Logrank test

Okay kiddo, let's talk about something called a logrank test. Imagine you and your friend both start a race at the same time. But after a while, your friend gets tired and takes a break. You keep going and cross the finish line before your friend. That's kind of like what a logrank test is for!

Except in a logrank test, we're not talking about races, we're talking about people who are sick. We want to see if one group of people who are sick live longer than another group of people who are sick. We call this "survival."

We look at how long each person in both groups survived. Then we compare the two groups to see if one group has more people who survived for longer periods of time than the other group.

To do this, we use something called a "hazard ratio." It's like a measure of how likely someone is to live for longer periods of time. If the hazard ratio is higher for one group than the other, it means that group has a better chance of survival.

So, just like in our race example, if more people in one group survive for longer periods of time than the other group, we say that the first group is better. The logrank test helps us figure out if this difference is big enough to be counted as "statistically significant," which is just a fancy way of saying it's not just due to chance.

So that's the logrank test! It helps us figure out if one group of sick people has a better chance of survival than another group of sick people, by comparing how long they lived.