I am comparing length of stay after laparoscopic and open appendectomy in over 160000 patients. LOS is typically a skewed variable so I use the median and interquartile range and ranksum test to describe the result, which is 2, IQR 2-3 and 2, IQR 2-4, p&lt;0.0001. So there is a highly significant difference but it does not show that well in the median and IQR. 

The difference in length of stay is very small. This finding is a negative finding but still interesting as it goes against what most people think about LOS after laparoscopic appendectomy. That is why I want to report on the difference in LOS which is not evident if I only report median and IQR with p-value.

The arithmetic mean (3.1 vs 2.8 and a difference of 0.3 days) is not recommended as the distribution is skewed. I wonder if any other measure could be used like, geometric mean (2.5 vs 2.3, difference 0.2 days) or harmonic mean (2.1 vs 1.9 days, difference 0.2 days)?  When can I use geometric mean or harmonic mean? 

I am inclined to use the harmonic mean which comes closest to the median and gives a difference of 0.2 days. Is this incorrect?


Question: How did Robert's visit to Claire's house help the plot?
Answer: I think that's also a part of their (Robert and Claire) plan. After Robert seeing Claire, he tells to Virgil something like "Claire is more beautiful than you described and I think I like her" and Virgil replies "are you trying to make me jealous?"

Since Virgil firmly believed that Robert is expert on women's matters, I think Robert is trying to send a subliminal message to Virgil Oldman that Claire is beautiful, this will result in having Virgil to be more addictive of Claire.