title: The predictive value of self-report questions in a clinical decision rule for pediatric lead poisoning screening.
abstract: OBJECTIVE
  We derived a clinical decision rule for determining which young children need testing for lead poisoning. We developed an equation that combines lead exposure self-report questions with the child's census-block housing and socioeconomic characteristics, personal demographic characteristics, and Medicaid status. This equation better predicts elevated blood lead level (EBLL) than one using ZIP code and Medicaid status.
  
  
  METHODS
  A survey regarding potential lead exposure was administered from October 2001 to January 2003 to Michigan parents at pediatric clinics (n=3,396). These self-report survey data were linked to a statewide clinical registry of blood lead level (BLL) tests. Sensitivity and specificity were calculated and then used to estimate the cost-effectiveness of the equation.
  
  
  RESULTS
  The census-block group prediction equation explained 18.1% of the variance in BLLs. Replacing block group characteristics with the self-report questions and dichotomized ZIP code risk explained only 12.6% of the variance. Adding three self-report questions to the census-block group model increased the variance explained to 19.9% and increased specificity with no loss in sensitivity in detecting EBLLs of ≥ 10 micrograms per deciliter.
  
  
  CONCLUSIONS
  Relying solely on self-reports of lead exposure predicted BLL less effectively than the block group model. However, adding three of 13 self-report questions to our clinical decision rule significantly improved prediction of which children require a BLL test. Using the equation as the clinical decision rule would annually eliminate more than 7,200 unnecessary tests in Michigan and save more than $220,000.
authors: Michigan State University, Department of Sociology, East Lansing, MI 48824-1111, USA. kaplowi1@msu.edu
authors: Stan A
authors: SA
authors: Kaplowitz
authors: Harry
authors: H
authors: Perlstadt
authors: Gail
authors: G
authors: D'Onofrio
authors: Edward R
authors: ER
authors: Melnick
authors: Carl R
authors: CR
authors: Baum
authors: Barbara M
authors: BM
authors: Kirrane
authors: Lori A
authors: LA
authors: Post
mesh_terms: D002487:Centers for Disease Control and Prevention, U.S.; D002675:Child, Preschool; D003657:Decision Making; D004781:Environmental Exposure / Q000032:analysis*; D006801:Humans; D007854:Lead / Q000097:blood*; D007855:Lead Poisoning / Q000175:diagnosis*; D008403:Mass Screening / Q000592:standards*; D008484:Medicaid; D010290:Parents; D010865:Pilot Projects; D011237:Predictive Value of Tests; D057566:Self Report; D012680:Sensitivity and Specificity; D011795:Surveys and Questionnaires; D014481:United States
chemical_list: D007854:Lead