y*****w
发帖数: 1350 | 1 It seems survreg() in R and PROC LIFEREG in SAS run the same type of
survival analysis. However, when I ran both of them on a survival data, I
got different results. Both were set as exponential distribution, and have
right censored data. See below. Could anybody tell me why the results are
different? Did I miss specifying any important parameters in R? Thanks!
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The R code:
survFit <- survreg(Surv(time, event, type="right") ~... 阅读全帖 |
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发帖数: 242 | 2 > library(survival)
Loading required package: splines
> weib.fit<-survreg(Surv(time,status)~x,dist="weib",data=aml)
> summary(weib.fit)
Call:
survreg(formula = Surv(time, status) ~ x, data = aml, dist = "weib")
Value Std. Error z p
(Intercept) 4.109 0.300 13.70 9.89e-43
xNonmaintained -0.929 0.383 -2.43 1.51e-02
Log(scale) -0.235 0.178 -1.32 1.88e-01
Scale= 0.791
Weibull distribution
Loglik(model)= -80.5 Loglik(intercept only)= -83.2
Ch |
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G***G
发帖数: 16778 | 3 is there any difference between survreg and coxph?
what are they respectively? |
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G***G
发帖数: 16778 | 4 is there any difference between survreg and coxph?
what are they respectively? |
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发帖数: 346 | 5 Kind of remeber coxph is used for cox mode, survreg is used for AFT model. |
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Y******Y
发帖数: 8753 | 6 cox ph model is a semi-parametric model, it makes no assumption on the
distribution of the baseline hazard.
the paramatric ph models fitted by survreg assume the hazard function
follows a specific distrubution such as exponential, weibull, etc. |
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G***G
发帖数: 16778 | 7 thank you very much.
1)do you know when we choose to use cox ph model and when to use survreg?
2)what does the survfit do?
what is difference between survfit and ph model?
3) what we use ph model for? can we use it for prediction? |
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G***G
发帖数: 16778 | 8 I have another question.
if dist is omitted, what kind of distribution does survreg use? |
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G***G
发帖数: 16778 | 9 yes, my question is actually what is difference between cox model
and proportional regression model? |
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G***G
发帖数: 16778 | 11 no, they are not. I mean the result is not.
most of us say cox is non-parameter.
survfit (proportional progression) is parameter model. |
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Y******Y
发帖数: 8753 | 12 only weibull distribution satisfies AFT and Cox PH models simultaneously. |
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