[Maarten Buis]

The Chi square value is just a test statistic and the Prob > chi2 is just its corresponding p-value. So this is just the output of a statistical test, and the relevance of a statistical test is solely determined by the relevance of the null-hypothesis. If the null-hypothesis is not interesting than those two values are also irrelevant. In this case the null hypothesis is discussed by Clive in #4. I have never been in a situation where that null-hypothesis was interesting, so I always had to ignore that part of the output.