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Questions tagged [hazard]

The hazard rate is the instantaneous rate at which units that have survived until time $t$ die at $t$. The hazard ratio is the ratio of 2 specified hazards.

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Cox regression baseline risk and interpretation of coefficients

I recently encountered a problem with Cox regression that I couldn't find an answer to (please direct me to the appropriate resources if you know of any). So the problem goes as follows: I have a ...
Ania6789's user avatar
6 votes
1 answer
702 views

How can a hazard function be negative?

I've been reading through Survival Analysis in R, an ebook that I found for independent study, and have run into a point of confusion. They define the hazard function as follows: where T is whichever ...
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How to find difference between two hazard ratios (ratio of hazard ratios)

I am reading a meta-analysis and in this paper the authors somehow compared HR from two groups with different treatments in each study. As I know, we can compare outcomes from two groups with ...
reress's user avatar
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10 votes
3 answers
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How to explain Hazard Ratio in layperson's terms

In the context of a Cox regression, I recently heard someone say that "the hazard ratio of 0.70 between the two treatment groups indicates that, during the whole followup time, of 100 persons in ...
Survival's user avatar
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In which cases should the time be transformed when plotting the smoothed scaled Schoenfeld residual plot?

I previously asked this question but didn't get any answers, so I'm reposting it now. I aim to address the argument transform = '' in R, particularly concerning the ...
Devi Sita's user avatar
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1 answer
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Should the curve be around zero when assessing the smoothed scaled Schoenfeld residual plot for proportional hazard assumption?

I'm using the smoothed scaled Schoenfeld residual plot to assess the proportional hazard assumption. I have a decent understanding of what a smoothed scaled Schoenfeld residual plot shows, but I'm ...
Devi Sita's user avatar
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0 answers
21 views

Does it make sense to convert the Y-axis by exp() on the smooth scaled schoenfeld residual plot?

I posted a question on Stack Overflow. But the question got closed as the person who closed it wrote that it should belong here in Stack Exchange. I'm not sure why but here is the link for the post. I'...
Devi Sita's user avatar
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0 answers
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How to assess the goodness-of-fit of an extended Cox model?

I'm trying to build an extended Cox hazard model on a dataset with time-varying covariates, using Python's Lifeline package. However, I've a hard time trying to find out how I can assess the goodness-...
wanderingcatto's user avatar
1 vote
1 answer
35 views

Pooled Hazard Ratio or Crude events (M-H to RR or OR) for mortality outcomes in Meta-Analysis?

I'm performing a MA to estimate the effect of treatment A respect to Placebo (or propensity-matched control group) respect to all-cause death. All the studies included in my MA report both crude ...
Michele Maremmani's user avatar
0 votes
0 answers
43 views

How do I incorporate background mortality to produce an excess hazard model using flexsurv?

The flexsurv package in R facilitates the use of background mortality estimates to model excess hazard. In the examples I can find (the ...
connor's user avatar
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0 answers
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Start of instantaneous hazard rate

I'm looking at survival of organizations, with survival in years. I want to produce an instantaneous hazard plot with a confidence interval. I first used pehaz from ...
swhalemwo's user avatar
2 votes
1 answer
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When should the robust error function in R be used in Cox proportional hazard regressions?

Let's consider a scenario where I compute a HR that appears to violate the proportional hazard assumption according to the cox.zph test, but when plotting the ...
Devi Sita's user avatar
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1 vote
1 answer
83 views

How do I interpret the HRs for each time interval computed by survSplit in R?

I’m testing the association between an exposure and outcome. I have performed a Cox proportional hazard model in R and estimated a HR. Both the exposure and the outcome are binary variables, where 1 = ...
Devi Sita's user avatar
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0 votes
0 answers
17 views

Return period of vine copula

In the formula for "OR" joint return period of 3-dimensional copula modeling, we need to find C(u,v,w) but when we model using vine, we are only able to obtain the copula C(uv|w). So, how to ...
user387921's user avatar
1 vote
0 answers
30 views

Bayesian Approach to Estimating Item Return Probability Given Time Since Sale

I'm attempting to estimate the probability of an item being returned given that X days have passed since the sale, using a Bayesian approach. I can calculate the overall probability of an item being ...
Natan Rajchenberg's user avatar
1 vote
0 answers
33 views

Getting hazard ratios from a univariate logistic regression model

The authors in the article mention that, The subgroup analysis was conducted using a univariate logistic regression model, fitting separate models for each subgroup to assess the association between ...
Happy Cretine's user avatar
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0 answers
30 views

Interpreting hazard ratio in table

This poster has been making headlines lately due to its subject and conclusions. Specifically, I'm interested in understanding how the hazard ratios are being calculated in this table: For example, ...
Bryan Shalloway's user avatar
1 vote
0 answers
18 views

Survival analysis where the total count of different types of events matter?

