For reference, here were the questions:
1) What are some of the challenges of using retrospective data from electronic health records?
2) The paper states that "the presence of a white blood cell count test order is associated with a 2.1% lower survival rate (P<0.001)". What does the P<0.001 signify?
3) a) All else equal, would we expect the survival rate to be higher for a patient with a 5pm white blood test or a 5am white blood test? b) All else equal, would we expect the survival rate to be higher for a patient with a Sunday white blood test or a Wednesday white blood test?
4) Besides time of lab test and the lab test value, what other healthcare process variables might give additional signal for prediction of 3-year survival?