An application of multivariate ranks to assess effects from combining factors: metal exposures and semen analysis outcomes.
In studies of environmental effects on human health outcomes, it is often difficult to assess the effects of a group of exposure variables when the individual exposures do not appear to have statistically significant effects. To address this situation, we propose a method of U-scores applied to subsets of multivariate data. We illustrate the usefulness of this approach by applying it to data collected as part of a study on the effects of metal exposure on human semen parameters. In this analysis, profiles (pairs) of metals containing copper and/or manganese were negatively correlated with total motile sperm and profiles containing copper were negatively correlated with sperm morphology; profiles containing selenium and chromium were positively correlated with total motile sperm.
Ramamoorthi
R V
RV
Department of Statistics and Probability, Michigan State University, East Lansing, MI 48824, USA.
Rossano
M G
MG
Paneth
N
N
Gardiner
J C
JC
Diamond
M P
MP
Puscheck
E
E
Daly
D C
DC
Potter
R C
RC
Wirth
J J
JJ
D004781:Environmental Exposure / Q000706:statistics & numerical data*; D004782:Environmental Health; D006801:Humans; D008297:Male; D008670:Metals / Q000494:pharmacology*; D015233:Models, Statistical; D012661:Semen / Q000187:drug effects / Q000502:physiology*
D008670:Metals