I'm currently trying to conduct survival analysis where events are not just the binary variables of 1/0 (i.e., did the event happen or not). However, I'm not quite sure how to proceed in this case. My ...
kay_m43's user avatar
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1 vote
2 answers
63 views

Can I use a Hazard Ratio to determine the absolute risk of a population?

I am trying to convert the Hazard Ratio from this paper (Risk of Gastrointestinal Adverse Events Associated With Glucagon-Like Peptide-1 Receptor Agonists for Weight Loss) to determine the prevalence ...
David Andrews's user avatar
1 vote
1 answer
194 views

How to calculate sample size from hazard ratio?

The marker gene XYX1 being high in breast cancer is associated with poor prognosis with higher hazard ratio : 3.5. I want to calculate sample size with 1 - β (power) = 80%, one sided, type I error? ...
svp's user avatar
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0 answers
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Handling Informative Censored Data in Comparative Analysis of Cumulative Outcomes Across Groups

Hello Cross Validated community, I am working on a dataset that involves multiple groups undergoing a series of interventions, with the aim to achieve a binary outcome (e.g., success or failure). The ...
insan's user avatar
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5 votes
1 answer
103 views

What to do with Cox proportional hazards regression, when exposure and outcome does not have the same follow up

I'm working on a cox regression to analyse the association between an exposure and outcome. I also have a start time (time start for follow-up) and end time (time when getting the outcome or censored)....
Devi Sita's user avatar
  • 333
2 votes
1 answer
53 views

Minimum follow up period survival analysis

Imagin there's a surgery for a disease A that can cause a disease B. The minimum period to diagnose the disease B after the surgery of the disease A are 3 monthts (before that period of time, we can't ...
Arthurr's user avatar
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4 votes
1 answer
95 views

smooth scaled Schoenfeld residual plot - how to interpret the plot which is based on a stratified cox model?

I understand what a Smoothed scaled Schoenfeld residual plot is, and what it shows. Before I go into details with my question, I will provide an example. I use R to code. Here is a cox model: ...
Devi Sita's user avatar
  • 333
1 vote
1 answer
54 views

Calculating overall survival probability for being a part of a group in Cox regression

I have created a mixed-effects Cox regression in r: This can be created in coxph: ...
Luke Jenner's user avatar
1 vote
0 answers
19 views

Reweighting hazard ratios

Assume I have two populations (pop 1 and pop 2). I also have three treatments (A, B, C). In population 1, I have $HR_{A vs B}$ In population 2, I have $HR_{A vs B}$ and $HR_{C vs B}$ When I want to ...
CIAndrews's user avatar
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5 votes
2 answers
196 views

Illustrating the hazard function across values of an independent continuous varable

I'm running a Cox model in which my main interest is the effect of a continuous independent variable on the hazard of committing crime. I want to illustrate the effect of this variable. For this ...
Eran's user avatar
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6 votes
2 answers
309 views

How do you convert hazard ratios to differences in life expectancy?

How do epidemiologists convert hazard ratios to difference in life expectancy? For example, let's say I find that the hazard ratio of all-cause mortality in City A is 1.25 compared to City B. I want ...
braces's user avatar
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0 votes
0 answers
62 views

How to properly order outcomes in tidycmprsk subdistribution hazard (crr)?

This feels like a naive question, but I am a bit confused by the documentation and vignettes that I have found for tidycmprsk and the instructions I have been given for my exercise. I am trying to ...
womy's user avatar
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2 votes
1 answer
65 views

Intepretation of hazard times delta t

I'm working through J.F. Lawless's 'Statistical Models and Methods for Lifetime Data'. At one point, it's said that: In particular, $h(t)\Delta t$ is the approximate probability of death in $[t,t+\...
Kai Aragaki's user avatar
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0 answers
79 views

Hazard ratios - one unit increase for a continuous variable measuring diversity (Blau index/ coefficient of variation), how to interpret?

I am having difficulty understanding how to interpret a one-unit increase/decrease for continuous variables in a Cox model. Specifically, I have created the variables gender, age & nationality ...
Laura Hill's user avatar
0 votes
1 answer
134 views

thoughts on this log - log plot ?suitable for cox proportional hazards model

I'm quite new at using the cox proportional hazards model and was wondering if someone can please offer some advice on whether this log - log plot shows whether proportional hazards assumption has ...
MFA's user avatar
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0 votes
0 answers
17 views

Understanding the output of AddHazard package

In a cohort study, I am trying to assess the excess number of deaths in patients with a specific condition during follw-up. I am trying to do this by using an additive hazard model and am using the ...
Mikkel Malham's user avatar
0 votes
1 answer
27 views

How is the non time dependent hazard ratio computed?

