Questions tagged [interval-censoring]

Interval censoring means the value of a data point is only known to lie w/i a given interval. The most common example is when data have been rounded, eg, a value of 5 implies the original value was in the interval [4.5, 5.5).

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3answers
1k views

Statistical methods for data where only a minimum/maximum value is known

Is there a branch of statistics that deals with data for which exact values are not known, but for each individual, we know either a maximum or minimum bound to the value? I suspect that my problem ...
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346 views

Survival rate trends in case-control studies

I submitted an article which was rejected due to the improper way of performing the survival analysis. The referee left no other details or explanations other than: "survival analysis on time trends ...
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Interval censored Cox proportional hazards model in R

Given interval censored survival times, how do I perform an interval censored Cox PH model in R? An rseek search turns up the package ...
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1answer
2k views

MLE/Likelihood of lognormally distributed interval

I have a variable set of responses that are expressed as an interval such as the sample below. ...
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1answer
3k views

How does dinterval() for interval censored data work in JAGS?

I am trying to understand how dinterval() works in JAGS for censored data. I am modeling coarse data where I only have upper and lower bounds for each data point (not the true value). Here is a ...
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5answers
510 views

How can I estimate the time at which 50% of a binomial variable will have transitioned?

I have the following data, representing the binary state of four subjects at four times, note that it is only possible for each subject to transition $0\to 1$ but not $1\to 0$: ...
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1answer
670 views

Interval censoring

I ran an interval censor survival curve with R, JMP and SAS. They both gave me identical graphs, but the tables differed a bit. This is the table JMP gave me. ...
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4answers
432 views

What is the mathematically rigorous definition of chunky data?

When in the workplace, certain measurement-taking devices are subject to different numerical accuracy; in some cases, the accuracy can be pretty weak (i.e., to one or two significant values only). ...
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2answers
370 views

Analysis of data given as intervals instead of points

I have a set of data that is not given as $ \boldsymbol{x} = x_1, \dots, x_n,$ but as pairs $\boldsymbol{x}_{interval} = (x^{(start)}_1, x^{(end)}_1), \dots, (x^{(start)}_n, x^{(end)}_n). $ For each ...
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430 views

How to model variables, where instead of values we observe intervals?

Consider a case where instead of observing actual variable values, we are observing variable range. The possible range-values could be enumerated (i.e. could be a fixed set of values, for e.g. fixed ...
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1answer
133 views

Inferring likely dates based on other related dates in incomplete data set

I'm taking my first steps in data science and machine learning. I'm experimenting with a project where I have no idea even what approaches I might start with, so I'd appreciate any leads: I have a ...
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3answers
7k views

Is it valid to derive a mean from categorical data?

I am working on a study to quantify average working hours for doctors. However, when I leave it empty for respondents to fill up, it remains unfilled. Changing it into categories as above yield ...
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1answer
193 views

How can I estimate the shape of a curve where the predictor variable is right censored interval variable?

Are there methods available to conduct interval-regression style analysis where a predictor variable is the interval variable and the outcome variable is a dichotomous variable? To give a bit of ...
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3answers
4k views

Fitting a Gaussian to a histogram when the bin size is significant

I'd like to fit a Gaussian to some experimental data that is binned (the binning is a result of the physical limits of the device). Importantly, the bin size is significant enough that the gaussian ...
6
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0answers
106 views

proportional hazards model with fixed interval censoring = cloglog GLM with fixed effect of time?

Consider a survival analysis with time-constant coefficients, interval-censored, where the observation intervals are consistent across all individuals (e.g. each individual is observed at the end of ...
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2answers
190 views

Standard practice for dealing with U flagged chemistry data

I have a large dataset of environmental chemistry data. Many results are U flagged by either the lab or validators. If I want to use these results to find average values over time I see there are ...
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2answers
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How to handle irregular interval censoring in a Cox model in R or Stata

I'm trying to model a weekly process of adoption (adoption events could only occur on Fridays) using the coxph function, but a large quantity of observations are ...
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1answer
77 views

Is it possible to do a forecast for an interval when the data are intervals?

For example, if I had a set of intervals prices, and then we need to do a forecast for the next period time.
4
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1answer
48 views

Survival analysis when exact time to event unknown?

My dataset (example here) represents a long-term capture-mark-recapture study, approximately 20 years duration. I am interested in looking at how the survival of animals is influenced by their sex and ...
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1answer
56 views

How to compare the distributions of censored data?

Is there a way to test if the distributions of the two samples of censored data? As the data is not defined exactly, Kolmogorov-Smirnov test does not seem to be directly applicable. Generally ...
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2answers
604 views

Tobit Model with a Variable Lower Censoring Bound?

I am working with NBA contract data and about 20 percent of my free agent sample do not receive contracts. Additionally, the distribution for those who do receive contracts is exponential. For each ...
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268 views

Interval Censored Survival Analysis

I am conducting a study on neurological diseased patients. I am looking into possible factors related to time-to-dementia. Costs associated with neurological testing allow us to assess all patients in ...
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2answers
573 views

Is there a standard way to treat events with unknown times (missing survival time data)?

