# 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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### What are the mean and variance of a 0-censored multivariate normal?

Let $Z \sim \mathcal N(\mu, \Sigma)$ be in $\mathbb R^d$. What are the mean and covariance matrix of $Z_+ = \max(0, Z)$ (with the max computed elementwise)? This comes up e.g. because, if we use the ...
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### what is a censoring hazard ratio?

I saw the following expression in paper [1] (equation 1) \Pi_{i=1}^{n} \left[\frac{HR(t_i,x_{\sigma(i)})}{\sum_{j=1}^{n}Y_j(t_i)HR(t_i,x_{j})}\right]^{\delta_i}\left[\frac{HR^C(t_i,...
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### Censoring or Measurement Error?

I have a satellite-recorded variable $X_{it}$ that is supposed to act as a proxy for some socio-economic variable $Y_{it}$. However, due to limitations of the recording device, $X_{it}$ is censored ...
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### Two types of left censoring in a time-to-event model

I have (population) survey data where I know one of three things about each respondent's experience of an event (A): The event A occurred at an age specified by the respondent. The event A is a ...
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### Survival analysis: Excluding cases of trivial follow-up time?

I am finishing up the data collection for my retrospective cohort study, which I have designed with the intention of conducting survival analysis. Our outcomes of interest are recurrence, metastasis, ...
322 views

### How to compare values between groups if data is left censored

Data I have a measurement with a detection threshold. I can see that one group has more succesfull measurements (larger number) and also have more higher measurements (longer tail). Comparing the ...
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### MCMC for model with cumulative hazard involving integrals?

Let $h(t\vert \theta, x)$ be a hazard function with parameter vector $\theta$ and covariate vector $x$, and let $H(t\vert \theta, x) = \int_0^t h(s\vert \theta, x)ds$ be the corresponding cumulative ...
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### imputing censored data when marginal sums are known

Let's say I have a large dataset of counts of all the fruits stored in the U.S. by State for a certain snapshot in time. ...
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### how to choose a transformation for left heavy tailed data due to arbitrary upper limit imposed by experimenter?

I have two vectors that look like this: I would like to make a significance test on the paired differences between the two vectors, as well as measure association. The process of data generation is "...
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### Normal copula vs Survival copula

Can someone tell me the actual differences between the Survival copula and Normal copula model in terms of the programming aspects in R. Am working on bivariate dataset with censored observations and ...
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### Survivor analysis when longest-term patient dies?

I have been given some data that has date of admission, date of disposition, disposition (death or live discharge), and some biomarker levels. I would like to model this, but here is the rub: The ...
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### Do I have Left Truncation or Right Censoring in my Survival/Event History Analysis?

I am doing study that starts at a specific date, January 1st 2015, and ends on a specific date, December 31st 2015. My overarching research question revolves around modeling time between orders of ...
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### Which Kaplan Meier Estimator to use?

I do have two data-sets and I am not shure which version of the KM estimator to use. Both datasets contain the following columns: ID | Issue Date | Last Recorded Date | Status Wheras the Status can ...
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### censored data estimation

Suppose $X_1, \cdots ,X_n$ are independent and identically distributed random variables with probability density function $$f(x|θ) = θ\, \exp(−θx),\quad \text{ for } x ≥ 0\,.$$ Each variable is ...
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### Poisson regression on devices that fail during observation period?

I am observing N devices over a period of time $[0,T]$ and counting the number of certain events $y_j$, for each device, during that period of time. I also have some specifications $x_j$ for each ...
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### Some concerns about using survival analysis in non-prospective designed study

I'm doing survival analysis using medical record, so the design is non-prospective. Is it alright to do so and is there any specifics I should concern? Suppose we are focusing on how long it takes for ...
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### Training on censored data with varying sequence length

I have a sequence of daily events, along with times between events. Each such sequence is labeled by $i$ and consists of $n_i$ events. For every $i$, each event $j$ has a list of features $x_{ij}$, ...
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### Right-censored cash flows and survival analysis

I am doing survival analysis on a disability claims dataset - each row tells me how long a person has been on claim and whether they have gone off claim yet. Ultimately I am interested in predicting ...
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### Dealing with censored count data from a limited pool of potential customers

I have daily data of reservations for a restaurant with a certain capacity. I also know about the population size that will possibly visit this restaurant. I would like to do some analysis to get more ...
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### Skewness, Kurtosis and Box-Cox for Censored Data?

