Medicaid recommends children have their blood lead levels tested at 12 and 24 months old.1 Those not on Medicaid are advised to get tested if they are considered high-risk, which includes factors such as housing built prior to 1978, known exposure to lead, and low income, though some health departments are encouraging this practice for all children.1,2
To assess the potential benefit of a second lead level test, we studied 42,709 children who had their blood lead levels tested at both 12 and 24 months of age. We found that only 0.53% of children tested positive at both 12 and 24 months of age. We found that an additional 1.72% had a positive blood lead level at 24 months after having tested negative at 12 months. This indicates that further testing among those whose initial test was negative is beneficial in identifying future exposure to lead. Conversely, 1.47% of children tested positive at 12 months then went on to test negative at 24 months, indicating improvement one year later. Of note, overall positivity rates remain low, as seen in Figure 1.
