Abstract
Before 1999, few children in Florida’s Miami–Dade County were being screened for lead poisoning. To improve screening rates, the county’s department of health developed screening recommendations and a screening tool using surveillance and census data and disseminated these materials to primary care providers. Each year, recommendations have been reviewed to assess their sensitivity, and revised recommendations have been disseminated to health care providers.
The percentage of children 6 years or younger screened in Florida who reside in Miami–Dade County increased from 4.1% in 1998 to 20.3% in 2002. Analysis and dissemination of blood lead surveillance data not only guide development of screening recommendations but also educate health care providers regarding the importance of childhood screening.
CHILDHOOD LEAD POISONING adversely affects cognitive and behavioral development,1 even at low blood lead levels.2–5 An estimated 434000 US children aged 1 to 5 years have blood lead levels of 10 μg/dL or higher (the surveillance case level used in defining lead poisoning),6 and children living in older housing are disproportionately affected, as are children of low socioeconomic status.6 Although industrial activities, parental occupations and hobbies, folk remedies, water, and ceramics have been identified as sources of lead exposure, the most common sources among US children are dust and soil contaminated by deteriorated lead-based paint and, to a lesser extent, leaded gasoline exhaust.7 Identification of children with lead poisoning can lead to treatment as well as interventions designed to reduce blood lead levels or prevent future exposures.8–11
In 1997, the Centers for Disease Control and Prevention (CDC) recommended that screening be conducted among 1- and 2-year-old children who (1) lived in zip code areas in which 27% or more of dwellings were built before 1950, (2) received public assistance, (3) resided or frequently spent time in housing built before 1950 or in housing built before 1978 that had undergone recent or continuing renovation, or (4) had a sibling or playmate who had contracted lead poisoning. The CDC also recommended that 36- to 72-month-old children who had not previously been screened undergo screening. Universal screening was recommended in areas with lead poisoning prevalence rates of 12% or more. The CDC further advised that state and local public health authorities modify their recommendations on the basis of reviews of local data and community input.12
In 2000, 147016 children aged 1 to 5 years resided in Miami–Dade County (MDC).13 The total number of children at risk of lead poisoning is unknown, but today more than 32000 reside in areas with a high percentage of older housing,13 and approximately 20000 live in poverty outside these areas.14 Even though 15.4% of all Florida children 6 years or younger live in MDC,13 the county accounted for only 4.1% (1554 of 38039) of screening tests among this age group reported during 1998 (T. Thompson, Florida Department of Health, written communication, April 2003). In addition, only 21% of 1- and 2-year-old children enrolled in Medicaid were screened during fiscal year 1999–2000.15
Before 1999, the MDC Health Department had not disseminated lead poisoning surveillance data or screening recommendations to local health care providers in a comprehensive manner. In July 1999, the department was awarded a grant from the CDC’s Childhood Lead Poisoning Prevention Program (CLPPP). Because of the county’s low screening rates, one of the program priorities was to develop and disseminate local screening recommendations.
In October 1999, the Health Department’s CLPPP staff convened a screening guidelines committee, composed of pediatricians, a Medicaid representative, epidemiologists, and department staff, whose purpose was to adapt the CDC’s targeted screening guidelines to MDC. The committee considered CDC,12 state (in draft form),16 and other17,18 recommendations and reviewed surveillance data and geographic information system maps depicting the following zip code–specific characteristics: housing ages; lead poisoning rates; rates of enrollment in the Special Supplemental Nutrition Program for Women, Infants, and Children; and income levels. Because no prevalence data were available, the 12% prevalence cutoff criterion for universal screening could not be considered. The committee determined the zip code areas that warranted universal screening on the basis of prevalence rates of pre-1950 housing. In other zip code areas, screening was recommended if children met any other CDC targeted screening criterion.