I am currently working on a classification plus regression problem on a dataset with over 500 predictors. Each predictor has on average 15% in-range values (above a defined threshold of signal ...
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### Dealing with censored dates as regressors

I'm estimating a linear model, with one of the independent variables being a date of appearance. I consider the date to be a minimum date of appearance, not an obeserved one. Thus it is censored. What ...
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### Censored Regression with different limits for some observations

I'm attempting to model some data using regression analysis that has different upper limits for different observations, i.e. there is no universal limit for the entire data set. However I do have ...
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### Probability one Weibull is less than another, given upper-bound

I have two random variables $X$ and $Y$, representing times-to-event, drawn from Weibull distributions. When $Y$ occurs, then $X$ cannot occur after that. Aside from this, we can assume independence. ...
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### Expected ratio of right-censored to non-censored waiting times in Poisson proces

I am trying to calculate the expected value of $Y = \frac{\sum_{i=1}^n min(x, X_i)}{\sum_{i=1}^n X_i}$, where $X_i$ are independent random variables of exponential distribution of ratio $\lambda$. I ...
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### How to estimate parameters of a distribution with left-truncated and right-censored data?

I have been trying to find the best way of estimating parameters for a known pdf from a data-set that is left-truncated and right-censored. More precisely, I have lifetimes for a system where there ...
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### Mean calculation

I have a situation where I have to calculate a mean in a group of N=80. But 7 participants have a score of the measured variable <3. It's a medial measure and I don't have the exact numeric value ...
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### Manually right-censoring (top-coding) data for survival modeling: justified?

Say we have survival-time data that has a long right tail. Does it make analytical/statistical sense to set a time limit and then manually right-censor (top-code) all times-to-event that exceed this ...
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### Does deleting right censoring data make it to be left truncated?

If data have right censoring and complete data, I delete the right censored ones. Does it make the data to be left truncated? And why?
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### Zero inflated model for censored data

I have a zero-inflated model with censored data Is there a package in R that can combine zero- inflated model with right-censored data? Alternatively, is there a general way to model right-censored ...
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### Probability model for duration, how to write log-likelihood function for Weibull distribution to fit aggreate data

Background: I have a basic to moderate knowledge on probability and statistics. I have familiarity with R programming language and optimization routines. I'm reading an excellent article "Jobs, ...
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### Kaplan-Meier Estimate with no censoring

Let $T_i$ is the survival time for individual $i$ $(i=1,2,\ldots, n)$ and $C_i$ be the time to censoring. Let $U_i=\min(T_i,C_i)$. And $\hat S(U_i)$ is the Kaplan-Meier estimator for the censoring ...
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We want to correlate customer lifetime (dependent variable) with feedback rating the customers leave (independent variable) to determine whether we can use the feedback as a prediction for customer ...
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### Non-parametric estimator of the joint distribution of two random variables where one is right-censored

I have 2-D samples of two continuous, correlated random variables where one of them is right-censored. I would like to estimate their joint distribution function using some non-parametric estimator. ...
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### Survival Analysis vs. Classification for High Dimensional Dataset

I started learning about survival analysis only recently, so I am not sure if this question fits in survival analysis. If you think I lack the background to do what I am trying to do, please point me ...
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### Bias in average age for grandmaster title qualification by age groups?

It has been known for quite some time that the youngest age at which chess players managed to qualify for the grandmaster title has significantly decreased since the 1950s, and there are currently ...
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### independent censoring

Independent censoring is one of the fundamental assumptions in the survival analysis. However, I cannot find any test for it or any paper which discusses how real that assumption is. I would be ...
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### interval censored survival analysis with time dependent covariates

I'm working on a long-term, large tree data set from Africa. I have data on the same set of individuals from year 2006, 2008, 2011 and 2015. The data consist of tree status (alive/dead) at each time ...
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I want to formulate the likelihood function in a linear regression problem in which I have censored observations. Considering the dataset $(x_i,y_i)$, I suppose that the dependent variable is normally ...