[Maternal serum screening for Down's syndrome: a user's club experience]

Area of Science:

• Biochemistry
• Medical Diagnostics
• Quality Management

Background:

• Maternal serum marker screening for Down syndrome necessitates stringent quality control.
• The Down's Club Abbott user group evaluated the performance of specific reagents and software for this screening.

Purpose of the Study:

• To assess the performance and quality management of Down syndrome screening using maternal serum markers.
• To evaluate the effectiveness of a user's club in monitoring laboratory performance over time.

Main Methods:

• Collected data from five laboratories over three years (1998-2000) for total beta hCG and AFP reagents with Maciel software.
• Calculated medians, multiples of medians, and initial positive rates (cut-off 1/250) for a population of 31,020 women.
• Re-evaluated medians following a reagent change in July 1999 in collaboration with the manufacturer.

Main Results:

• Concomitant analysis of medians, multiples of medians, and positive rates is essential for detecting performance drifts.
• A significant population size (31,020 women) enhanced the statistical power of performance evaluations.
• User club participation improved individual laboratory quality management and long-term performance tracking.

Conclusions:

• Continuous, multi-parameter monitoring is vital for ensuring the reliability of Down syndrome screening tests.
• User clubs serve as an effective platform for collaborative quality assurance in diagnostic laboratories.
• The study highlights the importance of adapting quality management protocols to reagent or software updates.