Performance Verification Program for Serum Micronutrients

Overview

Target participants

Laboratories engaged in public health work assessing micronutrient status in populations.

Program goals

Maintain the quality of micronutrient measurements and document continued laboratory proficiency through an annual performance report.

Featured analytes

• Fat-soluble vitamins (vitamins A and D)
• Water-soluble vitamins (folate and vitamin B12)
• Iron-status indicators (ferritin and soluble transferrin receptor)
• Inflammation indicators (C-reactive protein and alpha-1-glycoprotein)

Participant requirements

• Receive 40 serum samples and 8 quality control samples per year
• Analyze 10 serum samples and 2 quality control samples per quarter in duplicate and return data to CDC after each of the 4 challenges
• Receive a brief summary report after each challenge and a comprehensive annual performance report showing the measurement imprecision and the percent difference compared to CDC CLIA-approved methods; the annual performance report is valid for one year
• Alternatively, analyze all 40 samples in duplicate over a shorter period of time for a one-time assessment of method comparability to CDC

About the program

CDC's Nutritional Biomarkers Branch (NBB) established the serum micronutrients performance verification program in 2019. The program provides an independent assessment and documentation of analytical performance to laboratories working to determine population micronutrient status.

The program complements a larger collaborative project between CDC, the CDC Foundation, the Nutrition International Folate Task Team, and the Bill and Melinda Gates Foundation to develop regional laboratory capacity for the measurement of folate and other micronutrients (Pfeiffer et al., 2018).

The performance verification program follows the CLSI EP9-A2 guideline (Clinical Laboratory Standards Institute, 2002) and provides 40 samples to allow a comprehensive method comparison to the CDC CLIA-approved methods. The program assesses the mean difference between the test and the CDC method, as well as the relationship between the 2 methods across the concentration range. It also provides 8 quality control samples to assess multi-day method imprecision. Some of the program materials are pooled serum, while others are single-donor materials.

The performance verification program is voluntary and non-regulatory, and does not provide laboratory accreditation. Participation can be either on a one-time basis to assess method performance (e.g., upcoming survey) or a continuous basis, where the 40 samples are analyzed over the course of one year (e.g., 10 samples per quarter). The program uses objective quality goals based on biologic variation to assess the acceptability of method performance (Fraser et al., 1997).

Shipping and reporting schedule

Participating laboratories must be able to receive frozen samples packed in dry ice, retrieve samples from customs at the airport, and pay for any costs required by customs.

Program costs

CDC offers materials for verification of 1 analyte, up to 3 analytes, and up to 8 analytes. Participants pay a user fee to cover CDC’s costs for developing program materials. Participants also pay for material shipping costs.

How to enroll

For additional program and enrollment information, contact micronutrbiomarkers@cdc.gov, noting your analytes of interest. Please include the country and/or laboratory name and "Micronutrients performance verification program" in the subject line.

References

Clinical Laboratory Standards Institute. Method Comparison and Bias Estimation Using Patient Samples (CLSI document EP9-A1). Wayne, PA: Clinical Laboratory Standards Institute. 2002.

Fraser CG, Hyltoft PP, Libeer JC, Ricos C. Proposals for setting generally applicable quality goals solely based on biology. Ann Clin Biochem 1997;34:8–12.

Pfeiffer CM, Zhang M, Jabbar S. Framework for laboratory harmonization of folate measurements in low- and middle-income countries and regions. Ann N Y Acad Sci 2018; 1414:96–108.