A Systematic Review of Screening Questionnaires for Childhood Lead Poisoning

Abstract

The Centers for Disease Control and Prevention encourages the use of risk factor questionnaires to screen children for lead poisoning. A majority of state health departments have formal lead screening guidelines that recommend health care providers use questionnaires. We conducted a systematic review to evaluate the ability of lead screening questionnaires to predict lead poisoning risk among children. Articles that reported the evaluation of a predesigned lead screening questionnaire were obtained by searching Medline/PubMed and by examining references of articles obtained through the online search. From each evaluation, we abstracted the number of children that were true positive, false positive, true negative, and false negative, according to the results of the screening questionnaire and the follow-up blood lead test. From these data, we calculated specificity and sensitivity of the questionnaire for each evaluation. Twenty articles met the inclusion criteria: these included 28 separate questionnaire evaluations. Among 17 evaluations of the 1991 Centers for Disease Control and Prevention questionnaire, sensitivity ranged from 0.25 to 0.87, specificity from 0.31 to 0.80, and accuracy (sum of sensitivity and specificity) from 0.74 to 1.39. The pooled mean estimates for this questionnaire were sensitivity 0.61 (95% confidence interval: 0.53-0.68); specificity 0.52 (0.45-0.60); accuracy 1.12 (1.06-1.18). Among 11 evaluations of all other questionnaires, sensitivity ranged from 0.43 to 0.90, specificity from 0.17 to 0.66, and accuracy from 0.94 to 1.27. For these questionnaires, the pooled mean estimates were sensitivity 0.76 (0.68-0.85), specificity 0.41 (0.33-0.49), and accuracy 1.12 (1.06-1.18). Lead screening questionnaires showed a wide range of sensitivity and specificity and performed little better than chance at predicting lead poisoning risk among children.