[R] pMCMC and HPD in MCMCglmm

[m.fenati at libero.it]

Dear R users,
I’d like to pose aquestion about pMCMC and HDP. 
I have performed a mixed logistic regression by MCMCglmm (a very good package) 
obtaining the following results:

Iterations = 250001:799901
Thinning interval = 100
Sample size = 5500 

 DIC: 10.17416 

G-structure: ~ID_an

 post.mean l-95% CI u-95% CIeff.samp
ID_an 0.7023 0.0001367 3.678 2126

 R-structure: ~units

 post.mean l-95% CIu-95% CI eff.samp
units 1 1 1 0

 Location effects: febbreq~ as.factor(sex) 

 post.mean l-95% CIu-95% CI eff.samp pMCMC 
(Intercept) -3.6332 -5.6136 -1.7719 3045 <2e-04 ***
as.factor(sex)M -2.9959 -6.0690 0.1969 2628 0.0455 * 
---
Signif. codes: 0 ‘***’0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1


As you can see, pMCMC for gender is just less than 5%, but the credible 
interval (HPD) is wide and includes the 0 value.
How can I interpret these different results?

Thank you in advance

Massimo

-----------------------
Massimo Fenati
DVM
Padova - Italy