Clinical and Health Affairs
Blood Lead Screening among Newly Arrived Refugees in Minnesota
By Mandi Proue, M.P.H., Rhonda Jones-Webb, Dr.P.H., and Charles Oberg, M.P.H., M.D.
Abstract
During the last 10 years, the prevalence rate of elevated blood lead levels (EBLLs) in the general population in the United States has decreased, while the rate of EBLLs among refugee children in this country has remained high. Because of this, national guidelines recommend both an initial and a repeat screening of refugee children. To explore blood lead screening among refugee children in Minnesota, we examined data on 1,256 children who arrived in Minnesota between 2004 and 2007. Our objectives were to describe the characteristics of refugee children who are screened for blood lead; identify the characteristics of refugee children with an EBLL following screening; and describe the characteristics of refugee children who received a repeat blood lead test. Our results showed that approximately 6% of refugee children in Minnesota had an EBLL and fewer than half of all refugee children in the sample received a repeat test. For that reason, primary care providers should be periodically reminded of the importance of repeat lead screening for refugee children.
One of the goals of Healthy People 2010, a set of objectives developed by the federal government for promoting health and preventing disease, is to eliminate elevated blood lead levels (>10µg/dL) in children.1 Exposure to lead is associated with poor school performance, learning disabilities, hearing damage, poor muscle coordination, decreased muscle and bone growth, and nervous system damage. Over the past decade, the prevalence rate of elevated levels of lead in the blood of people in the United States has decreased from 2.2% to 0.7%.2 However, the prevalence of elevated blood lead levels (EBLL) among refugee children in this country remains high.3-6 Geltman and colleagues analyzed the blood lead levels of refugee children arriving in Massachusetts and found the rate of elevated levels was twice as high among refugee children as it was among children born in the United States.3
Elevated blood lead levels are especially common among refugee children who are male, younger, and living in older homes.5,6 Trepka and colleagues found being male, having a racial/ethnic identification other than white, eating paint chips, and living in a home built after 1979 were associated with EBLLs in Cuban refugee children.6
The Centers for Disease Control and Prevention’s (CDC) 2005 guidelines call for all refugee children ages 6 months to 16 years to have a blood lead screening done within 90 days of their arrival in the United States.7 The guidelines also recommend that a repeat test be done on refugee children ages 6 months to 6 years within three to six months of their arrival, regardless of initial test results. Some children may not have an EBLL on arrival but will upon follow-up, reinforcing the need for a repeat test after they settle into a permanent residence.
Few studies have looked at whether refugee children are receiving repeat blood lead tests and, if so, which ones are most likely to receive them. Geltman and colleagues found only 30% of the refugee children in their sample were retested; but this study was conducted prior to the release of the 2005 CDC guidelines.3 Zabel, Smith, and O’Fallon evaluated the feasibility and practicality of implementing the CDC recommendations in Minnesota and reported that 93% of the 150 refugee children in their sample had a repeat blood lead test.8
Blood Lead Screening in Minnesota
Our study examined blood lead screening among refugee children in Minnesota between 2004 and 2007. Our objectives were to 1) describe the characteristics of refugee children who receive a blood lead screening; 2) identify the characteristics of refugee children who tested positive for an EBLL; and 3) describe the characteristics of refugee children who receive a repeat blood lead test. By understanding who is most likely to be at risk and screened for an EBLL, health professionals may be able to better target blood lead screening efforts among refugee children.
Minnesota is an ideal place to examine blood lead screening efforts among refugee children. Between 1979 and 2007, 88,643 refugees from 74 countries were resettled in the state. In 2007 alone, 2,867 refugees from 29 countries made Minnesota their home.9 These refugees include all individuals who are classified as primary refugees, asylees, parolees, or victims of trafficking.
Methodology
The data for our study were drawn from the Minnesota Department of Health’s Refugee Health Program and the Lead Surveillance Database in the Environmental Health Division. The Refugee Health Program receives assessment data on clinical measures including blood lead levels from clinics and providers who administer a mandatory health assessment to refugees within 90 days of their arrival. About 98% of refugees in Minnesota receive an initial refugee health assessment.10 The results from this assessment and any subsequent lead test results are also stored in the Lead Surveillance Database. Assessment of blood lead level is mandatory for children who are younger than 5 years of age.
Our sample included refugee children who were younger than 6 years of age at the time of their arrival. Only children who received at least one blood lead screening between January 1, 2004, and December 31, 2007, and had a result stored in the Lead Surveillance Database were analyzed. We identified 1,256 refugee children who met those criteria.
■ Measures
Dependent variables were the number of refugee children who were determined to have an EBLL and the number of refugee children who had a repeat blood lead screening test regardless of their EBLL status at baseline. An EBLL was defined as a lead level ≥10 µg/dL. We first gathered the names and birthdates of all children who were 6 years of age and younger who arrived in Minnesota between January 1, 2004, and December 31, 2007. We matched their blood lead levels reported to the Minnesota Department of Health with the follow-up blood lead test results stored in the Minnesota Lead Surveillance Database through June 1, 2008.
Independent variables included sex, age at first screening, year of arrival, county of resettlement, region of origin, and result of first blood lead test. We ascertained age at first screening (0 to 3 years, 4 to 5 years, and 5 years and older) by calculating the difference between the date of the first screening and the child’s date of birth. We obtained year of arrival information from the Department of Health’s refugee health database. We assessed region of origin from each refugee’s overseas documents and included the region where the family lived prior to arrival in the United States (Southeast Asia, Eastern Europe and Russia, West Africa, and East Africa). We obtained counts and frequencies to describe the characteristics of refugee children in Minnesota who had been identified as having EBLL. We employed Chi-square analyses to describe the characteristics of refugee children who received a repeat blood lead test.
