Research
Research
Research
The MHD CLPPP has partnered with the Centers for Disease Control and Prevention, the National Center for Lead Safe Housing, The Environmental Protection Agency, the NonProfit Center of Milwaukee and the University of Wisconsin School of Preventive Medicine to conduct multiple research and evaluation projects since 1992. These studies, which have resulted in the continuous improvement of MHD CLPPP interventions, include:
- Screening for Pediatric Lead Poisoning - Comparability of Simultaneously Drawn Capillary and Venous Samples, 1994
- Feasibility and Effectiveness of Screening for Childhood Lead Poisoning in Private Medical Practice, 1994
- A Retrospective Examination of In-Home Educational Visits to Reduce Childhood Lead Levels and Lead Hazard Reduction Techniques, 1995
- Milwaukee Prospective Educational Intervention Study, 1996
- Seasonal Trends of Blood Lead Levels in Milwaukee, 1996
- Early Intervention Educational Outreach Study in Lowering Blood Lead Levels in Children with Initial Blood Lead Levels 15-19 µg/dL, 1998
- Blood Lead Level Changes Over Time in Milwaukee, 1998
- Risk Assessment Research Project, 1998-1999
- A Prospective Study of the Effectiveness of Low Cost Household Paint Abatement to Reduce Blood Lead Levels in Children, 1999
The MHD CLPPP commitment to and value for ongoing program evaluation to continue, expand and enhance both primary prevention efforts and services to lead poisoned children and their families remains a program priority.
Below are brief descriptions of some of these studies.
UW School of Preventive Medicine, EPA, & MHD CLPPP
UW School of Preventive Medicine, EPA, & MHD CLPPP
UW School of Preventive Medicine, EPA, & MHD CLPPP
A Retrospective Examination of In-Home Educational Visits to Reduce Childhood Lead Levels and Lead Hazard Reduction Techniques
In-Home Education: This study was implemented through data extracted from the MHD CLPPP STELLAR database. Study design and analysis on standard program interventions was conducted by UW and the EPA. This study identified an average decrease in blood lead levels (n=187) of 4.2 µg/dL, or by about 21%. A decline of 1.2 µg/dL (6%) was identified in a reference group of 236 children who did not receive an MHD in-home visit due to non responsiveness or "loss to follow up". The intervention group had a decline in blood lead levels 3.1 µg/dL (15%) greater than the reference group, with the difference between groups statistically significant with a p-value less than .001. For the 236 children (controls) who did not receive the intervention, the average decrease in lead levels was 1.1 µg /dL.
Lead Hazard Reduction: For children in this study, the average pre-abatement blood lead level was 34 µg/dL and decreased to an average post-abatement blood lead level of 26 µg/dL, a 24% decline. The strength of this study is based on examination of normal service delivery as compared to highly-controlled services delivered as a part of prospective studies.
Milwaukee Prospective Educational Intervention Study: The objective of this study was to evaluate the effectiveness of public health worker educational visits in the homes of children with lead levels 20-24 µg/dL. The homes of children were monitored for various environmental levels (dust, water, soil) and families received an educational intervention. Follow-up measures included examination of the environment and the tracking of blood lead levels as the main measure of effectiveness.
Blood lead levels declined, on average, 5.1 µg/dL approximately two months after the intervention. A reference group of children not receiving the educational visit due to non responsiveness or a "loss to follow up" was also studied. The study group had a decline in blood lead levels 5 µg/dL greater than the reference group receiving no educational home visit, with the difference between the two groups statistically significant at the .05 level. This study concluded that although elevated blood lead levels remained in most of the children studied, important reductions occurred with this relatively inexpensive ($100 per visit) and simple educational intervention.
A Prospective Study of the Effectiveness of Low-Cost Household Paint Abatement to Reduce Blood Lead levels in Children: This study's objective was to examine the effectiveness of low-cost lead hazard reduction on the blood lead levels of children in Milwaukee, Wisconsin. The MHD CLPPP provides environmental inspection, abatement, and public health nurse case management services to children with lead levels 25 µg/dL and greater. The homes of 37 children between the age of 6 months to 7 years were enrolled in the study. The mean decline of 7.2 µg/dL (95% CI -9.5,-4.8) one to six months after this two-part intervention was identified. After adjustment for seasonality and age, the decline was 6.0% (95% CI -9.2,-2.8.)
Early Intervention Educational Outreach Study in Lowering Blood Lead Levels in Children with Initial Blood Lead Levels 15-19 µg/dL: The purpose of this research project is to test the hypothesis that a child with low-level exposure whose family received a MHD educational home-visit would have a greater reduction in blood lead concentration, on average, than a child who does not, and that education will produce long term effects (greater than one year.) This project is being implemented by identifying children ages 6-24 months who had initial blood lead levels of 15-19 µg/dL. Each child is randomly assigned to one of two groups: control or education. For each child in the education group, two matched control children were included in the control groups- a primary control and a back up control. A sample size of 200 ( 100 intervention children with at least one matched control child) was designed to allow for reasonably powerful prediction of the width of confidence intervals around parameters of interest.
Seasonal Trends of Blood Lead Levels in Milwaukee: (738kb) This study examines blood lead screening data collected in Milwaukee from 1986-1996, and discusses the extent and implications of seasonal fluctuations in blood lead levels. This research is particularly significant in that it isolates the impact of fluctuations in blood lead levels on the ability to measure the effectiveness of lead intervention. The data set contains blood lead screening data on 26,335 children with 20,925 children drawn from 1992-1996. This study found that blood lead levels reached their peak in late summer, with average lead levels about 30% greater than in winter. Blood lead levels were also found to peak between the ages of 21-36 months of age. This data is helpful in predicting the effects of season, age and lead interventions on blood lead levels and has been utilized to design services aimed at strategically reducing lead exposures. The model developed has been applied to previous research detailed as an adjustment for the impact of season.
