Questions tagged [censoring]

The process of censoring yields data w/ only partial information. The most common example of censoring is *right censoring* in survival analysis, where the time until the event occurred is only known to be longer than some duration because the event had not occurred when the study ended.

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591 views

Can censored data act as the dependent variable for a logistic regression?

I need to do the research about the risk factors that contribute to heart failure. The data I have just the censored data with some risk factors of heart failure. And I need to use logistic ...
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1answer
86 views

How to do “partial” survival analysis on randomly censored data?

Suppose that we monitor a population of devices over an interval $[a,b]$. Some devices are added before $a$ and some are added during $[a,b]$. Furthermore, some devices fail during $[a,b]$ and some ...
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122 views

Censored regression with Poisson distribution

I am trying to fit a Poisson distribution for left censored data. Let $x_1,x_2,...x_n$ be the observations with the first $r$ observations being less than the threshold of $c$ and hence censored. The ...
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18 views

Parametric estimator for straightforward interval-censored data

$X_i$ is iid from some distribution, such as $N(\mu, \sigma^2)$. All I want is to estimate the parameters of the distribution. However, I don't observe $x_i$, instead, I observe $(a_i, b_i)$ such that ...
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0answers
72 views

Distribution of shifted and censored random variable

Suppose I have a non-negative random variable $X$ with finite mean $\mu$. Let's for example assume it denotes demand, and we denote by $X(t)$ demand in period $t$, demand in different periods are iid. ...
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3answers
134 views

Can left-censored data be normal distributed?

Very often I read that the distribution of IQ-test results is normal. However, the IQ-scale is left-censored, i.e. test results cannot be lower than zero. The normal distribution, however, is usually ...
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1answer
132 views

Effect of continuous variable with many repeated values on Random Forest

I am trying to build a random forest regression model in R using all continuous panel data. There is a large amount of data relative to the number of predictors. Say 500,000 rows and about 40 ...
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1answer
58 views

multivariate truncated survival analysis

I have many short time series (1-5 data points) that document the development of morphological traits (length and pigmentation) of some lab critters in response to different dietary supplement. I ...
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2answers
77 views

Calculate E[X] from incomplete data?

The exercise I'm doing describes the random variable $X$ as the following ...
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2answers
387 views

Are cancer studies cases always left-censored?

I'm used to traditionnal studies with plain old Cox PH models and right censoring. But lately I was wondering about the outcome date in cancer studies. Indeed, the date we usually use as outcome ...
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1answer
89 views

5-year EFS > 5-year OS

I had a data of 24 cancer patients; their 5-year overall survival (i.e. event as death) was around 57%, however, when I calculated 5-year event-free survival for the same cohort, defining the event as ...
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1answer
71 views

Equivalence of Kaplan-Meier estimator and EM algorithm

For right-censored failure time data, in a non-parametric setting, is there an equivalence between using the EM algorithm (i.e. calculating the expected log-likelihood and maximizing) and the Kaplan-...
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1answer
121 views

Survival Analysis - Account for heterogeneous time of entry with administrative censoring at year=T

I am new to survival analysis, although in the past weeks I have done my share of reading, hence this might be a non-problem. I have marriage and divorce data, spanning many years. I'm trying to model ...
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321 views

Exclude observations with measurements below limit of detection?

I am analysing a dataset for the relationship between an exposure variable x and a response y (in my case, these are urinary ...
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1answer
110 views

First passage time distribution via Monte Carlo simulation

The problem: I want to assess the first passage time distribution via Monte Carlo Simulation, where the first passage time is defined as: $$\tau=\inf\left\{t: X_t > l\right\}$$ where $l$ is the ...
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1answer
52 views

Using survival analysis in hockey analytics- Period 1 vs Period 2 as Treatment variable

In my article on hockey analytics, I answer how different are the rates of goals, shots, or hits from the NHL regular season to the playoffs (Playoffs are games played by the top 16 teams in the ...
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1answer
453 views

Simulation censored data in R

I am trying to simulate a data set of interval censored data(finite interval censored data, right censored data ,and left censored data). In fact, I created two monitoring times in R and I have the ...
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1answer
86 views

Inverting data for Zero-inflated mixed effects models

I am looking for some advice on my analyses, I have been going back and forth between co-authors about the validity of my approach and would appreciate some external input. My data are derived from ...
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344 views

Censored Regression/Tobit: coefficients decrease drastically when non-normal distribution is assumed

I am trying to use a Tobit/ censored regression model to estimate the effect of a certain political condition on a tax. Our dependent variable is zero-inflated because in most of our observations this ...
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1answer
35 views

How do we maximise power for observational proportional hazards model?

This question relates to the optimal study design when looking at survival to event based on observational data (i.e. the precise time of event will be unobserved but we can observe status at times ...
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1answer
99 views

In survival analysis, is all censored data weighted the same?

I am working on a survival analysis problem and I am having trouble wrapping my head around the weighting on right censored data. If I have a group of right censored data where the time is longer ...
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73 views

regression approach for missing data (left censoring?)

I have a regression problem where I want to predict actuals (dependent variable) of some process where I only have values for a small number of independent variables at the beginning of the process ...
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152 views

Censored regression with right censored data

I'm kind of new to Stats and R in general and I'm looking to clear some doubts. I'm trying to use Censored regression models to do the analysis of my qPCR data. The response variable is continuous (Ct ...
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159 views

Tobit model: Left and right censoring

In my data, my outcome variable days.to.event is conceptually left censored at 0 days and right censored at 30 days. However, since the ...
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1answer
181 views

Tobit model with flexible censoring point in R

I am currently writing my MSc thesis and I am using a Tobit model. My data consists of fleet and sales data. The censored dependent variable is quantity and this quantity is higher than the fleet ...
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41 views

Piecewise integration

I am trying to estimate residential demand for electricity in a country where electricity is sold (to all households (HH)) at an increasing two-part tariff. By choosing marginal prices as my key ...
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13 views

Survival Statistics Independence

If we observe follow-up times $T_i = \min(X_i,C_i)$ and right censoring indicators $δ_i = I(X_i \le C_i)$ under noninformative censoring. Is $X_i$ independent of $δ_i$? Please explain why!
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1answer
197 views

Is data censored if it's “still alive”?