We used logistic regression analysis in multivariate analyses. An EBLL at baseline was regressed on sex, age at first screening, year of arrival, county of resettlement, and region of origin. Obtaining a repeat blood lead test was regressed on sex, age at first screening, year of arrival, county of resettlement, region of origin, and blood lead level at baseline. No logistical analyses were conducted examining the demographic characteristics of children with an EBLL at follow-up because the numbers were too small (n=43). A P value of <0.05 was considered significant in the regression models.
Results
We found almost half of the 1,256 refugee children screened at arrival were younger than 3 years of age (43.2%) and about one-third (34.2%) were between 4 and 5 years of age (Table 1). A majority of the children (62.9%) were from Southeast Asia and lived in Ramsey County (48.1%). The largest number of refugee children screened over the four-year period arrived in 2005 (37.5%). Of the 1,256 children who were screened at baseline, 72 (about 6%) had elevated levels of lead in their blood (Table 2). Children with an EBLL were more likely to be younger than 3 years of age (n=34), male (n=45), from Southeast Asia (n=47), and live in Ramsey County (n=42).
We found that less than half (47%) of the children tested at baseline received a repeat blood lead test. Children who were younger, male, and from Southeast Asia and East Africa were significantly more likely than other children to receive a repeat blood lead test (Table 3). County of resettlement was not associated with having a repeat blood lead test. Of the children who received a repeat blood lead test, 7% had an EBLL. Refugee children who had an EBLL at follow-up had many of the same demographic characteristics as those who had an EBLL at baseline (Table 2).
Our multivariate analysis showed that none of the demographic variables were associated with having an EBLL at baseline in adjusted analyses (data not shown). However, sex was marginally associated with an EBLL (OR=0.62; CI=0.38, 1.02), with male refugee children having higher odds of having an EBLL than females.
We did find that age at first screening, region of origin, having an EBLL at baseline, and year of arrival were significantly associated with having a repeat blood lead test (Table 4). The odds of having a repeat test were higher for children who were younger, from East Africa, and who had an EBLL at baseline. The likelihood of having a second test was greatest for refugee children arriving in 2005.
Discussion
Our results suggest that refugee children in Minnesota are at increased risk for EBLL. The prevalence rate of EBLLs among refugee children was nearly six times the rate for all Minnesota children in 2008 and eight times the rate nationally in 2005.11
National guidelines recommend repeat lead screening regardless of EBLL status upon arrival for all refugee children. In Minnesota, less than half the number of refugee children screened for an EBLL at baseline received a repeat blood test. There may be several reasons for this. For one, refugee families may not be fully aware of the risks of lead poisoning and the importance of lead screening. Trepka and colleagues found this to be the case in their study of Cuban refugee families.6 Also, refugee families may be dealing with other more pressing issues such as securing housing and employment, which prevents them from seeking a repeat blood lead test for their children. Additionally, for some families, there may be no one in the household who is proficient enough in English to understand reminder cards or other outreach efforts regarding lead screening. Finally, health care providers may have become less vigilant about following the 2005 guidelines regarding repeat blood lead testing. In our study, refugee children arriving in 2007 were significantly less likely to receive a repeat screening than those who arrived in 2006 or 2005.
Younger children were more likely than older children to receive a repeat blood lead test. This may be because younger children are more likely than older children to be at risk for lead poisoning and to come in contact with primary care providers through regular check-ups and immunization appointments.
The odds of receiving a repeat blood lead test also were higher for refugee children who had an EBLL at the first screening (OR=6.19). This suggests that those children are being managed according to Minnesota Department of Health and CDC guidelines.
Our results on repeat blood lead testing differed from those of Zabel and colleagues, who found a much higher percentage of refugee children in Ramsey County being retested for EBLL.8 In contrast, our study included a larger sample (1,256 vs. 150), a longer time frame (four years compared with one), and children from throughout the state. It is also important to note that Zabel and colleagues conducted their study immediately after the adoption of the 2005 CDC guidelines when there may have been greater awareness of them. Their study was also specifically designed to assess the feasibility and practicality of following the 2005 CDC guidelines in Minnesota.
Our results should be viewed in light of certain limitations. First, the number of refugee children with an EBLL at baseline was 72 (6%). This small number may have limited our ability to detect significant differences in the demographic characteristics of refugee children with and without an EBLL. Second, our results may have been different had we collected data over a longer period of time. Third, as with any surveillance database, there may be errors in reporting the number of refugee children screened for EBLLs. Finally, our results can only be generalized to refugee children who received at least one blood lead screening and not to all refugee children in Minnesota. In the future, researchers may wish to use larger samples, cover a longer period of time, and include refugee children regardless of their screening status.
Implications
Formative research is needed to identify potential barriers to repeat lead screening among refugee children, the best sources for conveying information to families about lead screening, and which health messages regarding lead screening are most likely to resonate with refugee families. Health care providers may wish to work with cultural organizations and community-based programs that serve refugee families to identify potential barriers to lead screening. Taylor and Holtrop found that involving the community in the development of outreach programs was important to the success of their blood lead screening program.12 Finally, primary care providers may need to be periodically reminded about the importance of repeat blood lead testing of refugee children. MM
Mandi Proue is a recent graduate of the University of Minnesota School of Public Health’s maternal and child health program.Rhonda Jones-Webb is an associate professor in the division of epidemiology and community health at the University of Minnesota School of Public Health and co-chair of the school’s health disparities work group. Charles Oberg is an associate professor in the school’s division of epidemiology and community health.
References
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