The Challenges of Survival Analysis
My AMSI VRS project involved learning a great deal about a particular branch of statistics known as survival analysis. Survival analysis is an extremely deep and rich area of statistics which has a wide variety of applications in fields such as engineering, economics and medicine. Through my project, I focused specifically on its medical applications. The goal of survival analysis, simply put, is to understand how long something/someone will last. The most common example in the medical field is how long an individual will survive after a particular point, such as diagnosis of a particular disease or some kind of surgery or treatment. Survival Analysis isn’t limited just to death, however; it can be used to analyse the time taken to any “event”. The definition of “event” is in this instance carefully constructed, as it must be something that is both easily definable and something which usually only occurs once for each individual (for example, mechanical component failure, loan default or divorce).
Like all areas of statistics, survival analysis comes with its own unique challenges. The primary challenge is that when gathering data on survival times, some (if not most) individuals studied may not experience an “event” in the time during which you are observing. In survival analysis, this is called censoring and truncation. Censoring is where most relevant facts about an individual are known, but for some reason a key point of data (either their start or event date) is missing or unknown. Truncation, on the other hand, is when nothing about an individual is known at all. Both of these can cause complexities in our analysis and motivate many of the techniques of survival analysis.
Survival analysis is an interesting statistical field because of both its wide areas of application as well as the continued research in the field. I’m glad that this project gave me the opportunity to learn more about this fascinating field, whilst applying my new skills to answer real clinical questions currently being posed by a hospital in my city.
James Beck was one of the recipients of a 2017/18 AMSI Vacation Research Scholarship.