>Joseph doesn't specify whether the really interesting predictor is race >or
age group, or whether race is in any way ordinal (including binary eg >1 for
"Black" and 2 for "White"). However, assuming that race is a boring
>categorical variable and age group is an interesting ordinal variable,
>then Joseph might calculate a Somers' D for the association of viral >load
with age for each race, and then meta-analyse these Somers' D
>values for each race to create a grand mean Somers' D measuring the
>ability of higher age to predict higher viral load within races.
>More information on the -somersd- and -parmest- packages is available on
>my website (see my signature). Somers' D and Kendall's tau-a are >detailed
in my Stata Journal paper (Newson, 2002), which is available in
>pre-publication draft form on my website. (As is my Stata tip about
>calculating geometric means using the -eform()- option of -regress-.)
>I hope this helps. I would be able to make more specific suggestions if I
>knew more about precisely what association Joseph is trying to measure.
I should've specified - race is, in fact, a categorical variable. I am
interested in the effect of age on viral load by race.
Could you explain what you mean by "meta-analyse" in terms of using STATA?
Meta-analysis in Stata is documented in the manuals under -[R] meta-. If
you install the program -meta-, written by Stephen Sharp and Jonathan
Sterne and downloadable using
