mercury {submax}

NHANES Mercury/Fish Data

Description

Data from NHANES 2009-2010. 397 treated people who ate at least 15 servings of fish or shellfish during the previous month are matched to two controls who ate at most one serving of fish or shellfish. The values in methylmercury record the level of methylmercury in blood in mu-g/dl.

Usage

data("mercury")

Format

A data frame with 1191 observations on the following 6 variables.

SEQN

NHANES 2009-2010 id number

methylmercury

Methylmercury in blood in mu-g/dl

fish

1 if ate >= 15 servings of fish or shellfish, 0 if <=1 serving

mset

Matched set indicator, 1,...,397.

female

1 if female, 0 if male

black

1 if black, 0 otherwise

Details

Sets were matched 2-to-1 for for age, sex, ratio of household income to the poverty level, education, ethnic group (black, Hispanic, or other), and cigarette smoking. A table showing covariate balance after matching is in Rosenbaum (2014, Table 1).

Source

From NHANES 2009-2010, publicly available at the NHANES web page at CDC.

References

Rosenbaum, P. R. (2014) Weighted M-statistics with superior design sensitivity in matched observational studies with multiple controls. Journal of the American Statistical Association, 2014. <doi:10.1080/01621459.2013.879261>

Examples

data(mercury)
boxplot(mercury$methylmercury~mercury$fish)