Blood Lead Level Changes Over Time in Milwaukee: The objective of this study was to describe trends and changes over time in children's blood lead levels in Milwaukee, and to compare results to NHANES III Part 2 estimates. Data was compiled and extracted from the MHD CLPPP STELLAR database. The data set included 20,295 blood lead measurements from 1992-1996. Summary statistics were calculated for semi-monthly time periods to analyze and characterize trends. Average blood lead levels were found to decrease 10% per year from 1993-1996. The observed rate of decline in Milwaukee is consistent with, but more recent than, declines reported by NHANES during 1988-1991 and 1991-1994.
Note: Although significant progress has been made in reducing blood lead incidence rates in Milwaukee since 1991, the City's case finding rate identified in 1997 was 22.5% compared to the 4.4% national average. Furthermore, some target high risk areas report prevalence rates of 58% pointing to the need for focused, housing-based interventions.
UW School of Preventive Medicine
HUD Evaluation Grant and its Extension (Round 1): The ability of the MHD CLPPP to successfully implement complex field research is based on the infrastructure that developed for the Evaluation of Lead-Based Paint Hazard Control Grant Program (HUD Round 1). As a sub-grantee of the State of Wisconsin, the City of Milwaukee began conducting this research in 1994; the extended evaluation will continue through 1999. As a result of this research, window components have been identified as the primary source of lead-based paint exposure for young children in Milwaukee, and a cost-effective abatement treatment to address this particular source of exposure has been designed. The concept of cost-effectiveness continues to be refined and reflected in housing standards that differentiate between deferred maintenance of lead-painted surfaces and controlling lead hazards which pose the greatest exposure to children. This philosophy that " all lead paint in a housing unit is not created equal" in terms of content, condition, and accessibility has been the key to the MHD CLPPP ability to develop and implement targeted environmental interventions to protect children while maintaining affordable housing stock in economically distressed neighborhoods.
An additional outcome of this evaluation was the development of a cost-effective window specification that abates all lead-based painted surfaces. Current costs are $135 per window unit for a total window abatement cost per housing unit of $1,740. This standard treatment is reflected in the Pilot Project Ordinance and will be evaluated by this proposal.
LAND Community-Based Demonstration Project (EPA): This EPA-funded environmental justice initiative was undertaken from 1995 to 1998. It represented a partnership of the MHD CLPPP and LAND (Lisbon Avenue Neighborhood Development) agency, and was the MHD's first experience with community-based primary prevention. Lessons learned from this initiative follow:
- In the LAND neighborhood, (a one square mile area of Milwaukee), 88% of housing units inspected had lead-based paint hazards.
- The average cost of lead hazard reduction for housing units in the LAND area was $3,200, which is 12% of the average assessed value of the housing units.
- Government support for voluntary lead hazard reduction is not enough. Enforcement or legislation requiring compliance with housing standards are needed to achieve primary prevention in high risk areas with low-income rental units.
- A minimum of eight (8) hours of training is needed for property owners and their work crews to become proficient in lead-safe maintenance of painted surfaces and abatement of high-risk window components.
- Community-based primary prevention strategies must be flexible and integrate insights gained from unsuccessful approaches.
- Rental units turn over three times per year, on average, supporting the need for targeting homes, not lead-poisoned children.
- For communities with large at-risk populations, risk-reduction training for low-income families who rent is needed in order to protect children temporarily.
- Lead-safe housing standards must be clearly defined and communicated.
- Community-involvement and capacity-building are needed in support of housing based primary prevention.
These insights garnered from this demonstration project have been integrated into the strategies and work plan of the Pilot Project for Lead-Based Paint Hazard Control.
Risk Assessment Research Project (HUD& NCLSH): Beginning in June of 1998, the MHD CLPPP, under contract with the National Center for Lead Safe Housing, began the execution of the HUD-funded Risk Assessment Research Study. The purpose of this study is to determine which sources of lead exposure and risk assessment tests are most predictive of children's blood lead levels. This study will fine-tune cost-effective approaches to producing lead-safe housing for families with young children.
Milwaukee Pilot Ordinance Overview (HUD): The MHD CLPPP is coordinating the local efforts of a three year study to evaluate the effectiveness of lead hazard reduction treatments. This study has been commissioned by HUD in order to evaluate the Milwaukee Pilot Primary Prevention Ordinance. National partners in this study include the Battelle Memorial Institute of Columbus, Ohio (responsible for the study design and data analysis) and the National Center for Lead-Safe Housing of Columbia, Maryland (responsible for quality assurance and data interpretation). The Sixteenth Street Community Health Center of Milwaukee is a local partner, assisting the MHD with field data collection.
Key data collection components of this overall evaluation include participant interviews, blood sample collection from children less than six years of age, and environmental sampling and visual review of the housing.
The evaluation is designed to follow children born into treated units in order to monitor blood lead levels over a two year period and to analyze respective environmental information collected in a similar time frame. A comparison group living in similar, but untreated, housing will be sampled correspondingly in order to determine differences in blood lead levels.
Two door-to-door sampling campaigns (pre-abatement and post-abatement with a one year interim) are additional components of the overall evaluation. These neighborhood efforts include the study of blood lead levels of children living in treated housing in the pilot ordinance areas and will be compared to children's blood lead levels living in comparable neighborhoods in untreated housing.
This evaluation project is scheduled to conclude in June 2002. A preliminary report will be available in December 2002.