Targeting lead screening: The Ohio Lead Risk Score.

OBJECTIVE

Annual blood lead (BPb) screening is recommended for children </=2 years of age residing in high-risk areas. Strategies for identifying these areas exist but lack specificity. We sought to develop an efficient method for identifying risk factors for undue lead exposure in children by using community variables.

DESIGN

Logistic regression for model development in one half of the sample followed by validation of the model in the remaining half.

METHODS

The association between selected census tract characteristics from 19 Ohio counties and the BPb test results of children living in those census tracts was evaluated. The dependent variable, high-risk status, was defined as a census tract with >/=12% of BPb test results >/=10 microg/dL.

RESULTS

Data from 897 census tracts were available. Higher risk for lead toxicity existed in areas where: 1) >/=55% of houses were built before 1950 (adjusted odds ratio [AOR]: 10.9 [6.1,19.6]); 2) >/=35% of residents were black (AOR: 3.5 [2.0,6. 3]); 3) >/=35% of residents had less than a high school education (AOR: 6.1 [3.6,10.4]); and 4) >/=50% of housing units were renter-occupied (AOR: 3.6 [2.1,6.2]). Receiver operator characteristic (ROC) curves demonstrated no significant differences after applying the model in a second dataset.

CONCLUSIONS

Several community characteristics predict risk for lead toxicity in children and may provide a useful approach to focus lead screening, especially in communities where public health resources are limited. The approach described here may also prove helpful in identifying factors within a community associated with other environmental public health hazards for children.