I'm a bit confused as it relates to the hazard ratio. It seems to me that the hazard ratio is a time varying quantity however it seems that studies report a single number. Read this https://www.ncbi....
evan54's user avatar
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3 votes
1 answer
51 views

Cumulative Incidence Function given no event before time $t_d$

Suppose we have a simple competing risks model and have a calculated $CIF_K$ for two events $\{k_1, k_2\} \in K$. By definition $CIF_{k_1}(t_i)$ gives us the probability that event $k_1$ has occurred ...
JBB's user avatar
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1 vote
1 answer
78 views

How does length of follow-up affect hazard ratio (prop hazards vs non-prop hazards)

As the title says, I'm trying to figure out how the length of follow-up affects the value of the hazard ratio (e.g. from a Cox model). If proportional hazard holds, then presumably the hazard ratio ...
elbord77's user avatar
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2 votes
0 answers
75 views

Proportional hazard assumption: graphical approach vs subsampling

Hopefully someone can guide me on the following. I have a large dataset (> 151k firms with multiple observations per firm). My dataset looks at firm failure using counting process style and my ...
Laura Hill's user avatar
1 vote
1 answer
32 views

Predicting hazard function before left truncation point in survival analysis

I want to know if it is not only possible to handle left-truncation of data in a survival model, but to know/predict the hazard function (probability of event) before the start point, i.e. the point ...
Matthew Horn's user avatar
0 votes
0 answers
26 views

Why does one make TTT Plot instead of Empirical Hazard Rate Plot?

The total time on test (TTT) transform procedure is used as a tool to identify the hazard behavior of the data distribution. There is a correspondence of the TTT plot and the shape of the empirical ...
fletcherwrw's user avatar
0 votes
0 answers
19 views

Log-likelihood function for CoxTimeVaryingFitter

The mathematical formulation of partial log-likelihood function (https://in.mathworks.com/help/stats/cox-proportional-hazard-regression.html) is defined as: The above formulation does not take into ...
NN_Developer's user avatar
1 vote
1 answer
29 views

Making inferences from summary data: Can one relate chi squared tests to output from a Cox PH models?

This might be a silly question, but I've been asked about interpretation of a paper and have a query on how much one can ascertain without access to the raw data used, illustrated by example here. In ...
DRG's user avatar
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0 votes
1 answer
35 views

Direction of main effects in cox regression and negative binomial regression changes when adding variables

For a research I am conducting I am looking at the effect of two categorical variables (dummy with values 0 and 1 for each group) on the speed and quantity with which customers make future purchases. ...
user234's user avatar
1 vote
1 answer
135 views

It is possible to calculate the Hazard Ratio and 95% CI on different reference groups

I'm working on a meta-analysis and pooling hazard ratio (HR) using the metafor package in R. While most of the studies compare two categories (Biopsy vs Surgical resection) some studies report HR and ...
Jacopob9996's user avatar
1 vote
0 answers
84 views

How do I get the correct forestplot with each variable with its categories, indicating the reference variable and the values of those that are not

When doing the Coxph analysis with the variables selected from an excel file, it gives a numerical result indicating the HR of each one of them according to the reference one. However, when I ...
user392262's user avatar
0 votes
0 answers
42 views

p for interaction in cohort study

I have data from a cohort of 10,000 people who were followed for ten years to analyze the relationship between stress and the risk of dementia. The stress levels were independent variables, and the ...
li jiaqi's user avatar
1 vote
1 answer
182 views

When is a conditional hazard rate increasing?

Cross posted from Mathoverflow Let $X$ and $Y$ be two random variables such that $X\sim Exp(\lambda)$ and $Y$ have positive support and (strictly) increasing hazard rate $h_Y$. $X$ and $Y$ are ...
Robin_oud's user avatar
2 votes
1 answer
404 views

DIfference between hazard ratio and partial hazard in survival analysis

The hazard function in survival analysis is represented as (https://in.mathworks.com/help/stats/cox-proportional-hazard-regression.html): Here the exponential term is termed as hazard ratio as ...
NN_Developer's user avatar
0 votes
2 answers
244 views

Confusion between hazard ratios and odds ratios

I am getting into survival analysis and am a bit confused about the definition of hazard ratio and odds ratios. This question implies that there is a clear difference between hazard ratios and odds ...
n_arch's user avatar
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0 votes
1 answer
281 views

Relationship of incidence rate and hazard function

I like to figure out how I can retrieve an incidence rate based on a hazard function. So background could be that my hazard function models the prob of the event based on the age of a person (t = time ...
Dirk's user avatar
  • 3
1 vote
1 answer
44 views

Logic to caluclate shape and scale parameter in survival analysis

I have the below dataset: ...
NN_Developer's user avatar

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