# Survival Analysis

Survival analysis is concerned with the time it takes until a certain event occurs, especially when censored data is present. The event could be the death (or relapse) of a patient with cancer or the date when a student graduates from high school. Thus, the key event can be viewed as success (getting a law degree) or failure (death), although generally the terminology used is most suited to the second type of situation.

Failure (i.e. the key event) can correspond to a component breaking in an engineering context (reliability analysis), an organism dying in a biological context (survival analysis) or the end of an economic downturn in an economic context (duration analysis).

Topics:

For those with a calculus background, you can also see the proofs of some of the properties described on the above webpages at

### 2 Responses to Survival Analysis

1. Peru says:

Hello

Do you have references (papers or book) for the formula to get Hazard rate. I saw this used a couple of places without reference (I need a reference to give for my research):

Hazard Rate = (ln(1-Events/N)) / t

Also, if total events in experimental are Eexp and lost to follow-up is Nexplft then is there a way to estimate Hazard RATE in exp arm?

If not, then if evenets in control arm is Ectl and lost to follow up is Nctllft then is there a way to get Hazard RATIO?

• Charles says:

Peru,

There are many references for the formula for the hazard rate. E.g.
Antimicrob Agents Chemother. 2004 Aug; 48(8): 2787–2792.
doi: 1 0.1 1 28/AAC.48.8.2787­2792.2004
Hazard Ratio in Clinical Trials
Spotswood L. Spruance, Julia E. Reid, Michael Grace, and Matthew Samore

Sorry, but I don’t understand your other questions. What are Eexp, Nexplft, Ectl, etc.

Charles