BloodLead: Blood lead levels data from Pruzek & Helmreich (2009)

In PairedData: Paired Data Analysis

Description

This dataset presents matched paired data corresponding to blood lead levels for 33 children of parents who had worked in a lead related factory and 33 control children from their neighborhood. The two samples have different dispersions and their correlation is small.

Usage

data(BloodLead)

Format

A dataframe with 33 rows and 3 columns:

[,1]	Pair	factor	matched pair of chidren
[,2]	Exposed	numeric	blood lead levels (mg/dl) for exposed children
[,3]	Control	numeric	blood lead levels for controls

Source

Morton, D., Saah, A., Silberg, S., Owens, W., Roberts, M. & Saah, M. (1982) Lead absorption in children of employees in a lead related industry. American Journal of Epimediology, 115, 549-55.

References

Pruzek, R.M. & Helmreich, J.E. (2009) Enhancing dependent sample analysis with graphics. Journal of Statistics Education, 17 (1).

Examples

data(BloodLead)

# Control values are clealy less dispersed (and inferior)
# than exposed levels
with(BloodLead,plot(paired(Control,Exposed),type="McNeil"))
with(BloodLead,Var.test(paired(Control,Exposed)))

with(BloodLead,grambsch.Var.test(paired(Control,Exposed)))
with(BloodLead,bonettseier.Var.test(paired(Control,Exposed)))

# Correlation is small (bad matching)
with(BloodLead,cor.test(Control,Exposed))
with(BloodLead,winsor.cor.test(Control,Exposed))

Example output

Loading required package: MASS
Loading required package: gld
Loading required package: mvtnorm
Loading required package: lattice
Loading required package: ggplot2

Attaching package: 'PairedData'

The following object is masked from 'package:base':

    summary


	Paired Pitman-Morgan test

data:  Control and Exposed
t = -8.0889, df = 31, p-value = 3.906e-09
alternative hypothesis: true ratio of variances is not equal to 1
95 percent confidence interval:
 0.04901302 0.20114472
sample estimates:
variance of x variance of y 
     20.60985     207.57008 


	Paired Grambsch test

data:  Control and Exposed
z = -3.1926, p-value = 0.00141
alternative hypothesis: true ratio of variances is not equal to 1


	Paired Bonett-Seier test

data:  Control and Exposed
z = -5.9106, p-value = 3.409e-09
alternative hypothesis: true ratio of means absolute deviations is not equal to 1
95 percent confidence interval:
 0.2162321 0.4636218
sample estimates:
 mean abs. dev. of x  mean abs. dev. of y 
            3.636364            11.484848 


	Pearson's product-moment correlation

data:  Control and Exposed
t = -1.0157, df = 31, p-value = 0.3176
alternative hypothesis: true correlation is not equal to 0
95 percent confidence interval:
 -0.4924287  0.1746085
sample estimates:
      cor 
-0.179458 


	winsorized correlation, trim=0.2

data:  Control and Exposed
t = -0.45752, df = 19, p-value = 0.6525
alternative hypothesis: true (winsorized) correlation is not equal to 0
sample estimates:
        cor 
-0.08189653 

PairedData documentation built on May 1, 2019, 6:49 p.m.