Questions regarding Dialysis study

1. Were other potentially confounding variables also recorded for the patients (e.g. age, sex, etc.) and controlled for during the study? If not, can we check to see if there were significant differences between the groups in the study?

1. How rare is emphhypotension normally? If it is a rare occurrence, then we may, by chance, observe many instances of the adverse effect for one of the temperatures and mistakenly attribute the temperature as an indicator of emphhypotension.

1. Checking wikipedia, there seems to be 3 potential disadvantages to a cross-over study. (a) the order of the treatments may affect the results (b) there may be a "carry-over" effect of one treatment over to the next treatment and (c) a learning effect, which probably will not affect this study. How will issues (a) and (b) be addressed in the study?