Suppose we are studying some event and the observations are the pairs: time and indicator whether the event has already happened at this time. We have one observation per subject. No events happen ...
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5answers
440 views

Alternative for mi impute intreg

Is there a free alternative available for the Stata procedure mi impute intreg (Impute using interval regression)? For example as an R package. I have not found any yet.
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1answer
101 views

Is there a way to correct for continuity for the Shapiro-Wilk test?

I wish to investigate whether endocranial volume (the volume inside the skull) is normally distributed, ideally with a sample size in the hundreds. Few studies have released their data on this subject,...
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1answer
285 views

Plotting survival times

I have been looking for ways to plot survival times as in the following graph And having this data: ...
3
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1answer
596 views

Bayesian inference MCMC model for interval censored data

I have interval censored data for incubation period and I suppose that the exact time Ti included in each interval of the data [L;U] follows a lognormal distribution (mu,sigma2). I would like to use a ...
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1answer
225 views

How to code output in survival analysis with interval data

I have data of several patients with several observation points. At each observation points we test if the patient has a condition (0) or not (1). I want to perform survival analysis on this data but ...
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3answers
165 views

Methods for censored covariates

I am facing the situation that I have different data sources that in principle it makes sense to combine. The outcome (independent) variable is defined the same way, but the (likely) most important ...
3
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1answer
399 views

Gaussian process likelihood with binned data

I have some binned data (no access to underlying info) and prior knowledge that the value in each bin smoothly varies in space. So I am modeling using a Gaussian Process prior, which according to ...
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0answers
42 views

Weighing toilet paper with an imprecise scale

A practical, topical problem: Consider a typical roll of toilet paper (TP) with perforated sheets of fairly uniform size, and suppose we're interested in the distribution of a sheet's weight $W$ but ...
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0answers
1k views

Is there a way to model left truncated and interval censored data in R or SAS?

We have a study where our participant underwent some surgery at time = 0, but at various ages. Our follow-up is based only on Medicare age-eligible people, so we have to wait until they reach the age ...
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0answers
462 views

Simulate censored data cox model

I would like to simulate interval-censored data in a Cox model. In the R package intcox I found the following code: ...
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1answer
285 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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1answer
2k views

Survival Analysis using interval censored data: Please help

I have a database of 22,720 nurses with four observation points say Jan 2011, Jan 2012, Jan 2013 and Jan 2014. I know at each observation point if they developed a condition or not. Some new nurses ...
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1answer
187 views

Is there any repository with interval censored time-to-event datasets?

I'm looking for this particular structure of data for working on my thesis. In particular, I need interval censored with a cure fraction data. This kind is actually popular in medicine and clinical ...
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1answer
2k views

Survival analysis in SAS-is there a way to include a random effect with interval censored data?

I'm trying to use some form of survival analysis (e.g. accelerated failure time or proportional hazards) to study seed germination time. My data is interval censored (also called "grouped-time") and ...
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0answers
17 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
180 views

Mean of an interval censored random variable

It is likely that I am incorrect terminology here, but I am trying to compute a "mean" of an interval censored random variable. Here is an example where: 1. a random sample from the standard normal ...
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0answers
189 views

Estimate values below the limit of detection from a left-censored dataset

I have 32/180 determinations of a laboratory marker below the limit of detection (LOD) and would like to estimate them by maximum likelihood estimation. By using Minitab's reliability / survival ...
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0answers
614 views

Statistics for rounded data

I wonder about the existence of "standard" statistical procedures for rounded (log)normal data. Indeed, in my work I often encounter rounded data which potentially cause some problems: "awful" qqplots,...
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1answer
729 views

Software for survival regression with interval censoring and frailty

I'm conducting regression analysis on sleeping time data. The data is survey data and the answer possibilities are of type "less than 4 h", "5 h", "6 h", etc. so they can be thought to be interval ...
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1answer
285 views

References for the interval regression

I am using the interval regression in my dissertation (intreg command in Stata), but I can't find any publications describing this particular model. Should I just briefly describe the model in the ...
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1answer
959 views

Right censored survival analysis with interval data in R

How do you perform a survival analysis on a data set that is right censored (i.e. some samples are removed before failure) where the measurement points are non-regular discreet intervals (i.e. failure ...
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1answer
288 views

Can an interval censored survival model be used to predict an event in a future interval?

Suppose I have an interval censored survival model in which each interval is a month long period, and there are twelve intervals (i.e. one year total). Also suppose that this model has been trained ...
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1answer
260 views

Burns survival dataset - meaning of midpoint of set interval

I'm using the well-known USC Burns Survival dataset to explore logistic regression in R. The independent variable is burn area, and the outcome is binary survival (yes/no). In the documentation, ...
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1answer
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Independence of censoring time $C$ and event time $T$ for randomised entry to a study

While reading through the textbook 'Modern Applied Statistics With S' by Venables and Ripley, I came across the following paragraph detailing the different types of censoring possible when dealing ...
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1answer
400 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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0answers
21 views

Bootstrapping to address interval censored data

I am trying to run a cox proportional hazards model on data that is interval-censored (and I guess right censored). Within this model, I believe one of my covariates' relationship should be modeled ...
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0answers
37 views

Predicted values well outside of the censored range

I am working with an endogenous independent survey variable, $x$, which has a value range from 0 - 10, where 0 is always and 10 is never. Because the question pertains to wrongdoing, the answer to the ...