e**h
发帖数: 46 | 1 haha, I got it. Thanks.
However, be careful, the logrank test is not normally distributed, but chis-
quare, under h0. Only the logrank statistic, +/- sqrt(logrank test), is
approximately standard normal.
I will send you baozi |
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e**h
发帖数: 46 | 2 向版上大牛们请教个问题:
我有两组肿瘤病人，分别用两种治疗方法。用logrank test检测两组病人存活时间是否
相同。但是logrank test 只能得到two-sided pvalue。现在我们需要one-sided
pvalue。该怎么计算？请版上大牛推荐个方法和学习资料。包子感谢。 |
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e****t
发帖数: 766 | 3 也报个offer，临床统计， PhD, experienced. 工作从7月份开始找到现在， 主
要是当前工作的公司在裁人，安全起见， 所以开始骑驴找马。 Recruiter 电话很多，
但是到HM 只有5个， 三个onsite， 1 个offer。 也算圆满了。工资少了些， 主要是
离LD 从250 mile 变成 90 mile， 钱不是很重要了。 有点遗憾的是， 绿卡又得从新
开始了。
还记得一些面试题， 回馈本版， 谢谢其他贴面经的朋友。
Linear regression: basic assumptions, how to diagonistic,
if violate any assumption, how to handle
Bootstrap basic idea.
Bayesian theory/Frequetist difference. How to explain to non statistician.
What is empirical Bayesian?
What is difference between logrank test and wilco... 阅读全帖 |
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j*****7
发帖数: 4348 | 4 请问如何suppress在图中的logrank test的结果？ |
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S********a
发帖数: 359 | 5 有个conditional logistic regression,想看AIC,但是结果里并没有给出来，请教什么
code或者命令把AIC求出来。谢谢。
> result0<-clogit(case~hr0+strata(subjid), data=mydata)
> summary(result0)
Call:
coxph(formula = Surv(rep(1, 9704L), case) ~ hr0 + strata(subjid),
data = mydata, method = "exact")
n=8397 (1307 observations deleted due to missingness)
coef exp(coef) se(coef) z Pr(>|z|)
hr0 0 0.001158 1.001158 0.005376 0.215 0.83
exp(coef) exp(-coef) lower .95 upper .95
hr0 1.001 ... 阅读全帖 |
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s*****b
发帖数: 106 | 6 生存分析的最常用的东西，随便在网上搜索 survival analysis+
log rank test都能找到相关内容。
通过logrank test,发现两组数据的生存函数没有显著差异。(p-value 很大0.98 接近1)
最下面的两行， numbers at risk指的是 服不同药物的两组试验人群
还有多少人没有生病 (no cadivascular disease yet)，而且还在
试验中(没有 Loss to follow up). |
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y*****w
发帖数: 1350 | 7 If anyone happens to have SAS 9.22 or SAS 9.3 (not SAS 9.2), may I have an
earnest request that you take half a minute to run PROC POWER for me? I am
asking this because I only have 9.2 whereas there is a new option
EVENTSTOTAL= in 9.22/9.3, which is exactly the number I need to know now.
The SAS code is as follows which automatically calculates number of total
events:
proc power;
twosamplesurvival test=logrank
groupsurvexphazards = (0.001684 0.000838)
accrualtime = 0
followuptim... 阅读全帖 |
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y*****w
发帖数: 1350 | 8 Thank you neardistance! If npergroup= and eventstotal= cannot appear at the
same time, could you try one more time using the following code? If it could
not run, then add "accrualtime=0". If you have already run the code like
that, then stop here. I am asking this because there is no "Computing Actual
Event Total" in your output, which is also what I would like to know.
Thanks!
proc power;
twosamplesurvival test=logrank
groupsurvexphazards = (0.001684 0.000838)
followuptime = 12
... 阅读全帖 |
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n**********e
发帖数: 18 | 9 This one doesn't work
the code I used
proc power;
twosamplesurvival test=logrank
eventstotal=.
groupsurvexphazards = (0.001684 0.000838)
accrualtime = 0
followuptime = 12
power = 0.80
;
run;
the
could
Actual |
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t*******t
发帖数: 633 | 10 http://en.wikipedia.org/wiki/Logrank_test
According to WIKI, the distribution of the test statistic is asymptotic
normal, which means it's symmetric, so the one sided p-vlaue=two sided p-
value/2. |
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s********1
发帖数: 54 | 11 ______________________________________________________________________
In terms of the variance structure
______________________________________________________________________
Normal structure depend on each individual,Spatial structure depends on the
distances between two points and compound, etc.
______________________________________________________________________
In terms of the likelihood:
______________________________________________________________________
The PL method is based on Wol... 阅读全帖 |
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