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Published on: September 16, 2012
Influence of sample collection and preanalytical sample processing on the analyses of biological markers in the
J Peplies1, K Günther, K Bammann
1Bremen Institute for Prevention Research and Social Medicine, University of Bremen, Germany.
Insights
Standardized sampling protocols are crucial for accurate biochemical measurements in multicenter studies like IDEFICS (Identification and prevention of dietary- and lifestyle-induced health effects in children and infants). Documenting deviations is key to avoid errors in biomarker concentration analysis.
Area of Science:
- Pediatric Health Research
- Biochemical Analysis
- Public Health Interventions
Background:
- The IDEFICS (Identification and prevention of dietary- and lifestyle-induced health effects in children and infants) study involved a large cohort of European children aged 2-8 years.
- Biochemical measurements from blood, urine, and saliva samples were collected during the baseline survey.
Purpose of the Study:
- To assess the impact of standardized sampling protocols and process quality on biochemical measurement outcomes across IDEFICS study centers.
- To identify variations in biomarker concentrations related to quality indicators and between participating countries.
Main Methods:
- Analysis of blood and urine measurements from 16,224 children (aged 2-8 years) across 8 European countries.
- Stratification of biomarker results by selected quality indicators, including fasting status and urine collection timing.
Main Results:
- Biomarker concentrations in blood and urine showed associations with quality indicators.
- Fasting status significantly influenced certain biomarker concentrations.
- Potential errors in morning urine biomarkers were identified due to nighttime voiding or non-first morning samples.
Conclusions:
- A standardized sampling protocol is essential for multicenter studies to ensure reliable biochemical data.
- Non-compliance with protocols can occur despite clear procedures; documentation of deviations is vital.
- Accurate documentation of protocol deviations helps mitigate errors in biological marker concentration interpretation.
Objective:
To evaluate the influence of a standardised sampling protocol and process quality across the different IDEFICS (Identification and prevention of dietary- and lifestyle-induced health effects in children and infants) centres on the results of the biochemical measurements.
Design:
Baseline survey within the community-based intervention study.
Subjects:
A total of 16,224 children, aged 2-8 years, enrolled in the IDEFICS baseline survey in 8 European countries. Venous or capillary blood samples were collected from 12,430 children, urine samples from 13,890 children and saliva samples from 14,019 children.
Methods:
A set of quality indicators was recorded for the biological blood, urine and saliva samples collected during the IDEFICS study. Results of blood and urine measurements were analysed and stratified by selected quality indicators.
Results:
Concentrations of biological markers in blood and urine measured during the IDEFICS baseline survey are associated with several quality indicators assessed in this study. Between-country variations of these biomarkers are described. It was confirmed that fasting has a big influence on the concentration of certain biomarkers. Biomarkers in morning urine samples may be erroneous if the study subjects void during the night or if samples are not taken from the very first morning urine.
Conclusions:
The analysed data underline that a standardised sampling protocol is of major importance, especially in multicentre studies, but non-compliance is ever present in spite of well-defined standard operation procedures. Deviations from the protocol should therefore always be documented to avoid error pertaining to the concentration of biological markers.
