Update to Evaluation for IHPAT Diffusive Sampler Program

Following an internal data review and discussion with the PAT Board, AIHA PAT Programs has updated the evaluation methodology for the IHPAT Diffusive Sampler program.

Beginning with Round 244, the fixed 6% relative standard deviation (RSD) previously applied to diffusive samplers has been removed. Moving forward, diffusive samplers will be evaluated using the same methodology applied to all other IHPAT samples. Acceptance limits will now be derived from:

• The reference group SD, or
• The calculated SD based on a capped 4%–20% RSD range 

This update promotes greater alignment and consistency across IHPAT analytes and reflects current program data and performance trends.

The revised evaluation methodology takes effect with IHPAT Diffusive Sampler Round 244.