Researchers at the Pacific Northwest Evidence Based Practice Center at OHSU have determined that current clinical prediction tools and patient questionnaires are not effective in identifying the risk of potential blood lead exposure in the most vulnerable patient populations: children and pregnant women.
A systematic review of data evaluating the effects of lead screening, testing and treatment published today in JAMA. This finding poses a challenge in primary care settings as, according to lead author Amy Cantor, M.D., M.P.H., the majority of individuals exposed to lead may not show typical symptoms of illness.
“In lieu of accurate screening instruments for identifying children at risk, alternative strategies would be to consider targeted screening in communities with high prevalence of elevated lead levels,” she said.
This requires health care practitioners to take a careful history to determine and assess the potential risk of exposure and need for further testing. When the available risk assessment tools are not effective, the potential for misdiagnosis increases.
Based on these results, the U.S. Preventative Services Task Force – an independent panel of experts dedicated to making evidence-based recommendations regarding the effectiveness of preventive care services – has updated its 2006 blood lead level screening recommendations to suggest that additional research is necessary to determine what primary care clinicians can do to help identify and treat the health problems resulting from lead exposure. This may include various neurological and physical development challenges in children, as well as increased risk of pre-eclampsia or adverse perinatal outcomes during pregnancy.
In the United States, approximately 24 million housing units contain lead-based paint, or contaminated dusts, according to the Centers for Disease Control and Prevention. Four million of these residences inhabit children who are highly vulnerable to the impacts of lead poisoning.
The best way to protect an individual from lead exposure is prevention.
In the meantime, Cantor, an associate professor in the departments of medical informatics and clinical epidemiology, family medicine and obstetrics and gynecology at the OHSU School of Medicine, recommends that patients or parents concerned about a household or community exposure should discuss it with their health care provider to determine the necessity, risk and benefit of diagnostic testing.
“The good news is that blood tests to detect levels of lead exposure are accurate. Patients may be reassured by normal levels, or can determine appropriate management or monitoring of elevated levels with a provider in the face of elevated blood lead, ” she said. “However, while no level of lead is safe, the most important strategy is to identify potential sources of lead and prevent ongoing or repeated exposures.”
This study was funded under contract HHSA290201500009I, Task Order No. 7, from the Agency for Healthcare Research and Quality U.S. Department of Health and Human Services, under a contract to support the USPSTF.