# Tagged Questions

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### Force range in R Kaplan-Meier time component [migrated]

I have a numeric time variable and I want to observe my data using R's Kaplan-Meier implementation. The common way is: ...
41 views

### Comparison of Kaplan-Meier curves across ordered groups

I am familiar with the log-rank test for comparing multiple Kaplan-Meier curves, but I am looking for a test that will compare across ordered groups (an ordinal variable). A significant result from ...
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### Risk table for a Kaplan Meier plot in R

I need to make a Kaplan Meier plot with a risk table beneath it. Otherwise stated, I need a table of the number of subjects at risk at different time points aligned below the figure. I found a website ...
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### Can Kaplan Meier method be used to estimate left-censored data?

I have a set of 1000 datapoints of measured concentrations that may include up to 300 values which are censored (below the detection limit that the lab could reliably measure). The range of detection ...
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### relation between median survival and HR

What would be the mathematical relation between 2 comparing survival medians (difference or relation of medians) and the HR? I know that the relation of medians of survival time (MSTc/MSTi), were ...
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### Kaplan-Meier statistic with no censoring reduces to empirical survival function

I just started taking survival analysis class and I'm stumped on this question. We need to show that when there are no censored observations $\hat{S}(t)=\prod_t_{(i)\le t}(n_i-d_i)/n_i$ equals to the ...
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### How do I use the “survival” package and “Surv” function in R with left-truncated data?

I am trying to run survival analysis using the Surv and survfit functions from the survival ...
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### Kaplan Meier - Can I use to assess recovery of function, not just loss?

In my experience and readings, Kaplan-Meier has always been used to calculate differential survival between a certain number of groups. However, I'm looking to assess how time to recovery from a ...
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### Kaplan Meier curve with different time lengths across groups

I'm not too familiar with survival analysis, so this may be a somewhat basic question. I am interested in the time between two events [$A$ - medication] and [$B$ - time of first treatment], the ...
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### Is it valid to compare 'time to separation of curves' between 2 Kaplan-Meier curves?

Suppose one has 2 placebo-controlled clinical drug trials (drug X vs placebo; and drug Y vs placebo). And suppose one creates a Kaplan-Meier plot for time to some event (eg, disease progression) for ...
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### Why does the hazard ratio represent the magnitude of distance between the Kaplan-Meier plots?

From Wikipedia The hazard ratio is simply the relationship between the instantaneous hazards in the two groups and represents, in a single number, the magnitude of distance between the ...
339 views

### How do you prepare longitudinal data for survival analysis?

I'm trying to plot a Kaplan-Meier curve of my data with R. Currently, the data is in the following format: ...
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### projecting future survival rate

I'm working on a customer retention project that predicts the probability a customer is still subscribing to our services at time T. Unfortunately, we only have the most recent two years of customer ...
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### calculation of 12 week PFS rate

what type of setup is needed to calculate 12 weeks PFS rate using Kaplan Meier method in SAS? Do we calculate PFS at 84 days and also the patients status? alive, dead, lost to follow-up. then what? ...
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### High censoring rate in survival analysis

I have some data which I've analyzed using Kaplan Meier estimation. However, I have a gut feeling that this estimator is biased due to the high censoring rate in my data (nearly 50% censored at later ...
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### KM curve: log rank test significant but HR crosses 1

Hello and thanks for this source about statistics. My Problem is about a situation where Kaplan Meier curves differ in meaning of a significant log rank test, but the hazard ratio crosses 1 when ...
286 views

### Kaplan-Meier p-values

I have breast cancer trial data where, for subgroups 1 and 2, two treatment arms are being compared. The results are: For subgroup 1, N=33, median survival in ...
257 views

### Basic questions about discrete time survival analysis

I am attempting to carry out a discrete time survival analysis using a logistic regression model, and I'm not sure I completely understand the process. I would greatly appreciate assistance with a ...
378 views

### Comparison of Cox models

I am new to statistics and SPSS v 20. I am doing survival analysis - KM and Cox regression with SPSS. I am trying to make Cox models with different variables - clinical, genetic etc. I am interested ...
353 views

### Is Cox regression analysis including demographic covariates required for observational studies instead of Kaplan-Meier?

I have been reading quite a few papers and recently have started analyzing some data on a review that I am doing. I am trying to examine the effect of two different treatment options on a group of ...
1k views

### How to get 1, 3 and 5 year KM survival for large database using SPSS?

I have large database of hundreds of thousands observations. When I used spss to analyze KM survival, it gave me mean and median survivals with 95 % confidence interval. However, I need 1-, 3- and 5- ...
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### R packages (or SAS code) to produce two simultaneous Kaplan-Meier curves?

There's a way to do survival analysis of two (or more I suppose) mutually exclusive competing risks as a mixture of two different survival curves. Something like what you see in A.C. Ghani et al. ...
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### Cumulative Incidence vs. Kaplan Meier to estimate probability of failure

To estimate the probability failure in medical sciences, it is not atypical to use 1-KM. However this does not account for competing risks, such as death by natural causes or causes unrelated with the ...
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### Estimating a survival probability in R (2)

Following Brian Diggs's answer, I have tried to estimate some survival probability in R. However, the result is wrong (1 instead ...
Based on a sample of $n$ survival times, I would like to estimate the probability of surviving time $t$, for some specific $t$, using the Kaplan-Meier estimator. Is it possible to do this in ...