After development of the local screening recommendations, CLPPP staff developed a tool designed to communicate these recommendations to clinicians. The tool included a geographic information system in which lead poisoning cases were superimposed on a map of target zip code areas (i.e., areas where universal screening was recommended) (Figure 1 ▶).
FIGURE 1—
Miami–Dade County’s screening recommendations tool for health care providers.
Guidelines were first disseminated by mail in June 2000 to pediatric primary care providers. Included in this mailing were 2 laminated copies of the screening tool (a coat-pocket-sized copy and a paper-sized copy), background information about lead poisoning and local sources of lead exposure, a resource list, a reporting form, and a Rolodex card with CLPPP contact information.
Surveillance data were reviewed annually to ensure that more than 95% of reported lead poisoning cases met at least one criterion. During fiscal year 1999–2000, the sensitivity of the screening recommendations was 98%, and this value remained above 95% through fiscal year 2002–2003. In 2001, the criterion of recent immigration was added to the recommendations because some of the highest blood lead levels and prevalence rates were observed among recent immigrants; 12% of children screened at the Health Department’s Refugee Health Assessment Center between October 1999 and September 2001 had blood lead levels of 10 μg/dL or higher.19
DISCUSSION AND EVALUATION
The percentage of MDC children 6 years or younger who underwent screening tests increased from 4.1% of the state’s total number of reported tests among this age group (1554 of 38039) in 1998 to 20.3% (15221 of 74982) in 2003 (T. Thompson, Florida Department of Health, written communication, April 2003). However, given that 32617 children reside in areas with older housing and that many additional children are at risk, screening remains suboptimum. On the other hand, the increase in screening suggests that primary care providers did respond to the information they received about the local childhood lead poisoning problem, and a screening increase was also noted in Minnesota after development and distribution of screening guidelines.20
Between 1998 and 2002, the number of lead poisoning cases identified in MDC among children aged 1 to 5 years declined by 19% from 346 to 279, despite an increase in the number of screening tests conducted. Nationally, lead poisoning prevalence among tested children declined 54% between 1998 and 2001 (from 6.7% to 3.1%).6
A surveillance system should include not only data collection and analysis but effective communication of data to those involved in prevention and control.21 In the present case, 4 months after the first mailing, 55% of a random sample of 371 surveyed pediatric providers (response rate: 58%) reported recalling the recommendations made. (However, during the Health Department’s staff visits, some clinicians reported surprise at the number of lead poisoning cases in MDC, given that they and their colleagues encountered only a few cases, or no cases, each year.) Also, in the case of MDC, surveillance data were useful in assessing the sensitivity of local screening criteria and in identifying recent immigration as a risk factor.
NEXT STEPS
Health Department CLPPP staff continue to periodically analyze surveillance data to ensure that more than 95% of reported lead poisoning cases are captured by at least one criterion of the current recommendations. If the epidemiology of childhood lead poisoning in MDC changes, screening recommendations may need to be revised. Epidemiological information about local lead poisoning risk factors is and should continue to be communicated regularly to clinicians to help guide their decisions and elicit their partnership in screening, reporting, and case management.
KEY FINDINGS.
Surveillance data can help direct development of recommendations.
Surveillance data should be continually disseminated to health care providers to guide their decisionmaking.
Geographic information system maps are effective in communicating surveillance data to clinicians.
Tailoring national recommendations using local data not only is necessary but builds support among health care providers for screening efforts.
Acknowledgments
Development and dissemination of the screening recommendations were supported by the Centers for Disease Control and Prevention (grant number H64/CCH416785-03-01).
I would like to thank the following people who assisted in the development and dissemination of the screening recommendations: Michel Dodard, Nancy Fawcett, Dolly Katz, Ann Avazian, Eleni D. Sfakianaki, Tally Hustace, Michelle Edouard, Virginia Gilbert, Joanna Weisbord, Guoyan Zhang, Lydia Sandoval, Trina Thompson, and Vukosava Pekovic.
Peer Reviewed
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