Lucy wrote:
How does one interpret the following command:
xi: stcox i.mastitis*i.age, robust
this is enquiring the proportional hazard of interaction between age
and mastitis, correct?
So would it be "whether the effect of mastitis increases or decreases
with age.."?
Supposingly, there should be no difference in the order of the
covariates, ie.,
xi: stcox i.mastitis*i.age, robust versus,
xi: stcox i.age*i.mastitis, robust
However, the output is distinctly different. Anyone got comments?
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"whether the effect of mastitis increases or decreases
with age.." sounds right to me.
I tried a similar ting, but I did not find that the
coefficients from i.a*i.b are different from i.b*i.a,
except for the sequence.
Svend
________________________________________________________
Svend Juul
Institut for Folkesundhed, Afdeling for Epidemiologi
(Institute of Public Health, Department of Epidemiology)
Vennelyst Boulevard 6
DK-8000 Aarhus C, Denmark
Phone, work: +45 8942 6090
Phone, home: +45 8693 7796
Fax: +45 8613 1580
E-mail: [email protected]
_________________________________________________________
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