title: Analysis of a novel field dilution method for testing samples that exceed the analytic range of point-of-care blood lead analyzers.
abstract: Investigators developed and evaluated a dilution method for the LeadCare II analyzer (LCII) for blood lead levels >65 μg/dL, the analyzer's maximum reporting value. Venous blood samples from lead-poisoned children were initially analyzed in the field using the dilution method. Split samples were analyzed at the US Centers for Disease Control and Prevention (CDC) laboratory using both the dilution method and inductively coupled plasma-mass spectrometry (ICP-MS). The concordance correlation coefficient of CDC LCII vs. ICP-MS values (N = 211) was 0.976 (95 % confidence interval (CI) 0.970-0.981); of Field LCII vs. ICP-MS (N = 68) was 0.910 (95% CI 0.861-0.942), and CDC LCII vs. Field LCII (N = 53) was 0.721 (95% CI 0.565-0.827). Sixty percent of CDC and 54% of Field LCII values were within ±10% of the ICP-MS value. Results from the dilution method approximated ICP-MS values and were useful for field-based decision-making. Specific recommendations for additional evaluation are provided.
authors.affiliation: a US Centers for Disease Control Prevention , Atlanta , GA , USA.
authors.forename: Antonio James
authors.initials: AJ
authors.lastname: Neri
authors.forename: Joannie
authors.initials: J
authors.lastname: Roy
authors.forename: Jeffery
authors.initials: J
authors.lastname: Jarrett
authors.forename: Yi
authors.initials: Y
authors.lastname: Pan
authors.forename: Carrie
authors.initials: C
authors.lastname: Dooyema
authors.forename: Kathleen
authors.initials: K
authors.lastname: Caldwell
authors.forename: Nasir Tsafe
authors.initials: NT
authors.lastname: Umar-Tsafe
authors.forename: Ruth
authors.initials: R
authors.lastname: Olubiyo
authors.forename: Mary Jean
authors.initials: MJ
authors.lastname: Brown
mesh_terms: D001774:Blood Chemical Analysis / Q000379:methods*; D002675:Child, Preschool; D004785:Environmental Pollutants / Q000097:blood*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007854:Lead / Q000097:blood*; D009549:Nigeria; D013054:Spectrophotometry, Atomic / Q000379:methods*
chemical_list: D004785:Environmental Pollutants; D007854:Lead
keywords: dilution methods; laboratory; lead poisoning