Limitations on the uses of multimedia exposure measurements for multipathway exposure assessment--Part II: Effects of missing data and imprecision.
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.
Clayton
C Andrew
CA
RTI International, PO Box 12194, 3040 Cornwallis Road, Research Triangle Park, NC 27709, USA. clayton@rti.org
Michael
Larry
L
Pellizzari
Edo D
ED
Quackenboss
James J
JJ
D002648:Child; D002675:Child, Preschool; D004781:Environmental Exposure; D004812:Epidemiologic Methods; D006801:Humans; D006838:Hydrocarbons / Q000032:analysis*; D008670:Metals / Q000032:analysis*; D015233:Models, Statistical; D019212:Multimedia; D010755:Organophosphates / Q000032:analysis*; D011159:Population Surveillance / Q000379:methods; D014481:United States; D014484:United States Environmental Protection Agency
D006838:Hydrocarbons; D008670:Metals; D010755:Organophosphates