Screening for pediatric lead poisoning. Comparability of simultaneously drawn capillary and venous blood samples

OBJECTIVE: To determine the ability of capillary blood lead levels to accurately reflect true blood lead levels in children at risk for lead poisoning. DESIGN: A correlation study in which lead levels of capillary blood specimens obtained by four different methods were compared with lead levels of simultaneously drawn venous blood specimens. SETTING: A central-city pediatric primary care clinic and door-to-door home visits in one central-city neighborhood. PATIENTS: Two hundred ninety-five children at high risk for lead poisoning aged 6 months to 6 years. MAIN OUTCOME MEASURES: Blood lead levels of simultaneously drawn capillary and venous blood specimens. RESULTS: Lead levels of all four capillary sampling methods were highly correlated (correlation coefficient > or = 0.96) with matched venous blood lead levels, with mean capillary-venous differences less than 0.05 mumol/L (1 microgram/dL). CONCLUSIONS: Capillary sampling is an acceptable alternative to venipuncture for lead-poisoning screening in young children.