The correlation between paired, simultaneously drawn extraction method filter paper and venous samples is >.970. Additionally, undetected-elevated and, falsely-elevated rates may be considered clinically insignificant. These findings are documented by three published, peer-reviewed studies involving 363 paired, simultaneously drawn extraction method filter paper and venous sample comparisons.
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Keyrati Srivuthana et al. A New Filter Paper Method to Measure Capillary Blood Lead Level in Children. Arch. Pediatr. Adolesc. Med., 150: 498-502 (1996).
Hugh Y. Yee. An Improved Capillary Blood-Filter Paper-Graphite Furnace Atomic Absorption Spectrometric Method for Lead Screening. Journal of Analytical Toxicology, Vol. 21: 142-148 (1997).