fast bacillus (AFB) detection in fine needle aspiration cytology.
• To enhance overall laboratory quality assurance for TB diagnostics.

Main Methods:

• An audit-based quality assurance study was conducted on 1,421 patients with suspected tubercular lymphadenopathy.
• Laboratory practices for Z-N smear selection were evaluated over an 8-month period (Group 1).
• A two-step corrective intervention was implemented and assessed over 2 months (Group 2), with statistical analysis using the chi-squared test.

Main Results:

• In Group 1 (n=1,172), 368 diagnoses were not tuberculosis, and overall AFB positivity was 42%.
• Following corrective measures in Group 2 (n=249), AFB positivity dramatically increased to 89%.
• The observed improvement in AFB positivity was statistically significant (P < .0001).

Conclusions:

• Laboratory quality assurance issues directly impact the effectiveness of Z-N staining.
• Addressing routine laboratory problems yields substantial benefits for personnel, resource management, and workflow efficiency.
• The implemented corrective measures significantly enhanced the diagnostic yield of AFB detection through Z-N staining.