Limitations on the Uses of Multimedia Exposure Measurements for Multipathway Exposure Assessment - Part II: Effects of Missing Data and Imprecision
Clayton, C., Michael, L., Pellizzari, E., & Quackenboss, J. (2003). Limitations on the Uses of Multimedia Exposure Measurements for Multipathway Exposure Assessment - Part II: Effects of Missing Data and Imprecision. Quality assurance (San Diego, Calif.), Vol. 10(3-4), 161 - 175.
Multimedia data from two probability-based exposure studies were investigated in terms of how missing data and measurement-error imprecision affected estimation of population parameters and associations. Missing data resulted mainly from individuals'refusing to participate in certain measurement activities, rather than from field or laboratory problems; it suggests that future studies should focus on methods for maximizing participation rates. Measurement error variances computed from duplicate-sample data were small relative to the inherent variation in the populations; consequently, adjustments in nonparametric percentile estimates to account for measurement imprecision were small. Methods of adjustment based on lognormality assumptions, however, appeared to perform poorly.