Let's say I'm observing the mortality of flies. Say I have 100 flies that are born throughout the year. And also say I am recording the alive/dead status of a fly every single day, without fail. So ...
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1answer
371 views

Mean of a censored Poisson random variable

Consider a real demand estimation problem of a retailer where matrix $Y$ (contains Poisson random variables) is the real demand and its mean need to be estimated by using sales data (matrix) $X$ which ...
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1answer
180 views

Help with Right Censoring for survival analysis

Hi all I would like to do some survival analysis. The most difficult part for me is setting up the censoring data correctly and I would appreciated if someone can help confirm if I'm doing this ...
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98 views

Estimator of (left-)censored normal distribution when mean>>std

Suppose there is a left-censored normal distribution, and we know there is a total of $m$ samples, for which we know $n$ of them. I am trying to estimate the mean and variance of the underlying normal ...
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227 views

What is the distribution of min{0,X} when X follows some general normal distribution?

What is the distribution of $\min\{0, X\}$ when $X$ follows some general normal distribution?
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1answer
71 views

Linear regression: how to treat an explanatory variable that is discrete but does not have a natural zero

Background/study system: One of my MS students is studying the biomechanics of strand breakage in Spanish moss (an epiphyte--or plant that lives on other plants). Spanish moss has strands that can ...
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1answer
53 views

Calculating censoring proportion in recurrent event time data

My question pertains to how to calculate censoring proportion in the perspective of recurrent event data in which an individual subject can have multiple survival times related to repeated occurrences ...
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0answers
73 views

Survival model - sample with only censored observations

I have a question related to survival models: for instance, the survival probability of people that have a disease. In all examples I've seen so far, the data used to estimate those models sometimes ...
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1answer
40 views

survival analysis with varying follow-up time

I have a retrospectively enrolled cohort of patients with aortic disease. The endpoint is aortic enlargement at or after postoperative 6 months. Patients experiencing aortic enlargement within 6 ...
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0answers
16 views

Estimate the conditional probability given contaminated output?

I have a dataset with exam grades and for each student an indicator variable that is equal to $y=1$ if the student was cribbing and $y=0$ otherwise. As a result of the crib the grade is expected to be ...
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1answer
697 views

Fitting distributions on censored data

My question deals with fitting distributions on censored data; for the purposes of clarity, we can consider a continuous distribution which is both left and right-censored. In such a case, the ...
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0answers
158 views

How to fit a (gaussian) mixture model to a dataset with (right) censored data in R?

I am trying to fit a mixture distribution to a dataset in R. Exploiting the R package mixtools, this goes pretty well. However, up to 20% of the data point in the dataset are right censored, therefore ...
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1answer
51 views

Censored regression methods for analyzing extreme end of a normally-distributed variable

I have a normally distributed continuous variable referring to an observed human behavior, and I'm interested in measuring or rather analyzing the extreme of this behavior, namely, the top 10% of the ...
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0answers
75 views

Which duration model to use with a fully right censored database

Currently I'm examining the duration of residence of households. I have a database at my disposal that indicates how long a specific household resides in its current home. I want to explain their ...
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0answers
70 views

Continuous or categorical data. Modeling depth, that is continuous through a range of values, but has a max depth that is discrete

I'm modeling depth to bedrock. These data are continuous through a range of depths, but have a max value that equates to as far as we could dig with our soil auger. So they are continuous through a ...
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1answer
460 views

How to model left-censored and right-truncated data on Stata? [closed]

I have data that is left-censored and right-truncated. I'd like to run a tobit or truncreg. Although, using ...
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1answer
197 views

Residual Useful Life estimation from multivariate time series with lots of missing data and censoring, using neural networks

I have a set of industrial machines, for which I collect measurements from a few sensors (say, $d=20$) in time. So I have a $d-$variate time series for each machine. Let $t=0$ denote the start of my ...
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0answers
38 views

How can we deal with limit of detection independent variables in regression

Suppose that you have a regression in which one or more of the independent variables has a lower limit of detection (e.g. some result of blood tests). How best to deal with this? Any pointers to the ...
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0answers
12 views

Proper way to assess median failure distance in the presence of censoring

I would like to measure the median distance at which a material fails when it is stretched. At first pass, this sounds trivial and there is a simple version of this by which I pull a material until ...
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2answers
2k views

How do left-censored data and right-censored data impact Cox Regression?

My application is not a traditional survival analysis scenario. However, I believe survival analysis methods, e.g., Cox regression, can be a possible solution. In particular, my dataset contains two ...
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0answers
34 views

Right-censored predictor where censorship means “never”

My major predictor is "time to consultation" (of the specialist), which ranges from 0 to roughly 72 hours. There are also patients in this group whose value is "never". That is the procedure in ...
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1answer
169 views

How to deal with different likelihood of censoring across groups in survival analysis?

I am analysing survival data for nematode worms fed on four different bacterial diets (four groups). Each group has at least 70 events (deaths), but there is often a very uneven proportion of ...
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1answer
327 views

Learning a continuous model from binned data

A very similar question has been asked before, but it didn't get a real answer. Background I would like to develop a probability model for a continuous, ratio-scale random variable $Y$. Let's say it ...

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