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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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Modeling count data (left skewed, underdispersed, right-censored)

I am seeking to model a count response variable-- number of times subject enacted a compensatory behavioral strategy-- as a function of cognitive and behavioral symptomatology, which are both ...
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Survival analysis with quarterly data: Is it really interval-censored?

I'm looking at data where all of the measurements are only available with quarterly time points, e.g. 2005-Q1, 2005-Q2, ..., 2016-Q4, 2017-Q1. This means that the event-of-interest (e.g. death) falls ...
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Using log data with censored Poisson regression

I am trying to minimise a likelihood function and estimate the parameter value of $\lambda$ by fitting to the following data. $t$ is the time and $N(t)$ is the population measured at those specific ...
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36 views

Censoring linearly splined predictor in regression

I'm developing a logistic regression where one of the independent variables has a non-linear relationship to the probability of the event occurring. I have created linear splines based on this ...
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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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30 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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23 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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30 views

ggsurvplot for counting type data showing censoring of all at risk subjects?

I've been trying to create KM plots using the R packages survminer and survival for counting type data. I have the following columns, ...
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parameter estimation using censored data by fitting a Maximum likelihood to a differential equation

I have a population data ($N$) measured over certain time points ($t$). The rate of change of the population is modelled as a ODE as, ${dN\over dt}=-\lambda N$ My intention is to estimate the ...
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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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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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Multi State Models to analyze/plot disease progression and probability of being misdiagnosed

Let's say that I have the following dataset containing information for 100 patients that have been followed up for a certain number of years to check if they develop a certain disease. We know up-...
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Correct Specification for Censored Data

I have some construction data, which shows the starting year of unfinished and finished projects but don’t have any information on the completion time of finished projects. If I had data on the ...
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Survival Analysis: event & censor coding

Simple query I suspect. I've been running a cox regression in R and noticed that my time-to event and time-to-censoring models produce identical output. Is that what I should expect? That is, does it ...
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51 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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Tobit versus OLS, is dependent variable censored?

I would like to investigate possible relationships between arbitrage profit of crypto exchanges and exchange's order book characteristics, such as volatility, spread, liquidity. I compute the ...
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1answer
38 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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Compare samples with noisy data and maximums

Summary: I collected psychophysical data (i.e. yes/no responses to physical stimuli) testing the ability to feel a touch stimuli. I used a Bayesian algorithm to select the stimuli (30 trials per ...
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Missing Data for Binary Dependent Variable

I have a Binary dependent variable (0/1) with panel data of three years(1 2 3). I want to measure the determinants of a woman choosing abortion using ordinary probit or logit. The problem is that no ...
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19 views

Real 1 dimensional non-binary data where Cox Proportional hazards model fails

I am learning about the Cox Proportional Hazards model and understood that it is very flexible, even when the assumption of proportional hazards is not met, e.g. for additive hazards. But say we have ...
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35 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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75 views

Calculate E[X] from incomplete data?

The exercise I'm doing describes the random variable $X$ as the following ...
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167 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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31 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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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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Non-Informative Censoring for Non-Parametric Models

Under the assumption of a parametric failure time distribution and parametric censoring time distribution, the non-informative censoring assumption implies that the distributions share no parameters ...
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1answer
46 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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146 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
43 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
42 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
134 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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How to deal with the problem of censoring in tree-based machine learning?

Censoring occurs when the outcome of a unit is not observed, because the unit is lost to follow up in a longitudinal study. Let $Y_t$ be the survival time at $t$. Then a unit is censored at $t'$ if $...
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Right Censored Sales Data

Suppose I want to estimate the true demand D for product X. Where D = sales if the inventory > 0, and D = right censored from observations of sales if inventory = 0. Suppose I have the following data,...
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A survival (accelerated failure time) regression model for censored data across several trials

I have this experimental design: Two groups A and B. Individuals from group B were genetically manipulated such that when they are given a certain drug the drug turns on a gene that was inserted ...
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63 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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67 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
29 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
50 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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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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23 views

censored regression problem if dependent variable only above threshold?

I have to predict some continuous dependent variable of samples where the value of this continuous dependent variable is only above a certain threshold (i.e. predict large values). Does this ...
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Competing Risk Regression, events at same timepoint

I have multiple timepoints for Events like stroke, death, reoperation. I want to use competing Risk Regression for e.g. death and reoperation. While censoring, I realize, that aswell death and ...
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74 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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69 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
43 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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38 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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1answer
47 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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19 views

How does the tobit model relate to parametric survival model?

Is the Tobit model equivalent to a log-normal parametric survival model? If not, what are the pros and cons of a log-normal parametric survival model over a Tobit model?
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1answer
170 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
49 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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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 ...