[Sampling methods and errors appearing in the China National Human Biomonitoring Program]

Area of Science:

• Environmental Health
• Public Health Surveillance
• Biomonitoring

Background:

• The China National Human Biomonitoring Program (HBP) is crucial for assessing population exposure to environmental contaminants.
• Evaluating the accuracy and efficiency of HBP's sampling methodology is essential for reliable health data.
• Understanding sampling errors is key to interpreting biomonitoring results.

Purpose of the Study:

• To analyze the sampling methodology employed in the China National Human Biomonitoring Program (HBP).
• To identify and quantify sampling errors within the HBP framework.
• To assess the overall study design concerning sampling procedures.

Main Methods:

• Utilized a multistage sampling approach for the HBP.
• Applied multistage unequal probability sampling error calculations.
• Analyzed sampling data from Guizhou province as a case study, calculating sampling error and coefficient of variation.

Main Results:

• The HBP involved 152 sites and 21,888 residents across 31 provinces.
• Replacement rates at different sampling stages were 5.26%, 6.35%, and 40.6%.
• Guizhou province exhibited a sampling error of 3,207,594 with a coefficient of variation of 0.097.

Conclusions:

• The multistage unequal probability sampling method demonstrated high precision with low variability in Guizhou.
• The current method overlooks the adjustment for non-sampling errors like missing population data and response rates.
• Further research is needed on calculating multistage sampling errors for large public health monitoring initiatives.