Table 3 Multivariate Cox Regression Analysis of Purchase Interval on Add-on Buying

Variables	coef	exp(coef)	se(coef)	p-value
TRA.AGENT	0.56	1.75	0.13	0.00	***
ln(PUR.AMOUNT.FIRST)	-0.02	0.98	0.05	0.62
PUR.PAST	0.32	1.37	0.13	0.01	*
DES	0.11	1.11	0.12	0.35
AGE	-0.03	0.98	0.01	0.00	***
GENDER	0.29	1.34	0.14	0.03	*
AGENT.CLASS	0.09	1.10	0.07	0.18
Concordance = 0.65 (se = 0.02)
Likelihood ratio test = 78.16 on 7 df, p=3e-14
Wald test = 71.96 on 7 df, p=6e-13
Score(Log-Rank) test = 74.39 on 8 df, p=2e-13

p<.05;
p<.01;
p<.001