I am interested in knowing whether or not there is a consensus about the optimal way to analyze hospital length of stay (LOS) data from a RCT. This is typically a very right-skewed distribution, whereby most patients are discharged within a few days to a week, but the rest of the patients have quite unpredictable (and sometimes quite lengthy) stays, which form the right tail of the distribution.
Options for analysis include:
- t test (assumes normality which is not likely present)
- Mann Whitney U test
- logrank test
- Cox proportional hazards model conditioning on group allocation
Do any of these methods have demonstrably higher power?