Hi Was just looking for some guidance on the KM and NA survival functions, specifically on the time intervals for the survival estimates I'm a bit confused on how to write out the for the time interval for the final estimate. Usually for the other ones they follow the following format: where t(i) is the time of the ith decrement 1..... 0<=t<t(1) x...... t(1) <=t<t(2) y...... t(2) <=t<t(3) etc... then for the final one ive seen different solutions sometimes its written as t(n)<= t <= end of investigation and sometimes its t(n)<= t < end of investigation my confusion is which way the inequality should be as the examiners reports and solutions seem to differ sometimes. For example. CT4 September 2015 Q7 and April 2018 Q10 have different approaches Thank you
The inequality should be t(n)<= t <= end of investigation. From my Prof's notes, it seems that he adds one last category for both KM and NA estimates, which is t(n)<= t < infinity. This makes the second-last category become t(n)<= t < end of investigation, since you don't double-count within the same interval.
