Estimation of Burden of Lead for Offspring of Female Lead Workers: A Quality-Adjusted Life Year (QALY) Assessment

Abstract

This study demonstrates an empirical example that uses quality-adjusted life year (QALY) as a common metric for occupational health assessment to measure the utility loss of potential lead-exposed children delivered by female lead-battery-exposed workers. A set of nationwide health examination data was used for 1726 lead workers. Among them, there were 649 female workers. The numbers of offspring from female lead workers were estimated by multiplying the age-specific fertility rate (ASFR) by the number of workers in each age stratum. The quality of life assessment for these offspring was assumed impaired by increased absorption of lead using a measure of utility for quality of life that was adapted from Rosser’s index of health-related quality of life. The total utility loss was calculated by summing up the loss of QALY for these expected offspring. Dose-response and exposure assessments were based on their mothers’ blood lead levels. It was estimated that more than 38 babies were delivered in 1 yr. There would be 19 babies born with blood lead levels over 30 µg/dl, and about 17 babies with blood lead between 10 and 29 µg/dl. The expected utility loss of the babies was estimated to be about 216 QALY, of which 51.6 QALY was attributed to the babies with moderate blood lead level, while that of high blood lead was 164.4 QALY. An effective industrial hygiene program to reduce blood lead to 5, 10, and 15 µg/dl in female lead-exposed workers would decrease the utility loss to 169.5, 126.8, and 92.3 QALY, respectively, in the offspring. An alternative policy of raising the age of female workers by 5 or 10 yr before employment would also reduce the loss to 174.6 or 107.4 QALY. Data suggest that an effective industrial hygiene program should be implemented, and the use of QALY as a common metric for comparative assessment of occupational health policy may be feasible.

This work was supported by the Department of Health (grants DOH-87-HR-504 and NHRI-EX92-9204PP) and the National Science Council (grant NSC90-2320-B-037-045) of the Executive Yuan, Taiwan. The authors thank research assistants Der-Yuan Huang and Shih-Yuan Chang. We also appreciate the cooperation of workers and employers.