U.S. Preventive Services Task Force
Release Date: December 2006
Summary of Screening Recommendations / Supporting Documents
Summary of Recommendations
Children
Pregnant Women
Rationale
Importance: Blood lead levels in children have declined dramatically
in the United States over the past two decades. However, segments of the population
remain at increased risk for higher blood lead levels. Even relatively low
blood lead levels are associated with neurotoxic effects in children. Severely
elevated blood lead levels in symptomatic pregnant women are associated with
poor health outcomes; however, lead levels in this range are rare in the U.S.
population.
Detection: There is good evidence that venous sampling accurately
detects elevated blood lead levels and fair evidence that validated questionnaires
are modestly useful in identifying children at increased risk for elevated
blood lead levels.
Benefits of Detection and Early Intervention: The USPSTF
found good quality evidence that interventions do not result in sustained decreases
in blood lead levels and found insufficient evidence (no studies) evaluating
residential lead hazard control efforts (i.e., dust or paint removal, soil abatement,
counseling, or education) or nutritional interventions for improving neurodevelopmental
outcomes in children with mild to moderately elevated blood lead levels. The
USPSTF found no evidence examining the effectiveness of screening or interventions
in improving health outcomes in asymptomatic pregnant women. Given the low
prevalence of elevated blood lead levels in children at average risk and asymptomatic
pregnant women, the magnitude of potential benefit cannot be greater than small.
A theoretical benefit of screening is that identification may prevent lead
poisoning of other individuals in a shared environment, but the magnitude of
this theoretical benefit is uncertain.
Harms of Detection and Early Treatment: There is good quality
evidence that chelation treatment in asymptomatic children does not improve
neurodevelopmental outcomes and is associated with a slight diminution in cognitive
performance. Chelation therapy may result in transient renal, hepatic, and
other toxicity, mild gastrointestinal symptoms, sensitivity reactions, and
rare life-threatening reactions. Residential lead-based paint and dust hazard
control treatments may lead to acutely increased blood lead levels from improper
removal techniques. Potential harms of screening are false-positive results,
anxiety, inconvenience, work or school absenteeism, and financial costs associated
with repeated testing. Although the exact magnitude of these known and potential
harms is uncertain, the overall magnitude is at least small.
No studies have directly addressed the harms of screening and interventions
for pregnant women. Although there is little specific evidence concerning the
potential harms of interventions for pregnant women with elevated blood lead
levels, the magnitude of harms from such interventions is also at least small.
USPSTF Assessment: The USPSTF concludes
that the evidence is insufficient to assess the balance between potential benefits
and harms of routine screening for elevated blood lead levels in children at
increased risk. Given the significant potential harms of treatment and residential
lead hazard abatement, and no evidence of treatment benefit, the USPSTF concluded
that the harms of screening for elevated blood lead levels in children at average
risk and in asymptomatic pregnant women outweigh the benefits.
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Supporting Documents
Screening for Lead Levels in Childhood and Pregnancy, December
2006
Recommendation
Statement (PDF File, 140 KB; PDF
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Screening
for Elevated Lead Levels in Childhood and Pregnancy: An Updated Summary of Evidence (PDF
File, 1 MB; PDF
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Evidence Update (PDF File 230 KB; PDF
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Current as of December 2006
Internet Citation:
Screening for Lead Levels in Childhood and Pregnancy, Topic Page. December 2006. U.S. Preventive Services Task Force. Agency for Healthcare Research and Quality, Rockville, MD. http://www.ahrq.gov/clinic/uspstf/uspslead.htm
540 Gaither Road Rockville, MD 20850